[llvm] r219638 - Removing the static destructor from ManagedStatic.cpp by controlling the allocation and de-allocation of the mutex.
Chris Bieneman
beanz at apple.com
Mon Oct 13 15:37:25 PDT 2014
Author: cbieneman
Date: Mon Oct 13 17:37:25 2014
New Revision: 219638
URL: http://llvm.org/viewvc/llvm-project?rev=219638&view=rev
Log:
Removing the static destructor from ManagedStatic.cpp by controlling the allocation and de-allocation of the mutex.
This patch adds a new llvm_call_once function which is used by the ManagedStatic implementation to safely initialize a global to avoid static construction and destruction.
Modified:
llvm/trunk/include/llvm/Support/Threading.h
llvm/trunk/lib/Support/ManagedStatic.cpp
Modified: llvm/trunk/include/llvm/Support/Threading.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/Threading.h?rev=219638&r1=219637&r2=219638&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/Threading.h (original)
+++ llvm/trunk/include/llvm/Support/Threading.h Mon Oct 13 17:37:25 2014
@@ -15,6 +15,10 @@
#ifndef LLVM_SUPPORT_THREADING_H
#define LLVM_SUPPORT_THREADING_H
+#if !defined(__MINGW__)
+#include <mutex>
+#endif
+
namespace llvm {
/// Returns true if LLVM is compiled with support for multi-threading, and
/// false otherwise.
@@ -33,6 +37,20 @@ namespace llvm {
/// the thread stack.
void llvm_execute_on_thread(void (*UserFn)(void*), void *UserData,
unsigned RequestedStackSize = 0);
+
+template <void (*UserFn)(void)> void llvm_call_once() {
+
+#if !defined(__MINGW__)
+ static std::once_flag flag;
+ std::call_once(flag, UserFn);
+
+#else
+ struct InitOnceWrapper {
+ InitOnceWrapper() { UserFn(); }
+ };
+ static InitOnceWrapper InitOnceVar;
+#endif
+}
}
#endif
Modified: llvm/trunk/lib/Support/ManagedStatic.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/ManagedStatic.cpp?rev=219638&r1=219637&r2=219638&view=diff
==============================================================================
--- llvm/trunk/lib/Support/ManagedStatic.cpp (original)
+++ llvm/trunk/lib/Support/ManagedStatic.cpp Mon Oct 13 17:37:25 2014
@@ -16,16 +16,22 @@
#include "llvm/Support/Atomic.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 sys::Mutex& getManagedStaticMutex() {
+static void initializeMutex() {
+ ManagedStaticMutex = new sys::Mutex();
+}
+
+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;
+ llvm_call_once<initializeMutex>();
return ManagedStaticMutex;
}
@@ -33,7 +39,7 @@ void ManagedStaticBase::RegisterManagedS
void (*Deleter)(void*)) const {
assert(Creator);
if (llvm_is_multithreaded()) {
- MutexGuard Lock(getManagedStaticMutex());
+ MutexGuard Lock(*getManagedStaticMutex());
if (!Ptr) {
void* tmp = Creator();
@@ -83,8 +89,13 @@ void ManagedStaticBase::destroy() const
/// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
void llvm::llvm_shutdown() {
- MutexGuard Lock(getManagedStaticMutex());
+ {
+ MutexGuard Lock(*getManagedStaticMutex());
+
+ while (StaticList)
+ StaticList->destroy();
+ }
- while (StaticList)
- StaticList->destroy();
+ delete ManagedStaticMutex;
+ ManagedStaticMutex = nullptr;
}
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