#include "llvm/Support/ManagedStatic.h"
#include "llvm/Config/config.h"
-#include "llvm/System/Atomic.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 = 0;
+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()) {
- llvm_acquire_global_lock();
+ MutexGuard Lock(getManagedStaticMutex());
- if (Ptr == 0) {
- void* tmp = Creator ? Creator() : 0;
+ 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;
}
-
- llvm_release_global_lock();
} else {
- assert(Ptr == 0 && DeleterFn == 0 && Next == 0 &&
+ assert(!Ptr && !DeleterFn && !Next &&
"Partially initialized ManagedStatic!?");
- Ptr = Creator ? Creator() : 0;
+ Ptr = Creator();
DeleterFn = Deleter;
// Add to list of managed statics.
"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::llvm_shutdown() {
+ MutexGuard Lock(getManagedStaticMutex());
+
while (StaticList)
StaticList->destroy();
-
- if (llvm_is_multithreaded()) llvm_stop_multithreaded();
}
-