Make the lazy initialization of DefaultTimerGroup threadsafe.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73963 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Timer.cpp b/lib/Support/Timer.cpp
index 3c8879b..bcb27a4 100644
--- a/lib/Support/Timer.cpp
+++ b/lib/Support/Timer.cpp
@@ -52,8 +52,20 @@
static TimerGroup *DefaultTimerGroup = 0;
static TimerGroup *getDefaultTimerGroup() {
- if (DefaultTimerGroup) return DefaultTimerGroup;
- return DefaultTimerGroup = new TimerGroup("Miscellaneous Ungrouped Timers");
+ TimerGroup* tmp = DefaultTimerGroup;
+ sys::MemoryFence();
+ if (!tmp) {
+ llvm_acquire_global_lock();
+ tmp = DefaultTimerGroup;
+ if (!tmp) {
+ tmp = new TimerGroup("Miscellaneous Ungrouped Timers");
+ sys::MemoryFence();
+ DefaultTimerGroup = tmp;
+ }
+ llvm_release_global_lock();
+ }
+
+ return tmp;
}
Timer::Timer(const std::string &N)
@@ -377,11 +389,5 @@
if (OutStream != cerr.stream() && OutStream != cout.stream())
delete OutStream; // Close the file...
}
-
- // Delete default timer group!
- if (NumTimers == 0 && this == DefaultTimerGroup) {
- delete DefaultTimerGroup;
- DefaultTimerGroup = 0;
- }
}