forked from OSchip/llvm-project
79 lines
2.3 KiB
C++
79 lines
2.3 KiB
C++
//===-- ManagedStatic.cpp - Static Global wrapper -------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the ManagedStatic class and llvm_shutdown().
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Support/ManagedStatic.h"
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#include "llvm/Config/config.h"
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#include "llvm/Support/Threading.h"
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#include <cassert>
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#include <mutex>
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using namespace llvm;
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static const ManagedStaticBase *StaticList = nullptr;
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static std::recursive_mutex *getManagedStaticMutex() {
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static std::recursive_mutex m;
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return &m;
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}
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void ManagedStaticBase::RegisterManagedStatic(void *(*Creator)(),
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void (*Deleter)(void*)) const {
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assert(Creator);
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if (llvm_is_multithreaded()) {
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std::lock_guard<std::recursive_mutex> Lock(*getManagedStaticMutex());
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if (!Ptr.load(std::memory_order_relaxed)) {
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void *Tmp = Creator();
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Ptr.store(Tmp, std::memory_order_release);
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DeleterFn = Deleter;
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// Add to list of managed statics.
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Next = StaticList;
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StaticList = this;
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}
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} else {
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assert(!Ptr && !DeleterFn && !Next &&
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"Partially initialized ManagedStatic!?");
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Ptr = Creator();
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DeleterFn = Deleter;
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// Add to list of managed statics.
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Next = StaticList;
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StaticList = this;
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}
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}
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void ManagedStaticBase::destroy() const {
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assert(DeleterFn && "ManagedStatic not initialized correctly!");
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assert(StaticList == this &&
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"Not destroyed in reverse order of construction?");
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// Unlink from list.
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StaticList = Next;
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Next = nullptr;
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// Destroy memory.
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DeleterFn(Ptr);
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// Cleanup.
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Ptr = nullptr;
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DeleterFn = nullptr;
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}
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/// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
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/// IMPORTANT: it's only safe to call llvm_shutdown() in single thread,
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/// without any other threads executing LLVM APIs.
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/// llvm_shutdown() should be the last use of LLVM APIs.
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void llvm::llvm_shutdown() {
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while (StaticList)
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StaticList->destroy();
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}
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