2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2005, Dave Pare, Jeff Bailey, Thomas Ruschak,
4 * Ken Stevens, Steve McClure
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * See the "LEGAL", "LICENSE", "CREDITS" and "README" files for all the
23 * related information and legal notices. It is expected that any future
24 * projects/authors will amend these files as needed.
28 * pthread.c: Interface from Empire threads to POSIX threads
30 * Known contributors to this file:
40 #include <sys/types.h>
47 #include "empthread.h"
48 #include "prototypes.h"
54 #define EMPTH_KILLED 1
57 char *name; /* thread name */
58 char *desc; /* description */
59 void *ud; /* user data */
60 int state; /* my state */
61 void (*ep)(void *); /* entry point */
62 pthread_t id; /* thread id */
66 pthread_mutex_t mtx_update; /* use it to update count */
69 pthread_mutex_t mtx_sem;
70 pthread_cond_t cnd_sem;
73 /* Thread-specific data key */
74 static pthread_key_t ctx_key;
76 /* Flags that were passed to empth_init() */
77 static int empth_flags;
79 /* Pointer to thread context variable */
83 * Non-preemption mutex.
84 * Empire code outside this file is only executed while holding this
85 * mutex. This makes sure Empire code is never preempted by Empire
88 static pthread_mutex_t mtx_ctxsw;
90 static void empth_status(char *format, ...) ATTRIBUTE((format (printf, 1, 2)));
94 empth_start(void *arg)
99 /* actually it should inherit all this from main but... */
100 sigemptyset(&act.sa_mask);
101 act.sa_handler = shutdwn;
102 sigaction(SIGTERM, &act, NULL);
103 sigaction(SIGINT, &act, NULL);
104 act.sa_handler = panic;
105 sigaction(SIGBUS, &act, NULL);
106 sigaction(SIGSEGV, &act, NULL);
107 sigaction(SIGILL, &act, NULL);
108 sigaction(SIGFPE, &act, NULL);
109 act.sa_handler = SIG_IGN;
110 sigaction(SIGPIPE, &act, NULL);
112 act.sa_handler = empth_alarm;
113 sigaction(SIGALRM, &act, NULL);
115 ctx->id = pthread_self();
116 pthread_setspecific(ctx_key, ctx);
117 pthread_mutex_lock(&mtx_ctxsw);
125 empth_status(char *format, ...)
128 static struct timeval startTime;
134 va_start(ap, format);
135 if (empth_flags & EMPTH_PRINT) {
136 if (startTime.tv_sec == 0)
137 gettimeofday(&startTime, 0);
138 gettimeofday(&tv, 0);
139 sec = tv.tv_sec - startTime.tv_sec;
140 msec = (tv.tv_usec - startTime.tv_usec) / 1000;
145 vsprintf(buf, format, ap);
147 printf("%d:%02d.%03d %17s: %s\n", sec / 60, sec % 60, msec / 10,
156 empth_init(void **ctx_ptr, int flags)
159 struct sigaction act;
162 pthread_key_create(&ctx_key, NULL);
163 pthread_mutex_init(&mtx_ctxsw, NULL);
166 sigemptyset(&act.sa_mask);
167 act.sa_handler = empth_alarm;
168 sigaction(SIGALRM, &act, NULL);
171 ctx = malloc(sizeof(empth_t));
173 logerror("pthread init failed: not enough memory");
177 ctx->desc = "empire main";
180 ctx->id = pthread_self();
182 pthread_setspecific(ctx_key, ctx);
183 pthread_mutex_lock(&mtx_ctxsw);
185 logerror("pthreads initialized");
191 * prio can be used for setting scheeduling policy but...
192 * it seems to be optional in POSIX threads and Solaris
193 * for example just ignores it.
194 * More then that priority is not needed even in lwp threads.
197 empth_create(int prio, void (*entry)(void *), int size, int flags,
198 char *name, char *desc, void *ud)
205 empth_status("creating new thread %s:%s", name, desc);
207 ctx = malloc(sizeof(empth_t));
209 logerror("not enough memory to create thread: %s (%s)", name,
213 ctx->name = strdup(name);
214 ctx->desc = strdup(desc);
219 eno = pthread_attr_init(&attr);
221 logerror("can not create thread attribute %s (%s): %s", name, desc,
225 if (size < PTHREAD_STACK_MIN)
226 size = PTHREAD_STACK_MIN + 1;
227 pthread_attr_setstacksize(&attr, size);
228 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
230 eno = pthread_create(&t, &attr, empth_start, ctx);
232 logerror("can not create thread: %s (%s): %s", name, desc,
236 empth_status("new thread id is %ld", (long)t);
240 pthread_attr_destroy(&attr);
247 empth_restorectx(void)
251 ctx_ptr = pthread_getspecific(ctx_key);
252 *udata = ctx_ptr->ud;
253 if (ctx_ptr->state == EMPTH_KILLED) {
254 empth_status("i am dead");
257 empth_status("context restored");
263 return pthread_getspecific(ctx_key);
271 pthread_mutex_unlock(&mtx_ctxsw);
272 empth_status("empth_exit");
273 ctx_ptr = pthread_getspecific(ctx_key);
274 /* We want to leave the main thread around forever, until it's time
275 for it to die for real (in a shutdown) */
276 if (!strcmp(ctx_ptr->name, "Main")) {
289 pthread_mutex_unlock(&mtx_ctxsw);
290 sleep(10); /* take a nap pthread_yield(); */
291 pthread_mutex_lock(&mtx_ctxsw);
296 empth_terminate(empth_t *a)
298 empth_status("killing thread %s", a->name);
299 a->state = EMPTH_KILLED;
300 pthread_kill(a->id, SIGALRM);
304 empth_select(int fd, int flags)
312 pthread_mutex_unlock(&mtx_ctxsw);
313 empth_status("%s select on %d",
314 flags == EMPTH_FD_READ ? "read" : "write", fd);
324 FD_SET(fd, &readmask);
327 FD_SET(fd, &writemask);
330 logerror("bad flag %d passed to empth_select", flags);
334 n = select(fd + 1, &readmask, &writemask, (fd_set *) 0, &tv);
337 if (errno == EINTR) {
338 /* go handle the signal */
339 empth_status("select broken by signal");
343 /* strange but we dont get EINTR on select broken by signal */
344 empth_status("select failed (%s)", strerror(errno));
349 if (flags == EMPTH_FD_READ && FD_ISSET(fd, &readmask)) {
350 empth_status("input ready");
353 if (flags == EMPTH_FD_WRITE && FD_ISSET(fd, &writemask)) {
354 empth_status("output ready");
360 pthread_mutex_lock(&mtx_ctxsw);
369 struct sigaction act;
370 empth_status("got alarm signal");
372 act.sa_flags &= ~SA_RESTART;
374 sigemptyset(&act.sa_mask);
375 act.sa_handler = empth_alarm;
376 sigaction(SIGALRM, &act, NULL);
380 empth_wakeup(empth_t *a)
382 empth_status("waking up thread %s", a->name);
383 pthread_kill(a->id, SIGALRM);
384 empth_status("waiting for it to run");
388 empth_sleep(time_t until)
392 empth_status("going to sleep %ld sec", until - time(0));
393 pthread_mutex_unlock(&mtx_ctxsw);
394 tv.tv_sec = until - time(NULL);
397 select(0, NULL, NULL, NULL, &tv);
398 } while ((tv.tv_sec = until - time(NULL)) > 0);
399 empth_status("sleep done. Waiting for lock");
400 pthread_mutex_lock(&mtx_ctxsw);
406 empth_sem_create(char *name, int cnt)
410 sm = malloc(sizeof(empth_sem_t));
412 logerror("out of memory at %s:%d", __FILE__, __LINE__);
415 strncpy(sm->name, name, sizeof(sm->name) - 1);
417 pthread_mutex_init(&sm->mtx_update, NULL);
418 pthread_mutex_init(&sm->mtx_sem, NULL);
419 pthread_cond_init(&sm->cnd_sem, NULL);
424 empth_sem_signal(empth_sem_t *sm)
426 empth_status("signal on semaphore %s:%d", sm->name, sm->count);
427 pthread_mutex_lock(&sm->mtx_update);
428 if (sm->count++ < 0) {
429 pthread_mutex_unlock(&sm->mtx_update);
430 pthread_mutex_lock(&sm->mtx_sem);
431 pthread_cond_signal(&sm->cnd_sem);
432 pthread_mutex_unlock(&sm->mtx_sem);
434 pthread_mutex_unlock(&sm->mtx_update);
438 empth_sem_wait(empth_sem_t *sm)
440 empth_status("wait on semaphore %s:%d", sm->name, sm->count);
441 pthread_mutex_lock(&sm->mtx_update);
442 if (--sm->count < 0) {
443 pthread_mutex_unlock(&sm->mtx_update);
444 empth_status("blocking");
445 pthread_mutex_unlock(&mtx_ctxsw);
446 pthread_mutex_lock(&sm->mtx_sem);
447 pthread_cond_wait(&sm->cnd_sem, &sm->mtx_sem);
448 empth_status("waking up");
449 pthread_mutex_unlock(&sm->mtx_sem);
450 pthread_mutex_lock(&mtx_ctxsw);
453 pthread_mutex_unlock(&sm->mtx_update);