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| author | 2016-09-03 22:46:54 +0000 | |
|---|---|---|
| committer | 2016-09-03 22:46:54 +0000 | |
| commit | b5500b9ca0102f1ccaf32f0e77e96d0739aded9b (patch) | |
| tree | e1b7ebb5a0231f9e6d8d3f6f719582cebd64dc98 /gnu/llvm/lib/Support/ManagedStatic.cpp | |
| parent | clarify purpose of src/gnu/ directory. (diff) | |
| download | wireguard-openbsd-b5500b9ca0102f1ccaf32f0e77e96d0739aded9b.tar.xz wireguard-openbsd-b5500b9ca0102f1ccaf32f0e77e96d0739aded9b.zip | |
Use the space freed up by sparc and zaurus to import LLVM.
ok hackroom@
Diffstat (limited to 'gnu/llvm/lib/Support/ManagedStatic.cpp')
| -rw-r--r-- | gnu/llvm/lib/Support/ManagedStatic.cpp | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/gnu/llvm/lib/Support/ManagedStatic.cpp b/gnu/llvm/lib/Support/ManagedStatic.cpp new file mode 100644 index 00000000000..9868207b14f --- /dev/null +++ b/gnu/llvm/lib/Support/ManagedStatic.cpp @@ -0,0 +1,91 @@ +//===-- 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 "llvm/Support/Compiler.h" +#include "llvm/Support/Mutex.h" +#include "llvm/Support/MutexGuard.h" +#include <cassert> +using namespace llvm; + +static const ManagedStaticBase *StaticList = nullptr; + +static sys::Mutex& getManagedStaticMutex() { + // We need to use a function local static here, since this can get called + // during a static constructor and we need to guarantee that it's initialized + // correctly. + static sys::Mutex ManagedStaticMutex; + return ManagedStaticMutex; +} + +void ManagedStaticBase::RegisterManagedStatic(void *(*Creator)(), + void (*Deleter)(void*)) const { + assert(Creator); + if (llvm_is_multithreaded()) { + MutexGuard Lock(getManagedStaticMutex()); + + if (!Ptr) { + void* tmp = Creator(); + + 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; + } + } 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(); +} |
