fix for race condition when callback is invoked from thread pool

node-ffi · May 16, 2014 · 4b564f3 · 4b564f3
1 parent 8c8af2a
commit 4b564f3
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Showing 2 changed files with 10 additions and 3 deletions.
diff --git a/src/ffi.h b/src/ffi.h
@@ -100,7 +100,14 @@ class CallbackInfo {
     static uv_async_t         g_async;
 };
 
-
+/**
+ *   Synchronization object to ensure following order of execution:
+ *   -> WaitForExecution()     invoked
+ *   -> SignalDoneExecuting()  returned
+ *   -> WaitForExecution()     returned
+ *
+ *   ^WaitForExecution() must always be called from the thread which owns the object
+ */
 class ThreadedCallbackInvokation {
   public:
     ThreadedCallbackInvokation(callback_info *cbinfo, void *retval, void **parameters);

diff --git a/src/threaded_callback_invokation.cc b/src/threaded_callback_invokation.cc
@@ -6,10 +6,12 @@ ThreadedCallbackInvokation::ThreadedCallbackInvokation(callback_info *cbinfo, vo
   m_parameters = parameters;
 
   pthread_mutex_init(&m_mutex, NULL);
+  pthread_mutex_lock(&m_mutex);
   pthread_cond_init(&m_cond, NULL);
 }
 
 ThreadedCallbackInvokation::~ThreadedCallbackInvokation() {
+  pthread_mutex_unlock(&m_mutex);
   pthread_cond_destroy(&m_cond);
   pthread_mutex_destroy(&m_mutex);
 }
@@ -21,7 +23,5 @@ void ThreadedCallbackInvokation::SignalDoneExecuting() {
 }
 
 void ThreadedCallbackInvokation::WaitForExecution() {
-  pthread_mutex_lock(&m_mutex);
   pthread_cond_wait(&m_cond, &m_mutex);
-  pthread_mutex_unlock(&m_mutex);
 }