mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-10-23 13:02:52 +02:00
f03585d240
This reverts commit r221331 and reinstate r220932 as discussed in D19271. Original commit message was: This patch adds an llvm_call_once which is a wrapper around std::call_once on platforms where it is available and devoid of bugs. The patch also migrates the ManagedStatic mutex to be allocated using llvm_call_once. These changes are philosophically equivalent to the changes added in r219638, which were reverted due to a hang on Win32 which was the result of a bug in the Windows implementation of std::call_once. Differential Revision: http://reviews.llvm.org/D5922 From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 269577
76 lines
2.3 KiB
C++
76 lines
2.3 KiB
C++
//===-- llvm/Support/Threading.h - Control multithreading mode --*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file declares helper functions for running LLVM in a multi-threaded
|
|
// environment.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_SUPPORT_THREADING_H
|
|
#define LLVM_SUPPORT_THREADING_H
|
|
|
|
#include "llvm/Config/llvm-config.h" // for LLVM_ON_UNIX
|
|
|
|
#if defined(LLVM_ON_UNIX)
|
|
#include <mutex>
|
|
#else
|
|
#include "llvm/Support/Atomic.h"
|
|
#endif
|
|
|
|
namespace llvm {
|
|
/// Returns true if LLVM is compiled with support for multi-threading, and
|
|
/// false otherwise.
|
|
bool llvm_is_multithreaded();
|
|
|
|
/// llvm_execute_on_thread - Execute the given \p UserFn on a separate
|
|
/// thread, passing it the provided \p UserData and waits for thread
|
|
/// completion.
|
|
///
|
|
/// This function does not guarantee that the code will actually be executed
|
|
/// on a separate thread or honoring the requested stack size, but tries to do
|
|
/// so where system support is available.
|
|
///
|
|
/// \param UserFn - The callback to execute.
|
|
/// \param UserData - An argument to pass to the callback function.
|
|
/// \param RequestedStackSize - If non-zero, a requested size (in bytes) for
|
|
/// the thread stack.
|
|
void llvm_execute_on_thread(void (*UserFn)(void*), void *UserData,
|
|
unsigned RequestedStackSize = 0);
|
|
|
|
#if defined(LLVM_ON_UNIX)
|
|
typedef std::once_flag once_flag;
|
|
#define LLVM_DEFINE_ONCE_FLAG(flag) static once_flag flag
|
|
#else
|
|
enum InitStatus {
|
|
Done = -1,
|
|
Uninitialized = 0,
|
|
Wait = 1
|
|
};
|
|
typedef volatile sys::cas_flag once_flag;
|
|
|
|
#define LLVM_DEFINE_ONCE_FLAG(flag) static once_flag flag = Uninitialized
|
|
#endif
|
|
|
|
/// \brief Execute the function specified as a parameter once.
|
|
///
|
|
/// Typical usage:
|
|
/// \code
|
|
/// void foo() {...};
|
|
/// ...
|
|
/// LLVM_DEFINE_ONCE_FLAG(flag);
|
|
/// call_once(flag, foo);
|
|
/// \endcode
|
|
///
|
|
/// \param flag Flag used for tracking whether or not this has run.
|
|
/// \param UserFn Function to call once.
|
|
void call_once(once_flag &flag, void (*UserFn)(void));
|
|
}
|
|
|
|
#endif
|