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-rw-r--r--contrib/llvm/lib/Support/ManagedStatic.cpp90
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diff --git a/contrib/llvm/lib/Support/ManagedStatic.cpp b/contrib/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/Support/Atomic.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();
+}
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