SDL  2.0
SDL_systhread.c
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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 
22 #include "../../SDL_internal.h"
23 
24 #include <pthread.h>
25 
26 #if HAVE_PTHREAD_NP_H
27 #include <pthread_np.h>
28 #endif
29 
30 #include <signal.h>
31 
32 #ifdef __LINUX__
33 #include <sys/time.h>
34 #include <sys/resource.h>
35 #include <sys/syscall.h>
36 #include <unistd.h>
37 #endif /* __LINUX__ */
38 
39 #if defined(__LINUX__) || defined(__MACOSX__) || defined(__IPHONEOS__)
40 #include <dlfcn.h>
41 #ifndef RTLD_DEFAULT
42 #define RTLD_DEFAULT NULL
43 #endif
44 #endif
45 
46 #include "SDL_platform.h"
47 #include "SDL_thread.h"
48 #include "../SDL_thread_c.h"
49 #include "../SDL_systhread.h"
50 #ifdef __ANDROID__
51 #include "../../core/android/SDL_android.h"
52 #endif
53 
54 #ifdef __HAIKU__
55 #include <kernel/OS.h>
56 #endif
57 
58 #include "SDL_assert.h"
59 
60 #ifndef __NACL__
61 /* List of signals to mask in the subthreads */
62 static const int sig_list[] = {
63  SIGHUP, SIGINT, SIGQUIT, SIGPIPE, SIGALRM, SIGTERM, SIGCHLD, SIGWINCH,
64  SIGVTALRM, SIGPROF, 0
65 };
66 #endif
67 
68 static void *
70 {
71 #ifdef __ANDROID__
73 #endif
74  SDL_RunThread(data);
75  return NULL;
76 }
77 
78 #if defined(__MACOSX__) || defined(__IPHONEOS__)
79 static SDL_bool checked_setname = SDL_FALSE;
80 static int (*ppthread_setname_np)(const char*) = NULL;
81 #elif defined(__LINUX__)
82 static SDL_bool checked_setname = SDL_FALSE;
83 static int (*ppthread_setname_np)(pthread_t, const char*) = NULL;
84 #endif
85 int
86 SDL_SYS_CreateThread(SDL_Thread * thread, void *args)
87 {
88  pthread_attr_t type;
89 
90  /* do this here before any threads exist, so there's no race condition. */
91  #if defined(__MACOSX__) || defined(__IPHONEOS__) || defined(__LINUX__)
92  if (!checked_setname) {
93  void *fn = dlsym(RTLD_DEFAULT, "pthread_setname_np");
94  #if defined(__MACOSX__) || defined(__IPHONEOS__)
95  ppthread_setname_np = (int(*)(const char*)) fn;
96  #elif defined(__LINUX__)
97  ppthread_setname_np = (int(*)(pthread_t, const char*)) fn;
98  #endif
99  checked_setname = SDL_TRUE;
100  }
101  #endif
102 
103  /* Set the thread attributes */
104  if (pthread_attr_init(&type) != 0) {
105  return SDL_SetError("Couldn't initialize pthread attributes");
106  }
107  pthread_attr_setdetachstate(&type, PTHREAD_CREATE_JOINABLE);
108 
109  /* Set caller-requested stack size. Otherwise: use the system default. */
110  if (thread->stacksize) {
111  pthread_attr_setstacksize(&type, (size_t) thread->stacksize);
112  }
113 
114  /* Create the thread and go! */
115  if (pthread_create(&thread->handle, &type, RunThread, args) != 0) {
116  return SDL_SetError("Not enough resources to create thread");
117  }
118 
119  return 0;
120 }
121 
122 void
124 {
125 #if !defined(__NACL__)
126  int i;
127  sigset_t mask;
128 #endif /* !__NACL__ */
129 
130  if (name != NULL) {
131  #if defined(__MACOSX__) || defined(__IPHONEOS__) || defined(__LINUX__)
132  SDL_assert(checked_setname);
133  if (ppthread_setname_np != NULL) {
134  #if defined(__MACOSX__) || defined(__IPHONEOS__)
135  ppthread_setname_np(name);
136  #elif defined(__LINUX__)
137  ppthread_setname_np(pthread_self(), name);
138  #endif
139  }
140  #elif HAVE_PTHREAD_SETNAME_NP
141  #if defined(__NETBSD__)
142  pthread_setname_np(pthread_self(), "%s", name);
143  #else
144  pthread_setname_np(pthread_self(), name);
145  #endif
146  #elif HAVE_PTHREAD_SET_NAME_NP
147  pthread_set_name_np(pthread_self(), name);
148  #elif defined(__HAIKU__)
149  /* The docs say the thread name can't be longer than B_OS_NAME_LENGTH. */
150  char namebuf[B_OS_NAME_LENGTH];
151  SDL_snprintf(namebuf, sizeof (namebuf), "%s", name);
152  namebuf[sizeof (namebuf) - 1] = '\0';
153  rename_thread(find_thread(NULL), namebuf);
154  #endif
155  }
156 
157  /* NativeClient does not yet support signals.*/
158 #if !defined(__NACL__)
159  /* Mask asynchronous signals for this thread */
160  sigemptyset(&mask);
161  for (i = 0; sig_list[i]; ++i) {
162  sigaddset(&mask, sig_list[i]);
163  }
164  pthread_sigmask(SIG_BLOCK, &mask, 0);
165 #endif /* !__NACL__ */
166 
167 
168 #ifdef PTHREAD_CANCEL_ASYNCHRONOUS
169  /* Allow ourselves to be asynchronously cancelled */
170  {
171  int oldstate;
172  pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldstate);
173  }
174 #endif
175 }
176 
179 {
180  return ((SDL_threadID) pthread_self());
181 }
182 
183 int
185 {
186 #if __NACL__
187  /* FIXME: Setting thread priority does not seem to be supported in NACL */
188  return 0;
189 #elif __LINUX__
190  int value;
191 
192  if (priority == SDL_THREAD_PRIORITY_LOW) {
193  value = 19;
194  } else if (priority == SDL_THREAD_PRIORITY_HIGH) {
195  value = -20;
196  } else {
197  value = 0;
198  }
199  if (setpriority(PRIO_PROCESS, syscall(SYS_gettid), value) < 0) {
200  /* Note that this fails if you're trying to set high priority
201  and you don't have root permission. BUT DON'T RUN AS ROOT!
202 
203  You can grant the ability to increase thread priority by
204  running the following command on your application binary:
205  sudo setcap 'cap_sys_nice=eip' <application>
206  */
207  return SDL_SetError("setpriority() failed");
208  }
209  return 0;
210 #else
211  struct sched_param sched;
212  int policy;
213  pthread_t thread = pthread_self();
214 
215  if (pthread_getschedparam(thread, &policy, &sched) != 0) {
216  return SDL_SetError("pthread_getschedparam() failed");
217  }
218  if (priority == SDL_THREAD_PRIORITY_LOW) {
219  sched.sched_priority = sched_get_priority_min(policy);
220  } else if (priority == SDL_THREAD_PRIORITY_HIGH) {
221  sched.sched_priority = sched_get_priority_max(policy);
222  } else {
223  int min_priority = sched_get_priority_min(policy);
224  int max_priority = sched_get_priority_max(policy);
225  sched.sched_priority = (min_priority + (max_priority - min_priority) / 2);
226  }
227  if (pthread_setschedparam(thread, policy, &sched) != 0) {
228  return SDL_SetError("pthread_setschedparam() failed");
229  }
230  return 0;
231 #endif /* linux */
232 }
233 
234 void
236 {
237  pthread_join(thread->handle, 0);
238 }
239 
240 void
242 {
243  pthread_detach(thread->handle);
244 }
245 
246 /* vi: set ts=4 sw=4 expandtab: */
EGLint policy
Definition: eglext.h:593
static void * RunThread(void *data)
Definition: SDL_systhread.c:69
GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * data
Definition: SDL_opengl.h:1974
GLuint const GLchar * name
int Android_JNI_SetupThread(void)
SDL_threadID SDL_ThreadID(void)
Definition: SDL_systhread.c:48
void SDL_SYS_WaitThread(SDL_Thread *thread)
Definition: SDL_systhread.c:60
GLenum GLint GLuint mask
int SDL_SYS_SetThreadPriority(SDL_ThreadPriority priority)
Definition: SDL_systhread.c:54
GLsizei const GLfloat * value
void SDL_SYS_DetachThread(SDL_Thread *thread)
Definition: SDL_systhread.c:66
static const int sig_list[]
Definition: SDL_systhread.c:62
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:50
#define SDL_assert(condition)
Definition: SDL_assert.h:169
#define NULL
Definition: begin_code.h:164
SDL_bool
Definition: SDL_stdinc.h:139
SYS_ThreadHandle handle
Definition: SDL_thread_c.h:57
#define SDL_SetError
SDL_ThreadPriority
Definition: SDL_thread.h:59
void SDL_RunThread(void *data)
Definition: SDL_thread.c:265
void SDL_SYS_SetupThread(const char *name)
Definition: SDL_systhread.c:42
GLuint GLuint GLsizei GLenum type
Definition: SDL_opengl.h:1571
#define SDL_snprintf
int SDL_SYS_CreateThread(SDL_Thread *thread, void *args)
Definition: SDL_systhread.c:35
size_t stacksize
Definition: SDL_thread_c.h:62
unsigned long SDL_threadID
Definition: SDL_thread.h:49