matthew/The-Powder-Toy
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Condition variable instead of busy wait

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This commit is contained in:
Simon Robertshaw 2011-05-14 13:21:44 +01:00
parent 33eb485c9f
commit d0f236d6b9
1 changed files with 11 additions and 3 deletions
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14
src/main.c
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@ -188,6 +188,7 @@ int numCores = 4;
pthread_t gravthread; pthread_t gravthread;
pthread_mutex_t gravmutex; pthread_mutex_t gravmutex;
pthread_cond_t gravcv;
int grav_ready = 0; int grav_ready = 0;
int gravthread_done = 0; int gravthread_done = 0;
@ -1235,13 +1236,18 @@ void update_grav_async()
update_grav(); update_grav();
done = 1; done = 1;
pthread_mutex_lock(&gravmutex); pthread_mutex_lock(&gravmutex);
grav_ready = done; grav_ready = done;
thread_done = gravthread_done; thread_done = gravthread_done;
pthread_mutex_unlock(&gravmutex); pthread_mutex_unlock(&gravmutex);
} else { } else {
pthread_mutex_lock(&gravmutex); pthread_mutex_lock(&gravmutex);
done = grav_ready; pthread_cond_wait(&gravcv, &gravmutex);
done = grav_ready;
thread_done = gravthread_done; thread_done = gravthread_done;
pthread_mutex_unlock(&gravmutex); pthread_mutex_unlock(&gravmutex);
} }
} }
@ -1255,6 +1261,7 @@ void start_grav_async()
pthread_mutexattr_init(&gma);*/ pthread_mutexattr_init(&gma);*/
gravthread_done = 0; gravthread_done = 0;
pthread_mutex_init (&gravmutex, NULL); pthread_mutex_init (&gravmutex, NULL);
pthread_cond_init(&gravcv, NULL);
pthread_create(&gravthread, NULL, update_grav_async, NULL); //Start asynchronous gravity simulation pthread_create(&gravthread, NULL, update_grav_async, NULL); //Start asynchronous gravity simulation
ngrav_enable = 1; ngrav_enable = 1;
} }
@ -1555,7 +1562,6 @@ int main(int argc, char *argv[])
http_session_check = http_async_req_start(NULL, "http://" SERVER "/Login.api?Action=CheckSession", NULL, 0, 0); http_session_check = http_async_req_start(NULL, "http://" SERVER "/Login.api?Action=CheckSession", NULL, 0, 0);
http_auth_headers(http_session_check, svf_user_id, NULL, svf_session_id); http_auth_headers(http_session_check, svf_user_id, NULL, svf_session_id);
} }
while (!sdl_poll()) //the main loop while (!sdl_poll()) //the main loop
{ {
frameidx++; frameidx++;
@ -1600,8 +1606,10 @@ int main(int argc, char *argv[])
memcpy(th_gravmap, gravmap, sizeof(gravmap)); //Move our current gravmap to be processed other thread memcpy(th_gravmap, gravmap, sizeof(gravmap)); //Move our current gravmap to be processed other thread
memcpy(gravy, th_gravy, sizeof(gravy)); //Hmm, Gravy memcpy(gravy, th_gravy, sizeof(gravy)); //Hmm, Gravy
memcpy(gravx, th_gravx, sizeof(gravx)); //Move the processed velocity maps to be used memcpy(gravx, th_gravx, sizeof(gravx)); //Move the processed velocity maps to be used
if (!sys_pause||framerender) //Only update if not paused if (!sys_pause||framerender){ //Only update if not paused
grav_ready = 0; //Tell the other thread that we're ready for it to continue grav_ready = 0; //Tell the other thread that we're ready for it to continue
pthread_cond_signal(&gravcv);
}
} }
pthread_mutex_unlock(&gravmutex); pthread_mutex_unlock(&gravmutex);
} }