Bug 718025 - Add support for stacktraces on Windows to the built-in profiler; r=jrmuizel

tools/profiler/sps/TableTicker.cpp

@@ -56,6 +56,13 @@
  #include <execinfo.h>
 #endif
 
+#ifdef XP_WIN
+ #define USE_NS_STACKWALK
+#endif
+#ifdef USE_NS_STACKWALK
+ #include "nsStackWalk.h"
+#endif
+
 using std::string;
 using namespace mozilla;
 
@@ -272,7 +279,12 @@ class TableTicker: public Sampler {
   {
     return &mProfile;
   }
- private:
+
+private:
+  // Not implemented on platforms which do not support backtracing
+  void doBacktrace(Profile &aProfile);
+
+private:
   Profile mProfile;
   Stack *mStack;
   bool mSaveRequested;
@@ -337,8 +349,7 @@ void TableTicker::HandleSaveRequest()
 }
 
 #ifdef USE_BACKTRACE
-static
-void doBacktrace(Profile &aProfile)
+void TableTicker::doBacktrace(Profile &aProfile)
 {
   void *array[100];
   int count = backtrace (array, 100);
@@ -352,6 +363,45 @@ void doBacktrace(Profile &aProfile)
 }
 #endif
 
+#ifdef USE_NS_STACKWALK
+typedef struct {
+  void* array[];
+  size_t size;
+  size_t count;
+} PCArray;
+
+static
+void StackWalkCallback(void* aPC, void* aClosure)
+{
+  PCArray* array = static_cast<PCArray*>(aClosure);
+  if (array->count >= array->size) {
+    // too many frames, ignore
+    return;
+  }
+  array->array[array->count++] = aPC;
+}
+
+void TableTicker::doBacktrace(Profile &aProfile)
+{
+  uintptr_t thread = GetThreadHandle(platform_data());
+  MOZ_ASSERT(thread);
+  void* pc_array[1000];
+  PCArray array = {
+    pc_array,
+    mozilla::ArrayLength(array),
+    0
+  };
+  nsresult rv = NS_StackWalk(StackWalkCallback, 0, &array, thread);
+  if (NS_SUCCEEDED(rv)) {
+    aProfile.addTag(ProfileEntry('s', "XRE_Main", 0));
+
+    for (size_t i = array.count; i > 0; --i) {
+      aProfile.addTag(ProfileEntry('l', (const char*)array.array[i - 1]));
+    }
+  }
+}
+#endif
+
 static
 void doSampleStackTrace(Stack *aStack, Profile &aProfile, TickSample *sample)
 {
@@ -395,7 +445,7 @@ void TableTicker::Tick(TickSample* sample)
   }
 
   if (recordSample) {
-#ifdef USE_BACKTRACE
+#if defined(USE_BACKTRACE) || defined(USE_NS_STACKWALK)
     if (mUseStackWalk) {
       doBacktrace(mProfile);
     } else {

tools/profiler/sps/platform-win32.cc

@@ -33,6 +33,11 @@ class Sampler::PlatformData : public Malloced {
   HANDLE profiled_thread_;
 };
 
+uintptr_t
+Sampler::GetThreadHandle(Sampler::PlatformData* aData)
+{
+  return (uintptr_t) aData->profiled_thread();
+}
 
 class SamplerThread : public Thread {
  public:

tools/profiler/sps/platform.h

@@ -203,6 +203,11 @@ class Sampler {
 
   PlatformData* platform_data() { return data_; }
 
+#ifdef XP_WIN
+  // xxxehsan sucky hack :(
+  static uintptr_t GetThreadHandle(PlatformData*);
+#endif
+
  private:
   void SetActive(bool value) { NoBarrier_Store(&active_, value); }