src/thread/stdcpp/SDL_systhread.cpp
author Sam Lantinga <slouken@libsdl.org>
Thu, 13 Mar 2014 00:40:08 -0700
changeset 8615 097646deaef2
parent 8600 092802455aed
child 9619 b94b6d0bff0f
permissions -rw-r--r--
Fixed the copyright date on files contributed by David Ludwig
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2014 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 &) {
    58         SDL_OutOfMemory();
    59         return -1;
    60     }
    61 }
    62 
    63 extern "C"
    64 void
    65 SDL_SYS_SetupThread(const char *name)
    66 {
    67     // Make sure a thread ID gets assigned ASAP, for debugging purposes:
    68     SDL_ThreadID();
    69     return;
    70 }
    71 
    72 extern "C"
    73 SDL_threadID
    74 SDL_ThreadID(void)
    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
    96 SDL_SYS_SetThreadPriority(SDL_ThreadPriority priority)
    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
   115 SDL_SYS_WaitThread(SDL_Thread * thread)
   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
   135 SDL_SYS_DetachThread(SDL_Thread * thread)
   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 *
   155 SDL_SYS_GetTLSData()
   156 {
   157     return SDL_Generic_GetTLSData();
   158 }
   159 
   160 extern "C"
   161 int
   162 SDL_SYS_SetTLSData(SDL_TLSData *data)
   163 {
   164     return SDL_Generic_SetTLSData(data);
   165 }
   166 
   167 /* vi: set ts=4 sw=4 expandtab: */