testlock.c
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/* Test the thread and mutex locking functions
Also exercises the system's signal/thread interaction
*/
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include "SDL.h"
#include "SDL_mutex.h"
#include "SDL_thread.h"
static SDL_mutex *mutex = NULL;
static Uint32 mainthread;
static SDL_Thread *threads[6];
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/*
* SDL_Quit() shouldn't be used with atexit() directly because
* calling conventions may differ...
*/
static void SDL_Quit_Wrapper(void)
{
SDL_Quit();
}
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void printid(void)
{
printf("Process %u: exiting\n", SDL_ThreadID());
}
void terminate(int sig)
{
printf("Process %u: raising SIGTERM\n", SDL_ThreadID());
raise(SIGTERM);
}
void closemutex(int sig)
{
Uint32 id = SDL_ThreadID();
int i;
printf("Process %u: Cleaning up...\n", id == mainthread ? 0 : id);
for ( i=0; i<6; ++i )
SDL_KillThread(threads[i]);
SDL_DestroyMutex(mutex);
exit(sig);
}
int Run(void *data)
{
if ( SDL_ThreadID() == mainthread )
signal(SIGTERM, closemutex);
while ( 1 ) {
printf("Process %u ready to work\n", SDL_ThreadID());
if ( SDL_mutexP(mutex) < 0 ) {
fprintf(stderr, "Couldn't lock mutex: %s", SDL_GetError());
exit(1);
}
printf("Process %u, working!\n", SDL_ThreadID());
SDL_Delay(1*1000);
printf("Process %u, done!\n", SDL_ThreadID());
if ( SDL_mutexV(mutex) < 0 ) {
fprintf(stderr, "Couldn't unlock mutex: %s", SDL_GetError());
exit(1);
}
/* If this sleep isn't done, then threads may starve */
SDL_Delay(10);
}
return(0);
}
int main(int argc, char *argv[])
{
int i;
int maxproc = 6;
/* Load the SDL library */
if ( SDL_Init(0) < 0 ) {
fprintf(stderr, "%s\n", SDL_GetError());
exit(1);
}
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atexit(SDL_Quit_Wrapper);
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if ( (mutex=SDL_CreateMutex()) == NULL ) {
fprintf(stderr, "Couldn't create mutex: %s\n", SDL_GetError());
exit(1);
}
mainthread = SDL_ThreadID();
printf("Main thread: %u\n", mainthread);
atexit(printid);
for ( i=0; i<maxproc; ++i ) {
if ( (threads[i]=SDL_CreateThread(Run, NULL)) == NULL )
fprintf(stderr, "Couldn't create thread!\n");
}
signal(SIGINT, terminate);
Run(NULL);
return(0); /* Never reached */
}