Bug 1346356 (part 4) - Clean up notification in the profiler. r=mstange.

This patch does the following.

- Introduces NotifyObservers() for the simple notification cases in
  platform.cpp.

- Removes profiler_lock() and profiler_unlock() because they do notifications
  that the profiler add-on no longer listens for.

--HG--
extra : rebase_source : 77a1868ba494dea314702bbdf9478a1da36c9efb

tools/profiler/core/platform.cpp

@@ -1774,7 +1774,7 @@ NotifyProfilerStarted(const int aEntries, double aInterval,
 }
 
 static void
-NotifyProfilerStopped()
+NotifyObservers(const char* aTopic)
 {
   if (!CanNotifyObservers()) {
     return;
@@ -1785,7 +1785,7 @@ NotifyProfilerStopped()
     return;
   }
 
-  os->NotifyObservers(nullptr, "profiler-stopped", nullptr);
+  os->NotifyObservers(nullptr, aTopic, nullptr);
 }
 
 static void
@@ -1949,7 +1949,7 @@ profiler_shutdown()
   // We do these operations with gPSMutex unlocked. The comments in
   // profiler_stop() explain why.
   if (samplerThread) {
-    NotifyProfilerStopped();
+    NotifyObservers("profiler-stopped");
     delete samplerThread;
   }
 
@@ -2392,7 +2392,7 @@ profiler_start(int aEntries, double aInterval,
   // We do these operations with gPSMutex unlocked. The comments in
   // profiler_stop() explain why.
   if (samplerThread) {
-    NotifyProfilerStopped();
+    NotifyObservers("profiler-stopped");
     delete samplerThread;
   }
   NotifyProfilerStarted(aEntries, aInterval, aFeatures, aFeatureCount,
@@ -2508,7 +2508,7 @@ profiler_stop()
   // We notify observers with gPSMutex unlocked. Otherwise we might get a
   // deadlock, if code run by the observer calls a profiler function that locks
   // gPSMutex. (This has been seen in practise in bug 1346356.)
-  NotifyProfilerStopped();
+  NotifyObservers("profiler-stopped");
 
   // We delete with gPSMutex unlocked. Otherwise we would get a deadlock: we
   // would be waiting here with gPSMutex locked for SamplerThread::Run() to
@@ -2556,12 +2556,7 @@ profiler_pause()
   }
 
   // gPSMutex must be unlocked when we notify, to avoid potential deadlocks.
-  if (CanNotifyObservers()) {
-    nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
-    if (os) {
-      os->NotifyObservers(nullptr, "profiler-paused", nullptr);
-    }
-  }
+  NotifyObservers("profiler-paused");
 }
 
 void
@@ -2581,12 +2576,7 @@ profiler_resume()
   }
 
   // gPSMutex must be unlocked when we notify, to avoid potential deadlocks.
-  if (CanNotifyObservers()) {
-    nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
-    if (os) {
-      os->NotifyObservers(nullptr, "profiler-resumed", nullptr);
-    }
-  }
+  NotifyObservers("profiler-resumed");
 }
 
 bool
@@ -2644,31 +2634,6 @@ profiler_set_frame_number(int aFrameNumber)
   gPS->SetFrameNumber(lock, aFrameNumber);
 }
 
-void
-profiler_lock()
-{
-  MOZ_RELEASE_ASSERT(NS_IsMainThread());
-  MOZ_RELEASE_ASSERT(gPS);
-
-  profiler_stop();
-  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
-  if (os) {
-    os->NotifyObservers(nullptr, "profiler-locked", nullptr);
-  }
-}
-
-void
-profiler_unlock()
-{
-  MOZ_RELEASE_ASSERT(NS_IsMainThread());
-  MOZ_RELEASE_ASSERT(gPS);
-
-  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
-  if (os) {
-    os->NotifyObservers(nullptr, "profiler-unlocked", nullptr);
-  }
-}
-
 void
 profiler_register_thread(const char* aName, void* aGuessStackTop)
 {

tools/profiler/gecko/nsProfiler.cpp

@@ -56,17 +56,19 @@ nsProfiler::Observe(nsISupports *aSubject,
                     const char *aTopic,
                     const char16_t *aData)
 {
+  // The profiler's handling of private browsing is as simple as possible: it
+  // is stopped when the first PB window opens, and left stopped when the last
+  // PB window closes.
   if (strcmp(aTopic, "chrome-document-global-created") == 0) {
     nsCOMPtr<nsIInterfaceRequestor> requestor = do_QueryInterface(aSubject);
     nsCOMPtr<nsIWebNavigation> parentWebNav = do_GetInterface(requestor);
     nsCOMPtr<nsILoadContext> loadContext = do_QueryInterface(parentWebNav);
     if (loadContext && loadContext->UsePrivateBrowsing() && !mLockedForPrivateBrowsing) {
       mLockedForPrivateBrowsing = true;
-      profiler_lock();
+      profiler_stop();
     }
   } else if (strcmp(aTopic, "last-pb-context-exited") == 0) {
     mLockedForPrivateBrowsing = false;
-    profiler_unlock();
   }
   return NS_OK;
 }

tools/profiler/public/GeckoProfiler.h

@@ -274,14 +274,6 @@ static inline void profiler_get_buffer_info(uint32_t* aCurrentPosition,
   profiler_get_buffer_info_helper(aCurrentPosition, aEntries, aGeneration);
 }
 
-// Lock the profiler. When locked the profiler is (1) stopped,
-// (2) profile data is cleared, (3) 'profiler-locked' is fired.
-// This is used to lock down the profiler during private browsing.
-PROFILER_FUNC_VOID(profiler_lock())
-
-// Unlock the profiler, leaving it stopped, and fire 'profiler-unlocked'.
-PROFILER_FUNC_VOID(profiler_unlock())
-
 // Register/unregister threads with the profiler.
 PROFILER_FUNC_VOID(profiler_register_thread(const char* name,
                                             void* guessStackTop))