js/src/gc/GCInternals.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * vim: set ts=8 sts=4 et sw=4 tw=99:
   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 #ifndef gc_GCInternals_h
   8 #define gc_GCInternals_h
   9
  10 #include "jsworkers.h"
  11
  12 #include "vm/Runtime.h"
  13
  14 namespace js {
  15 namespace gc {
  16
  17 void
  18 MarkRuntime(JSTracer *trc, bool useSavedRoots = false);
  19
  20 void
  21 BufferGrayRoots(GCMarker *gcmarker);
  22
  23 class AutoCopyFreeListToArenas {
  24     JSRuntime *runtime;
  25
  26   public:
  27     AutoCopyFreeListToArenas(JSRuntime *rt);
  28     ~AutoCopyFreeListToArenas();
  29 };
  30
  31 struct AutoFinishGC
  32 {
  33     AutoFinishGC(JSRuntime *rt);
  34 };
  35
  36 /*
  37  * This class should be used by any code that needs to exclusive access to the
  38  * heap in order to trace through it...
  39  */
  40 class AutoTraceSession {
  41   public:
  42     AutoTraceSession(JSRuntime *rt, HeapState state = Tracing);
  43     ~AutoTraceSession();
  44
  45   protected:
  46     JSRuntime *runtime;
  47
  48   private:
  49     AutoTraceSession(const AutoTraceSession&) MOZ_DELETE;
  50     void operator=(const AutoTraceSession&) MOZ_DELETE;
  51
  52     js::HeapState prevState;
  53     AutoPauseWorkersForGC pause;
  54 };
  55
  56 struct AutoPrepareForTracing
  57 {
  58     AutoFinishGC finish;
  59     AutoTraceSession session;
  60     AutoCopyFreeListToArenas copy;
  61
  62     AutoPrepareForTracing(JSRuntime *rt);
  63 };
  64
  65 class IncrementalSafety
  66 {
  67     const char *reason_;
  68
  69     IncrementalSafety(const char *reason) : reason_(reason) {}
  70
  71   public:
  72     static IncrementalSafety Safe() { return IncrementalSafety(nullptr); }
  73     static IncrementalSafety Unsafe(const char *reason) { return IncrementalSafety(reason); }
  74
  75     typedef void (IncrementalSafety::* ConvertibleToBool)();
  76     void nonNull() {}
  77
  78     operator ConvertibleToBool() const {
  79         return reason_ == nullptr ? &IncrementalSafety::nonNull : 0;
  80     }
  81
  82     const char *reason() {
  83         JS_ASSERT(reason_);
  84         return reason_;
  85     }
  86 };
  87
  88 IncrementalSafety
  89 IsIncrementalGCSafe(JSRuntime *rt);
  90
  91 #ifdef JSGC_ROOT_ANALYSIS
  92 void *
  93 GetAddressableGCThing(JSRuntime *rt, uintptr_t w);
  94 #endif
  95
  96 #ifdef JS_GC_ZEAL
  97 void
  98 StartVerifyPreBarriers(JSRuntime *rt);
  99
 100 void
 101 EndVerifyPreBarriers(JSRuntime *rt);
 102
 103 void
 104 StartVerifyPostBarriers(JSRuntime *rt);
 105
 106 void
 107 EndVerifyPostBarriers(JSRuntime *rt);
 108
 109 void
 110 FinishVerifier(JSRuntime *rt);
 111
 112 class AutoStopVerifyingBarriers
 113 {
 114     JSRuntime *runtime;
 115     bool restartPreVerifier;
 116     bool restartPostVerifier;
 117     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 118
 119   public:
 120     AutoStopVerifyingBarriers(JSRuntime *rt, bool isShutdown
 121                        MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
 122       : runtime(rt)
 123     {
 124         restartPreVerifier = !isShutdown && rt->gcVerifyPreData;
 125         restartPostVerifier = !isShutdown && rt->gcVerifyPostData && rt->gcGenerationalEnabled;
 126         if (rt->gcVerifyPreData)
 127             EndVerifyPreBarriers(rt);
 128         if (rt->gcVerifyPostData)
 129             EndVerifyPostBarriers(rt);
 130         MOZ_GUARD_OBJECT_NOTIFIER_INIT;
 131     }
 132
 133     ~AutoStopVerifyingBarriers() {
 134         if (restartPreVerifier)
 135             StartVerifyPreBarriers(runtime);
 136         if (restartPostVerifier)
 137             StartVerifyPostBarriers(runtime);
 138     }
 139 };
 140 #else
 141 struct AutoStopVerifyingBarriers
 142 {
 143     AutoStopVerifyingBarriers(JSRuntime *, bool) {}
 144 };
 145 #endif /* JS_GC_ZEAL */
 146
 147 } /* namespace gc */
 148 } /* namespace js */
 149
 150 #endif /* gc_GCInternals_h */