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 * empthread.h: Definitions for Empire threading
30 * Known contributors to this file:
37 * This header defines Empire's abstract thread interface. There are
38 * several concrete implementations.
40 * Empire threads are non-preemptive, i.e. they run until they
41 * voluntarily yield the processor. The thread scheduler then picks
42 * one of the runnable threads with the highest priority. Priorities
43 * are static. Empire code relies on these properties heavily. The
44 * most common form of yielding the processor is sleeping for some
62 /* Abstract data types */
64 /* empth_t * represents a thread. */
65 typedef struct lwpProc empth_t;
67 /* empth_sem_t * represents a semaphore */
68 typedef struct lwpSem empth_sem_t;
70 /* Flags for empth_select(): whether to sleep on input or output */
71 #define EMPTH_FD_READ LWP_FD_READ
72 #define EMPTH_FD_WRITE LWP_FD_WRITE
74 /* Flags for empth_init() and empth_create() */
75 /* Request debug prints */
76 #define EMPTH_PRINT LWP_PRINT
77 /* Request stack checking */
78 #define EMPTH_STACKCHECK LWP_STACKCHECK
80 #endif /* _EMPTH_LWP */
84 #define _MIT_POSIX_THREADS 1
87 #define EMPTH_FD_READ 0x1
88 #define EMPTH_FD_WRITE 0x2
90 #define EMPTH_PRINT 0x1
91 #define EMPTH_STACKCHECK 0x2
93 #define EMPTH_KILLED 1
95 char *name; /* thread name */
96 char *desc; /* description */
97 void *ud; /* user data */
98 int state; /* my state */
99 void (*ep)(void *); /* entry point */
100 pthread_t id; /* thread id */
104 pthread_mutex_t mtx_update; /* use it to update count */
107 pthread_mutex_t mtx_sem;
108 pthread_cond_t cnd_sem;
111 #endif /* _EMPTH_POSIX */
113 /* DEC has slightly different names for whatever reason... */
115 #define pthread_key_create pthread_keycreate
116 #define pthread_attr_init pthread_attr_create
117 #define pthread_attr_destroy pthread_attr_delete
122 #if defined(_EMPTH_WIN32)
123 /* The Windows NT Threads */
124 #define EMPTH_FD_READ 0x1
125 #define EMPTH_FD_WRITE 0x2
127 #define EMPTH_PRINT 0x1
128 #define EMPTH_STACKCHECK 0x2
130 typedef struct loc_Thread_t empth_t;
131 typedef struct loc_Sem_t empth_sem_t;
133 void empth_request_shutdown(void);
134 #endif /* _EMPTH_WIN32 */
137 * Initialize thread package.
138 * CTX points to a thread context variable; see empth_create().
139 * FLAGS request optional features.
140 * Should return 0 on success, -1 on error, but currently always
143 int empth_init(void **ctx, int flags);
146 * Create a new thread.
147 * PRIO is the scheduling priority.
148 * ENTRY is the entry point. It will be called with argument UD.
149 * Thread stack is at least SIZE bytes.
150 * FLAGS should be the same as were passed to empth_init(), or zero.
151 * NAME is the threads name, and DESC its description. These are used
152 * for logging and debugging.
153 * UD is the value to pass to ENTRY. It is also assigned to the
154 * context variable defined with empth_init() whenever the thread gets
156 * Return the thread, or NULL on error.
158 empth_t *empth_create(int prio, void (*entry)(void *),
159 int size, int flags, char *name, char *desc, void *ud);
162 * Return the current thread.
164 empth_t *empth_self(void);
167 * Terminate the current thread.
170 void empth_exit(void);
173 * Yield the processor.
175 void empth_yield(void);
179 * THREAD will not be scheduled again. Instead, it will terminate as
180 * if it executed empth_exit(). It is unspecified when exactly that
182 * THREAD must not be the current thread.
184 void empth_terminate(empth_t *thread);
187 * Put current thread to sleep until file descriptor FD is ready for I/O.
188 * If FLAGS & EMPTH_FD_READ, wake up if FD is ready for input.
189 * If FLAGS & EMPTH_FD_WRITE, wake up if FD is ready for output.
190 * Note: Currently, Empire sleeps only on network I/O, i.e. FD is a
191 * socket. Implementations should not rely on that.
193 void empth_select(int fd, int flags);
196 * Awaken THREAD if it is sleeping in empth_select().
197 * Note: This must not awaken threads sleeping in other functions.
199 void empth_wakeup(empth_t *thread);
202 * Put current thread to sleep until the time is UNTIL.
203 * May sleep somehwat longer, but never shorter.
205 void empth_sleep(time_t until);
208 * Create a semaphore.
209 * NAME is its name, it is used for debugging.
210 * COUNT is the initial count value of the semaphore, it must not be
212 * Return the semaphore, or NULL on error.
214 empth_sem_t *empth_sem_create(char *name, int count);
218 * Increase SEM's count. If threads are sleeping on it, wake up
219 * exactly one of them. If that thread has a higher priority, yield
221 * This semaphore operation is often called `down' or `V' otherwhere.
223 void empth_sem_signal(empth_sem_t *sem);
227 * If SEM has a zero count, put current thread to sleep until
228 * empth_sem_signal() awakens it. SEM will have non-zero value then.
229 * Decrement SEM's count.
230 * This semaphore operation is often called `up' or `P' otherwhere.
232 void empth_sem_wait(empth_sem_t *sem);
234 /* Internal function, not part of the thread abstraction */
235 void empth_alarm(int);