130 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			130 lines
		
	
	
		
			3.5 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 defines helper functions for running LLVM in a multi-threaded
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| // environment.
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| //
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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/Host.h"
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| #include "llvm/Support/Mutex.h"
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| #include "llvm/Support/thread.h"
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| #include <cassert>
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| 
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| using namespace llvm;
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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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| 
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| #if LLVM_ENABLE_THREADS != 0 && defined(HAVE_PTHREAD_H)
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| #include <pthread.h>
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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|   // Wait for the thread and clean up.
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|   ::pthread_join(Thread, nullptr);
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| 
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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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| 
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| // Windows will at times define MemoryFence.
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| #ifdef MemoryFence
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| #undef MemoryFence
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| #endif
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| 
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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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| 
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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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| 
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|   return 0;
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| }
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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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| 
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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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| 
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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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| 
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| #endif
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| 
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| unsigned llvm::heavyweight_hardware_concurrency() {
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| #if !LLVM_ENABLE_THREADS
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|   return 1;
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| #endif
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|   int NumPhysical = sys::getHostNumPhysicalCores();
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|   if (NumPhysical == -1)
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|     return thread::hardware_concurrency();
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|   return NumPhysical;
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| }
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