Bug 1312883 - Use MozStackWalk to gather native stacks on Windows. r=gfritzsche,jchen,liuche

MozReview-Commit-ID: A2aZAL03FG2

xpcom/threads/ThreadStackHelper.cpp

@@ -162,6 +162,12 @@ public:
 
 void
 ThreadStackHelper::GetStack(Stack& aStack)
+{
+  GetStackInternal(aStack, /* aAppendNativeStack */ false);
+}
+
+void
+ThreadStackHelper::GetStackInternal(Stack& aStack, bool aAppendNativeStack)
 {
   // Always run PrepareStackBuffer first to clear aStack
   if (!PrepareStackBuffer(aStack)) {
@@ -195,6 +201,13 @@ ThreadStackHelper::GetStack(Stack& aStack)
     MOZ_ASSERT(false);
     return;
   }
+#ifdef _WIN64
+  AcquireStackWalkWorkaroundLock();
+#endif
+  if (aAppendNativeStack) {
+    aStack.EnsureNativeFrameCapacity(Telemetry::HangStack::sMaxNativeFrames);
+  }
+
   if (::SuspendThread(mThreadID) == DWORD(-1)) {
     MOZ_ASSERT(false);
     return;
@@ -209,6 +222,22 @@ ThreadStackHelper::GetStack(Stack& aStack)
     FillStackBuffer();
   }
 
+#ifdef _WIN64
+  ReleaseStackWalkWorkaroundLock();
+#endif
+
+  if (aAppendNativeStack) {
+    auto callback = [](uint32_t, void* aPC, void*, void* aClosure) {
+      Stack* stack = static_cast<Stack*>(aClosure);
+      stack->AppendNativeFrame(reinterpret_cast<uintptr_t>(aPC));
+    };
+
+    MozStackWalk(callback, /* skipFrames */ 0,
+                 /* maxFrames */ Telemetry::HangStack::sMaxNativeFrames,
+                 reinterpret_cast<void*>(&aStack),
+                 reinterpret_cast<uintptr_t>(mThreadID), nullptr);
+  }
+
   MOZ_ALWAYS_TRUE(::ResumeThread(mThreadID) != DWORD(-1));
 
 #elif defined(XP_MACOSX)
@@ -236,10 +265,7 @@ void
 ThreadStackHelper::GetNativeStack(Stack& aStack)
 {
 #ifdef MOZ_THREADSTACKHELPER_NATIVE
-  // Get pseudostack first and fill the thread context.
-  GetStack(aStack);
-
-  // TODO: walk the saved stack frames.
+  GetStackInternal(aStack, /* aAppendNativeStack */ true);
 #endif // MOZ_THREADSTACKHELPER_NATIVE
 }