platform_thread.h (3487B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. 4 // Use of this source code is governed by a BSD-style license that can be 5 // found in the LICENSE file. 6 7 // WARNING: You should *NOT* be using this class directly. PlatformThread is 8 // the low-level platform-specific abstraction to the OS's threading interface. 9 // You should instead be using a message-loop driven Thread, see thread.h. 10 11 #ifndef BASE_PLATFORM_THREAD_H_ 12 #define BASE_PLATFORM_THREAD_H_ 13 14 #include "base/basictypes.h" 15 16 // PlatformThreadHandle should not be assumed to be a numeric type, since the 17 // standard intends to allow pthread_t to be a structure. This means you 18 // should not initialize it to a value, like 0. If it's a member variable, the 19 // constructor can safely "value initialize" using () in the initializer list. 20 #if defined(XP_WIN) 21 # include <windows.h> 22 typedef DWORD PlatformThreadId; 23 typedef void* PlatformThreadHandle; // HANDLE 24 #else 25 # include <pthread.h> 26 typedef pthread_t PlatformThreadHandle; 27 # if defined(XP_LINUX) || defined(XP_OPENBSD) || defined(XP_SOLARIS) || \ 28 defined(__GLIBC__) 29 # include <unistd.h> 30 typedef pid_t PlatformThreadId; 31 # elif defined(__DragonFly__) || defined(XP_FREEBSD) || defined(XP_NETBSD) 32 # include <sys/types.h> 33 typedef lwpid_t PlatformThreadId; 34 # elif defined(XP_DARWIN) 35 # include <mach/mach.h> 36 typedef mach_port_t PlatformThreadId; 37 # endif 38 #endif 39 40 // A namespace for low-level thread functions. 41 class PlatformThread { 42 public: 43 // Gets the current thread id, which may be useful for logging purposes. 44 static PlatformThreadId CurrentId(); 45 46 // Yield the current thread so another thread can be scheduled. 47 static void YieldCurrentThread(); 48 49 // Sleeps for the specified duration (units are milliseconds). 50 static void Sleep(int duration_ms); 51 52 // Sets the thread name visible to a debugger. This has no effect otherwise. 53 static void SetName(const char* name); 54 55 // Implement this interface to run code on a background thread. Your 56 // ThreadMain method will be called on the newly created thread. 57 class Delegate { 58 public: 59 virtual ~Delegate() {} 60 virtual void ThreadMain() = 0; 61 }; 62 63 // Creates a new thread. The |stack_size| parameter can be 0 to indicate 64 // that the default stack size should be used. Upon success, 65 // |*thread_handle| will be assigned a handle to the newly created thread, 66 // and |delegate|'s ThreadMain method will be executed on the newly created 67 // thread. 68 // NOTE: When you are done with the thread handle, you must call Join to 69 // release system resources associated with the thread. You must ensure that 70 // the Delegate object outlives the thread. 71 static bool Create(size_t stack_size, Delegate* delegate, 72 PlatformThreadHandle* thread_handle); 73 74 // CreateNonJoinable() does the same thing as Create() except the thread 75 // cannot be Join()'d. Therefore, it also does not output a 76 // PlatformThreadHandle. 77 static bool CreateNonJoinable(size_t stack_size, Delegate* delegate); 78 79 // Joins with a thread created via the Create function. This function blocks 80 // the caller until the designated thread exits. This will invalidate 81 // |thread_handle|. 82 static void Join(PlatformThreadHandle thread_handle); 83 84 private: 85 DISALLOW_IMPLICIT_CONSTRUCTORS(PlatformThread); 86 }; 87 88 #endif // BASE_PLATFORM_THREAD_H_