1 //===-- llvm/Support/Threading.cpp- Control multithreading mode --*- C++ -*-==// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file defines helper functions for running LLVM in a multi-threaded 11 // environment. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "llvm/Support/Threading.h" 16 #include "llvm/Config/config.h" 17 #include "llvm/Support/Atomic.h" 18 #include "llvm/Support/Mutex.h" 19 #include <cassert> 20 21 using namespace llvm; 22 23 bool llvm::llvm_is_multithreaded() { 24 #if LLVM_ENABLE_THREADS != 0 25 return true; 26 #else 27 return false; 28 #endif 29 } 30 31 #if LLVM_ENABLE_THREADS != 0 && defined(HAVE_PTHREAD_H) 32 #include <pthread.h> 33 34 struct ThreadInfo { 35 void (*UserFn)(void *); 36 void *UserData; 37 }; 38 static void *ExecuteOnThread_Dispatch(void *Arg) { 39 ThreadInfo *TI = reinterpret_cast<ThreadInfo*>(Arg); 40 TI->UserFn(TI->UserData); 41 return nullptr; 42 } 43 44 void llvm::llvm_execute_on_thread(void (*Fn)(void*), void *UserData, 45 unsigned RequestedStackSize) { 46 ThreadInfo Info = { Fn, UserData }; 47 pthread_attr_t Attr; 48 pthread_t Thread; 49 50 // Construct the attributes object. 51 if (::pthread_attr_init(&Attr) != 0) 52 return; 53 54 // Set the requested stack size, if given. 55 if (RequestedStackSize != 0) { 56 if (::pthread_attr_setstacksize(&Attr, RequestedStackSize) != 0) 57 goto error; 58 } 59 60 // Construct and execute the thread. 61 if (::pthread_create(&Thread, &Attr, ExecuteOnThread_Dispatch, &Info) != 0) 62 goto error; 63 64 // Wait for the thread and clean up. 65 ::pthread_join(Thread, nullptr); 66 67 error: 68 ::pthread_attr_destroy(&Attr); 69 } 70 #elif LLVM_ENABLE_THREADS!=0 && defined(LLVM_ON_WIN32) 71 #include "Windows/WindowsSupport.h" 72 #include <process.h> 73 74 struct ThreadInfo { 75 void (*func)(void*); 76 void *param; 77 }; 78 79 static unsigned __stdcall ThreadCallback(void *param) { 80 struct ThreadInfo *info = reinterpret_cast<struct ThreadInfo *>(param); 81 info->func(info->param); 82 83 return 0; 84 } 85 86 void llvm::llvm_execute_on_thread(void (*Fn)(void*), void *UserData, 87 unsigned RequestedStackSize) { 88 struct ThreadInfo param = { Fn, UserData }; 89 90 HANDLE hThread = (HANDLE)::_beginthreadex(NULL, 91 RequestedStackSize, ThreadCallback, 92 ¶m, 0, NULL); 93 94 if (hThread) { 95 // We actually don't care whether the wait succeeds or fails, in 96 // the same way we don't care whether the pthread_join call succeeds 97 // or fails. There's not much we could do if this were to fail. But 98 // on success, this call will wait until the thread finishes executing 99 // before returning. 100 (void)::WaitForSingleObject(hThread, INFINITE); 101 ::CloseHandle(hThread); 102 } 103 } 104 #else 105 // Support for non-Win32, non-pthread implementation. 106 void llvm::llvm_execute_on_thread(void (*Fn)(void*), void *UserData, 107 unsigned RequestedStackSize) { 108 (void) RequestedStackSize; 109 Fn(UserData); 110 } 111 112 #endif 113