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//===-- ManagedStatic.cpp - Static Global wrapper -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the ManagedStatic class and llvm_shutdown().
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Config/config.h"
#include "llvm/Support/Atomic.h"
#include <cassert>
using namespace llvm;
static const ManagedStaticBase *StaticList = 0;
void ManagedStaticBase::RegisterManagedStatic(void *(*Creator)(),
void (*Deleter)(void*)) const {
if (llvm_is_multithreaded()) {
llvm_acquire_global_lock();
if (Ptr == 0) {
void* tmp = Creator ? Creator() : 0;
TsanHappensBefore(this);
sys::MemoryFence();
// This write is racy against the first read in the ManagedStatic
// accessors. The race is benign because it does a second read after a
// memory fence, at which point it isn't possible to get a partial value.
TsanIgnoreWritesBegin();
Ptr = tmp;
TsanIgnoreWritesEnd();
DeleterFn = Deleter;
// Add to list of managed statics.
Next = StaticList;
StaticList = this;
}
llvm_release_global_lock();
} else {
assert(Ptr == 0 && DeleterFn == 0 && Next == 0 &&
"Partially initialized ManagedStatic!?");
Ptr = Creator ? Creator() : 0;
DeleterFn = Deleter;
// Add to list of managed statics.
Next = StaticList;
StaticList = this;
}
}
void ManagedStaticBase::destroy() const {
assert(DeleterFn && "ManagedStatic not initialized correctly!");
assert(StaticList == this &&
"Not destroyed in reverse order of construction?");
// Unlink from list.
StaticList = Next;
Next = 0;
// Destroy memory.
DeleterFn(Ptr);
// Cleanup.
Ptr = 0;
DeleterFn = 0;
}
/// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
void llvm::llvm_shutdown() {
while (StaticList)
StaticList->destroy();
if (llvm_is_multithreaded()) llvm_stop_multithreaded();
}
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