llvm-project/llvm/lib/Support/Windows/Threading.inc

110 lines
3.1 KiB
C++

//===- Windows/Threading.inc - Win32 Threading Implementation - -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides the Win32 specific implementation of Threading functions.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/Twine.h"
#include "Windows/WindowsSupport.h"
#include <process.h>
// Windows will at times define MemoryFence.
#ifdef MemoryFence
#undef MemoryFence
#endif
namespace {
struct ThreadInfo {
void(*func)(void*);
void *param;
};
}
static unsigned __stdcall ThreadCallback(void *param) {
struct ThreadInfo *info = reinterpret_cast<struct ThreadInfo *>(param);
info->func(info->param);
return 0;
}
void llvm::llvm_execute_on_thread(void(*Fn)(void*), void *UserData,
unsigned RequestedStackSize) {
struct ThreadInfo param = { Fn, UserData };
HANDLE hThread = (HANDLE)::_beginthreadex(NULL,
RequestedStackSize, ThreadCallback,
&param, 0, NULL);
if (hThread) {
// We actually don't care whether the wait succeeds or fails, in
// the same way we don't care whether the pthread_join call succeeds
// or fails. There's not much we could do if this were to fail. But
// on success, this call will wait until the thread finishes executing
// before returning.
(void)::WaitForSingleObject(hThread, INFINITE);
::CloseHandle(hThread);
}
}
uint64_t llvm::get_threadid() {
return uint64_t(::GetCurrentThreadId());
}
uint32_t llvm::get_max_thread_name_length() { return 0; }
#if defined(_MSC_VER)
static void SetThreadName(DWORD Id, LPCSTR Name) {
constexpr DWORD MS_VC_EXCEPTION = 0x406D1388;
#pragma pack(push, 8)
struct THREADNAME_INFO {
DWORD dwType; // Must be 0x1000.
LPCSTR szName; // Pointer to thread name
DWORD dwThreadId; // Thread ID (-1 == current thread)
DWORD dwFlags; // Reserved. Do not use.
};
#pragma pack(pop)
THREADNAME_INFO info;
info.dwType = 0x1000;
info.szName = Name;
info.dwThreadId = Id;
info.dwFlags = 0;
__try {
::RaiseException(MS_VC_EXCEPTION, 0, sizeof(info) / sizeof(ULONG_PTR),
(ULONG_PTR *)&info);
}
__except (EXCEPTION_EXECUTE_HANDLER) {
}
}
#endif
void llvm::set_thread_name(const Twine &Name) {
#if defined(_MSC_VER)
// Make sure the input is null terminated.
SmallString<64> Storage;
StringRef NameStr = Name.toNullTerminatedStringRef(Storage);
SetThreadName(::GetCurrentThreadId(), NameStr.data());
#endif
}
void llvm::get_thread_name(SmallVectorImpl<char> &Name) {
// "Name" is not an inherent property of a thread on Windows. In fact, when
// you "set" the name, you are only firing a one-time message to a debugger
// which it interprets as a program setting its threads' name. We may be
// able to get fancy by creating a TLS entry when someone calls
// set_thread_name so that subsequent calls to get_thread_name return this
// value.
Name.clear();
}