Fix potential race-condition _beginthread

ppapi/tests/pp_thread.h

Index: ppapi/tests/pp_thread.h
diff --git a/ppapi/tests/pp_thread.h b/ppapi/tests/pp_thread.h
index c4af8f1bbf1094d95c06d2b4519577c23fc60d9c..4a8d2378970521e63c604fba6781ae2323db164a 100644
--- a/ppapi/tests/pp_thread.h
+++ b/ppapi/tests/pp_thread.h
@@ -33,14 +33,18 @@
  * used in ppapi/tests, so is not part of the published API.
  */
 
+typedef void (PP_ThreadFunction)(void* data);
+
 #if defined(PPAPI_POSIX)
 typedef pthread_t PP_ThreadType;
 #elif defined(PPAPI_OS_WIN)
-typedef uintptr_t PP_ThreadType;
+struct PP_ThreadType {

[bbudge, 2014/09/05 17:22:59]

Given that this is now a struct, PP_ThreadType doesn't seem like a great name.
How about PP_Thread? I think it's available, though you'd have to change 2 more
files that reference this.

+  HANDLE handle;
+  PP_ThreadFunction* thread_func;
+  void* thread_arg;
+};
 #endif
 
-typedef void (PP_ThreadFunction)(void* data);
-
 PP_INLINE bool PP_CreateThread(PP_ThreadType* thread,
                                PP_ThreadFunction function,
                                void* thread_arg);
@@ -86,19 +90,32 @@ PP_INLINE void PP_JoinThread(PP_ThreadType thread) {
 #elif defined(PPAPI_OS_WIN)
 typedef DWORD (PP_WindowsThreadFunction)(void* data);

[bbudge, 2014/09/05 17:22:59]

This typedef doesn't appear to be used anywhere.

 
+PP_INLINE unsigned int __stdcall ProxyThreadFunc(void* param) {

[bbudge, 2014/09/05 17:22:59]

This is really an adapter or 'thunk' for the thread function. Could you name it
PP_WindowsThreadFunction? Also, I think the return type should be DWORD or just
unsigned.
http://msdn.microsoft.com/en-us/library/kdzttdcb.aspx

+  PP_ThreadType* params = reinterpret_cast<PP_ThreadType*>(param);
+  params->thread_func(params->thread_arg);
+  return 0;
+}
+
 PP_INLINE bool PP_CreateThread(PP_ThreadType* thread,
                                PP_ThreadFunction function,
                                void* thread_arg) {
   if (!thread)
     return false;
-  *thread = ::_beginthread(function,
-                           0,  /* Use default stack size. */
-                           thread_arg);
-  return (*thread != NULL);
+  thread->thread_func = function;
+  thread->thread_arg = thread_arg;
+  uintptr_t raw_handle = ::_beginthreadex(NULL,
+                                    0,  /* Use default stack size. */

[bbudge, 2014/09/05 17:22:59]

nit: indent is strange

+                                    &ProxyThreadFunc,
+                                    thread,
+                                    0,
+                                    NULL);
+  thread->handle = reinterpret_cast<HANDLE>(raw_handle);
+  return (thread->handle != NULL);
 }
 
-PP_INLINE void PP_JoinThread(PP_ThreadType thread) {
-  ::WaitForSingleObject((HANDLE)thread, INFINITE);
+PP_INLINE void PP_JoinThread(PP_ThreadType thread_info) {
+  ::WaitForSingleObject(thread_info.handle, INFINITE);
+  ::CloseHandle(thread_info.handle);
 }
 
 #endif