6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-08 21:32:39 +00:00
Code Issues Projects Releases Wiki Activity

Fix PR8441, a race condition in the static attributes list. While the reference counting was itself threadsafe,

Browse Source 
the implicit removal of each object from the global list was not.  Make this operation atomic.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118461 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2010-11-09 00:27:03 +00:00
parent 4b97c55648
commit 3afb024907
1 changed files with 12 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
lib/VMCore/Attributes.cpp
View File

@ -106,7 +106,10 @@ Attributes Attribute::typeIncompatible(const Type *Ty) {
// AttributeListImpl Definition // AttributeListImpl Definition
//===----------------------------------------------------------------------===// //===----------------------------------------------------------------------===//
namespace llvm { namespace llvm {
static ManagedStatic<sys::SmartMutex<true> > ALMutex;
class AttributeListImpl : public FoldingSetNode { class AttributeListImpl : public FoldingSetNode {
sys::cas_flag RefCount; sys::cas_flag RefCount;
@ -122,10 +125,15 @@ public:
RefCount = 0; RefCount = 0;
} }
void AddRef() { sys::AtomicIncrement(&RefCount); } void AddRef() {
sys::SmartScopedLock<true> Lock(*ALMutex);
++RefCount;
}
void DropRef() { void DropRef() {
sys::cas_flag old = sys::AtomicDecrement(&RefCount); sys::SmartScopedLock<true> Lock(*ALMutex);
if (old == 0) delete this; sys::cas_flag old = RefCount++;
if (old == 0)
delete this;
} }
void Profile(FoldingSetNodeID &ID) const { void Profile(FoldingSetNodeID &ID) const {
@ -139,11 +147,10 @@ public:
}; };
} }
static ManagedStatic<sys::SmartMutex<true> > ALMutex;
static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists; static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists;
AttributeListImpl::~AttributeListImpl() { AttributeListImpl::~AttributeListImpl() {
sys::SmartScopedLock<true> Lock(*ALMutex); // NOTE: Lock must be acquired by caller.
AttributesLists->RemoveNode(this); AttributesLists->RemoveNode(this);
} }