/*
* Empire - A multi-player, client/server Internet based war game.
- * Copyright (C) 1986-2009, Dave Pare, Jeff Bailey, Thomas Ruschak,
- * Ken Stevens, Steve McClure
+ * Copyright (C) 1986-2011, Dave Pare, Jeff Bailey, Thomas Ruschak,
+ * Ken Stevens, Steve McClure, Markus Armbruster
*
- * This program is free software; you can redistribute it and/or modify
+ * Empire is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* ---
*
* Sasha Mikheev
* Doug Hay, 1998
* Steve McClure, 1998
- * Markus Armbruster, 2005-2008
+ * Markus Armbruster, 2005-2009
* Ron Koenderink, 2005-2009
*/
/* Abstract data types */
-/* empth_t * represents a thread. */
+/* A thread. */
typedef struct lwpProc empth_t;
-/* empth_rwlock_t * represents a read-write lock */
+/* A read-write lock, perferring writers */
typedef struct lwp_rwlock empth_rwlock_t;
/* Flags for empth_select(): whether to sleep on input or output */
/*
* Create a new thread.
* ENTRY is the entry point. It will be called with argument UD.
+ * If it returns, the thread terminates as if it called empth_exit().
* Thread stack is at least SIZE bytes.
* FLAGS should be the same as were passed to empth_init(), or zero.
* NAME is the thread's name, it is used for logging and debugging.
*/
void empth_yield(void);
-/*
- * Terminate THREAD.
- * THREAD will not be scheduled again. Instead, it will terminate as
- * if it executed empth_exit(). It is unspecified when exactly that
- * happens.
- * THREAD must not be the current thread.
- * Naive use of this function almost always leads to resource leaks.
- * Terminating a thread that may hold locks is not a good idea.
- */
-void empth_terminate(empth_t *thread);
-
/*
* Put current thread to sleep until file descriptor FD is ready for I/O.
* If FLAGS & EMPTH_FD_READ, wake up if FD is ready for input.
* If FLAGS & EMPTH_FD_WRITE, wake up if FD is ready for output.
* At most one thread may sleep on the same file descriptor.
* TIMEOUT, if non-null, limits the sleep time.
- * Return one when the FD is ready, zero on timeout, -1 on error with
- * errno set.
+ * Return one when the FD is ready, zero on timeout or early wakeup by
+ * empth_wakeup(), -1 on error with errno set.
* Note: Currently, Empire sleeps only on network I/O, i.e. FD is a
* socket. Implementations should not rely on that.
*/
/*
* Awaken THREAD if it is sleeping in empth_select() or empth_sleep().
- * Note: This must not awaken threads sleeping in other functions.
+ * This does not awaken threads sleeping in other functions.
* Does not yield the processor.
*/
void empth_wakeup(empth_t *thread);
/*
* Create a read-write lock.
* NAME is its name, it is used for debugging.
- * Return the reade-write lock, or NULL on error.
+ * Return the read-write lock, or NULL on error.
*/
empth_rwlock_t *empth_rwlock_create(char *name);
/*
* Lock RWLOCK for reading.
* A read-write lock can be locked for reading only when it is not
- * locked for writing. If this is not the case, put the current
- * thread to sleep until it is. Must not starve writers, and may
- * sleep to avoid that.
+ * locked for writing, and no other thread is attempting to lock it
+ * for writing. If this is not the case, put the current thread to
+ * sleep until it is.
*/
void empth_rwlock_rdlock(empth_rwlock_t *rwlock);