//===-- 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(); }