From f00d84599849c628735cff263cdf6d57874557df Mon Sep 17 00:00:00 2001
From: Evgeny <evgeny.shcherbakov@amd.com>
Date: Thu, 7 Mar 2019 23:57:04 -0600
Subject: [PATCH] fix instance creation

[ROCm/roctracer commit: 5dd9f0d9b25880af2e9966246ca7ef16afc3b3aa]
---
 projects/roctracer/src/core/loader.h      | 26 +++++++++++++++--------
 projects/roctracer/src/core/roctracer.cpp |  4 ++--
 2 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/projects/roctracer/src/core/loader.h b/projects/roctracer/src/core/loader.h
index 0df9b491fb..e23855e2a2 100644
--- a/projects/roctracer/src/core/loader.h
+++ b/projects/roctracer/src/core/loader.h
@@ -43,9 +43,13 @@ class HipLoader : protected Loader {
   typedef decltype(hipKernelNameRef) KernelNameRef_t;
 
   static HipLoader& Instance() {
-    std::lock_guard<mutex_t> lck(mutex_);
-    if (instance_ == NULL) {
-      instance_ = new HipLoader();
+    HipLoader* obj = instance_.load(std::memory_order_acquire);
+    if (obj == NULL) {
+      std::lock_guard<mutex_t> lck(mutex_);
+      if (instance_.load(std::memory_order_relaxed) == NULL) {
+        obj = new HipLoader();
+        instance_.store(obj, std::memory_order_release);
+      }
     }
     return *instance_;
   }
@@ -65,7 +69,7 @@ class HipLoader : protected Loader {
   KernelNameRef_t* KernelNameRef;
 
   private:
-  static HipLoader* instance_;
+  static std::atomic<HipLoader*> instance_;
 };
 
 // HCC runtime library loader class
@@ -80,11 +84,15 @@ class HccLoader : protected Loader {
   static HccLoader* GetRef() { return instance_; }
 
   static HccLoader& Instance() {
-    std::lock_guard<mutex_t> lck(mutex_);
-    if (instance_ == NULL) {
-      instance_ = new HccLoader();
+    HccLoader* obj = instance_.load(std::memory_order_acquire);
+    if (obj == NULL) {
+      std::lock_guard<mutex_t> lck(mutex_);
+      if (instance_.load(std::memory_order_relaxed) == NULL) {
+        obj = new HccLoader();
+        instance_.store(obj, std::memory_order_release);
+      }
     }
-    return *instance_;
+    return *obj;
   }
 
   HccLoader() : Loader("libmcwamp.so") {
@@ -101,7 +109,7 @@ class HccLoader : protected Loader {
   GetCmdName_t* GetCmdName;
 
   private:
-  static HccLoader* instance_;
+  static std::atomic<HccLoader*> instance_;
 };
 
 } // namespace roctracer
diff --git a/projects/roctracer/src/core/roctracer.cpp b/projects/roctracer/src/core/roctracer.cpp
index 36821c5733..acb94c0cfd 100644
--- a/projects/roctracer/src/core/roctracer.cpp
+++ b/projects/roctracer/src/core/roctracer.cpp
@@ -441,8 +441,8 @@ typedef std::recursive_mutex memory_pool_mutex_t;
 memory_pool_mutex_t memory_pool_mutex;
 
 Loader::mutex_t Loader::mutex_;
-HipLoader* HipLoader::instance_;
-HccLoader* HccLoader::instance_;
+std::atomic<HipLoader*> HipLoader::instance_{};
+std::atomic<HccLoader*> HccLoader::instance_{};
 }
 
 proxy::Tracker* proxy::Tracker::instance_ = NULL;