gfx/src/gfxCrashReporterUtils.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 "gfxCrashReporterUtils.h"
   8 #include <string.h>                  // for strcmp
   9 #include "mozilla/SchedulerGroup.h"  // for SchedulerGroup
  10 #include "mozilla/Services.h"        // for GetObserverService
  11 #include "mozilla/StaticMutex.h"
  12 #include "mozilla/mozalloc.h"    // for operator new, etc
  13 #include "mozilla/RefPtr.h"      // for RefPtr
  14 #include "MainThreadUtils.h"     // for NS_IsMainThread
  15 #include "nsCOMPtr.h"            // for nsCOMPtr
  16 #include "nsError.h"             // for NS_OK, NS_FAILED, nsresult
  17 #include "nsExceptionHandler.h"  // for AppendAppNotesToCrashReport
  18 #include "nsIObserver.h"         // for nsIObserver, etc
  19 #include "nsIObserverService.h"  // for nsIObserverService
  20 #include "nsIRunnable.h"         // for nsIRunnable
  21 #include "nsISupports.h"
  22 #include "nsThreadUtils.h"  // for Runnable
  23 #include "nsTArray.h"       // for nsTArray
  24 #include "nscore.h"         // for NS_IMETHOD, NS_IMETHODIMP, etc
  25
  26 namespace mozilla {
  27
  28 static nsTArray<nsCString>* gFeaturesAlreadyReported = nullptr;
  29 static StaticMutex gFeaturesAlreadyReportedMutex MOZ_UNANNOTATED;
  30
  31 class ObserverToDestroyFeaturesAlreadyReported final : public nsIObserver {
  32  public:
  33   NS_DECL_ISUPPORTS
  34   NS_DECL_NSIOBSERVER
  35
  36   ObserverToDestroyFeaturesAlreadyReported() = default;
  37
  38  private:
  39   virtual ~ObserverToDestroyFeaturesAlreadyReported() = default;
  40 };
  41
  42 NS_IMPL_ISUPPORTS(ObserverToDestroyFeaturesAlreadyReported, nsIObserver)
  43
  44 NS_IMETHODIMP
  45 ObserverToDestroyFeaturesAlreadyReported::Observe(nsISupports* aSubject,
  46                                                   const char* aTopic,
  47                                                   const char16_t* aData) {
  48   if (!strcmp(aTopic, "xpcom-shutdown")) {
  49     StaticMutexAutoLock al(gFeaturesAlreadyReportedMutex);
  50     if (gFeaturesAlreadyReported) {
  51       delete gFeaturesAlreadyReported;
  52       gFeaturesAlreadyReported = nullptr;
  53     }
  54   }
  55   return NS_OK;
  56 }
  57
  58 class RegisterObserverRunnable : public Runnable {
  59  public:
  60   RegisterObserverRunnable() : Runnable("RegisterObserverRunnable") {}
  61   NS_IMETHOD Run() override {
  62     // LeakLog made me do this. Basically, I just wanted
  63     // gFeaturesAlreadyReported to be a static nsTArray<nsCString>, and LeakLog
  64     // was complaining about leaks like this:
  65     //    leaked 1 instance of nsTArray_base with size 8 bytes
  66     //    leaked 7 instances of nsStringBuffer with size 8 bytes each (56 bytes
  67     //    total)
  68     // So this is a work-around using a pointer, and using a nsIObserver to
  69     // deallocate on xpcom shutdown. Yay for fighting bloat.
  70     nsCOMPtr<nsIObserverService> observerService =
  71         mozilla::services::GetObserverService();
  72     if (!observerService) return NS_OK;
  73     RefPtr<ObserverToDestroyFeaturesAlreadyReported> observer =
  74         new ObserverToDestroyFeaturesAlreadyReported;
  75     observerService->AddObserver(observer, "xpcom-shutdown", false);
  76     return NS_OK;
  77   }
  78 };
  79
  80 class AppendAppNotesRunnable : public Runnable {
  81  public:
  82   explicit AppendAppNotesRunnable(const nsACString& aFeatureStr)
  83       : Runnable("AppendAppNotesRunnable"), mFeatureString(aFeatureStr) {}
  84
  85   NS_IMETHOD Run() override {
  86     CrashReporter::AppendAppNotesToCrashReport(mFeatureString);
  87     return NS_OK;
  88   }
  89
  90  private:
  91   nsAutoCString mFeatureString;
  92 };
  93
  94 void ScopedGfxFeatureReporter::WriteAppNote(char statusChar,
  95                                             int32_t statusNumber) {
  96   StaticMutexAutoLock al(gFeaturesAlreadyReportedMutex);
  97
  98   if (!gFeaturesAlreadyReported) {
  99     gFeaturesAlreadyReported = new nsTArray<nsCString>;
 100     nsCOMPtr<nsIRunnable> r = new RegisterObserverRunnable();
 101     SchedulerGroup::Dispatch(r.forget());
 102   }
 103
 104   nsAutoCString featureString;
 105   if (statusNumber == 0) {
 106     featureString.AppendPrintf("%s%c ", mFeature, statusChar);
 107   } else {
 108     featureString.AppendPrintf("%s%c%d ", mFeature, statusChar, statusNumber);
 109   }
 110
 111   if (!gFeaturesAlreadyReported->Contains(featureString)) {
 112     gFeaturesAlreadyReported->AppendElement(featureString);
 113     AppNote(featureString);
 114   }
 115 }
 116
 117 void ScopedGfxFeatureReporter::AppNote(const nsACString& aMessage) {
 118   if (NS_IsMainThread()) {
 119     CrashReporter::AppendAppNotesToCrashReport(aMessage);
 120   } else {
 121     nsCOMPtr<nsIRunnable> r = new AppendAppNotesRunnable(aMessage);
 122     NS_DispatchToMainThread(r.forget());
 123   }
 124 }
 125
 126 }  // end namespace mozilla