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/Assertions.h"  // for MOZ_ASSERT_HELPER2
  10 #include "mozilla/Services.h"    // for GetObserverService
  11 #include "mozilla/StaticMutex.h"
  12 #include "mozilla/SystemGroup.h"  // for SystemGroup
  13 #include "mozilla/mozalloc.h"     // for operator new, etc
  14 #include "mozilla/RefPtr.h"       // for RefPtr
  15 #include "MainThreadUtils.h"      // for NS_IsMainThread
  16 #include "nsCOMPtr.h"             // for nsCOMPtr
  17 #include "nsError.h"              // for NS_OK, NS_FAILED, nsresult
  18 #include "nsExceptionHandler.h"   // for AppendAppNotesToCrashReport
  19 #include "nsID.h"
  20 #include "nsIEventTarget.h"      // for NS_DISPATCH_NORMAL
  21 #include "nsIObserver.h"         // for nsIObserver, etc
  22 #include "nsIObserverService.h"  // for nsIObserverService
  23 #include "nsIRunnable.h"         // for nsIRunnable
  24 #include "nsISupports.h"
  25 #include "nsTArray.h"  // for nsTArray
  26 #include "nscore.h"    // for NS_IMETHOD, NS_IMETHODIMP, etc
  27
  28 namespace mozilla {
  29
  30 static nsTArray<nsCString>* gFeaturesAlreadyReported = nullptr;
  31 static StaticMutex gFeaturesAlreadyReportedMutex;
  32
  33 class ObserverToDestroyFeaturesAlreadyReported final : public nsIObserver {
  34  public:
  35   NS_DECL_ISUPPORTS
  36   NS_DECL_NSIOBSERVER
  37
  38   ObserverToDestroyFeaturesAlreadyReported() {}
  39
  40  private:
  41   virtual ~ObserverToDestroyFeaturesAlreadyReported() {}
  42 };
  43
  44 NS_IMPL_ISUPPORTS(ObserverToDestroyFeaturesAlreadyReported, nsIObserver)
  45
  46 NS_IMETHODIMP
  47 ObserverToDestroyFeaturesAlreadyReported::Observe(nsISupports* aSubject,
  48                                                   const char* aTopic,
  49                                                   const char16_t* aData) {
  50   if (!strcmp(aTopic, "xpcom-shutdown")) {
  51     StaticMutexAutoLock al(gFeaturesAlreadyReportedMutex);
  52     if (gFeaturesAlreadyReported) {
  53       delete gFeaturesAlreadyReported;
  54       gFeaturesAlreadyReported = nullptr;
  55     }
  56   }
  57   return NS_OK;
  58 }
  59
  60 class RegisterObserverRunnable : public Runnable {
  61  public:
  62   RegisterObserverRunnable() : Runnable("RegisterObserverRunnable") {}
  63   NS_IMETHOD Run() override {
  64     // LeakLog made me do this. Basically, I just wanted
  65     // gFeaturesAlreadyReported to be a static nsTArray<nsCString>, and LeakLog
  66     // was complaining about leaks like this:
  67     //    leaked 1 instance of nsTArray_base with size 8 bytes
  68     //    leaked 7 instances of nsStringBuffer with size 8 bytes each (56 bytes
  69     //    total)
  70     // So this is a work-around using a pointer, and using a nsIObserver to
  71     // deallocate on xpcom shutdown. Yay for fighting bloat.
  72     nsCOMPtr<nsIObserverService> observerService =
  73         mozilla::services::GetObserverService();
  74     if (!observerService) return NS_OK;
  75     RefPtr<ObserverToDestroyFeaturesAlreadyReported> observer =
  76         new ObserverToDestroyFeaturesAlreadyReported;
  77     observerService->AddObserver(observer, "xpcom-shutdown", false);
  78     return NS_OK;
  79   }
  80 };
  81
  82 class AppendAppNotesRunnable : public CancelableRunnable {
  83  public:
  84   explicit AppendAppNotesRunnable(const nsACString& aFeatureStr)
  85       : CancelableRunnable("AppendAppNotesRunnable"),
  86         mFeatureString(aFeatureStr) {}
  87
  88   NS_IMETHOD Run() override {
  89     CrashReporter::AppendAppNotesToCrashReport(mFeatureString);
  90     return NS_OK;
  91   }
  92
  93  private:
  94   nsAutoCString mFeatureString;
  95 };
  96
  97 void ScopedGfxFeatureReporter::WriteAppNote(char statusChar,
  98                                             int32_t statusNumber) {
  99   StaticMutexAutoLock al(gFeaturesAlreadyReportedMutex);
 100
 101   if (!gFeaturesAlreadyReported) {
 102     gFeaturesAlreadyReported = new nsTArray<nsCString>;
 103     nsCOMPtr<nsIRunnable> r = new RegisterObserverRunnable();
 104     SystemGroup::Dispatch(TaskCategory::Other, r.forget());
 105   }
 106
 107   nsAutoCString featureString;
 108   if (statusNumber == 0) {
 109     featureString.AppendPrintf("%s%c ", mFeature, statusChar);
 110   } else {
 111     featureString.AppendPrintf("%s%c%d ", mFeature, statusChar, statusNumber);
 112   }
 113
 114   if (!gFeaturesAlreadyReported->Contains(featureString)) {
 115     gFeaturesAlreadyReported->AppendElement(featureString);
 116     AppNote(featureString);
 117   }
 118 }
 119
 120 void ScopedGfxFeatureReporter::AppNote(const nsACString& aMessage) {
 121   if (NS_IsMainThread()) {
 122     CrashReporter::AppendAppNotesToCrashReport(aMessage);
 123   } else {
 124     nsCOMPtr<nsIRunnable> r = new AppendAppNotesRunnable(aMessage);
 125     SystemGroup::Dispatch(TaskCategory::Other, r.forget());
 126   }
 127 }
 128
 129 }  // end namespace mozilla