//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Chris Lattner and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//===----------------------------------------------------------------------===//
#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 = 0;
+static const ManagedStaticBase *StaticList = nullptr;
-void ManagedStaticBase::RegisterManagedStatic(void *ObjPtr,
+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(Ptr == 0 && DeleterFn == 0 && Next == 0 &&
- "Partially init static?");
- Ptr = ObjPtr;
- DeleterFn = Deleter;
+ 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;
+ // Add to list of managed statics.
+ Next = StaticList;
+ StaticList = this;
+ }
}
void ManagedStaticBase::destroy() const {
- assert(Ptr && DeleterFn && "ManagedStatic not initialized correctly!");
+ assert(DeleterFn && "ManagedStatic not initialized correctly!");
assert(StaticList == this &&
"Not destroyed in reverse order of construction?");
// Unlink from list.
StaticList = Next;
- Next = 0;
+ Next = nullptr;
// Destroy memory.
DeleterFn(Ptr);
// Cleanup.
- Ptr = 0;
- DeleterFn = 0;
+ Ptr = nullptr;
+ DeleterFn = nullptr;
}
/// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
-void llvm_shutdown() {
+void llvm::llvm_shutdown() {
+ MutexGuard Lock(getManagedStaticMutex());
+
while (StaticList)
StaticList->destroy();
}
-