[sdl_omap.git] / src / thread / beos / SDL_syssem.c

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* Semaphores in the BeOS environment */

#include <be/kernel/OS.h>

#include "SDL_thread.h"


struct SDL_semaphore {
	sem_id id;
};

/* Create a counting semaphore */
SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
{
	SDL_sem *sem;

	sem = (SDL_sem *)SDL_malloc(sizeof(*sem));
	if ( sem ) {
		sem->id = create_sem(initial_value, "SDL semaphore");
		if ( sem->id < B_NO_ERROR ) {
			SDL_SetError("create_sem() failed");
			SDL_free(sem);
			sem = NULL;
		}
	} else {
		SDL_OutOfMemory();
	}
	return(sem);
}

/* Free the semaphore */
void SDL_DestroySemaphore(SDL_sem *sem)
{
	if ( sem ) {
		if ( sem->id >= B_NO_ERROR ) {
			delete_sem(sem->id);
		}
		SDL_free(sem);
	}
}

int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
{
	int32 val;
	int retval;

	if ( ! sem ) {
		SDL_SetError("Passed a NULL semaphore");
		return -1;
	}

  tryagain:
	if ( timeout == SDL_MUTEX_MAXWAIT ) {
		val = acquire_sem(sem->id);
	} else {
		timeout *= 1000; /* BeOS uses a timeout in microseconds */
		val = acquire_sem_etc(sem->id, 1, B_RELATIVE_TIMEOUT, timeout);
	}
	switch (val) {
	    case B_INTERRUPTED:
		goto tryagain;
	    case B_NO_ERROR:
		retval = 0;
		break;
	    case B_TIMED_OUT:
		retval = SDL_MUTEX_TIMEDOUT;
		break;
	    case B_WOULD_BLOCK:
		retval = SDL_MUTEX_TIMEDOUT;
		break;
	    default:
		SDL_SetError("acquire_sem() failed");
		retval = -1;
		break;
	}

	return retval;
}

int SDL_SemTryWait(SDL_sem *sem)
{
	return SDL_SemWaitTimeout(sem, 0);
}

int SDL_SemWait(SDL_sem *sem)
{
	return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
}

/* Returns the current count of the semaphore */
Uint32 SDL_SemValue(SDL_sem *sem)
{
	int32 count;
	Uint32 value;

	value = 0;
	if ( sem ) {
		get_sem_count(sem->id, &count);
		if ( count > 0 ) {
			value = (Uint32)count;
		}
	}
	return value;
}

/* Atomically increases the semaphore's count (not blocking) */
int SDL_SemPost(SDL_sem *sem)
{
	if ( ! sem ) {
		SDL_SetError("Passed a NULL semaphore");
		return -1;
	}

	if ( release_sem(sem->id) != B_NO_ERROR ) {
		SDL_SetError("release_sem() failed");
		return -1;
	}
	return 0;
}
Commit	Line	Data
e14743d1	1	/*
	2	SDL - Simple DirectMedia Layer
	3	Copyright (C) 1997-2009 Sam Lantinga
	4
	5	This library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	This library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with this library; if not, write to the Free Software
	17	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	18
	19	Sam Lantinga
	20	slouken@libsdl.org
	21	*/
	22	#include "SDL_config.h"
	23
	24	/* Semaphores in the BeOS environment */
	25
	26	#include <be/kernel/OS.h>
	27
	28	#include "SDL_thread.h"
	29
	30
	31	struct SDL_semaphore {
	32	sem_id id;
	33	};
	34
	35	/* Create a counting semaphore */
	36	SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
	37	{
	38	SDL_sem *sem;
	39
	40	sem = (SDL_sem )SDL_malloc(sizeof(sem));
	41	if ( sem ) {
	42	sem->id = create_sem(initial_value, "SDL semaphore");
	43	if ( sem->id < B_NO_ERROR ) {
	44	SDL_SetError("create_sem() failed");
	45	SDL_free(sem);
	46	sem = NULL;
	47	}
	48	} else {
	49	SDL_OutOfMemory();
	50	}
	51	return(sem);
	52	}
	53
	54	/* Free the semaphore */
	55	void SDL_DestroySemaphore(SDL_sem *sem)
	56	{
	57	if ( sem ) {
	58	if ( sem->id >= B_NO_ERROR ) {
	59	delete_sem(sem->id);
	60	}
	61	SDL_free(sem);
	62	}
	63	}
	64
65	int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
66	{
67	int32 val;
68	int retval;
69
70	if ( ! sem ) {
71	SDL_SetError("Passed a NULL semaphore");
72	return -1;
73	}
74
75	tryagain:
76	if ( timeout == SDL_MUTEX_MAXWAIT ) {
77	val = acquire_sem(sem->id);
78	} else {
79	timeout = 1000; / BeOS uses a timeout in microseconds */
80	val = acquire_sem_etc(sem->id, 1, B_RELATIVE_TIMEOUT, timeout);
81	}
82	switch (val) {
83	case B_INTERRUPTED:
84	goto tryagain;
85	case B_NO_ERROR:
86	retval = 0;
87	break;
88	case B_TIMED_OUT:
89	retval = SDL_MUTEX_TIMEDOUT;
90	break;
91	case B_WOULD_BLOCK:
92	retval = SDL_MUTEX_TIMEDOUT;
93	break;
94	default:
95	SDL_SetError("acquire_sem() failed");
96	retval = -1;
97	break;
98	}
99
100	return retval;
101	}
102
103	int SDL_SemTryWait(SDL_sem *sem)
104	{
105	return SDL_SemWaitTimeout(sem, 0);
106	}
107
108	int SDL_SemWait(SDL_sem *sem)
109	{
110	return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
111	}
112
113	/* Returns the current count of the semaphore */
114	Uint32 SDL_SemValue(SDL_sem *sem)
115	{
116	int32 count;
117	Uint32 value;
118
119	value = 0;
120	if ( sem ) {
121	get_sem_count(sem->id, &count);
122	if ( count > 0 ) {
123	value = (Uint32)count;
124	}
125	}
126	return value;
127	}
128
129	/* Atomically increases the semaphore's count (not blocking) */
130	int SDL_SemPost(SDL_sem *sem)
131	{
132	if ( ! sem ) {
133	SDL_SetError("Passed a NULL semaphore");
134	return -1;
135	}
136
137	if ( release_sem(sem->id) != B_NO_ERROR ) {
138	SDL_SetError("release_sem() failed");
139	return -1;
140	}
141	return 0;
142	}