Grab the event lock before fetching the last command

Hip applications assume that hipEventRecord called from multiple
threads will contain exactly the last queued command to the stream.

Change-Id: I1da3259f143d7670d0870d9a47c08e32336b2222

rocclr/hip_event.cpp

@@ -230,6 +230,7 @@ hipError_t hipEventElapsedTime(float *ms, hipEvent_t start, hipEvent_t stop) {
   HIP_RETURN(eStart->elapsedTime(*eStop, *ms), "Elapsed Time = ", *ms);
 }
 
+// ================================================================================================
 hipError_t hipEventRecord(hipEvent_t event, hipStream_t stream) {
   HIP_INIT_API(hipEventRecord, event, stream);
 
@@ -237,6 +238,9 @@ hipError_t hipEventRecord(hipEvent_t event, hipStream_t stream) {
     HIP_RETURN(hipErrorInvalidHandle);
   }
 
+  hip::Event* e = reinterpret_cast<hip::Event*>(event);
+  amd::ScopedLock lock(e->lock());
+
   amd::HostQueue* queue = hip::getQueue(stream);
   amd::Command* command = queue->getLastQueuedCommand(true);
   if (command == nullptr) {
@@ -244,12 +248,11 @@ hipError_t hipEventRecord(hipEvent_t event, hipStream_t stream) {
     command->enqueue();
   }
 
-  hip::Event* e = reinterpret_cast<hip::Event*>(event);
   e->addMarker(queue, command, true);
-
   HIP_RETURN(hipSuccess);
 }
 
+// ================================================================================================
 hipError_t hipEventSynchronize(hipEvent_t event) {
   HIP_INIT_API(hipEventSynchronize, event);
 

rocclr/hip_event.hpp

@@ -37,7 +37,7 @@ public:
 
 class Event {
 public:
-  Event(unsigned int flags) : flags(flags), lock_("hipEvent_t"),
+  Event(unsigned int flags) : flags(flags), lock_("hipEvent_t", true),
                               event_(nullptr), recorded_(false) {
     // No need to init event_ here as addMarker does that
   }
@@ -56,6 +56,8 @@ public:
 
   void addMarker(amd::HostQueue* queue, amd::Command* command, bool record);
 
+  amd::Monitor& lock() { return lock_; }
+
 private:
   amd::Monitor lock_;
   amd::HostQueue* stream_;