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Diffstat (limited to 'contrib/llvm/lib/Support/ManagedStatic.cpp')
| -rw-r--r-- | contrib/llvm/lib/Support/ManagedStatic.cpp | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Support/ManagedStatic.cpp b/contrib/llvm/lib/Support/ManagedStatic.cpp new file mode 100644 index 000000000000..1c884dc70fc9 --- /dev/null +++ b/contrib/llvm/lib/Support/ManagedStatic.cpp @@ -0,0 +1,85 @@ +//===-- 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/Mutex.h" +#include "llvm/Support/MutexGuard.h" +#include "llvm/Support/Threading.h" +#include <cassert> +using namespace llvm; + +static const ManagedStaticBase *StaticList = nullptr; +static sys::Mutex *ManagedStaticMutex = nullptr; +static llvm::once_flag mutex_init_flag; + +static void initializeMutex() { + ManagedStaticMutex = new sys::Mutex(); +} + +static sys::Mutex* getManagedStaticMutex() { + llvm::call_once(mutex_init_flag, initializeMutex); + return ManagedStaticMutex; +} + +void ManagedStaticBase::RegisterManagedStatic(void *(*Creator)(), + void (*Deleter)(void*)) const { + assert(Creator); + if (llvm_is_multithreaded()) { + MutexGuard Lock(*getManagedStaticMutex()); + + if (!Ptr.load(std::memory_order_relaxed)) { + void *Tmp = Creator(); + + Ptr.store(Tmp, std::memory_order_release); + DeleterFn = Deleter; + + // Add to list of managed statics. + Next = StaticList; + StaticList = this; + } + } else { + assert(!Ptr && !DeleterFn && !Next && + "Partially initialized ManagedStatic!?"); + Ptr = Creator(); + 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 = nullptr; + + // Destroy memory. + DeleterFn(Ptr); + + // Cleanup. + Ptr = nullptr; + DeleterFn = nullptr; +} + +/// llvm_shutdown - Deallocate and destroy all ManagedStatic variables. +void llvm::llvm_shutdown() { + MutexGuard Lock(*getManagedStaticMutex()); + + while (StaticList) + StaticList->destroy(); +} |
