SDL  2.0
SDL_systhread.cpp
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../../SDL_internal.h"
22 
23 /* Thread management routines for SDL */
24 
25 extern "C" {
26 #include "SDL_thread.h"
27 #include "../SDL_thread_c.h"
28 #include "../SDL_systhread.h"
29 #include "SDL_log.h"
30 }
31 
32 #include <mutex>
33 #include <thread>
34 #include <system_error>
35 
36 #ifdef __WINRT__
37 #include <Windows.h>
38 #endif
39 
40 static void
41 RunThread(void *args)
42 {
43  SDL_RunThread(args);
44 }
45 
46 extern "C"
47 int
48 SDL_SYS_CreateThread(SDL_Thread * thread, void *args)
49 {
50  try {
51  std::thread cpp_thread(RunThread, args);
52  thread->handle = (void *) new std::thread(std::move(cpp_thread));
53  return 0;
54  } catch (std::system_error & ex) {
55  SDL_SetError("unable to start a C++ thread: code=%d; %s", ex.code(), ex.what());
56  return -1;
57  } catch (std::bad_alloc &) {
59  return -1;
60  }
61 }
62 
63 extern "C"
64 void
66 {
67  // Make sure a thread ID gets assigned ASAP, for debugging purposes:
68  SDL_ThreadID();
69  return;
70 }
71 
72 extern "C"
75 {
76 #ifdef __WINRT__
77  return GetCurrentThreadId();
78 #else
79  // HACK: Mimick a thread ID, if one isn't otherwise available.
80  static thread_local SDL_threadID current_thread_id = 0;
81  static SDL_threadID next_thread_id = 1;
82  static std::mutex next_thread_id_mutex;
83 
84  if (current_thread_id == 0) {
85  std::lock_guard<std::mutex> lock(next_thread_id_mutex);
86  current_thread_id = next_thread_id;
87  ++next_thread_id;
88  }
89 
90  return current_thread_id;
91 #endif
92 }
93 
94 extern "C"
95 int
97 {
98  // Thread priorities do not look to be settable via C++11's thread
99  // interface, at least as of this writing (Nov 2012). std::thread does
100  // provide access to the OS' native handle, however, and some form of
101  // priority-setting could, in theory, be done through this interface.
102  //
103  // WinRT: UPDATE (Aug 20, 2013): thread priorities cannot be changed
104  // on WinRT, at least not for any thread that's already been created.
105  // WinRT threads appear to be based off of the WinRT class,
106  // ThreadPool, more info on which can be found at:
107  // http://msdn.microsoft.com/en-us/library/windows/apps/windows.system.threading.threadpool.aspx
108  //
109  // For compatibility sake, 0 will be returned here.
110  return (0);
111 }
112 
113 extern "C"
114 void
116 {
117  if ( ! thread) {
118  return;
119  }
120 
121  try {
122  std::thread * cpp_thread = (std::thread *) thread->handle;
123  if (cpp_thread->joinable()) {
124  cpp_thread->join();
125  }
126  } catch (std::system_error &) {
127  // An error occurred when joining the thread. SDL_WaitThread does not,
128  // however, seem to provide a means to report errors to its callers
129  // though!
130  }
131 }
132 
133 extern "C"
134 void
136 {
137  if ( ! thread) {
138  return;
139  }
140 
141  try {
142  std::thread * cpp_thread = (std::thread *) thread->handle;
143  if (cpp_thread->joinable()) {
144  cpp_thread->detach();
145  }
146  } catch (std::system_error &) {
147  // An error occurred when detaching the thread. SDL_DetachThread does not,
148  // however, seem to provide a means to report errors to its callers
149  // though!
150  }
151 }
152 
153 extern "C"
154 SDL_TLSData *
156 {
157  return SDL_Generic_GetTLSData();
158 }
159 
160 extern "C"
161 int
163 {
164  return SDL_Generic_SetTLSData(data);
165 }
166 
167 /* vi: set ts=4 sw=4 expandtab: */
static void RunThread(void *args)
SDL_TLSData * SDL_Generic_GetTLSData()
Definition: SDL_thread.c:123
int SDL_Generic_SetTLSData(SDL_TLSData *storage)
Definition: SDL_thread.c:162
GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * data
Definition: SDL_opengl.h:1967
void SDL_SYS_WaitThread(SDL_Thread *thread)
SDL_threadID SDL_ThreadID(void)
GLuint const GLchar * name
static SDL_mutex * mutex
Definition: testlock.c:23
void SDL_SYS_DetachThread(SDL_Thread *thread)
SDL_TLSData * SDL_SYS_GetTLSData()
int SDL_SYS_SetTLSData(SDL_TLSData *data)
void SDL_SYS_SetupThread(const char *name)
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
SYS_ThreadHandle handle
Definition: SDL_thread_c.h:57
#define SDL_SetError
int SDL_SYS_SetThreadPriority(SDL_ThreadPriority priority)
SDL_mutex * lock
Definition: SDL_events.c:75
SDL_ThreadPriority
Definition: SDL_thread.h:59
int SDL_SYS_CreateThread(SDL_Thread *thread, void *args)
void SDL_RunThread(void *data)
Definition: SDL_thread.c:264
unsigned long SDL_threadID
Definition: SDL_thread.h:49