dom/workers/RuntimeService.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "RuntimeService.h"
   8
   9 #include "nsContentSecurityUtils.h"
  10 #include "nsIContentSecurityPolicy.h"
  11 #include "mozilla/dom/Document.h"
  12 #include "nsIObserverService.h"
  13 #include "nsIScriptContext.h"
  14 #include "nsIStreamTransportService.h"
  15 #include "nsISupportsPriority.h"
  16 #include "nsITimer.h"
  17 #include "nsIURI.h"
  18 #include "nsIXULRuntime.h"
  19 #include "nsPIDOMWindow.h"
  20
  21 #include <algorithm>
  22 #include "mozilla/ipc/BackgroundChild.h"
  23 #include "GeckoProfiler.h"
  24 #include "js/ColumnNumber.h"  // JS::ColumnNumberOneOrigin
  25 #include "js/experimental/CTypes.h"  // JS::CTypesActivityType, JS::SetCTypesActivityCallback
  26 #include "jsfriendapi.h"
  27 #include "js/friend/ErrorMessages.h"  // js::GetErrorMessage, JSMSG_*
  28 #include "js/ContextOptions.h"
  29 #include "js/Initialization.h"
  30 #include "js/LocaleSensitive.h"
  31 #include "js/WasmFeatures.h"
  32 #include "mozilla/ArrayUtils.h"
  33 #include "mozilla/Atomics.h"
  34 #include "mozilla/Attributes.h"
  35 #include "mozilla/CycleCollectedJSContext.h"
  36 #include "mozilla/CycleCollectedJSRuntime.h"
  37 #include "mozilla/Telemetry.h"
  38 #include "mozilla/TimeStamp.h"
  39 #include "mozilla/dom/AtomList.h"
  40 #include "mozilla/dom/BindingUtils.h"
  41 #include "mozilla/dom/ErrorEventBinding.h"
  42 #include "mozilla/dom/EventTargetBinding.h"
  43 #include "mozilla/dom/FetchUtil.h"
  44 #include "mozilla/dom/MessageChannel.h"
  45 #include "mozilla/dom/MessageEventBinding.h"
  46 #include "mozilla/dom/PerformanceService.h"
  47 #include "mozilla/dom/RemoteWorkerChild.h"
  48 #include "mozilla/dom/WorkerBinding.h"
  49 #include "mozilla/dom/ScriptSettings.h"
  50 #include "mozilla/dom/ShadowRealmGlobalScope.h"
  51 #include "mozilla/dom/IndexedDatabaseManager.h"
  52 #include "mozilla/DebugOnly.h"
  53 #include "mozilla/Preferences.h"
  54 #include "mozilla/ScopeExit.h"
  55 #include "mozilla/dom/Navigator.h"
  56 #include "mozilla/Monitor.h"
  57 #include "nsContentUtils.h"
  58 #include "nsCycleCollector.h"
  59 #include "nsDOMJSUtils.h"
  60 #include "nsISupportsImpl.h"
  61 #include "nsLayoutStatics.h"
  62 #include "nsNetUtil.h"
  63 #include "nsServiceManagerUtils.h"
  64 #include "nsThreadUtils.h"
  65 #include "nsXPCOM.h"
  66 #include "nsXPCOMPrivate.h"
  67 #include "xpcpublic.h"
  68 #include "XPCSelfHostedShmem.h"
  69
  70 #if defined(XP_MACOSX)
  71 #  include "nsMacUtilsImpl.h"
  72 #endif
  73
  74 #include "WorkerDebuggerManager.h"
  75 #include "WorkerError.h"
  76 #include "WorkerLoadInfo.h"
  77 #include "WorkerRunnable.h"
  78 #include "WorkerScope.h"
  79 #include "WorkerThread.h"
  80 #include "prsystem.h"
  81
  82 #ifdef DEBUG
  83 #  include "nsICookieJarSettings.h"
  84 #endif
  85
  86 #define WORKERS_SHUTDOWN_TOPIC "web-workers-shutdown"
  87
  88 static mozilla::LazyLogModule gWorkerShutdownDumpLog("WorkerShutdownDump");
  89
  90 #ifdef SHUTDOWN_LOG
  91 #  undef SHUTDOWN_LOG
  92 #endif
  93 #define SHUTDOWN_LOG(msg) MOZ_LOG(gWorkerShutdownDumpLog, LogLevel::Debug, msg);
  94
  95 namespace mozilla {
  96
  97 using namespace ipc;
  98
  99 namespace dom {
 100
 101 using namespace workerinternals;
 102
 103 namespace workerinternals {
 104
 105 // The size of the worker runtime heaps in bytes. May be changed via pref.
 106 #define WORKER_DEFAULT_RUNTIME_HEAPSIZE 32 * 1024 * 1024
 107
 108 // The size of the worker JS allocation threshold in MB. May be changed via
 109 // pref.
 110 #define WORKER_DEFAULT_ALLOCATION_THRESHOLD 30
 111
 112 // Half the size of the actual C stack, to be safe.
 113 #define WORKER_CONTEXT_NATIVE_STACK_LIMIT 128 * sizeof(size_t) * 1024
 114
 115 // The maximum number of threads to use for workers, overridable via pref.
 116 #define MAX_WORKERS_PER_DOMAIN 512
 117
 118 static_assert(MAX_WORKERS_PER_DOMAIN >= 1,
 119               "We should allow at least one worker per domain.");
 120
 121 #define PREF_WORKERS_PREFIX "dom.workers."
 122 #define PREF_WORKERS_MAX_PER_DOMAIN PREF_WORKERS_PREFIX "maxPerDomain"
 123
 124 #define GC_REQUEST_OBSERVER_TOPIC "child-gc-request"
 125 #define CC_REQUEST_OBSERVER_TOPIC "child-cc-request"
 126 #define MEMORY_PRESSURE_OBSERVER_TOPIC "memory-pressure"
 127 #define LOW_MEMORY_DATA "low-memory"
 128 #define LOW_MEMORY_ONGOING_DATA "low-memory-ongoing"
 129 #define MEMORY_PRESSURE_STOP_OBSERVER_TOPIC "memory-pressure-stop"
 130
 131 // Prefixes for observing preference changes.
 132 #define PREF_JS_OPTIONS_PREFIX "javascript.options."
 133 #define PREF_MEM_OPTIONS_PREFIX "mem."
 134 #define PREF_GCZEAL "gczeal"
 135
 136 static NS_DEFINE_CID(kStreamTransportServiceCID, NS_STREAMTRANSPORTSERVICE_CID);
 137
 138 namespace {
 139
 140 const uint32_t kNoIndex = uint32_t(-1);
 141
 142 uint32_t gMaxWorkersPerDomain = MAX_WORKERS_PER_DOMAIN;
 143
 144 // Does not hold an owning reference.
 145 Atomic<RuntimeService*> gRuntimeService(nullptr);
 146
 147 // Only true during the call to Init.
 148 bool gRuntimeServiceDuringInit = false;
 149
 150 class LiteralRebindingCString : public nsDependentCString {
 151  public:
 152   template <int N>
 153   void RebindLiteral(const char (&aStr)[N]) {
 154     Rebind(aStr, N - 1);
 155   }
 156 };
 157
 158 template <typename T>
 159 struct PrefTraits;
 160
 161 template <>
 162 struct PrefTraits<bool> {
 163   using PrefValueType = bool;
 164
 165   static inline PrefValueType Get(const char* aPref) {
 166     AssertIsOnMainThread();
 167     return Preferences::GetBool(aPref);
 168   }
 169
 170   static inline bool Exists(const char* aPref) {
 171     AssertIsOnMainThread();
 172     return Preferences::GetType(aPref) == nsIPrefBranch::PREF_BOOL;
 173   }
 174 };
 175
 176 template <>
 177 struct PrefTraits<int32_t> {
 178   using PrefValueType = int32_t;
 179
 180   static inline PrefValueType Get(const char* aPref) {
 181     AssertIsOnMainThread();
 182     return Preferences::GetInt(aPref);
 183   }
 184
 185   static inline bool Exists(const char* aPref) {
 186     AssertIsOnMainThread();
 187     return Preferences::GetType(aPref) == nsIPrefBranch::PREF_INT;
 188   }
 189 };
 190
 191 template <typename T>
 192 T GetPref(const char* aFullPref, const T aDefault, bool* aPresent = nullptr) {
 193   AssertIsOnMainThread();
 194
 195   using PrefHelper = PrefTraits<T>;
 196
 197   T result;
 198   bool present = true;
 199
 200   if (PrefHelper::Exists(aFullPref)) {
 201     result = PrefHelper::Get(aFullPref);
 202   } else {
 203     result = aDefault;
 204     present = false;
 205   }
 206
 207   if (aPresent) {
 208     *aPresent = present;
 209   }
 210   return result;
 211 }
 212
 213 void LoadContextOptions(const char* aPrefName, void* /* aClosure */) {
 214   AssertIsOnMainThread();
 215
 216   RuntimeService* rts = RuntimeService::GetService();
 217   if (!rts) {
 218     // May be shutting down, just bail.
 219     return;
 220   }
 221
 222   const nsDependentCString prefName(aPrefName);
 223
 224   // Several other pref branches will get included here so bail out if there is
 225   // another callback that will handle this change.
 226   if (StringBeginsWith(
 227           prefName,
 228           nsLiteralCString(PREF_JS_OPTIONS_PREFIX PREF_MEM_OPTIONS_PREFIX))) {
 229     return;
 230   }
 231
 232 #ifdef JS_GC_ZEAL
 233   if (prefName.EqualsLiteral(PREF_JS_OPTIONS_PREFIX PREF_GCZEAL)) {
 234     return;
 235   }
 236 #endif
 237
 238   JS::ContextOptions contextOptions;
 239   xpc::SetPrefableContextOptions(contextOptions);
 240
 241   nsCOMPtr<nsIXULRuntime> xr = do_GetService("@mozilla.org/xre/runtime;1");
 242   if (xr) {
 243     bool safeMode = false;
 244     xr->GetInSafeMode(&safeMode);
 245     if (safeMode) {
 246       contextOptions.disableOptionsForSafeMode();
 247     }
 248   }
 249
 250   RuntimeService::SetDefaultContextOptions(contextOptions);
 251
 252   if (rts) {
 253     rts->UpdateAllWorkerContextOptions();
 254   }
 255 }
 256
 257 #ifdef JS_GC_ZEAL
 258 void LoadGCZealOptions(const char* /* aPrefName */, void* /* aClosure */) {
 259   AssertIsOnMainThread();
 260
 261   RuntimeService* rts = RuntimeService::GetService();
 262   if (!rts) {
 263     // May be shutting down, just bail.
 264     return;
 265   }
 266
 267   int32_t gczeal = GetPref<int32_t>(PREF_JS_OPTIONS_PREFIX PREF_GCZEAL, -1);
 268   if (gczeal < 0) {
 269     gczeal = 0;
 270   }
 271
 272   int32_t frequency =
 273       GetPref<int32_t>(PREF_JS_OPTIONS_PREFIX PREF_GCZEAL ".frequency", -1);
 274   if (frequency < 0) {
 275     frequency = JS_DEFAULT_ZEAL_FREQ;
 276   }
 277
 278   RuntimeService::SetDefaultGCZeal(uint8_t(gczeal), uint32_t(frequency));
 279
 280   if (rts) {
 281     rts->UpdateAllWorkerGCZeal();
 282   }
 283 }
 284 #endif
 285
 286 void UpdateCommonJSGCMemoryOption(RuntimeService* aRuntimeService,
 287                                   const char* aPrefName, JSGCParamKey aKey) {
 288   AssertIsOnMainThread();
 289   NS_ASSERTION(aPrefName, "Null pref name!");
 290
 291   int32_t prefValue = GetPref(aPrefName, -1);
 292   Maybe<uint32_t> value = (prefValue < 0 || prefValue >= 10000)
 293                               ? Nothing()
 294                               : Some(uint32_t(prefValue));
 295
 296   RuntimeService::SetDefaultJSGCSettings(aKey, value);
 297
 298   if (aRuntimeService) {
 299     aRuntimeService->UpdateAllWorkerMemoryParameter(aKey, value);
 300   }
 301 }
 302
 303 void UpdateOtherJSGCMemoryOption(RuntimeService* aRuntimeService,
 304                                  JSGCParamKey aKey, Maybe<uint32_t> aValue) {
 305   AssertIsOnMainThread();
 306
 307   RuntimeService::SetDefaultJSGCSettings(aKey, aValue);
 308
 309   if (aRuntimeService) {
 310     aRuntimeService->UpdateAllWorkerMemoryParameter(aKey, aValue);
 311   }
 312 }
 313
 314 void LoadJSGCMemoryOptions(const char* aPrefName, void* /* aClosure */) {
 315   AssertIsOnMainThread();
 316
 317   RuntimeService* rts = RuntimeService::GetService();
 318
 319   if (!rts) {
 320     // May be shutting down, just bail.
 321     return;
 322   }
 323
 324   constexpr auto memPrefix =
 325       nsLiteralCString{PREF_JS_OPTIONS_PREFIX PREF_MEM_OPTIONS_PREFIX};
 326   const nsDependentCString fullPrefName(aPrefName);
 327
 328   // Pull out the string that actually distinguishes the parameter we need to
 329   // change.
 330   nsDependentCSubstring memPrefName;
 331   if (StringBeginsWith(fullPrefName, memPrefix)) {
 332     memPrefName.Rebind(fullPrefName, memPrefix.Length());
 333   } else {
 334     NS_ERROR("Unknown pref name!");
 335     return;
 336   }
 337
 338   struct WorkerGCPref {
 339     nsLiteralCString memName;
 340     const char* fullName;
 341     JSGCParamKey key;
 342   };
 343
 344 #define PREF(suffix_, key_)                                          \
 345   {                                                                  \
 346     nsLiteralCString(PREF_MEM_OPTIONS_PREFIX suffix_),               \
 347         PREF_JS_OPTIONS_PREFIX PREF_MEM_OPTIONS_PREFIX suffix_, key_ \
 348   }
 349   constexpr WorkerGCPref kWorkerPrefs[] = {
 350       PREF("max", JSGC_MAX_BYTES),
 351       PREF("gc_high_frequency_time_limit_ms", JSGC_HIGH_FREQUENCY_TIME_LIMIT),
 352       PREF("gc_low_frequency_heap_growth", JSGC_LOW_FREQUENCY_HEAP_GROWTH),
 353       PREF("gc_high_frequency_large_heap_growth",
 354            JSGC_HIGH_FREQUENCY_LARGE_HEAP_GROWTH),
 355       PREF("gc_high_frequency_small_heap_growth",
 356            JSGC_HIGH_FREQUENCY_SMALL_HEAP_GROWTH),
 357       PREF("gc_small_heap_size_max_mb", JSGC_SMALL_HEAP_SIZE_MAX),
 358       PREF("gc_large_heap_size_min_mb", JSGC_LARGE_HEAP_SIZE_MIN),
 359       PREF("gc_balanced_heap_limits", JSGC_BALANCED_HEAP_LIMITS_ENABLED),
 360       PREF("gc_heap_growth_factor", JSGC_HEAP_GROWTH_FACTOR),
 361       PREF("gc_allocation_threshold_mb", JSGC_ALLOCATION_THRESHOLD),
 362       PREF("gc_malloc_threshold_base_mb", JSGC_MALLOC_THRESHOLD_BASE),
 363       PREF("gc_small_heap_incremental_limit",
 364            JSGC_SMALL_HEAP_INCREMENTAL_LIMIT),
 365       PREF("gc_large_heap_incremental_limit",
 366            JSGC_LARGE_HEAP_INCREMENTAL_LIMIT),
 367       PREF("gc_urgent_threshold_mb", JSGC_URGENT_THRESHOLD_MB),
 368       PREF("gc_incremental_slice_ms", JSGC_SLICE_TIME_BUDGET_MS),
 369       PREF("gc_min_empty_chunk_count", JSGC_MIN_EMPTY_CHUNK_COUNT),
 370       PREF("gc_max_empty_chunk_count", JSGC_MAX_EMPTY_CHUNK_COUNT),
 371       PREF("gc_compacting", JSGC_COMPACTING_ENABLED),
 372   };
 373 #undef PREF
 374
 375   auto pref = kWorkerPrefs;
 376   auto end = kWorkerPrefs + ArrayLength(kWorkerPrefs);
 377
 378   if (gRuntimeServiceDuringInit) {
 379     // During init, we want to update every pref in kWorkerPrefs.
 380     MOZ_ASSERT(memPrefName.IsEmpty(),
 381                "Pref branch prefix only expected during init");
 382   } else {
 383     // Otherwise, find the single pref that changed.
 384     while (pref != end) {
 385       if (pref->memName == memPrefName) {
 386         end = pref + 1;
 387         break;
 388       }
 389       ++pref;
 390     }
 391 #ifdef DEBUG
 392     if (pref == end) {
 393       nsAutoCString message("Workers don't support the '");
 394       message.Append(memPrefName);
 395       message.AppendLiteral("' preference!");
 396       NS_WARNING(message.get());
 397     }
 398 #endif
 399   }
 400
 401   while (pref != end) {
 402     switch (pref->key) {
 403       case JSGC_MAX_BYTES: {
 404         int32_t prefValue = GetPref(pref->fullName, -1);
 405         Maybe<uint32_t> value = (prefValue <= 0 || prefValue >= 0x1000)
 406                                     ? Nothing()
 407                                     : Some(uint32_t(prefValue) * 1024 * 1024);
 408         UpdateOtherJSGCMemoryOption(rts, pref->key, value);
 409         break;
 410       }
 411       case JSGC_SLICE_TIME_BUDGET_MS: {
 412         int32_t prefValue = GetPref(pref->fullName, -1);
 413         Maybe<uint32_t> value = (prefValue <= 0 || prefValue >= 100000)
 414                                     ? Nothing()
 415                                     : Some(uint32_t(prefValue));
 416         UpdateOtherJSGCMemoryOption(rts, pref->key, value);
 417         break;
 418       }
 419       case JSGC_COMPACTING_ENABLED:
 420       case JSGC_PARALLEL_MARKING_ENABLED:
 421       case JSGC_BALANCED_HEAP_LIMITS_ENABLED: {
 422         bool present;
 423         bool prefValue = GetPref(pref->fullName, false, &present);
 424         Maybe<uint32_t> value = present ? Some(prefValue ? 1 : 0) : Nothing();
 425         UpdateOtherJSGCMemoryOption(rts, pref->key, value);
 426         break;
 427       }
 428       case JSGC_HIGH_FREQUENCY_TIME_LIMIT:
 429       case JSGC_LOW_FREQUENCY_HEAP_GROWTH:
 430       case JSGC_HIGH_FREQUENCY_LARGE_HEAP_GROWTH:
 431       case JSGC_HIGH_FREQUENCY_SMALL_HEAP_GROWTH:
 432       case JSGC_SMALL_HEAP_SIZE_MAX:
 433       case JSGC_LARGE_HEAP_SIZE_MIN:
 434       case JSGC_ALLOCATION_THRESHOLD:
 435       case JSGC_MALLOC_THRESHOLD_BASE:
 436       case JSGC_SMALL_HEAP_INCREMENTAL_LIMIT:
 437       case JSGC_LARGE_HEAP_INCREMENTAL_LIMIT:
 438       case JSGC_URGENT_THRESHOLD_MB:
 439       case JSGC_MIN_EMPTY_CHUNK_COUNT:
 440       case JSGC_MAX_EMPTY_CHUNK_COUNT:
 441       case JSGC_HEAP_GROWTH_FACTOR:
 442         UpdateCommonJSGCMemoryOption(rts, pref->fullName, pref->key);
 443         break;
 444       default:
 445         MOZ_ASSERT_UNREACHABLE("Unknown JSGCParamKey value");
 446         break;
 447     }
 448     ++pref;
 449   }
 450 }
 451
 452 bool InterruptCallback(JSContext* aCx) {
 453   WorkerPrivate* worker = GetWorkerPrivateFromContext(aCx);
 454   MOZ_ASSERT(worker);
 455
 456   // Now is a good time to turn on profiling if it's pending.
 457   PROFILER_JS_INTERRUPT_CALLBACK();
 458
 459   return worker->InterruptCallback(aCx);
 460 }
 461
 462 class LogViolationDetailsRunnable final : public WorkerMainThreadRunnable {
 463   uint16_t mViolationType;
 464   nsString mFileName;
 465   uint32_t mLineNum;
 466   uint32_t mColumnNum;
 467   nsString mScriptSample;
 468
 469  public:
 470   LogViolationDetailsRunnable(WorkerPrivate* aWorker, uint16_t aViolationType,
 471                               const nsString& aFileName, uint32_t aLineNum,
 472                               uint32_t aColumnNum,
 473                               const nsAString& aScriptSample)
 474       : WorkerMainThreadRunnable(aWorker,
 475                                  "RuntimeService :: LogViolationDetails"_ns),
 476         mViolationType(aViolationType),
 477         mFileName(aFileName),
 478         mLineNum(aLineNum),
 479         mColumnNum(aColumnNum),
 480         mScriptSample(aScriptSample) {
 481     MOZ_ASSERT(aWorker);
 482   }
 483
 484   virtual bool MainThreadRun() override;
 485
 486  private:
 487   ~LogViolationDetailsRunnable() = default;
 488 };
 489
 490 bool ContentSecurityPolicyAllows(JSContext* aCx, JS::RuntimeCode aKind,
 491                                  JS::Handle<JSString*> aCode) {
 492   WorkerPrivate* worker = GetWorkerPrivateFromContext(aCx);
 493   worker->AssertIsOnWorkerThread();
 494
 495   bool evalOK;
 496   bool reportViolation;
 497   uint16_t violationType;
 498   nsAutoJSString scriptSample;
 499   if (aKind == JS::RuntimeCode::JS) {
 500     if (NS_WARN_IF(!scriptSample.init(aCx, aCode))) {
 501       JS_ClearPendingException(aCx);
 502       return false;
 503     }
 504
 505     if (!nsContentSecurityUtils::IsEvalAllowed(
 506             aCx, worker->UsesSystemPrincipal(), scriptSample)) {
 507       return false;
 508     }
 509
 510     evalOK = worker->IsEvalAllowed();
 511     reportViolation = worker->GetReportEvalCSPViolations();
 512     violationType = nsIContentSecurityPolicy::VIOLATION_TYPE_EVAL;
 513   } else {
 514     evalOK = worker->IsWasmEvalAllowed();
 515     reportViolation = worker->GetReportWasmEvalCSPViolations();
 516     violationType = nsIContentSecurityPolicy::VIOLATION_TYPE_WASM_EVAL;
 517   }
 518
 519   if (reportViolation) {
 520     nsString fileName;
 521     uint32_t lineNum = 0;
 522     JS::ColumnNumberOneOrigin columnNum;
 523
 524     JS::AutoFilename file;
 525     if (JS::DescribeScriptedCaller(aCx, &file, &lineNum, &columnNum) &&
 526         file.get()) {
 527       CopyUTF8toUTF16(MakeStringSpan(file.get()), fileName);
 528     } else {
 529       MOZ_ASSERT(!JS_IsExceptionPending(aCx));
 530     }
 531
 532     RefPtr<LogViolationDetailsRunnable> runnable =
 533         new LogViolationDetailsRunnable(worker, violationType, fileName,
 534                                         lineNum, columnNum.zeroOriginValue(),
 535                                         scriptSample);
 536
 537     ErrorResult rv;
 538     runnable->Dispatch(Killing, rv);
 539     if (NS_WARN_IF(rv.Failed())) {
 540       rv.SuppressException();
 541     }
 542   }
 543
 544   return evalOK;
 545 }
 546
 547 void CTypesActivityCallback(JSContext* aCx, JS::CTypesActivityType aType) {
 548   WorkerPrivate* worker = GetWorkerPrivateFromContext(aCx);
 549   worker->AssertIsOnWorkerThread();
 550
 551   switch (aType) {
 552     case JS::CTypesActivityType::BeginCall:
 553       worker->BeginCTypesCall();
 554       break;
 555
 556     case JS::CTypesActivityType::EndCall:
 557       worker->EndCTypesCall();
 558       break;
 559
 560     case JS::CTypesActivityType::BeginCallback:
 561       worker->BeginCTypesCallback();
 562       break;
 563
 564     case JS::CTypesActivityType::EndCallback:
 565       worker->EndCTypesCallback();
 566       break;
 567
 568     default:
 569       MOZ_CRASH("Unknown type flag!");
 570   }
 571 }
 572
 573 // JSDispatchableRunnables are WorkerRunnables used to dispatch JS::Dispatchable
 574 // back to their worker thread. A WorkerRunnable is used for two reasons:
 575 //
 576 // 1. The JS::Dispatchable::run() callback may run JS so we cannot use a control
 577 // runnable since they use async interrupts and break JS run-to-completion.
 578 //
 579 // 2. The DispatchToEventLoopCallback interface is *required* to fail during
 580 // shutdown (see jsapi.h) which is exactly what WorkerRunnable::Dispatch() will
 581 // do. Moreover, JS_DestroyContext() does *not* block on JS::Dispatchable::run
 582 // being called, DispatchToEventLoopCallback failure is expected to happen
 583 // during shutdown.
 584 class JSDispatchableRunnable final : public WorkerRunnable {
 585   JS::Dispatchable* mDispatchable;
 586
 587   ~JSDispatchableRunnable() { MOZ_ASSERT(!mDispatchable); }
 588
 589   // Disable the usual pre/post-dispatch thread assertions since we are
 590   // dispatching from some random JS engine internal thread:
 591
 592   bool PreDispatch(WorkerPrivate* aWorkerPrivate) override { return true; }
 593
 594   void PostDispatch(WorkerPrivate* aWorkerPrivate,
 595                     bool aDispatchResult) override {
 596     // For the benefit of the destructor assert.
 597     if (!aDispatchResult) {
 598       mDispatchable = nullptr;
 599     }
 600   }
 601
 602  public:
 603   JSDispatchableRunnable(WorkerPrivate* aWorkerPrivate,
 604                          JS::Dispatchable* aDispatchable)
 605       : WorkerRunnable(aWorkerPrivate, WorkerRunnable::WorkerThread),
 606         mDispatchable(aDispatchable) {
 607     MOZ_ASSERT(mDispatchable);
 608   }
 609
 610   bool WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) override {
 611     MOZ_ASSERT(aWorkerPrivate == mWorkerPrivate);
 612     MOZ_ASSERT(aCx == mWorkerPrivate->GetJSContext());
 613     MOZ_ASSERT(mDispatchable);
 614
 615     AutoJSAPI jsapi;
 616     jsapi.Init();
 617
 618     mDispatchable->run(mWorkerPrivate->GetJSContext(),
 619                        JS::Dispatchable::NotShuttingDown);
 620     mDispatchable = nullptr;  // mDispatchable may delete itself
 621
 622     return true;
 623   }
 624
 625   nsresult Cancel() override {
 626     MOZ_ASSERT(mDispatchable);
 627
 628     AutoJSAPI jsapi;
 629     jsapi.Init();
 630
 631     mDispatchable->run(mWorkerPrivate->GetJSContext(),
 632                        JS::Dispatchable::ShuttingDown);
 633     mDispatchable = nullptr;  // mDispatchable may delete itself
 634
 635     return NS_OK;
 636   }
 637 };
 638
 639 static bool DispatchToEventLoop(void* aClosure,
 640                                 JS::Dispatchable* aDispatchable) {
 641   // This callback may execute either on the worker thread or a random
 642   // JS-internal helper thread.
 643
 644   // See comment at JS::InitDispatchToEventLoop() below for how we know the
 645   // WorkerPrivate is alive.
 646   WorkerPrivate* workerPrivate = reinterpret_cast<WorkerPrivate*>(aClosure);
 647
 648   // Dispatch is expected to fail during shutdown for the reasons outlined in
 649   // the JSDispatchableRunnable comment above.
 650   RefPtr<JSDispatchableRunnable> r =
 651       new JSDispatchableRunnable(workerPrivate, aDispatchable);
 652   return r->Dispatch();
 653 }
 654
 655 static bool ConsumeStream(JSContext* aCx, JS::Handle<JSObject*> aObj,
 656                           JS::MimeType aMimeType,
 657                           JS::StreamConsumer* aConsumer) {
 658   WorkerPrivate* worker = GetWorkerPrivateFromContext(aCx);
 659   if (!worker) {
 660     JS_ReportErrorNumberASCII(aCx, js::GetErrorMessage, nullptr,
 661                               JSMSG_WASM_ERROR_CONSUMING_RESPONSE);
 662     return false;
 663   }
 664
 665   return FetchUtil::StreamResponseToJS(aCx, aObj, aMimeType, aConsumer, worker);
 666 }
 667
 668 bool InitJSContextForWorker(WorkerPrivate* aWorkerPrivate,
 669                             JSContext* aWorkerCx) {
 670   aWorkerPrivate->AssertIsOnWorkerThread();
 671   NS_ASSERTION(!aWorkerPrivate->GetJSContext(), "Already has a context!");
 672
 673   JSSettings settings;
 674   aWorkerPrivate->CopyJSSettings(settings);
 675
 676   JS::ContextOptionsRef(aWorkerCx) = settings.contextOptions;
 677
 678   // This is the real place where we set the max memory for the runtime.
 679   for (const auto& setting : settings.gcSettings) {
 680     if (setting.value) {
 681       JS_SetGCParameter(aWorkerCx, setting.key, *setting.value);
 682     } else {
 683       JS_ResetGCParameter(aWorkerCx, setting.key);
 684     }
 685   }
 686
 687   JS_SetNativeStackQuota(aWorkerCx, WORKER_CONTEXT_NATIVE_STACK_LIMIT);
 688
 689   // Security policy:
 690   static const JSSecurityCallbacks securityCallbacks = {
 691       ContentSecurityPolicyAllows};
 692   JS_SetSecurityCallbacks(aWorkerCx, &securityCallbacks);
 693
 694   // A WorkerPrivate lives strictly longer than its JSRuntime so we can safely
 695   // store a raw pointer as the callback's closure argument on the JSRuntime.
 696   JS::InitDispatchToEventLoop(aWorkerCx, DispatchToEventLoop,
 697                               (void*)aWorkerPrivate);
 698
 699   JS::InitConsumeStreamCallback(aWorkerCx, ConsumeStream,
 700                                 FetchUtil::ReportJSStreamError);
 701
 702   // When available, set the self-hosted shared memory to be read, so that we
 703   // can decode the self-hosted content instead of parsing it.
 704   auto& shm = xpc::SelfHostedShmem::GetSingleton();
 705   JS::SelfHostedCache selfHostedContent = shm.Content();
 706
 707   if (!JS::InitSelfHostedCode(aWorkerCx, selfHostedContent)) {
 708     NS_WARNING("Could not init self-hosted code!");
 709     return false;
 710   }
 711
 712   JS_AddInterruptCallback(aWorkerCx, InterruptCallback);
 713
 714   JS::SetCTypesActivityCallback(aWorkerCx, CTypesActivityCallback);
 715
 716 #ifdef JS_GC_ZEAL
 717   JS_SetGCZeal(aWorkerCx, settings.gcZeal, settings.gcZealFrequency);
 718 #endif
 719
 720   return true;
 721 }
 722
 723 static bool PreserveWrapper(JSContext* cx, JS::Handle<JSObject*> obj) {
 724   MOZ_ASSERT(cx);
 725   MOZ_ASSERT(obj);
 726   MOZ_ASSERT(mozilla::dom::IsDOMObject(obj));
 727
 728   return mozilla::dom::TryPreserveWrapper(obj);
 729 }
 730
 731 static bool IsWorkerDebuggerGlobalOrSandbox(JS::Handle<JSObject*> aGlobal) {
 732   return IsWorkerDebuggerGlobal(aGlobal) || IsWorkerDebuggerSandbox(aGlobal);
 733 }
 734
 735 JSObject* Wrap(JSContext* cx, JS::Handle<JSObject*> existing,
 736                JS::Handle<JSObject*> obj) {
 737   JS::Rooted<JSObject*> targetGlobal(cx, JS::CurrentGlobalOrNull(cx));
 738
 739   // Note: the JS engine unwraps CCWs before calling this callback.
 740   JS::Rooted<JSObject*> originGlobal(cx, JS::GetNonCCWObjectGlobal(obj));
 741
 742   const js::Wrapper* wrapper = nullptr;
 743   if (IsWorkerDebuggerGlobalOrSandbox(targetGlobal) &&
 744       IsWorkerDebuggerGlobalOrSandbox(originGlobal)) {
 745     wrapper = &js::CrossCompartmentWrapper::singleton;
 746   } else {
 747     wrapper = &js::OpaqueCrossCompartmentWrapper::singleton;
 748   }
 749
 750   if (existing) {
 751     js::Wrapper::Renew(existing, obj, wrapper);
 752   }
 753   return js::Wrapper::New(cx, obj, wrapper);
 754 }
 755
 756 static const JSWrapObjectCallbacks WrapObjectCallbacks = {
 757     Wrap,
 758     nullptr,
 759 };
 760
 761 class WorkerJSRuntime final : public mozilla::CycleCollectedJSRuntime {
 762  public:
 763   // The heap size passed here doesn't matter, we will change it later in the
 764   // call to JS_SetGCParameter inside InitJSContextForWorker.
 765   explicit WorkerJSRuntime(JSContext* aCx, WorkerPrivate* aWorkerPrivate)
 766       : CycleCollectedJSRuntime(aCx), mWorkerPrivate(aWorkerPrivate) {
 767     MOZ_COUNT_CTOR_INHERITED(WorkerJSRuntime, CycleCollectedJSRuntime);
 768     MOZ_ASSERT(aWorkerPrivate);
 769
 770     {
 771       JS::UniqueChars defaultLocale = aWorkerPrivate->AdoptDefaultLocale();
 772       MOZ_ASSERT(defaultLocale,
 773                  "failure of a WorkerPrivate to have a default locale should "
 774                  "have made the worker fail to spawn");
 775
 776       if (!JS_SetDefaultLocale(Runtime(), defaultLocale.get())) {
 777         NS_WARNING("failed to set workerCx's default locale");
 778       }
 779     }
 780   }
 781
 782   void Shutdown(JSContext* cx) override {
 783     // The CC is shut down, and the superclass destructor will GC, so make sure
 784     // we don't try to CC again.
 785     mWorkerPrivate = nullptr;
 786
 787     CycleCollectedJSRuntime::Shutdown(cx);
 788   }
 789
 790   ~WorkerJSRuntime() {
 791     MOZ_COUNT_DTOR_INHERITED(WorkerJSRuntime, CycleCollectedJSRuntime);
 792   }
 793
 794   virtual void PrepareForForgetSkippable() override {}
 795
 796   virtual void BeginCycleCollectionCallback(
 797       mozilla::CCReason aReason) override {}
 798
 799   virtual void EndCycleCollectionCallback(
 800       CycleCollectorResults& aResults) override {}
 801
 802   void DispatchDeferredDeletion(bool aContinuation, bool aPurge) override {
 803     MOZ_ASSERT(!aContinuation);
 804
 805     // Do it immediately, no need for asynchronous behavior here.
 806     nsCycleCollector_doDeferredDeletion();
 807   }
 808
 809   virtual void CustomGCCallback(JSGCStatus aStatus) override {
 810     if (!mWorkerPrivate) {
 811       // We're shutting down, no need to do anything.
 812       return;
 813     }
 814
 815     mWorkerPrivate->AssertIsOnWorkerThread();
 816
 817     if (aStatus == JSGC_END) {
 818       bool collectedAnything =
 819           nsCycleCollector_collect(CCReason::GC_FINISHED, nullptr);
 820       mWorkerPrivate->SetCCCollectedAnything(collectedAnything);
 821     }
 822   }
 823
 824  private:
 825   WorkerPrivate* mWorkerPrivate;
 826 };
 827
 828 }  // anonymous namespace
 829
 830 }  // namespace workerinternals
 831
 832 class WorkerJSContext final : public mozilla::CycleCollectedJSContext {
 833  public:
 834   // The heap size passed here doesn't matter, we will change it later in the
 835   // call to JS_SetGCParameter inside InitJSContextForWorker.
 836   explicit WorkerJSContext(WorkerPrivate* aWorkerPrivate)
 837       : mWorkerPrivate(aWorkerPrivate) {
 838     MOZ_COUNT_CTOR_INHERITED(WorkerJSContext, CycleCollectedJSContext);
 839     MOZ_ASSERT(aWorkerPrivate);
 840     // Magical number 2. Workers have the base recursion depth 1, and normal
 841     // runnables run at level 2, and we don't want to process microtasks
 842     // at any other level.
 843     SetTargetedMicroTaskRecursionDepth(2);
 844   }
 845
 846   // MOZ_CAN_RUN_SCRIPT_BOUNDARY because otherwise we have to annotate the
 847   // SpiderMonkey JS::JobQueue's destructor as MOZ_CAN_RUN_SCRIPT, which is a
 848   // bit of a pain.
 849   MOZ_CAN_RUN_SCRIPT_BOUNDARY ~WorkerJSContext() {
 850     MOZ_COUNT_DTOR_INHERITED(WorkerJSContext, CycleCollectedJSContext);
 851     JSContext* cx = MaybeContext();
 852     if (!cx) {
 853       return;  // Initialize() must have failed
 854     }
 855
 856     // We expect to come here with the cycle collector already shut down.
 857     // The superclass destructor will run the GC one final time and finalize any
 858     // JSObjects that were participating in cycles that were broken during CC
 859     // shutdown.
 860     // Make sure we don't try to CC again.
 861     mWorkerPrivate = nullptr;
 862   }
 863
 864   WorkerJSContext* GetAsWorkerJSContext() override { return this; }
 865
 866   CycleCollectedJSRuntime* CreateRuntime(JSContext* aCx) override {
 867     return new WorkerJSRuntime(aCx, mWorkerPrivate);
 868   }
 869
 870   nsresult Initialize(JSRuntime* aParentRuntime) {
 871     nsresult rv = CycleCollectedJSContext::Initialize(
 872         aParentRuntime, WORKER_DEFAULT_RUNTIME_HEAPSIZE);
 873     if (NS_WARN_IF(NS_FAILED(rv))) {
 874       return rv;
 875     }
 876
 877     JSContext* cx = Context();
 878
 879     js::SetPreserveWrapperCallbacks(cx, PreserveWrapper, HasReleasedWrapper);
 880     JS_InitDestroyPrincipalsCallback(cx, nsJSPrincipals::Destroy);
 881     JS_InitReadPrincipalsCallback(cx, nsJSPrincipals::ReadPrincipals);
 882     JS_SetWrapObjectCallbacks(cx, &WrapObjectCallbacks);
 883     if (mWorkerPrivate->IsDedicatedWorker()) {
 884       JS_SetFutexCanWait(cx);
 885     }
 886
 887     return NS_OK;
 888   }
 889
 890   virtual void DispatchToMicroTask(
 891       already_AddRefed<MicroTaskRunnable> aRunnable) override {
 892     RefPtr<MicroTaskRunnable> runnable(aRunnable);
 893
 894     MOZ_ASSERT(!NS_IsMainThread());
 895     MOZ_ASSERT(runnable);
 896
 897     std::deque<RefPtr<MicroTaskRunnable>>* microTaskQueue = nullptr;
 898
 899     JSContext* cx = Context();
 900     NS_ASSERTION(cx, "This should never be null!");
 901
 902     JS::Rooted<JSObject*> global(cx, JS::CurrentGlobalOrNull(cx));
 903     NS_ASSERTION(global, "This should never be null!");
 904
 905     // On worker threads, if the current global is the worker global or
 906     // ShadowRealm global, we use the main micro task queue. Otherwise, the
 907     // current global must be either the debugger global or a debugger sandbox,
 908     // and we use the debugger micro task queue instead.
 909     if (IsWorkerGlobal(global) || IsShadowRealmGlobal(global)) {
 910       microTaskQueue = &GetMicroTaskQueue();
 911     } else {
 912       MOZ_ASSERT(IsWorkerDebuggerGlobal(global) ||
 913                  IsWorkerDebuggerSandbox(global));
 914
 915       microTaskQueue = &GetDebuggerMicroTaskQueue();
 916     }
 917
 918     JS::JobQueueMayNotBeEmpty(cx);
 919     microTaskQueue->push_back(std::move(runnable));
 920   }
 921
 922   bool IsSystemCaller() const override {
 923     return mWorkerPrivate->UsesSystemPrincipal();
 924   }
 925
 926   void ReportError(JSErrorReport* aReport,
 927                    JS::ConstUTF8CharsZ aToStringResult) override {
 928     mWorkerPrivate->ReportError(Context(), aToStringResult, aReport);
 929   }
 930
 931   WorkerPrivate* GetWorkerPrivate() const { return mWorkerPrivate; }
 932
 933  private:
 934   WorkerPrivate* mWorkerPrivate;
 935 };
 936
 937 namespace workerinternals {
 938
 939 namespace {
 940
 941 class WorkerThreadPrimaryRunnable final : public Runnable {
 942   WorkerPrivate* mWorkerPrivate;
 943   SafeRefPtr<WorkerThread> mThread;
 944   JSRuntime* mParentRuntime;
 945
 946   class FinishedRunnable final : public Runnable {
 947     SafeRefPtr<WorkerThread> mThread;
 948
 949    public:
 950     explicit FinishedRunnable(SafeRefPtr<WorkerThread> aThread)
 951         : Runnable("WorkerThreadPrimaryRunnable::FinishedRunnable"),
 952           mThread(std::move(aThread)) {
 953       MOZ_ASSERT(mThread);
 954     }
 955
 956     NS_INLINE_DECL_REFCOUNTING_INHERITED(FinishedRunnable, Runnable)
 957
 958    private:
 959     ~FinishedRunnable() = default;
 960
 961     NS_DECL_NSIRUNNABLE
 962   };
 963
 964  public:
 965   WorkerThreadPrimaryRunnable(WorkerPrivate* aWorkerPrivate,
 966                               SafeRefPtr<WorkerThread> aThread,
 967                               JSRuntime* aParentRuntime)
 968       : mozilla::Runnable("WorkerThreadPrimaryRunnable"),
 969         mWorkerPrivate(aWorkerPrivate),
 970         mThread(std::move(aThread)),
 971         mParentRuntime(aParentRuntime) {
 972     MOZ_ASSERT(aWorkerPrivate);
 973     MOZ_ASSERT(mThread);
 974   }
 975
 976   NS_INLINE_DECL_REFCOUNTING_INHERITED(WorkerThreadPrimaryRunnable, Runnable)
 977
 978  private:
 979   ~WorkerThreadPrimaryRunnable() = default;
 980
 981   NS_DECL_NSIRUNNABLE
 982 };
 983
 984 void PrefLanguagesChanged(const char* /* aPrefName */, void* /* aClosure */) {
 985   AssertIsOnMainThread();
 986
 987   nsTArray<nsString> languages;
 988   Navigator::GetAcceptLanguages(languages);
 989
 990   RuntimeService* runtime = RuntimeService::GetService();
 991   if (runtime) {
 992     runtime->UpdateAllWorkerLanguages(languages);
 993   }
 994 }
 995
 996 void AppVersionOverrideChanged(const char* /* aPrefName */,
 997                                void* /* aClosure */) {
 998   AssertIsOnMainThread();
 999
1000   nsAutoString override;
1001   Preferences::GetString("general.appversion.override", override);
1002
1003   RuntimeService* runtime = RuntimeService::GetService();
1004   if (runtime) {
1005     runtime->UpdateAppVersionOverridePreference(override);
1006   }
1007 }
1008
1009 void PlatformOverrideChanged(const char* /* aPrefName */,
1010                              void* /* aClosure */) {
1011   AssertIsOnMainThread();
1012
1013   nsAutoString override;
1014   Preferences::GetString("general.platform.override", override);
1015
1016   RuntimeService* runtime = RuntimeService::GetService();
1017   if (runtime) {
1018     runtime->UpdatePlatformOverridePreference(override);
1019   }
1020 }
1021
1022 } /* anonymous namespace */
1023
1024 // This is only touched on the main thread. Initialized in Init() below.
1025 UniquePtr<JSSettings> RuntimeService::sDefaultJSSettings;
1026
1027 RuntimeService::RuntimeService()
1028     : mMutex("RuntimeService::mMutex"),
1029       mObserved(false),
1030       mShuttingDown(false),
1031       mNavigatorPropertiesLoaded(false) {
1032   AssertIsOnMainThread();
1033   MOZ_ASSERT(!GetService(), "More than one service!");
1034 }
1035
1036 RuntimeService::~RuntimeService() {
1037   AssertIsOnMainThread();
1038
1039   // gRuntimeService can be null if Init() fails.
1040   MOZ_ASSERT(!GetService() || GetService() == this, "More than one service!");
1041
1042   gRuntimeService = nullptr;
1043 }
1044
1045 // static
1046 RuntimeService* RuntimeService::GetOrCreateService() {
1047   AssertIsOnMainThread();
1048
1049   if (!gRuntimeService) {
1050     // The observer service now owns us until shutdown.
1051     gRuntimeService = new RuntimeService();
1052     if (NS_FAILED((*gRuntimeService).Init())) {
1053       NS_WARNING("Failed to initialize!");
1054       (*gRuntimeService).Cleanup();
1055       gRuntimeService = nullptr;
1056       return nullptr;
1057     }
1058   }
1059
1060   return gRuntimeService;
1061 }
1062
1063 // static
1064 RuntimeService* RuntimeService::GetService() { return gRuntimeService; }
1065
1066 bool RuntimeService::RegisterWorker(WorkerPrivate& aWorkerPrivate) {
1067   aWorkerPrivate.AssertIsOnParentThread();
1068
1069   WorkerPrivate* parent = aWorkerPrivate.GetParent();
1070   if (!parent) {
1071     AssertIsOnMainThread();
1072
1073     if (mShuttingDown) {
1074       return false;
1075     }
1076   }
1077
1078   const bool isServiceWorker = aWorkerPrivate.IsServiceWorker();
1079   const bool isSharedWorker = aWorkerPrivate.IsSharedWorker();
1080   const bool isDedicatedWorker = aWorkerPrivate.IsDedicatedWorker();
1081   if (isServiceWorker) {
1082     AssertIsOnMainThread();
1083     Telemetry::Accumulate(Telemetry::SERVICE_WORKER_SPAWN_ATTEMPTS, 1);
1084   }
1085
1086   nsCString sharedWorkerScriptSpec;
1087   if (isSharedWorker) {
1088     AssertIsOnMainThread();
1089
1090     nsCOMPtr<nsIURI> scriptURI = aWorkerPrivate.GetResolvedScriptURI();
1091     NS_ASSERTION(scriptURI, "Null script URI!");
1092
1093     nsresult rv = scriptURI->GetSpec(sharedWorkerScriptSpec);
1094     if (NS_FAILED(rv)) {
1095       NS_WARNING("GetSpec failed?!");
1096       return false;
1097     }
1098
1099     NS_ASSERTION(!sharedWorkerScriptSpec.IsEmpty(), "Empty spec!");
1100   }
1101
1102   bool exemptFromPerDomainMax = false;
1103   if (isServiceWorker) {
1104     AssertIsOnMainThread();
1105     exemptFromPerDomainMax = Preferences::GetBool(
1106         "dom.serviceWorkers.exemptFromPerDomainMax", false);
1107   }
1108
1109   const nsCString& domain = aWorkerPrivate.Domain();
1110
1111   bool queued = false;
1112   {
1113     MutexAutoLock lock(mMutex);
1114
1115     auto* const domainInfo =
1116         mDomainMap
1117             .LookupOrInsertWith(
1118                 domain,
1119                 [&domain, parent] {
1120                   NS_ASSERTION(!parent, "Shouldn't have a parent here!");
1121                   Unused << parent;  // silence clang -Wunused-lambda-capture in
1122                                      // opt builds
1123                   auto wdi = MakeUnique<WorkerDomainInfo>();
1124                   wdi->mDomain = domain;
1125                   return wdi;
1126                 })
1127             .get();
1128
1129     queued = gMaxWorkersPerDomain &&
1130              domainInfo->ActiveWorkerCount() >= gMaxWorkersPerDomain &&
1131              !domain.IsEmpty() && !exemptFromPerDomainMax;
1132
1133     if (queued) {
1134       domainInfo->mQueuedWorkers.AppendElement(&aWorkerPrivate);
1135
1136       // Worker spawn gets queued due to hitting max workers per domain
1137       // limit so let's log a warning.
1138       WorkerPrivate::ReportErrorToConsole("HittingMaxWorkersPerDomain2");
1139
1140       if (isServiceWorker) {
1141         Telemetry::Accumulate(Telemetry::SERVICE_WORKER_SPAWN_GETS_QUEUED, 1);
1142       } else if (isSharedWorker) {
1143         Telemetry::Accumulate(Telemetry::SHARED_WORKER_SPAWN_GETS_QUEUED, 1);
1144       } else if (isDedicatedWorker) {
1145         Telemetry::Accumulate(Telemetry::DEDICATED_WORKER_SPAWN_GETS_QUEUED, 1);
1146       }
1147     } else if (parent) {
1148       domainInfo->mChildWorkerCount++;
1149     } else if (isServiceWorker) {
1150       domainInfo->mActiveServiceWorkers.AppendElement(&aWorkerPrivate);
1151     } else {
1152       domainInfo->mActiveWorkers.AppendElement(&aWorkerPrivate);
1153     }
1154   }
1155
1156   // From here on out we must call UnregisterWorker if something fails!
1157   if (parent) {
1158     if (!parent->AddChildWorker(aWorkerPrivate)) {
1159       UnregisterWorker(aWorkerPrivate);
1160       return false;
1161     }
1162   } else {
1163     if (!mNavigatorPropertiesLoaded) {
1164       if (NS_FAILED(Navigator::GetAppVersion(
1165               mNavigatorProperties.mAppVersion, aWorkerPrivate.GetDocument(),
1166               false /* aUsePrefOverriddenValue */)) ||
1167           NS_FAILED(Navigator::GetPlatform(
1168               mNavigatorProperties.mPlatform, aWorkerPrivate.GetDocument(),
1169               false /* aUsePrefOverriddenValue */))) {
1170         UnregisterWorker(aWorkerPrivate);
1171         return false;
1172       }
1173
1174       // The navigator overridden properties should have already been read.
1175
1176       Navigator::GetAcceptLanguages(mNavigatorProperties.mLanguages);
1177       mNavigatorPropertiesLoaded = true;
1178     }
1179
1180     nsPIDOMWindowInner* window = aWorkerPrivate.GetWindow();
1181
1182     if (!isServiceWorker) {
1183       // Service workers are excluded since their lifetime is separate from
1184       // that of dom windows.
1185       if (auto* const windowArray = mWindowMap.GetOrInsertNew(window, 1);
1186           !windowArray->Contains(&aWorkerPrivate)) {
1187         windowArray->AppendElement(&aWorkerPrivate);
1188       } else {
1189         MOZ_ASSERT(aWorkerPrivate.IsSharedWorker());
1190       }
1191     }
1192   }
1193
1194   if (!queued && !ScheduleWorker(aWorkerPrivate)) {
1195     return false;
1196   }
1197
1198   if (isServiceWorker) {
1199     AssertIsOnMainThread();
1200     Telemetry::Accumulate(Telemetry::SERVICE_WORKER_WAS_SPAWNED, 1);
1201   }
1202   return true;
1203 }
1204
1205 void RuntimeService::UnregisterWorker(WorkerPrivate& aWorkerPrivate) {
1206   aWorkerPrivate.AssertIsOnParentThread();
1207
1208   WorkerPrivate* parent = aWorkerPrivate.GetParent();
1209   if (!parent) {
1210     AssertIsOnMainThread();
1211   }
1212
1213   const nsCString& domain = aWorkerPrivate.Domain();
1214
1215   WorkerPrivate* queuedWorker = nullptr;
1216   {
1217     MutexAutoLock lock(mMutex);
1218
1219     WorkerDomainInfo* domainInfo;
1220     if (!mDomainMap.Get(domain, &domainInfo)) {
1221       NS_ERROR("Don't have an entry for this domain!");
1222     }
1223
1224     // Remove old worker from everywhere.
1225     uint32_t index = domainInfo->mQueuedWorkers.IndexOf(&aWorkerPrivate);
1226     if (index != kNoIndex) {
1227       // Was queued, remove from the list.
1228       domainInfo->mQueuedWorkers.RemoveElementAt(index);
1229     } else if (parent) {
1230       MOZ_ASSERT(domainInfo->mChildWorkerCount, "Must be non-zero!");
1231       domainInfo->mChildWorkerCount--;
1232     } else if (aWorkerPrivate.IsServiceWorker()) {
1233       MOZ_ASSERT(domainInfo->mActiveServiceWorkers.Contains(&aWorkerPrivate),
1234                  "Don't know about this worker!");
1235       domainInfo->mActiveServiceWorkers.RemoveElement(&aWorkerPrivate);
1236     } else {
1237       MOZ_ASSERT(domainInfo->mActiveWorkers.Contains(&aWorkerPrivate),
1238                  "Don't know about this worker!");
1239       domainInfo->mActiveWorkers.RemoveElement(&aWorkerPrivate);
1240     }
1241
1242     // See if there's a queued worker we can schedule.
1243     if (domainInfo->ActiveWorkerCount() < gMaxWorkersPerDomain &&
1244         !domainInfo->mQueuedWorkers.IsEmpty()) {
1245       queuedWorker = domainInfo->mQueuedWorkers[0];
1246       domainInfo->mQueuedWorkers.RemoveElementAt(0);
1247
1248       if (queuedWorker->GetParent()) {
1249         domainInfo->mChildWorkerCount++;
1250       } else if (queuedWorker->IsServiceWorker()) {
1251         domainInfo->mActiveServiceWorkers.AppendElement(queuedWorker);
1252       } else {
1253         domainInfo->mActiveWorkers.AppendElement(queuedWorker);
1254       }
1255     }
1256
1257     if (domainInfo->HasNoWorkers()) {
1258       MOZ_ASSERT(domainInfo->mQueuedWorkers.IsEmpty());
1259       mDomainMap.Remove(domain);
1260     }
1261   }
1262
1263   // NB: For Shared Workers we used to call ShutdownOnMainThread on the
1264   // RemoteWorkerController; however, that was redundant because
1265   // RemoteWorkerChild uses a WeakWorkerRef which notifies at about the
1266   // same time as us calling into the code here and would race with us.
1267
1268   if (parent) {
1269     parent->RemoveChildWorker(aWorkerPrivate);
1270   } else if (aWorkerPrivate.IsSharedWorker()) {
1271     AssertIsOnMainThread();
1272
1273     mWindowMap.RemoveIf([&aWorkerPrivate](const auto& iter) {
1274       const auto& workers = iter.Data();
1275       MOZ_ASSERT(workers);
1276
1277       if (workers->RemoveElement(&aWorkerPrivate)) {
1278         MOZ_ASSERT(!workers->Contains(&aWorkerPrivate),
1279                    "Added worker more than once!");
1280
1281         return workers->IsEmpty();
1282       }
1283
1284       return false;
1285     });
1286   } else if (aWorkerPrivate.IsDedicatedWorker()) {
1287     // May be null.
1288     nsPIDOMWindowInner* window = aWorkerPrivate.GetWindow();
1289     if (auto entry = mWindowMap.Lookup(window)) {
1290       MOZ_ALWAYS_TRUE(entry.Data()->RemoveElement(&aWorkerPrivate));
1291       if (entry.Data()->IsEmpty()) {
1292         entry.Remove();
1293       }
1294     } else {
1295       MOZ_ASSERT_UNREACHABLE("window is not in mWindowMap");
1296     }
1297   }
1298
1299   if (queuedWorker && !ScheduleWorker(*queuedWorker)) {
1300     UnregisterWorker(*queuedWorker);
1301   }
1302 }
1303
1304 bool RuntimeService::ScheduleWorker(WorkerPrivate& aWorkerPrivate) {
1305   if (!aWorkerPrivate.Start()) {
1306     // This is ok, means that we didn't need to make a thread for this worker.
1307     return true;
1308   }
1309
1310   const WorkerThreadFriendKey friendKey;
1311
1312   SafeRefPtr<WorkerThread> thread = WorkerThread::Create(friendKey);
1313   if (!thread) {
1314     UnregisterWorker(aWorkerPrivate);
1315     return false;
1316   }
1317
1318   if (NS_FAILED(thread->SetPriority(nsISupportsPriority::PRIORITY_NORMAL))) {
1319     NS_WARNING("Could not set the thread's priority!");
1320   }
1321
1322   aWorkerPrivate.SetThread(thread.unsafeGetRawPtr());
1323   JSContext* cx = CycleCollectedJSContext::Get()->Context();
1324   nsCOMPtr<nsIRunnable> runnable = new WorkerThreadPrimaryRunnable(
1325       &aWorkerPrivate, thread.clonePtr(), JS_GetParentRuntime(cx));
1326   if (NS_FAILED(
1327           thread->DispatchPrimaryRunnable(friendKey, runnable.forget()))) {
1328     UnregisterWorker(aWorkerPrivate);
1329     return false;
1330   }
1331
1332   return true;
1333 }
1334
1335 nsresult RuntimeService::Init() {
1336   AssertIsOnMainThread();
1337
1338   nsLayoutStatics::AddRef();
1339
1340   // Initialize JSSettings.
1341   sDefaultJSSettings = MakeUnique<JSSettings>();
1342   SetDefaultJSGCSettings(JSGC_MAX_BYTES, Some(WORKER_DEFAULT_RUNTIME_HEAPSIZE));
1343   SetDefaultJSGCSettings(JSGC_ALLOCATION_THRESHOLD,
1344                          Some(WORKER_DEFAULT_ALLOCATION_THRESHOLD));
1345
1346   // nsIStreamTransportService is thread-safe but it must be initialized on the
1347   // main-thread. FileReader needs it, so, let's initialize it now.
1348   nsresult rv;
1349   nsCOMPtr<nsIStreamTransportService> sts =
1350       do_GetService(kStreamTransportServiceCID, &rv);
1351   NS_ENSURE_TRUE(sts, NS_ERROR_FAILURE);
1352
1353   nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
1354   NS_ENSURE_TRUE(obs, NS_ERROR_FAILURE);
1355
1356   rv = obs->AddObserver(this, NS_XPCOM_SHUTDOWN_THREADS_OBSERVER_ID, false);
1357   NS_ENSURE_SUCCESS(rv, rv);
1358
1359   rv = obs->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
1360   NS_ENSURE_SUCCESS(rv, rv);
1361
1362   mObserved = true;
1363
1364   if (NS_FAILED(obs->AddObserver(this, GC_REQUEST_OBSERVER_TOPIC, false))) {
1365     NS_WARNING("Failed to register for GC request notifications!");
1366   }
1367
1368   if (NS_FAILED(obs->AddObserver(this, CC_REQUEST_OBSERVER_TOPIC, false))) {
1369     NS_WARNING("Failed to register for CC request notifications!");
1370   }
1371
1372   if (NS_FAILED(
1373           obs->AddObserver(this, MEMORY_PRESSURE_OBSERVER_TOPIC, false))) {
1374     NS_WARNING("Failed to register for memory pressure notifications!");
1375   }
1376
1377   if (NS_FAILED(
1378           obs->AddObserver(this, NS_IOSERVICE_OFFLINE_STATUS_TOPIC, false))) {
1379     NS_WARNING("Failed to register for offline notification event!");
1380   }
1381
1382   MOZ_ASSERT(!gRuntimeServiceDuringInit, "This should be false!");
1383   gRuntimeServiceDuringInit = true;
1384
1385 #define WORKER_PREF(name, callback) \
1386   NS_FAILED(Preferences::RegisterCallbackAndCall(callback, name))
1387
1388   if (NS_FAILED(Preferences::RegisterPrefixCallbackAndCall(
1389           LoadJSGCMemoryOptions,
1390           PREF_JS_OPTIONS_PREFIX PREF_MEM_OPTIONS_PREFIX)) ||
1391 #ifdef JS_GC_ZEAL
1392       NS_FAILED(Preferences::RegisterCallback(
1393           LoadGCZealOptions, PREF_JS_OPTIONS_PREFIX PREF_GCZEAL)) ||
1394 #endif
1395       WORKER_PREF("intl.accept_languages", PrefLanguagesChanged) ||
1396       WORKER_PREF("general.appversion.override", AppVersionOverrideChanged) ||
1397       WORKER_PREF("general.platform.override", PlatformOverrideChanged) ||
1398       NS_FAILED(Preferences::RegisterPrefixCallbackAndCall(
1399           LoadContextOptions, PREF_JS_OPTIONS_PREFIX))) {
1400     NS_WARNING("Failed to register pref callbacks!");
1401   }
1402
1403 #undef WORKER_PREF
1404
1405   MOZ_ASSERT(gRuntimeServiceDuringInit, "Should be true!");
1406   gRuntimeServiceDuringInit = false;
1407
1408   int32_t maxPerDomain =
1409       Preferences::GetInt(PREF_WORKERS_MAX_PER_DOMAIN, MAX_WORKERS_PER_DOMAIN);
1410   gMaxWorkersPerDomain = std::max(0, maxPerDomain);
1411
1412   if (NS_WARN_IF(!IndexedDatabaseManager::GetOrCreate())) {
1413     return NS_ERROR_UNEXPECTED;
1414   }
1415
1416   // PerformanceService must be initialized on the main-thread.
1417   PerformanceService::GetOrCreate();
1418
1419   return NS_OK;
1420 }
1421
1422 void RuntimeService::Shutdown() {
1423   AssertIsOnMainThread();
1424
1425   MOZ_ASSERT(!mShuttingDown);
1426   // That's it, no more workers.
1427   mShuttingDown = true;
1428
1429   nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
1430   NS_WARNING_ASSERTION(obs, "Failed to get observer service?!");
1431
1432   // Tell anyone that cares that they're about to lose worker support.
1433   if (obs && NS_FAILED(obs->NotifyObservers(nullptr, WORKERS_SHUTDOWN_TOPIC,
1434                                             nullptr))) {
1435     NS_WARNING("NotifyObservers failed!");
1436   }
1437
1438   {
1439     AutoTArray<WorkerPrivate*, 100> workers;
1440
1441     {
1442       MutexAutoLock lock(mMutex);
1443
1444       AddAllTopLevelWorkersToArray(workers);
1445     }
1446
1447     // Cancel all top-level workers.
1448     for (const auto& worker : workers) {
1449       if (!worker->Cancel()) {
1450         NS_WARNING("Failed to cancel worker!");
1451       }
1452     }
1453   }
1454
1455   sDefaultJSSettings = nullptr;
1456 }
1457
1458 namespace {
1459
1460 class DumpCrashInfoRunnable : public WorkerControlRunnable {
1461  public:
1462   explicit DumpCrashInfoRunnable(WorkerPrivate* aWorkerPrivate)
1463       : WorkerControlRunnable(aWorkerPrivate, WorkerThread),
1464         mMonitor("DumpCrashInfoRunnable::mMonitor") {}
1465
1466   bool WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) override {
1467     MonitorAutoLock lock(mMonitor);
1468     if (!mHasMsg) {
1469       aWorkerPrivate->DumpCrashInformation(mMsg);
1470       mHasMsg.Flip();
1471     }
1472     lock.Notify();
1473     return true;
1474   }
1475
1476   nsresult Cancel() override {
1477     MonitorAutoLock lock(mMonitor);
1478     if (!mHasMsg) {
1479       mMsg.Assign("Canceled");
1480       mHasMsg.Flip();
1481     }
1482     lock.Notify();
1483
1484     return NS_OK;
1485   }
1486
1487   bool DispatchAndWait() {
1488     MonitorAutoLock lock(mMonitor);
1489
1490     if (!Dispatch()) {
1491       // The worker is already dead but the main thread still didn't remove it
1492       // from RuntimeService's registry.
1493       return false;
1494     }
1495
1496     // To avoid any possibility of process hangs we never receive reports on
1497     // we give the worker 1sec to react.
1498     lock.Wait(TimeDuration::FromMilliseconds(1000));
1499     if (!mHasMsg) {
1500       mMsg.Append("NoResponse");
1501       mHasMsg.Flip();
1502     }
1503     return true;
1504   }
1505
1506   const nsCString& MsgData() const { return mMsg; }
1507
1508  private:
1509   bool PreDispatch(WorkerPrivate* aWorkerPrivate) override { return true; }
1510
1511   void PostDispatch(WorkerPrivate* aWorkerPrivate,
1512                     bool aDispatchResult) override {}
1513
1514   Monitor mMonitor MOZ_UNANNOTATED;
1515   nsCString mMsg;
1516   FlippedOnce<false> mHasMsg;
1517 };
1518
1519 struct ActiveWorkerStats {
1520   template <uint32_t ActiveWorkerStats::*Category>
1521   void Update(const nsTArray<WorkerPrivate*>& aWorkers) {
1522     for (const auto worker : aWorkers) {
1523       RefPtr<DumpCrashInfoRunnable> runnable =
1524           new DumpCrashInfoRunnable(worker);
1525       if (runnable->DispatchAndWait()) {
1526         ++(this->*Category);
1527         mMessage.Append(runnable->MsgData());
1528       }
1529     }
1530   }
1531
1532   uint32_t mWorkers = 0;
1533   uint32_t mServiceWorkers = 0;
1534   nsCString mMessage;
1535 };
1536
1537 }  // namespace
1538
1539 void RuntimeService::CrashIfHanging() {
1540   MutexAutoLock lock(mMutex);
1541
1542   // If we never wanted to shut down we cannot hang.
1543   if (!mShuttingDown) {
1544     return;
1545   }
1546
1547   ActiveWorkerStats activeStats;
1548   uint32_t inactiveWorkers = 0;
1549
1550   for (const auto& aData : mDomainMap.Values()) {
1551     activeStats.Update<&ActiveWorkerStats::mWorkers>(aData->mActiveWorkers);
1552     activeStats.Update<&ActiveWorkerStats::mServiceWorkers>(
1553         aData->mActiveServiceWorkers);
1554
1555     // These might not be top-level workers...
1556     inactiveWorkers += std::count_if(
1557         aData->mQueuedWorkers.begin(), aData->mQueuedWorkers.end(),
1558         [](const auto* const worker) { return !worker->GetParent(); });
1559   }
1560
1561   if (activeStats.mWorkers + activeStats.mServiceWorkers + inactiveWorkers ==
1562       0) {
1563     return;
1564   }
1565
1566   nsCString msg;
1567
1568   // A: active Workers | S: active ServiceWorkers | Q: queued Workers
1569   msg.AppendPrintf("Workers Hanging - %d|A:%d|S:%d|Q:%d", mShuttingDown ? 1 : 0,
1570                    activeStats.mWorkers, activeStats.mServiceWorkers,
1571                    inactiveWorkers);
1572   msg.Append(activeStats.mMessage);
1573
1574   // This string will be leaked.
1575   MOZ_CRASH_UNSAFE(strdup(msg.BeginReading()));
1576 }
1577
1578 // This spins the event loop until all workers are finished and their threads
1579 // have been joined.
1580 void RuntimeService::Cleanup() {
1581   AssertIsOnMainThread();
1582
1583   if (!mShuttingDown) {
1584     Shutdown();
1585   }
1586
1587   nsCOMPtr<nsIObserverService> obs = services::GetObserverService();
1588   NS_WARNING_ASSERTION(obs, "Failed to get observer service?!");
1589
1590   {
1591     MutexAutoLock lock(mMutex);
1592
1593     AutoTArray<WorkerPrivate*, 100> workers;
1594     AddAllTopLevelWorkersToArray(workers);
1595
1596     if (!workers.IsEmpty()) {
1597       nsIThread* currentThread = NS_GetCurrentThread();
1598       NS_ASSERTION(currentThread, "This should never be null!");
1599
1600       // If the loop below takes too long, we probably have a problematic
1601       // worker.  MOZ_LOG some info before the parent process forcibly
1602       // terminates us so that in the event we are a content process, the log
1603       // output can provide useful context about the workers that did not
1604       // cleanly shut down.
1605       nsCOMPtr<nsITimer> timer;
1606       RefPtr<RuntimeService> self = this;
1607       nsresult rv = NS_NewTimerWithCallback(
1608           getter_AddRefs(timer),
1609           [self](nsITimer*) { self->DumpRunningWorkers(); },
1610           TimeDuration::FromSeconds(1), nsITimer::TYPE_ONE_SHOT,
1611           "RuntimeService::WorkerShutdownDump");
1612       Unused << NS_WARN_IF(NS_FAILED(rv));
1613
1614       // And make sure all their final messages have run and all their threads
1615       // have joined.
1616       while (mDomainMap.Count()) {
1617         MutexAutoUnlock unlock(mMutex);
1618
1619         if (!NS_ProcessNextEvent(currentThread)) {
1620           NS_WARNING("Something bad happened!");
1621           break;
1622         }
1623       }
1624
1625       if (NS_SUCCEEDED(rv)) {
1626         timer->Cancel();
1627       }
1628     }
1629   }
1630
1631   NS_ASSERTION(!mWindowMap.Count(), "All windows should have been released!");
1632
1633 #define WORKER_PREF(name, callback) \
1634   NS_FAILED(Preferences::UnregisterCallback(callback, name))
1635
1636   if (mObserved) {
1637     if (NS_FAILED(Preferences::UnregisterPrefixCallback(
1638             LoadContextOptions, PREF_JS_OPTIONS_PREFIX)) ||
1639         WORKER_PREF("intl.accept_languages", PrefLanguagesChanged) ||
1640         WORKER_PREF("general.appversion.override", AppVersionOverrideChanged) ||
1641         WORKER_PREF("general.platform.override", PlatformOverrideChanged) ||
1642 #ifdef JS_GC_ZEAL
1643         NS_FAILED(Preferences::UnregisterCallback(
1644             LoadGCZealOptions, PREF_JS_OPTIONS_PREFIX PREF_GCZEAL)) ||
1645 #endif
1646         NS_FAILED(Preferences::UnregisterPrefixCallback(
1647             LoadJSGCMemoryOptions,
1648             PREF_JS_OPTIONS_PREFIX PREF_MEM_OPTIONS_PREFIX))) {
1649       NS_WARNING("Failed to unregister pref callbacks!");
1650     }
1651
1652 #undef WORKER_PREF
1653
1654     if (obs) {
1655       if (NS_FAILED(obs->RemoveObserver(this, GC_REQUEST_OBSERVER_TOPIC))) {
1656         NS_WARNING("Failed to unregister for GC request notifications!");
1657       }
1658
1659       if (NS_FAILED(obs->RemoveObserver(this, CC_REQUEST_OBSERVER_TOPIC))) {
1660         NS_WARNING("Failed to unregister for CC request notifications!");
1661       }
1662
1663       if (NS_FAILED(
1664               obs->RemoveObserver(this, MEMORY_PRESSURE_OBSERVER_TOPIC))) {
1665         NS_WARNING("Failed to unregister for memory pressure notifications!");
1666       }
1667
1668       if (NS_FAILED(
1669               obs->RemoveObserver(this, NS_IOSERVICE_OFFLINE_STATUS_TOPIC))) {
1670         NS_WARNING("Failed to unregister for offline notification event!");
1671       }
1672       obs->RemoveObserver(this, NS_XPCOM_SHUTDOWN_THREADS_OBSERVER_ID);
1673       obs->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
1674       mObserved = false;
1675     }
1676   }
1677
1678   nsLayoutStatics::Release();
1679 }
1680
1681 void RuntimeService::AddAllTopLevelWorkersToArray(
1682     nsTArray<WorkerPrivate*>& aWorkers) {
1683   for (const auto& aData : mDomainMap.Values()) {
1684 #ifdef DEBUG
1685     for (const auto& activeWorker : aData->mActiveWorkers) {
1686       MOZ_ASSERT(!activeWorker->GetParent(),
1687                  "Shouldn't have a parent in this list!");
1688     }
1689     for (const auto& activeServiceWorker : aData->mActiveServiceWorkers) {
1690       MOZ_ASSERT(!activeServiceWorker->GetParent(),
1691                  "Shouldn't have a parent in this list!");
1692     }
1693 #endif
1694
1695     aWorkers.AppendElements(aData->mActiveWorkers);
1696     aWorkers.AppendElements(aData->mActiveServiceWorkers);
1697
1698     // These might not be top-level workers...
1699     std::copy_if(aData->mQueuedWorkers.begin(), aData->mQueuedWorkers.end(),
1700                  MakeBackInserter(aWorkers),
1701                  [](const auto& worker) { return !worker->GetParent(); });
1702   }
1703 }
1704
1705 nsTArray<WorkerPrivate*> RuntimeService::GetWorkersForWindow(
1706     const nsPIDOMWindowInner& aWindow) const {
1707   AssertIsOnMainThread();
1708
1709   nsTArray<WorkerPrivate*> result;
1710   if (nsTArray<WorkerPrivate*>* const workers = mWindowMap.Get(&aWindow)) {
1711     NS_ASSERTION(!workers->IsEmpty(), "Should have been removed!");
1712     result.AppendElements(*workers);
1713   }
1714   return result;
1715 }
1716
1717 void RuntimeService::CancelWorkersForWindow(const nsPIDOMWindowInner& aWindow) {
1718   AssertIsOnMainThread();
1719
1720   for (WorkerPrivate* const worker : GetWorkersForWindow(aWindow)) {
1721     MOZ_ASSERT(!worker->IsSharedWorker());
1722     worker->Cancel();
1723   }
1724 }
1725
1726 void RuntimeService::FreezeWorkersForWindow(const nsPIDOMWindowInner& aWindow) {
1727   AssertIsOnMainThread();
1728
1729   for (WorkerPrivate* const worker : GetWorkersForWindow(aWindow)) {
1730     MOZ_ASSERT(!worker->IsSharedWorker());
1731     worker->Freeze(&aWindow);
1732   }
1733 }
1734
1735 void RuntimeService::ThawWorkersForWindow(const nsPIDOMWindowInner& aWindow) {
1736   AssertIsOnMainThread();
1737
1738   for (WorkerPrivate* const worker : GetWorkersForWindow(aWindow)) {
1739     MOZ_ASSERT(!worker->IsSharedWorker());
1740     worker->Thaw(&aWindow);
1741   }
1742 }
1743
1744 void RuntimeService::SuspendWorkersForWindow(
1745     const nsPIDOMWindowInner& aWindow) {
1746   AssertIsOnMainThread();
1747
1748   for (WorkerPrivate* const worker : GetWorkersForWindow(aWindow)) {
1749     MOZ_ASSERT(!worker->IsSharedWorker());
1750     worker->ParentWindowPaused();
1751   }
1752 }
1753
1754 void RuntimeService::ResumeWorkersForWindow(const nsPIDOMWindowInner& aWindow) {
1755   AssertIsOnMainThread();
1756
1757   for (WorkerPrivate* const worker : GetWorkersForWindow(aWindow)) {
1758     MOZ_ASSERT(!worker->IsSharedWorker());
1759     worker->ParentWindowResumed();
1760   }
1761 }
1762
1763 void RuntimeService::PropagateStorageAccessPermissionGranted(
1764     const nsPIDOMWindowInner& aWindow) {
1765   AssertIsOnMainThread();
1766   MOZ_ASSERT_IF(aWindow.GetExtantDoc(), aWindow.GetExtantDoc()
1767                                             ->CookieJarSettings()
1768                                             ->GetRejectThirdPartyContexts());
1769
1770   for (WorkerPrivate* const worker : GetWorkersForWindow(aWindow)) {
1771     worker->PropagateStorageAccessPermissionGranted();
1772   }
1773 }
1774
1775 template <typename Func>
1776 void RuntimeService::BroadcastAllWorkers(const Func& aFunc) {
1777   AssertIsOnMainThread();
1778
1779   AutoTArray<WorkerPrivate*, 100> workers;
1780   {
1781     MutexAutoLock lock(mMutex);
1782
1783     AddAllTopLevelWorkersToArray(workers);
1784   }
1785
1786   for (const auto& worker : workers) {
1787     aFunc(*worker);
1788   }
1789 }
1790
1791 void RuntimeService::UpdateAllWorkerContextOptions() {
1792   BroadcastAllWorkers([](auto& worker) {
1793     worker.UpdateContextOptions(sDefaultJSSettings->contextOptions);
1794   });
1795 }
1796
1797 void RuntimeService::UpdateAppVersionOverridePreference(
1798     const nsAString& aValue) {
1799   AssertIsOnMainThread();
1800   mNavigatorProperties.mAppVersionOverridden = aValue;
1801 }
1802
1803 void RuntimeService::UpdatePlatformOverridePreference(const nsAString& aValue) {
1804   AssertIsOnMainThread();
1805   mNavigatorProperties.mPlatformOverridden = aValue;
1806 }
1807
1808 void RuntimeService::UpdateAllWorkerLanguages(
1809     const nsTArray<nsString>& aLanguages) {
1810   MOZ_ASSERT(NS_IsMainThread());
1811
1812   mNavigatorProperties.mLanguages = aLanguages.Clone();
1813   BroadcastAllWorkers(
1814       [&aLanguages](auto& worker) { worker.UpdateLanguages(aLanguages); });
1815 }
1816
1817 void RuntimeService::UpdateAllWorkerMemoryParameter(JSGCParamKey aKey,
1818                                                     Maybe<uint32_t> aValue) {
1819   BroadcastAllWorkers([aKey, aValue](auto& worker) {
1820     worker.UpdateJSWorkerMemoryParameter(aKey, aValue);
1821   });
1822 }
1823
1824 #ifdef JS_GC_ZEAL
1825 void RuntimeService::UpdateAllWorkerGCZeal() {
1826   BroadcastAllWorkers([](auto& worker) {
1827     worker.UpdateGCZeal(sDefaultJSSettings->gcZeal,
1828                         sDefaultJSSettings->gcZealFrequency);
1829   });
1830 }
1831 #endif
1832
1833 void RuntimeService::SetLowMemoryStateAllWorkers(bool aState) {
1834   BroadcastAllWorkers(
1835       [aState](auto& worker) { worker.SetLowMemoryState(aState); });
1836 }
1837
1838 void RuntimeService::GarbageCollectAllWorkers(bool aShrinking) {
1839   BroadcastAllWorkers(
1840       [aShrinking](auto& worker) { worker.GarbageCollect(aShrinking); });
1841 }
1842
1843 void RuntimeService::CycleCollectAllWorkers() {
1844   BroadcastAllWorkers([](auto& worker) { worker.CycleCollect(); });
1845 }
1846
1847 void RuntimeService::SendOfflineStatusChangeEventToAllWorkers(bool aIsOffline) {
1848   BroadcastAllWorkers([aIsOffline](auto& worker) {
1849     worker.OfflineStatusChangeEvent(aIsOffline);
1850   });
1851 }
1852
1853 void RuntimeService::MemoryPressureAllWorkers() {
1854   BroadcastAllWorkers([](auto& worker) { worker.MemoryPressure(); });
1855 }
1856
1857 uint32_t RuntimeService::ClampedHardwareConcurrency(
1858     bool aShouldResistFingerprinting) const {
1859   // The Firefox Hardware Report says 70% of Firefox users have exactly 2 cores.
1860   // When the resistFingerprinting pref is set, we want to blend into the crowd
1861   // so spoof navigator.hardwareConcurrency = 2 to reduce user uniqueness.
1862   if (MOZ_UNLIKELY(aShouldResistFingerprinting)) {
1863     return 2;
1864   }
1865
1866   // This needs to be atomic, because multiple workers, and even mainthread,
1867   // could race to initialize it at once.
1868   static Atomic<uint32_t> unclampedHardwareConcurrency;
1869
1870   // No need to loop here: if compareExchange fails, that just means that some
1871   // other worker has initialized numberOfProcessors, so we're good to go.
1872   if (!unclampedHardwareConcurrency) {
1873     int32_t numberOfProcessors = 0;
1874 #if defined(XP_MACOSX)
1875     if (nsMacUtilsImpl::IsTCSMAvailable()) {
1876       // On failure, zero is returned from GetPhysicalCPUCount()
1877       // and we fallback to PR_GetNumberOfProcessors below.
1878       numberOfProcessors = nsMacUtilsImpl::GetPhysicalCPUCount();
1879     }
1880 #endif
1881     if (numberOfProcessors == 0) {
1882       numberOfProcessors = PR_GetNumberOfProcessors();
1883     }
1884     if (numberOfProcessors <= 0) {
1885       numberOfProcessors = 1;  // Must be one there somewhere
1886     }
1887     Unused << unclampedHardwareConcurrency.compareExchange(0,
1888                                                            numberOfProcessors);
1889   }
1890
1891   return std::min(uint32_t(unclampedHardwareConcurrency),
1892                   StaticPrefs::dom_maxHardwareConcurrency());
1893 }
1894
1895 // nsISupports
1896 NS_IMPL_ISUPPORTS(RuntimeService, nsIObserver)
1897
1898 // nsIObserver
1899 NS_IMETHODIMP
1900 RuntimeService::Observe(nsISupports* aSubject, const char* aTopic,
1901                         const char16_t* aData) {
1902   AssertIsOnMainThread();
1903
1904   if (!strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
1905     Shutdown();
1906     return NS_OK;
1907   }
1908   if (!strcmp(aTopic, NS_XPCOM_SHUTDOWN_THREADS_OBSERVER_ID)) {
1909     Cleanup();
1910     return NS_OK;
1911   }
1912   if (!strcmp(aTopic, GC_REQUEST_OBSERVER_TOPIC)) {
1913     GarbageCollectAllWorkers(/* shrinking = */ false);
1914     return NS_OK;
1915   }
1916   if (!strcmp(aTopic, CC_REQUEST_OBSERVER_TOPIC)) {
1917     CycleCollectAllWorkers();
1918     return NS_OK;
1919   }
1920   if (!strcmp(aTopic, MEMORY_PRESSURE_OBSERVER_TOPIC)) {
1921     nsDependentString data(aData);
1922     // Don't continue to GC/CC if we are in an ongoing low-memory state since
1923     // its very slow and it likely won't help us anyway.
1924     if (data.EqualsLiteral(LOW_MEMORY_ONGOING_DATA)) {
1925       return NS_OK;
1926     }
1927     if (data.EqualsLiteral(LOW_MEMORY_DATA)) {
1928       SetLowMemoryStateAllWorkers(true);
1929     }
1930     GarbageCollectAllWorkers(/* shrinking = */ true);
1931     CycleCollectAllWorkers();
1932     MemoryPressureAllWorkers();
1933     return NS_OK;
1934   }
1935   if (!strcmp(aTopic, MEMORY_PRESSURE_STOP_OBSERVER_TOPIC)) {
1936     SetLowMemoryStateAllWorkers(false);
1937     return NS_OK;
1938   }
1939   if (!strcmp(aTopic, NS_IOSERVICE_OFFLINE_STATUS_TOPIC)) {
1940     SendOfflineStatusChangeEventToAllWorkers(NS_IsOffline());
1941     return NS_OK;
1942   }
1943
1944   MOZ_ASSERT_UNREACHABLE("Unknown observer topic!");
1945   return NS_OK;
1946 }
1947
1948 namespace {
1949 const char* WorkerKindToString(WorkerKind kind) {
1950   switch (kind) {
1951     case WorkerKindDedicated:
1952       return "dedicated";
1953     case WorkerKindShared:
1954       return "shared";
1955     case WorkerKindService:
1956       return "service";
1957     default:
1958       NS_WARNING("Unknown worker type");
1959       return "unknown worker type";
1960   }
1961 }
1962
1963 void LogWorker(WorkerPrivate* worker, const char* category) {
1964   AssertIsOnMainThread();
1965
1966   SHUTDOWN_LOG(("Found %s (%s): %s", category,
1967                 WorkerKindToString(worker->Kind()),
1968                 NS_ConvertUTF16toUTF8(worker->ScriptURL()).get()));
1969
1970   if (worker->Kind() == WorkerKindService) {
1971     SHUTDOWN_LOG(("Scope: %s", worker->ServiceWorkerScope().get()));
1972   }
1973
1974   nsCString origin;
1975   worker->GetPrincipal()->GetOrigin(origin);
1976   SHUTDOWN_LOG(("Principal: %s", origin.get()));
1977
1978   nsCString loadingOrigin;
1979   worker->GetLoadingPrincipal()->GetOrigin(loadingOrigin);
1980   SHUTDOWN_LOG(("LoadingPrincipal: %s", loadingOrigin.get()));
1981
1982   RefPtr<DumpCrashInfoRunnable> runnable = new DumpCrashInfoRunnable(worker);
1983   if (runnable->DispatchAndWait()) {
1984     SHUTDOWN_LOG(("CrashInfo: %s", runnable->MsgData().get()));
1985   } else {
1986     SHUTDOWN_LOG(("CrashInfo: dispatch failed"));
1987   }
1988 }
1989 }  // namespace
1990
1991 void RuntimeService::DumpRunningWorkers() {
1992   // Temporarily set the LogLevel high enough to be certain the messages are
1993   // visible.
1994   LogModule* module = gWorkerShutdownDumpLog;
1995   LogLevel prevLevel = module->Level();
1996
1997   const auto cleanup =
1998       MakeScopeExit([module, prevLevel] { module->SetLevel(prevLevel); });
1999
2000   if (prevLevel < LogLevel::Debug) {
2001     module->SetLevel(LogLevel::Debug);
2002   }
2003
2004   MutexAutoLock lock(mMutex);
2005
2006   for (const auto& info : mDomainMap.Values()) {
2007     for (WorkerPrivate* worker : info->mActiveWorkers) {
2008       LogWorker(worker, "ActiveWorker");
2009     }
2010
2011     for (WorkerPrivate* worker : info->mActiveServiceWorkers) {
2012       LogWorker(worker, "ActiveServiceWorker");
2013     }
2014
2015     for (WorkerPrivate* worker : info->mQueuedWorkers) {
2016       LogWorker(worker, "QueuedWorker");
2017     }
2018   }
2019 }
2020
2021 bool LogViolationDetailsRunnable::MainThreadRun() {
2022   AssertIsOnMainThread();
2023
2024   nsIContentSecurityPolicy* csp = mWorkerPrivate->GetCsp();
2025   if (csp) {
2026     csp->LogViolationDetails(mViolationType,
2027                              nullptr,  // triggering element
2028                              mWorkerPrivate->CSPEventListener(), mFileName,
2029                              mScriptSample, mLineNum, mColumnNum, u""_ns,
2030                              u""_ns);
2031   }
2032
2033   return true;
2034 }
2035
2036 // MOZ_CAN_RUN_SCRIPT_BOUNDARY until Runnable::Run is MOZ_CAN_RUN_SCRIPT.  See
2037 // bug 1535398.
2038 MOZ_CAN_RUN_SCRIPT_BOUNDARY
2039 NS_IMETHODIMP
2040 WorkerThreadPrimaryRunnable::Run() {
2041   NS_ConvertUTF16toUTF8 url(mWorkerPrivate->ScriptURL());
2042   AUTO_PROFILER_LABEL_DYNAMIC_CSTR("WorkerThreadPrimaryRunnable::Run", OTHER,
2043                                    url.get());
2044
2045   using mozilla::ipc::BackgroundChild;
2046
2047   {
2048     auto failureCleanup = MakeScopeExit([&]() {
2049       // The creation of threadHelper above is the point at which a worker is
2050       // considered to have run, because the `mPreStartRunnables` are all
2051       // re-dispatched after `mThread` is set.  We need to let the WorkerPrivate
2052       // know so it can clean up the various event loops and delete the worker.
2053       mWorkerPrivate->RunLoopNeverRan();
2054     });
2055
2056     mWorkerPrivate->SetWorkerPrivateInWorkerThread(mThread.unsafeGetRawPtr());
2057
2058     const auto threadCleanup = MakeScopeExit([&] {
2059       // This must be called before ScheduleDeletion, which is either called
2060       // from failureCleanup leaving scope, or from the outer scope.
2061       mWorkerPrivate->ResetWorkerPrivateInWorkerThread();
2062     });
2063
2064     mWorkerPrivate->AssertIsOnWorkerThread();
2065
2066     // This needs to be initialized on the worker thread before being used on
2067     // the main thread and calling BackgroundChild::GetOrCreateForCurrentThread
2068     // exposes it to the main thread.
2069     mWorkerPrivate->EnsurePerformanceStorage();
2070
2071     if (NS_WARN_IF(!BackgroundChild::GetOrCreateForCurrentThread())) {
2072       return NS_ERROR_FAILURE;
2073     }
2074
2075     nsWeakPtr globalScopeSentinel;
2076     nsWeakPtr debuggerScopeSentinel;
2077     // Never use the following pointers without checking their corresponding
2078     // nsWeakPtr sentinel, defined above and initialized after DoRunLoop ends.
2079     WorkerGlobalScopeBase* globalScopeRawPtr = nullptr;
2080     WorkerGlobalScopeBase* debuggerScopeRawPtr = nullptr;
2081     {
2082       nsCycleCollector_startup();
2083
2084       auto context = MakeUnique<WorkerJSContext>(mWorkerPrivate);
2085       nsresult rv = context->Initialize(mParentRuntime);
2086       if (NS_WARN_IF(NS_FAILED(rv))) {
2087         return rv;
2088       }
2089
2090       JSContext* cx = context->Context();
2091
2092       if (!InitJSContextForWorker(mWorkerPrivate, cx)) {
2093         return NS_ERROR_FAILURE;
2094       }
2095
2096       failureCleanup.release();
2097
2098       {
2099         PROFILER_SET_JS_CONTEXT(cx);
2100
2101         {
2102           // We're on the worker thread here, and WorkerPrivate's refcounting is
2103           // non-threadsafe: you can only do it on the parent thread.  What that
2104           // means in practice is that we're relying on it being kept alive
2105           // while we run.  Hopefully.
2106           MOZ_KnownLive(mWorkerPrivate)->DoRunLoop(cx);
2107           // The AutoJSAPI in DoRunLoop should have reported any exceptions left
2108           // on cx.
2109           MOZ_ASSERT(!JS_IsExceptionPending(cx));
2110         }
2111
2112         mWorkerPrivate->ShutdownModuleLoader();
2113
2114         mWorkerPrivate->RunShutdownTasks();
2115
2116         BackgroundChild::CloseForCurrentThread();
2117
2118         PROFILER_CLEAR_JS_CONTEXT();
2119       }
2120
2121       // There may still be runnables on the debugger event queue that hold a
2122       // strong reference to the debugger global scope. These runnables are not
2123       // visible to the cycle collector, so we need to make sure to clear the
2124       // debugger event queue before we try to destroy the context. If we don't,
2125       // the garbage collector will crash.
2126       // Note that this just releases the runnables and does not execute them.
2127       mWorkerPrivate->ClearDebuggerEventQueue();
2128
2129       // Before shutting down the cycle collector we need to do one more pass
2130       // through the event loop to clean up any C++ objects that need deferred
2131       // cleanup.
2132       NS_ProcessPendingEvents(nullptr);
2133
2134       // At this point we expect the scopes to be alive if they were ever
2135       // created successfully, keep weak references and set up the sentinels.
2136       globalScopeRawPtr = mWorkerPrivate->GlobalScope();
2137       if (globalScopeRawPtr) {
2138         globalScopeSentinel = do_GetWeakReference(globalScopeRawPtr);
2139       }
2140       MOZ_ASSERT(!globalScopeRawPtr || globalScopeSentinel);
2141       debuggerScopeRawPtr = mWorkerPrivate->DebuggerGlobalScope();
2142       if (debuggerScopeRawPtr) {
2143         debuggerScopeSentinel = do_GetWeakReference(debuggerScopeRawPtr);
2144       }
2145       MOZ_ASSERT(!debuggerScopeRawPtr || debuggerScopeSentinel);
2146
2147       // To our best knowledge nobody should need a reference to our globals
2148       // now (NS_ProcessPendingEvents is the last expected potential usage)
2149       // and we can unroot them.
2150       mWorkerPrivate->UnrootGlobalScopes();
2151
2152       // Perform a full GC until we collect the main worker global and CC,
2153       // which should break all cycles that touch JS.
2154       bool repeatGCCC = true;
2155       while (repeatGCCC) {
2156         JS::PrepareForFullGC(cx);
2157         JS::NonIncrementalGC(cx, JS::GCOptions::Shutdown,
2158                              JS::GCReason::WORKER_SHUTDOWN);
2159
2160         // If we CCed something or got new events as a side effect, repeat.
2161         repeatGCCC = mWorkerPrivate->isLastCCCollectedAnything() ||
2162                      NS_HasPendingEvents(nullptr);
2163         NS_ProcessPendingEvents(nullptr);
2164       }
2165
2166       // The worker global should be unrooted and the shutdown of cycle
2167       // collection should break all the remaining cycles.
2168       nsCycleCollector_shutdown();
2169
2170       // If ever the CC shutdown run caused side effects, process them.
2171       NS_ProcessPendingEvents(nullptr);
2172
2173       // Now WorkerJSContext goes out of scope. Do not use any cycle
2174       // collectable objects nor JS after this point!
2175     }
2176
2177     // Check sentinels if we actually removed all global scope references.
2178     // In case use the earlier set-aside raw pointers to not mess with the
2179     // ref counting after the cycle collector has gone away.
2180     if (globalScopeSentinel) {
2181       MOZ_ASSERT(!globalScopeSentinel->IsAlive());
2182       if (NS_WARN_IF(globalScopeSentinel->IsAlive())) {
2183         globalScopeRawPtr->NoteWorkerTerminated();
2184         globalScopeRawPtr = nullptr;
2185       }
2186     }
2187     if (debuggerScopeSentinel) {
2188       MOZ_ASSERT(!debuggerScopeSentinel->IsAlive());
2189       if (NS_WARN_IF(debuggerScopeSentinel->IsAlive())) {
2190         debuggerScopeRawPtr->NoteWorkerTerminated();
2191         debuggerScopeRawPtr = nullptr;
2192       }
2193     }
2194   }
2195
2196   mWorkerPrivate->ScheduleDeletion(WorkerPrivate::WorkerRan);
2197
2198   // It is no longer safe to touch mWorkerPrivate.
2199   mWorkerPrivate = nullptr;
2200
2201   // Now recycle this thread.
2202   nsCOMPtr<nsIEventTarget> mainTarget = GetMainThreadSerialEventTarget();
2203   MOZ_ASSERT(mainTarget);
2204
2205   RefPtr<FinishedRunnable> finishedRunnable =
2206       new FinishedRunnable(std::move(mThread));
2207   MOZ_ALWAYS_SUCCEEDS(
2208       mainTarget->Dispatch(finishedRunnable, NS_DISPATCH_NORMAL));
2209
2210   return NS_OK;
2211 }
2212
2213 NS_IMETHODIMP
2214 WorkerThreadPrimaryRunnable::FinishedRunnable::Run() {
2215   AssertIsOnMainThread();
2216
2217   SafeRefPtr<WorkerThread> thread = std::move(mThread);
2218   if (thread->ShutdownRequired()) {
2219     MOZ_ALWAYS_SUCCEEDS(thread->Shutdown());
2220   }
2221
2222   return NS_OK;
2223 }
2224
2225 }  // namespace workerinternals
2226
2227 // This is mostly for invoking within a debugger.
2228 void DumpRunningWorkers() {
2229   RuntimeService* runtimeService = RuntimeService::GetService();
2230   if (runtimeService) {
2231     runtimeService->DumpRunningWorkers();
2232   } else {
2233     NS_WARNING("RuntimeService not found");
2234   }
2235 }
2236
2237 void CancelWorkersForWindow(const nsPIDOMWindowInner& aWindow) {
2238   AssertIsOnMainThread();
2239   RuntimeService* runtime = RuntimeService::GetService();
2240   if (runtime) {
2241     runtime->CancelWorkersForWindow(aWindow);
2242   }
2243 }
2244
2245 void FreezeWorkersForWindow(const nsPIDOMWindowInner& aWindow) {
2246   AssertIsOnMainThread();
2247   RuntimeService* runtime = RuntimeService::GetService();
2248   if (runtime) {
2249     runtime->FreezeWorkersForWindow(aWindow);
2250   }
2251 }
2252
2253 void ThawWorkersForWindow(const nsPIDOMWindowInner& aWindow) {
2254   AssertIsOnMainThread();
2255   RuntimeService* runtime = RuntimeService::GetService();
2256   if (runtime) {
2257     runtime->ThawWorkersForWindow(aWindow);
2258   }
2259 }
2260
2261 void SuspendWorkersForWindow(const nsPIDOMWindowInner& aWindow) {
2262   AssertIsOnMainThread();
2263   RuntimeService* runtime = RuntimeService::GetService();
2264   if (runtime) {
2265     runtime->SuspendWorkersForWindow(aWindow);
2266   }
2267 }
2268
2269 void ResumeWorkersForWindow(const nsPIDOMWindowInner& aWindow) {
2270   AssertIsOnMainThread();
2271   RuntimeService* runtime = RuntimeService::GetService();
2272   if (runtime) {
2273     runtime->ResumeWorkersForWindow(aWindow);
2274   }
2275 }
2276
2277 void PropagateStorageAccessPermissionGrantedToWorkers(
2278     const nsPIDOMWindowInner& aWindow) {
2279   AssertIsOnMainThread();
2280   MOZ_ASSERT_IF(aWindow.GetExtantDoc(), aWindow.GetExtantDoc()
2281                                             ->CookieJarSettings()
2282                                             ->GetRejectThirdPartyContexts());
2283
2284   RuntimeService* runtime = RuntimeService::GetService();
2285   if (runtime) {
2286     runtime->PropagateStorageAccessPermissionGranted(aWindow);
2287   }
2288 }
2289
2290 WorkerPrivate* GetWorkerPrivateFromContext(JSContext* aCx) {
2291   MOZ_ASSERT(!NS_IsMainThread());
2292   MOZ_ASSERT(aCx);
2293
2294   CycleCollectedJSContext* ccjscx = CycleCollectedJSContext::GetFor(aCx);
2295   if (!ccjscx) {
2296     return nullptr;
2297   }
2298
2299   WorkerJSContext* workerjscx = ccjscx->GetAsWorkerJSContext();
2300   // GetWorkerPrivateFromContext is called only for worker contexts.  The
2301   // context private is cleared early in ~CycleCollectedJSContext() and so
2302   // GetFor() returns null above if called after ccjscx is no longer a
2303   // WorkerJSContext.
2304   MOZ_ASSERT(workerjscx);
2305   return workerjscx->GetWorkerPrivate();
2306 }
2307
2308 WorkerPrivate* GetCurrentThreadWorkerPrivate() {
2309   if (NS_IsMainThread()) {
2310     return nullptr;
2311   }
2312
2313   CycleCollectedJSContext* ccjscx = CycleCollectedJSContext::Get();
2314   if (!ccjscx) {
2315     return nullptr;
2316   }
2317
2318   WorkerJSContext* workerjscx = ccjscx->GetAsWorkerJSContext();
2319   // Even when GetCurrentThreadWorkerPrivate() is called on worker
2320   // threads, the ccjscx will no longer be a WorkerJSContext if called from
2321   // stable state events during ~CycleCollectedJSContext().
2322   if (!workerjscx) {
2323     return nullptr;
2324   }
2325
2326   return workerjscx->GetWorkerPrivate();
2327 }
2328
2329 bool IsCurrentThreadRunningWorker() {
2330   return !NS_IsMainThread() && !!GetCurrentThreadWorkerPrivate();
2331 }
2332
2333 bool IsCurrentThreadRunningChromeWorker() {
2334   WorkerPrivate* wp = GetCurrentThreadWorkerPrivate();
2335   return wp && wp->UsesSystemPrincipal();
2336 }
2337
2338 JSContext* GetCurrentWorkerThreadJSContext() {
2339   WorkerPrivate* wp = GetCurrentThreadWorkerPrivate();
2340   if (!wp) {
2341     return nullptr;
2342   }
2343   return wp->GetJSContext();
2344 }
2345
2346 JSObject* GetCurrentThreadWorkerGlobal() {
2347   WorkerPrivate* wp = GetCurrentThreadWorkerPrivate();
2348   if (!wp) {
2349     return nullptr;
2350   }
2351   WorkerGlobalScope* scope = wp->GlobalScope();
2352   if (!scope) {
2353     return nullptr;
2354   }
2355   return scope->GetGlobalJSObject();
2356 }
2357
2358 JSObject* GetCurrentThreadWorkerDebuggerGlobal() {
2359   WorkerPrivate* wp = GetCurrentThreadWorkerPrivate();
2360   if (!wp) {
2361     return nullptr;
2362   }
2363   WorkerDebuggerGlobalScope* scope = wp->DebuggerGlobalScope();
2364   if (!scope) {
2365     return nullptr;
2366   }
2367   return scope->GetGlobalJSObject();
2368 }
2369
2370 }  // namespace dom
2371 }  // namespace mozilla