Make the Plugin Interface tracing thread-safe

Author: againull

sycl/source/detail/plugin.hpp

@@ -12,6 +12,8 @@
 #include <CL/sycl/detail/pi.hpp>
 #include <CL/sycl/stl.hpp>
 #include <detail/plugin_printers.hpp>
+#include <memory>
+#include <mutex>
 
 #ifdef XPTI_ENABLE_INSTRUMENTATION
 // Include the headers necessary for emitting traces using the trace framework
@@ -33,7 +35,8 @@ class plugin {
   plugin() = delete;
 
   plugin(RT::PiPlugin Plugin, backend UseBackend)
-      : MPlugin(Plugin), MBackend(UseBackend) {}
+      : MPlugin(Plugin), MBackend(UseBackend),
+        TracingMutex(std::make_shared<std::mutex>()) {}
 
   plugin &operator=(const plugin &) = default;
   plugin(const plugin &) = default;
@@ -73,13 +76,12 @@ class plugin {
     std::string PIFnName = PiCallInfo.getFuncName();
     uint64_t CorrelationID = pi::emitFunctionBeginTrace(PIFnName.c_str());
 #endif
+    RT::PiResult R = PiCallInfo.getFuncPtr(MPlugin)(Args...);
     if (pi::trace(pi::TraceLevel::PI_TRACE_CALLS)) {
+      std::lock_guard<std::mutex> Guard(*TracingMutex);
       std::string FnName = PiCallInfo.getFuncName();
       std::cout << "---> " << FnName << "(" << std::endl;
       RT::printArgs(Args...);
-    }
-    RT::PiResult R = PiCallInfo.getFuncPtr(MPlugin)(Args...);
-    if (pi::trace(pi::TraceLevel::PI_TRACE_CALLS)) {
       std::cout << ") ---> ";
       RT::printArgs(R);
       RT::printOuts(Args...);
@@ -106,6 +108,7 @@ class plugin {
 private:
   RT::PiPlugin MPlugin;
   backend MBackend;
+  std::shared_ptr<std::mutex> TracingMutex;
 }; // class plugin
 } // namespace detail
 } // namespace sycl