llvm-project/llvm/lib/Support/ManagedStatic.cpp

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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/System/Atomic.h"
#include "llvm/System/Mutex.h"
#include <cassert>
using namespace llvm;
static const ManagedStaticBase *StaticList = 0;
static sys::Mutex* ManagedStaticMutex = 0;
void ManagedStaticBase::RegisterManagedStatic(void *(*Creator)(),
void (*Deleter)(void*)) const {
if (ManagedStaticMutex) {
ManagedStaticMutex->acquire();
if (Ptr == 0) {
void* tmp = Creator ? Creator() : 0;
sys::MemoryFence();
Ptr = tmp;
DeleterFn = Deleter;
// Add to list of managed statics.
Next = StaticList;
StaticList = this;
}
ManagedStaticMutex->release();
} 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;
}
bool llvm::llvm_start_multithreaded() {
#if LLVM_MULTITHREADED
assert(ManagedStaticMutex == 0 && "Multithreaded LLVM already initialized!");
ManagedStaticMutex = new sys::Mutex(true);
return true;
#else
return false;
#endif
}
/// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
void llvm::llvm_shutdown() {
while (StaticList)
StaticList->destroy();
if (ManagedStaticMutex) {
delete ManagedStaticMutex;
ManagedStaticMutex = 0;
}
}