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https://github.com/c64scene-ar/llvm-6502.git
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529e9d307e
This patch removes the functions llvm_start_multithreaded() and llvm_stop_multithreaded(), and changes llvm_is_multithreaded() to return a constant value based on the value of the compile-time definition LLVM_ENABLE_THREADS. Previously, it was possible to have compile-time support for threads on, and runtime support for threads off, in which case certain mutexes were not allocated or ever acquired. Now, if the build is created with threads enabled, mutexes are always acquired. A test before/after patch of compiling a very large TU showed no noticeable performance impact of this change. Reviewers: rnk Differential Revision: http://reviews.llvm.org/D4076 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210600 91177308-0d34-0410-b5e6-96231b3b80d8
117 lines
3.2 KiB
C++
117 lines
3.2 KiB
C++
//===-- llvm/Support/Threading.cpp- Control multithreading mode --*- C++ -*-==//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements llvm_start_multithreaded() and friends.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Support/Threading.h"
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#include "llvm/Config/config.h"
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#include "llvm/Support/Atomic.h"
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#include "llvm/Support/Mutex.h"
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#include <cassert>
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using namespace llvm;
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llvm::recursive_mutex& llvm::llvm_get_global_lock() {
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static llvm::recursive_mutex global_lock;
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return global_lock;
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}
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bool llvm::llvm_is_multithreaded() {
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#if LLVM_ENABLE_THREADS != 0
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return true;
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#else
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return false;
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#endif
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}
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#if LLVM_ENABLE_THREADS != 0 && defined(HAVE_PTHREAD_H)
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#include <pthread.h>
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struct ThreadInfo {
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void (*UserFn)(void *);
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void *UserData;
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};
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static void *ExecuteOnThread_Dispatch(void *Arg) {
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ThreadInfo *TI = reinterpret_cast<ThreadInfo*>(Arg);
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TI->UserFn(TI->UserData);
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return nullptr;
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}
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void llvm::llvm_execute_on_thread(void (*Fn)(void*), void *UserData,
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unsigned RequestedStackSize) {
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ThreadInfo Info = { Fn, UserData };
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pthread_attr_t Attr;
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pthread_t Thread;
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// Construct the attributes object.
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if (::pthread_attr_init(&Attr) != 0)
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return;
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// Set the requested stack size, if given.
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if (RequestedStackSize != 0) {
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if (::pthread_attr_setstacksize(&Attr, RequestedStackSize) != 0)
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goto error;
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}
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// Construct and execute the thread.
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if (::pthread_create(&Thread, &Attr, ExecuteOnThread_Dispatch, &Info) != 0)
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goto error;
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// Wait for the thread and clean up.
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::pthread_join(Thread, nullptr);
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error:
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::pthread_attr_destroy(&Attr);
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}
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#elif LLVM_ENABLE_THREADS!=0 && defined(LLVM_ON_WIN32)
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#include "Windows/WindowsSupport.h"
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#include <process.h>
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struct ThreadInfo {
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void (*func)(void*);
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void *param;
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};
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static unsigned __stdcall ThreadCallback(void *param) {
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struct ThreadInfo *info = reinterpret_cast<struct ThreadInfo *>(param);
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info->func(info->param);
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return 0;
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}
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void llvm::llvm_execute_on_thread(void (*Fn)(void*), void *UserData,
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unsigned RequestedStackSize) {
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struct ThreadInfo param = { Fn, UserData };
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HANDLE hThread = (HANDLE)::_beginthreadex(NULL,
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RequestedStackSize, ThreadCallback,
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¶m, 0, NULL);
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if (hThread) {
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// We actually don't care whether the wait succeeds or fails, in
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// the same way we don't care whether the pthread_join call succeeds
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// or fails. There's not much we could do if this were to fail. But
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// on success, this call will wait until the thread finishes executing
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// before returning.
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(void)::WaitForSingleObject(hThread, INFINITE);
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::CloseHandle(hThread);
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}
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}
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#else
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// Support for non-Win32, non-pthread implementation.
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void llvm::llvm_execute_on_thread(void (*Fn)(void*), void *UserData,
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unsigned RequestedStackSize) {
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(void) RequestedStackSize;
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Fn(UserData);
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}
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#endif
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