SDL  2.0
SDL_systhread.cpp
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 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  // !!! FIXME: no way to set a thread stack size here.
52  std::thread cpp_thread(RunThread, args);
53  thread->handle = (void *) new std::thread(std::move(cpp_thread));
54  return 0;
55  } catch (std::system_error & ex) {
56  SDL_SetError("unable to start a C++ thread: code=%d; %s", ex.code(), ex.what());
57  return -1;
58  } catch (std::bad_alloc &) {
60  return -1;
61  }
62 }
63 
64 extern "C"
65 void
67 {
68  // Make sure a thread ID gets assigned ASAP, for debugging purposes:
69  SDL_ThreadID();
70  return;
71 }
72 
73 extern "C"
76 {
77 #ifdef __WINRT__
78  return GetCurrentThreadId();
79 #else
80  // HACK: Mimick a thread ID, if one isn't otherwise available.
81  static thread_local SDL_threadID current_thread_id = 0;
82  static SDL_threadID next_thread_id = 1;
83  static std::mutex next_thread_id_mutex;
84 
85  if (current_thread_id == 0) {
86  std::lock_guard<std::mutex> lock(next_thread_id_mutex);
87  current_thread_id = next_thread_id;
88  ++next_thread_id;
89  }
90 
91  return current_thread_id;
92 #endif
93 }
94 
95 extern "C"
96 int
98 {
99  // Thread priorities do not look to be settable via C++11's thread
100  // interface, at least as of this writing (Nov 2012). std::thread does
101  // provide access to the OS' native handle, however, and some form of
102  // priority-setting could, in theory, be done through this interface.
103  //
104  // WinRT: UPDATE (Aug 20, 2013): thread priorities cannot be changed
105  // on WinRT, at least not for any thread that's already been created.
106  // WinRT threads appear to be based off of the WinRT class,
107  // ThreadPool, more info on which can be found at:
108  // http://msdn.microsoft.com/en-us/library/windows/apps/windows.system.threading.threadpool.aspx
109  //
110  // For compatibility sake, 0 will be returned here.
111  return (0);
112 }
113 
114 extern "C"
115 void
117 {
118  if ( ! thread) {
119  return;
120  }
121 
122  try {
123  std::thread * cpp_thread = (std::thread *) thread->handle;
124  if (cpp_thread->joinable()) {
125  cpp_thread->join();
126  }
127  } catch (std::system_error &) {
128  // An error occurred when joining the thread. SDL_WaitThread does not,
129  // however, seem to provide a means to report errors to its callers
130  // though!
131  }
132 }
133 
134 extern "C"
135 void
137 {
138  if ( ! thread) {
139  return;
140  }
141 
142  try {
143  std::thread * cpp_thread = (std::thread *) thread->handle;
144  if (cpp_thread->joinable()) {
145  cpp_thread->detach();
146  }
147  } catch (std::system_error &) {
148  // An error occurred when detaching the thread. SDL_DetachThread does not,
149  // however, seem to provide a means to report errors to its callers
150  // though!
151  }
152 }
153 
154 extern "C"
155 SDL_TLSData *
157 {
158  return SDL_Generic_GetTLSData();
159 }
160 
161 extern "C"
162 int
164 {
165  return SDL_Generic_SetTLSData(data);
166 }
167 
168 /* vi: set ts=4 sw=4 expandtab: */
static void RunThread(void *args)
int SDL_Generic_SetTLSData(SDL_TLSData *storage)
Definition: SDL_thread.c:163
SDL_TLSData * SDL_Generic_GetTLSData(void)
Definition: SDL_thread.c:124
void SDL_SYS_WaitThread(SDL_Thread *thread)
SDL_threadID SDL_ThreadID(void)
GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * data
Definition: SDL_opengl.h:1974
static SDL_mutex * mutex
Definition: testlock.c:23
GLuint const GLchar * name
void SDL_SYS_DetachThread(SDL_Thread *thread)
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:78
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:265
SDL_TLSData * SDL_SYS_GetTLSData(void)
unsigned long SDL_threadID
Definition: SDL_thread.h:49