2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2006, 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 files README, COPYING and CREDITS in the root of the source
23 * tree for related information and legal notices. It is expected
24 * that future projects/authors will amend these files as needed.
28 * pthread.c: Interface from Empire threads to POSIX threads
30 * Known contributors to this file:
33 * Markus Armbruster, 2005
36 /* Required for PTHREAD_STACK_MIN on some systems, e.g. Solaris: */
37 #define _XOPEN_SOURCE 500
46 #include <sys/types.h>
53 #include "empthread.h"
54 #include "prototypes.h"
58 #define EMPTH_KILLED 1
61 char *name; /* thread name */
62 char *desc; /* description */
63 void *ud; /* user data */
64 int state; /* my state */
65 void (*ep)(void *); /* entry point */
66 pthread_t id; /* thread id */
70 pthread_mutex_t mtx_update; /* use it to update count */
73 pthread_mutex_t mtx_sem;
74 pthread_cond_t cnd_sem;
77 /* Thread-specific data key */
78 static pthread_key_t ctx_key;
80 /* Flags that were passed to empth_init() */
81 static int empth_flags;
83 /* Pointer to thread context variable */
87 * Non-preemption mutex.
88 * Empire code outside this file is only executed while holding this
89 * mutex. This makes sure Empire code is never preempted by Empire
92 static pthread_mutex_t mtx_ctxsw;
94 static void empth_status(char *format, ...)
95 ATTRIBUTE((format (printf, 1, 2)));
96 static void empth_alarm(int sig);
99 empth_start(void *arg)
103 ctx->id = pthread_self();
104 pthread_setspecific(ctx_key, ctx);
105 pthread_mutex_lock(&mtx_ctxsw);
113 empth_status(char *format, ...)
116 static struct timeval startTime;
122 va_start(ap, format);
123 if (empth_flags & EMPTH_PRINT) {
124 if (startTime.tv_sec == 0)
125 gettimeofday(&startTime, 0);
126 gettimeofday(&tv, 0);
127 sec = tv.tv_sec - startTime.tv_sec;
128 msec = (tv.tv_usec - startTime.tv_usec) / 1000;
133 vsprintf(buf, format, ap);
135 printf("%d:%02d.%03d %17s: %s\n", sec / 60, sec % 60, msec / 10,
144 empth_init(void **ctx_ptr, int flags)
147 struct sigaction act;
152 empth_init_signals();
154 sigemptyset(&act.sa_mask);
155 act.sa_handler = empth_alarm;
156 sigaction(SIGALRM, &act, NULL);
158 pthread_key_create(&ctx_key, NULL);
159 pthread_mutex_init(&mtx_ctxsw, NULL);
161 ctx = malloc(sizeof(empth_t));
163 logerror("pthread init failed: not enough memory");
167 ctx->desc = "empire main";
170 ctx->id = pthread_self();
172 pthread_setspecific(ctx_key, ctx);
173 pthread_mutex_lock(&mtx_ctxsw);
174 logerror("pthreads initialized");
180 * prio can be used for setting scheeduling policy but...
181 * it seems to be optional in POSIX threads and Solaris
182 * for example just ignores it.
183 * More then that priority is not needed even in lwp threads.
186 empth_create(int prio, void (*entry)(void *), int size, int flags,
187 char *name, char *desc, void *ud)
194 empth_status("creating new thread %s:%s", name, desc);
196 ctx = malloc(sizeof(empth_t));
198 logerror("not enough memory to create thread: %s (%s)",
202 ctx->name = strdup(name);
203 ctx->desc = strdup(desc);
208 eno = pthread_attr_init(&attr);
210 logerror("can not create thread attribute %s (%s): %s",
211 name, desc, strerror(eno));
214 if (size < PTHREAD_STACK_MIN)
215 size = PTHREAD_STACK_MIN;
216 pthread_attr_setstacksize(&attr, size);
217 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
219 eno = pthread_create(&t, &attr, empth_start, ctx);
221 logerror("can not create thread: %s (%s): %s",
222 name, desc, strerror(eno));
225 empth_status("new thread id is %ld", (long)t);
230 pthread_attr_destroy(&attr);
237 empth_restorectx(void)
241 ctx_ptr = pthread_getspecific(ctx_key);
242 *udata = ctx_ptr->ud;
243 if (ctx_ptr->state == EMPTH_KILLED) {
244 empth_status("i am dead");
247 empth_status("context restored");
253 return pthread_getspecific(ctx_key);
261 pthread_mutex_unlock(&mtx_ctxsw);
262 empth_status("empth_exit");
263 ctx_ptr = pthread_getspecific(ctx_key);
264 /* We want to leave the main thread around forever, until it's time
265 for it to die for real (in a shutdown) */
266 if (!strcmp(ctx_ptr->name, "Main")) {
279 pthread_mutex_unlock(&mtx_ctxsw);
280 pthread_mutex_lock(&mtx_ctxsw);
285 empth_terminate(empth_t *a)
287 empth_status("killing thread %s", a->name);
288 a->state = EMPTH_KILLED;
289 pthread_kill(a->id, SIGALRM);
293 empth_select(int fd, int flags)
301 pthread_mutex_unlock(&mtx_ctxsw);
302 empth_status("%s select on %d",
303 flags == EMPTH_FD_READ ? "read" : "write", fd);
313 FD_SET(fd, &readmask);
316 FD_SET(fd, &writemask);
319 logerror("bad flag %d passed to empth_select", flags);
323 n = select(fd + 1, &readmask, &writemask, (fd_set *) 0, &tv);
326 if (errno == EINTR) {
327 /* go handle the signal */
328 empth_status("select broken by signal");
332 /* strange but we dont get EINTR on select broken by signal */
333 empth_status("select failed (%s)", strerror(errno));
338 if (flags == EMPTH_FD_READ && FD_ISSET(fd, &readmask)) {
339 empth_status("input ready");
342 if (flags == EMPTH_FD_WRITE && FD_ISSET(fd, &writemask)) {
343 empth_status("output ready");
349 pthread_mutex_lock(&mtx_ctxsw);
359 * Nothing to do --- we handle this signal just to let
360 * empth_wakeup() interrupt system calls.
362 empth_status("got alarm signal");
366 empth_wakeup(empth_t *a)
368 empth_status("waking up thread %s", a->name);
369 pthread_kill(a->id, SIGALRM);
373 empth_sleep(time_t until)
377 empth_status("going to sleep %ld sec", until - time(0));
378 pthread_mutex_unlock(&mtx_ctxsw);
379 tv.tv_sec = until - time(NULL);
382 select(0, NULL, NULL, NULL, &tv);
383 } while ((tv.tv_sec = until - time(NULL)) > 0);
384 empth_status("sleep done. Waiting for lock");
385 pthread_mutex_lock(&mtx_ctxsw);
391 empth_sem_create(char *name, int cnt)
395 sm = malloc(sizeof(empth_sem_t));
397 logerror("out of memory at %s:%d", __FILE__, __LINE__);
400 strncpy(sm->name, name, sizeof(sm->name) - 1);
402 pthread_mutex_init(&sm->mtx_update, NULL);
403 pthread_mutex_init(&sm->mtx_sem, NULL);
404 pthread_cond_init(&sm->cnd_sem, NULL);
409 empth_sem_signal(empth_sem_t *sm)
411 empth_status("signal on semaphore %s:%d", sm->name, sm->count);
412 pthread_mutex_lock(&sm->mtx_update);
413 if (sm->count++ < 0) {
414 pthread_mutex_unlock(&sm->mtx_update);
415 pthread_mutex_lock(&sm->mtx_sem);
416 pthread_cond_signal(&sm->cnd_sem);
417 pthread_mutex_unlock(&sm->mtx_sem);
419 pthread_mutex_unlock(&sm->mtx_update);
423 empth_sem_wait(empth_sem_t *sm)
425 empth_status("wait on semaphore %s:%d", sm->name, sm->count);
426 pthread_mutex_lock(&sm->mtx_update);
427 if (--sm->count < 0) {
428 pthread_mutex_unlock(&sm->mtx_update);
429 empth_status("blocking");
430 pthread_mutex_unlock(&mtx_ctxsw);
431 pthread_mutex_lock(&sm->mtx_sem);
432 pthread_cond_wait(&sm->cnd_sem, &sm->mtx_sem);
433 empth_status("waking up");
434 pthread_mutex_unlock(&sm->mtx_sem);
435 pthread_mutex_lock(&mtx_ctxsw);
438 pthread_mutex_unlock(&sm->mtx_update);