[llvm-commits] [llvm] r73701 - /llvm/trunk/lib/VMCore/Pass.cpp
Owen Anderson
resistor at mac.com
Thu Jun 18 09:08:33 PDT 2009
Author: resistor
Date: Thu Jun 18 11:08:27 2009
New Revision: 73701
URL: http://llvm.org/viewvc/llvm-project?rev=73701&view=rev
Log:
As pointed out by Duncan, I accidentally dropped the first MemoryFence of the
double-checked locking pattern here.
Modified:
llvm/trunk/lib/VMCore/Pass.cpp
Modified: llvm/trunk/lib/VMCore/Pass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Pass.cpp?rev=73701&r1=73700&r2=73701&view=diff
==============================================================================
--- llvm/trunk/lib/VMCore/Pass.cpp (original)
+++ llvm/trunk/lib/VMCore/Pass.cpp Thu Jun 18 11:08:27 2009
@@ -197,17 +197,21 @@
// Use double-checked locking to safely initialize the registrar when
// we're running in multithreaded mode.
- if (!PassRegistrarObj) {
+ PassRegistrar* tmp = PassRegistrarObj;
+ sys::MemoryFence();
+ if (!tmp) {
if (llvm_is_multithreaded()) {
llvm_acquire_global_lock();
- if (!PassRegistrarObj) {
- PassRegistrar* tmp = new PassRegistrar();
+ tmp = PassRegistrarObj;
+ if (!tmp) {
+ tmp = new PassRegistrar();
sys::MemoryFence();
PassRegistrarObj = tmp;
}
llvm_release_global_lock();
- } else
+ } else {
PassRegistrarObj = new PassRegistrar();
+ }
}
return PassRegistrarObj;
}
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