/*
* Empire - A multi-player, client/server Internet based war game.
- * Copyright (C) 1986-2000, Dave Pare, Jeff Bailey, Thomas Ruschak,
- * Ken Stevens, Steve McClure
+ * Copyright (C) 1986-2021, 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/>.
*
* ---
*
- * See the "LEGAL", "LICENSE", "CREDITS" and "README" files for all the
- * related information and legal notices. It is expected that any future
- * projects/authors will amend these files as needed.
+ * See files README, COPYING and CREDITS in the root of the source
+ * tree for related information and legal notices. It is expected
+ * that future projects/authors will amend these files as needed.
*
* ---
*
* empthread.h: Definitions for Empire threading
- *
+ *
* Known contributors to this file:
* Sasha Mikheev
* Doug Hay, 1998
* Steve McClure, 1998
+ * Markus Armbruster, 2005-2012
+ * Ron Koenderink, 2005-2009
*/
-#ifndef _EMTHREAD_H_
-#define _EMTHREAD_H_
+/*
+ * This header defines Empire's abstract thread interface. There are
+ * several concrete implementations.
+ *
+ * Empire threads are non-preemptive, i.e. they run until they
+ * voluntarily yield the processor. The thread scheduler then picks
+ * one of the runnable threads. The most common form of yielding the
+ * processor is sleeping for some event to happen.
+ */
-#include "misc.h"
+#ifndef EMPTHREAD_H
+#define EMPTHREAD_H
-#if defined(_WIN32)
-#undef _EMPTH_LWP
-#undef _EMPTH_POSIX
-#define _EMPTH_WIN32
-#endif
+#include <sys/time.h>
+#include <time.h>
-#ifdef _EMPTH_LWP
+#ifdef EMPTH_LWP
#include "lwp.h"
+
+/* Abstract data types */
+
+/* A thread. */
typedef struct lwpProc empth_t;
-typedef struct lwpSem empth_sem_t;
+
+/* A read-write lock, perferring writers */
+typedef struct lwp_rwlock empth_rwlock_t;
+
+/* Flags for empth_select(): whether to sleep on input or output */
#define EMPTH_FD_READ LWP_FD_READ
#define EMPTH_FD_WRITE LWP_FD_WRITE
+
+/* Flags for empth_init() and empth_create() */
+/* Request debug prints */
#define EMPTH_PRINT LWP_PRINT
+/* Request stack checking */
#define EMPTH_STACKCHECK LWP_STACKCHECK
-#endif
-#ifdef _EMPTH_POSIX
-#ifdef __linux__
-#define _MIT_POSIX_THREADS 1
-#endif
-#include <pthread.h>
+#endif /* EMPTH_LWP */
+
+#ifdef EMPTH_POSIX
#define EMPTH_FD_READ 0x1
#define EMPTH_FD_WRITE 0x2
#define EMPTH_PRINT 0x1
#define EMPTH_STACKCHECK 0x2
-#define EMPTH_KILLED 1
-typedef struct {
- char *name; /* thread name */
- char *desc; /* description */
- void *ud; /* user data */
- int state; /* my state */
- void (*ep)(void *); /* entry point */
- pthread_t id; /* thread id */
-} empth_t;
-
-typedef struct {
- pthread_mutex_t mtx_update; /* use it to update count */
- int count;
- char name[80];
- pthread_mutex_t mtx_sem;
- pthread_cond_t cnd_sem;
-} empth_sem_t;
-
-#endif
-
-/* DEC has slightly different names for whatever reason... */
-#ifdef _DECTHREADS_
-#define pthread_key_create pthread_keycreate
-#define pthread_attr_init pthread_attr_create
-#define pthread_attr_destroy pthread_attr_delete
-
-#endif
+typedef struct empth_t empth_t;
+typedef struct empth_rwlock_t empth_rwlock_t;
+#endif /* EMPTH_POSIX */
-#if defined(_EMPTH_WIN32)
+#ifdef EMPTH_W32
/* The Windows NT Threads */
#define EMPTH_FD_READ 0x1
#define EMPTH_FD_WRITE 0x2
#define EMPTH_PRINT 0x1
#define EMPTH_STACKCHECK 0x2
-typedef struct loc_Thread_t empth_t;
-typedef struct loc_Sem_t empth_sem_t;
+typedef struct loc_Thread empth_t;
+typedef struct loc_RWLock empth_rwlock_t;
-#endif
+void empth_request_shutdown(void);
+#endif /* EMPTH_W32 */
-int empth_init(char **ctx, int flags);
-empth_t *empth_create(int, void (*)(void *), int, int, char *, char *, void *);
+/*
+ * Initialize thread package.
+ * @ctx points to a thread context variable; see empth_create().
+ * @flags request optional features.
+ * Should return 0 on success, -1 on error, but currently always
+ * returns 0.
+ */
+int empth_init(void **ctx, int flags);
+
+/*
+ * 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.
+ * @ud is the value to pass to @entry. It is also assigned to the
+ * context variable defined with empth_init() whenever the thread gets
+ * scheduled.
+ * Yield the processor.
+ * Return the thread, or NULL on error.
+ */
+empth_t *empth_create(void (*entry)(void *),
+ int size, int flags, char *name, void *ud);
+
+/*
+ * Return the current thread, NULL before empth_init().
+ * This is the only function that may be called before empth_init().
+ */
empth_t *empth_self(void);
+
+/*
+ * Return @thread's name.
+ */
+char *empth_name(empth_t *thread);
+
+/*
+ * Set @thread's name to @name.
+ */
+void empth_set_name(empth_t *thread, char *name);
+
+/*
+ * Terminate the current thread.
+ * The current thread should not be the thread that executed main().
+ * If it is, implementations may terminate the process rather than the
+ * thread.
+ * Never returns.
+ */
void empth_exit(void);
+
+/*
+ * Yield the processor.
+ */
void empth_yield(void);
-void empth_terminate(empth_t *);
-void empth_select(int fd, int flags);
-void empth_wakeup(empth_t *);
-void empth_sleep(long until);
-empth_sem_t *empth_sem_create(char *name, int count);
-void empth_sem_signal(empth_sem_t *);
-void empth_sem_wait(empth_sem_t *);
-void empth_alarm(int);
+/*
+ * 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 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.
+ */
+int empth_select(int fd, int flags, struct timeval *timeout);
+
+/*
+ * Awaken @thread if it is sleeping in empth_select() or empth_sleep().
+ * This does not awaken threads sleeping in other functions.
+ * Does not yield the processor.
+ */
+void empth_wakeup(empth_t *thread);
+
+/*
+ * Put current thread to sleep until the time is @until.
+ * Return 0 if it slept until that time.
+ * Return -1 if woken up early, by empth_wakeup().
+ */
+int empth_sleep(time_t until);
+
+/*
+ * Put current thread to sleep until SIGHUP, SIGINT or SIGTERM is received.
+ * Return the signal number.
+ */
+int empth_wait_for_signal(void);
+
+/*
+ * Create a read-write lock.
+ * @name is its name, it is used for debugging.
+ * Return the read-write lock, or NULL on error.
+ */
+empth_rwlock_t *empth_rwlock_create(char *name);
+
+/*
+ * Destroy @rwlock.
+ */
+void empth_rwlock_destroy(empth_rwlock_t *rwlock);
+
+/*
+ * Lock @rwlock for writing.
+ * A read-write lock can be locked for writing only when it is
+ * unlocked. If this is not the case, put the current thread to sleep
+ * until it is.
+ */
+void empth_rwlock_wrlock(empth_rwlock_t *rwlock);
+
+/*
+ * Lock @rwlock for reading.
+ * A read-write lock can be locked for reading only when it is not
+ * 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);
+
+/*
+ * Unlock read-write lock @rwlock.
+ * The current thread must hold @rwlock.
+ * Wake up threads that can now lock it.
+ */
+void empth_rwlock_unlock(empth_rwlock_t *rwlock);
+
+
+/*
+ * Stuff for implementations, not for clients.
+ */
+
+void empth_init_signals(void);
-#include "prototypes.h" /* must come at end, after defines and typedefs */
#endif
projects / empserver / blobdiff