Resolve deadlock caused by cyclic call

Author: dm-vodopyanov

sycl/source/detail/scheduler/scheduler.cpp

@@ -189,8 +189,8 @@ void Scheduler::cleanupFinishedCommands(EventImplPtr FinishedEvent) {
       if (FinishedCmd)
         MGraphBuilder.cleanupFinishedCommands(FinishedCmd, StreamsToDeallocate);
     }
-    deallocateStreams(StreamsToDeallocate);
   }
+  deallocateStreams(StreamsToDeallocate);
 }
 
 void Scheduler::removeMemoryObject(detail::SYCLMemObjI *MemObj) {
@@ -226,9 +226,9 @@ void Scheduler::removeMemoryObject(detail::SYCLMemObjI *MemObj) {
       MGraphBuilder.decrementLeafCountersForRecord(Record);
       MGraphBuilder.cleanupCommandsForRecord(Record, StreamsToDeallocate);
       MGraphBuilder.removeRecordForMemObj(MemObj);
-      deallocateStreams(StreamsToDeallocate);
     }
   }
+  deallocateStreams(StreamsToDeallocate);
 }
 
 EventImplPtr Scheduler::addHostAccessor(Requirement *Req) {
@@ -276,13 +276,13 @@ void Scheduler::enqueueLeavesOfReqUnlocked(const Requirement *const Req) {
 void Scheduler::allocateStreamBuffers(stream_impl *Impl,
                                       size_t StreamBufferSize,
                                       size_t FlushBufferSize) {
-  std::lock_guard<std::mutex> lock(StreamBuffersPoolMutex);
+  std::lock_guard<std::recursive_mutex> lock(StreamBuffersPoolMutex);
   StreamBuffersPool.insert(
       {Impl, new StreamBuffers(StreamBufferSize, FlushBufferSize)});
 }
 
 void Scheduler::deallocateStreamBuffers(stream_impl *Impl) {
-  std::lock_guard<std::mutex> lock(StreamBuffersPoolMutex);
+  std::lock_guard<std::recursive_mutex> lock(StreamBuffersPoolMutex);
   delete StreamBuffersPool[Impl];
   StreamBuffersPool.erase(Impl);
 }
@@ -302,7 +302,7 @@ Scheduler::~Scheduler() {
   // the kernel. Otherwise resources for stream will not be released, issue a
   // warning in this case.
   if (pi::trace(pi::TraceLevel::PI_TRACE_BASIC)) {
-    std::lock_guard<std::mutex> lock(StreamBuffersPoolMutex);
+    std::lock_guard<std::recursive_mutex> lock(StreamBuffersPoolMutex);
     if (!StreamBuffersPool.empty())
       fprintf(
           stderr,

sycl/source/detail/scheduler/scheduler.hpp

@@ -766,7 +766,7 @@ class Scheduler {
   friend class stream_impl;
 
   // Protects stream buffers pool
-  std::mutex StreamBuffersPoolMutex;
+  std::recursive_mutex StreamBuffersPoolMutex;
 
   // We need to store a pointer to the structure with stream buffers because we
   // want to avoid a situation when buffers are destructed during destruction of