Back out the thread-safe ManagedStatic for now. Too many people have too many problems with it for the moment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71931 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2009-05-16 07:20:52 +00:00
parent 0394c4fb3d
commit 18ad4cb95d

View File

@ -14,8 +14,6 @@
#ifndef LLVM_SUPPORT_MANAGED_STATIC_H
#define LLVM_SUPPORT_MANAGED_STATIC_H
#include "llvm/System/Atomic.h"
namespace llvm {
/// object_deleter - Helper method for ManagedStatic.
@ -28,8 +26,6 @@ void object_deleter(void *Ptr) {
/// ManagedStaticBase - Common base class for ManagedStatic instances.
class ManagedStaticBase {
protected:
mutable sys::cas_flag InitFlag;
// This should only be used as a static variable, which guarantees that this
// will be zero initialized.
mutable void *Ptr;
@ -51,35 +47,23 @@ public:
///
template<class C>
class ManagedStatic : public ManagedStaticBase {
private:
void checkInit() {
sys::cas_flag OldFlag = sys::CompareAndSwap(&InitFlag, 1, 0);
if (OldFlag == 0) {
LazyInit();
sys::MemoryFence();
InitFlag = 2;
} else if (OldFlag == 1) {
while (InitFlag == 1) ;
sys::MemoryFence();
}
}
public:
// Accessors.
C &operator*() {
checkInit();
if (!Ptr) LazyInit();
return *static_cast<C*>(Ptr);
}
C *operator->() {
checkInit();
if (!Ptr) LazyInit();
return static_cast<C*>(Ptr);
}
const C &operator*() const {
checkInit();
if (!Ptr) LazyInit();
return *static_cast<C*>(Ptr);
}
const C *operator->() const {
checkInit();
if (!Ptr) LazyInit();
return static_cast<C*>(Ptr);
}