[Offload] [OMPT] Move trace record manager to plugin manager.

Removed the global trace record manager object, instead creating
and destroying it now as part of runtime init/deinit. This leads
to a deterministic lifetime for the trace record manager.

Change-Id: Id351d7e9a6fc42c222dd865d84c7f02bda0a50de

offload/include/OmptTracing.h

@@ -132,9 +132,6 @@ extern thread_local uint64_t TraceRecordStopTime;
 /// Thread local thread-id.
 extern thread_local uint64_t ThreadId;
 
-/// Manage all tracing records in one place.
-extern OmptTracingBufferMgr TraceRecordManager;
-
 /// OMPT global tracing status. Indicates if at least one device is traced.
 extern bool TracingActive;
 

offload/include/OmptTracingBuffer.h

@@ -390,6 +390,8 @@ class OmptTracingBufferMgr {
   int flushAllBuffers(int DeviceId);
 };
 
+#else
+class OmptTracingBufferMgr {};
 #endif // OMPT_SUPPORT
 
 #endif // OPENMP_LIBOMPTARGET_OMPTTRACINGBUFFER_H

offload/include/PluginManager.h

@@ -13,6 +13,7 @@
 #ifndef OMPTARGET_PLUGIN_MANAGER_H
 #define OMPTARGET_PLUGIN_MANAGER_H
 
+#include "OmptTracingBuffer.h"
 #include "PluginInterface.h"
 
 #include "DeviceImage.h"
@@ -46,7 +47,7 @@ struct PluginManager {
   /// Exclusive accessor type for the device container.
   using ExclusiveDevicesAccessorTy = Accessor<DeviceContainerTy>;
 
-  PluginManager() {}
+  PluginManager() : TraceRecordManager(nullptr) {}
 
   void init();
 
@@ -144,6 +145,13 @@ struct PluginManager {
     return count;
   }
 
+  auto getTraceRecordManager() const {
+    // Must be called after runtime is initialized. Since the runtime init
+    // allocates TraceRecordManager, we assert below.
+    assert(TraceRecordManager && "Trace record manager not initialized");
+    return TraceRecordManager;
+  }
+
 private:
   bool RTLsLoaded = false;
   llvm::SmallVector<__tgt_bin_desc *> DelayedBinDesc;
@@ -169,6 +177,8 @@ struct PluginManager {
 
   /// Devices associated with plugins, accesses to the container are exclusive.
   ProtectedObj<DeviceContainerTy> Devices;
+
+  OmptTracingBufferMgr *TraceRecordManager;
 };
 
 /// Initialize the plugin manager and OpenMP runtime.