[qemu.git] / ui / vnc-jobs.c

/*
 * QEMU VNC display driver
 *
 * Copyright (C) 2006 Anthony Liguori <[email protected]>
 * Copyright (C) 2006 Fabrice Bellard
 * Copyright (C) 2009 Red Hat, Inc
 * Copyright (C) 2010 Corentin Chary <[email protected]>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */


#include "vnc.h"
#include "vnc-jobs.h"
#include "qemu/sockets.h"
#include "block/aio.h"

/*
 * Locking:
 *
 * There are three levels of locking:
 * - jobs queue lock: for each operation on the queue (push, pop, isEmpty?)
 * - VncDisplay global lock: mainly used for framebuffer updates to avoid
 *                      screen corruption if the framebuffer is updated
 *                      while the worker is doing something.
 * - VncState::output lock: used to make sure the output buffer is not corrupted
 *                          if two threads try to write on it at the same time
 *
 * While the VNC worker thread is working, the VncDisplay global lock is held
 * to avoid screen corruption (this does not block vnc_refresh() because it
 * uses trylock()) but the output lock is not held because the thread works on
 * its own output buffer.
 * When the encoding job is done, the worker thread will hold the output lock
 * and copy its output buffer in vs->output.
 */

struct VncJobQueue {
    QemuCond cond;
    QemuMutex mutex;
    QemuThread thread;
    Buffer buffer;
    bool exit;
    QTAILQ_HEAD(, VncJob) jobs;
};

typedef struct VncJobQueue VncJobQueue;

/*
 * We use a single global queue, but most of the functions are
 * already reentrant, so we can easily add more than one encoding thread
 */
static VncJobQueue *queue;

static void vnc_lock_queue(VncJobQueue *queue)
{
    qemu_mutex_lock(&queue->mutex);
}

static void vnc_unlock_queue(VncJobQueue *queue)
{
    qemu_mutex_unlock(&queue->mutex);
}

VncJob *vnc_job_new(VncState *vs)
{
    VncJob *job = g_malloc0(sizeof(VncJob));

    job->vs = vs;
    vnc_lock_queue(queue);
    QLIST_INIT(&job->rectangles);
    vnc_unlock_queue(queue);
    return job;
}

int vnc_job_add_rect(VncJob *job, int x, int y, int w, int h)
{
    VncRectEntry *entry = g_malloc0(sizeof(VncRectEntry));

    entry->rect.x = x;
    entry->rect.y = y;
    entry->rect.w = w;
    entry->rect.h = h;

    vnc_lock_queue(queue);
    QLIST_INSERT_HEAD(&job->rectangles, entry, next);
    vnc_unlock_queue(queue);
    return 1;
}

void vnc_job_push(VncJob *job)
{
    vnc_lock_queue(queue);
    if (queue->exit || QLIST_EMPTY(&job->rectangles)) {
        g_free(job);
    } else {
        QTAILQ_INSERT_TAIL(&queue->jobs, job, next);
        qemu_cond_broadcast(&queue->cond);
    }
    vnc_unlock_queue(queue);
}

static bool vnc_has_job_locked(VncState *vs)
{
    VncJob *job;

    QTAILQ_FOREACH(job, &queue->jobs, next) {
        if (job->vs == vs || !vs) {
            return true;
        }
    }
    return false;
}

bool vnc_has_job(VncState *vs)
{
    bool ret;

    vnc_lock_queue(queue);
    ret = vnc_has_job_locked(vs);
    vnc_unlock_queue(queue);
    return ret;
}

void vnc_jobs_clear(VncState *vs)
{
    VncJob *job, *tmp;

    vnc_lock_queue(queue);
    QTAILQ_FOREACH_SAFE(job, &queue->jobs, next, tmp) {
        if (job->vs == vs || !vs) {
            QTAILQ_REMOVE(&queue->jobs, job, next);
        }
    }
    vnc_unlock_queue(queue);
}

void vnc_jobs_join(VncState *vs)
{
    vnc_lock_queue(queue);
    while (vnc_has_job_locked(vs)) {
        qemu_cond_wait(&queue->cond, &queue->mutex);
    }
    vnc_unlock_queue(queue);
    vnc_jobs_consume_buffer(vs);
}

void vnc_jobs_consume_buffer(VncState *vs)
{
    bool flush;

    vnc_lock_output(vs);
    if (vs->jobs_buffer.offset) {
        vnc_write(vs, vs->jobs_buffer.buffer, vs->jobs_buffer.offset);
        buffer_reset(&vs->jobs_buffer);
    }
    flush = vs->csock != -1 && vs->abort != true;
    vnc_unlock_output(vs);

    if (flush) {
      vnc_flush(vs);
    }
}

/*
 * Copy data for local use
 */
static void vnc_async_encoding_start(VncState *orig, VncState *local)
{
    local->vnc_encoding = orig->vnc_encoding;
    local->features = orig->features;
    local->vd = orig->vd;
    local->lossy_rect = orig->lossy_rect;
    local->write_pixels = orig->write_pixels;
    local->client_pf = orig->client_pf;
    local->client_be = orig->client_be;
    local->tight = orig->tight;
    local->zlib = orig->zlib;
    local->hextile = orig->hextile;
    local->zrle = orig->zrle;
    local->output =  queue->buffer;
    local->csock = -1; /* Don't do any network work on this thread */

    buffer_reset(&local->output);
}

static void vnc_async_encoding_end(VncState *orig, VncState *local)
{
    orig->tight = local->tight;
    orig->zlib = local->zlib;
    orig->hextile = local->hextile;
    orig->zrle = local->zrle;
    orig->lossy_rect = local->lossy_rect;

    queue->buffer = local->output;
}

static int vnc_worker_thread_loop(VncJobQueue *queue)
{
    VncJob *job;
    VncRectEntry *entry, *tmp;
    VncState vs;
    int n_rectangles;
    int saved_offset;

    vnc_lock_queue(queue);
    while (QTAILQ_EMPTY(&queue->jobs) && !queue->exit) {
        qemu_cond_wait(&queue->cond, &queue->mutex);
    }
    /* Here job can only be NULL if queue->exit is true */
    job = QTAILQ_FIRST(&queue->jobs);
    vnc_unlock_queue(queue);

    if (queue->exit) {
        return -1;
    }

    vnc_lock_output(job->vs);
    if (job->vs->csock == -1 || job->vs->abort == true) {
        vnc_unlock_output(job->vs);
        goto disconnected;
    }
    vnc_unlock_output(job->vs);

    /* Make a local copy of vs and switch output buffers */
    vnc_async_encoding_start(job->vs, &vs);

    /* Start sending rectangles */
    n_rectangles = 0;
    vnc_write_u8(&vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
    vnc_write_u8(&vs, 0);
    saved_offset = vs.output.offset;
    vnc_write_u16(&vs, 0);

    vnc_lock_display(job->vs->vd);
    QLIST_FOREACH_SAFE(entry, &job->rectangles, next, tmp) {
        int n;

        if (job->vs->csock == -1) {
            vnc_unlock_display(job->vs->vd);
            /* Copy persistent encoding data */
            vnc_async_encoding_end(job->vs, &vs);
            goto disconnected;
        }

        n = vnc_send_framebuffer_update(&vs, entry->rect.x, entry->rect.y,
                                        entry->rect.w, entry->rect.h);

        if (n >= 0) {
            n_rectangles += n;
        }
        g_free(entry);
    }
    vnc_unlock_display(job->vs->vd);

    /* Put n_rectangles at the beginning of the message */
    vs.output.buffer[saved_offset] = (n_rectangles >> 8) & 0xFF;
    vs.output.buffer[saved_offset + 1] = n_rectangles & 0xFF;

    vnc_lock_output(job->vs);
    if (job->vs->csock != -1) {
        buffer_reserve(&job->vs->jobs_buffer, vs.output.offset);
        buffer_append(&job->vs->jobs_buffer, vs.output.buffer,
                      vs.output.offset);
        /* Copy persistent encoding data */
        vnc_async_encoding_end(job->vs, &vs);

	qemu_bh_schedule(job->vs->bh);
    }  else {
        /* Copy persistent encoding data */
        vnc_async_encoding_end(job->vs, &vs);
    }
    vnc_unlock_output(job->vs);

disconnected:
    vnc_lock_queue(queue);
    QTAILQ_REMOVE(&queue->jobs, job, next);
    vnc_unlock_queue(queue);
    qemu_cond_broadcast(&queue->cond);
    g_free(job);
    return 0;
}

static VncJobQueue *vnc_queue_init(void)
{
    VncJobQueue *queue = g_malloc0(sizeof(VncJobQueue));

    qemu_cond_init(&queue->cond);
    qemu_mutex_init(&queue->mutex);
    QTAILQ_INIT(&queue->jobs);
    return queue;
}

static void vnc_queue_clear(VncJobQueue *q)
{
    qemu_cond_destroy(&queue->cond);
    qemu_mutex_destroy(&queue->mutex);
    buffer_free(&queue->buffer);
    g_free(q);
    queue = NULL; /* Unset global queue */
}

static void *vnc_worker_thread(void *arg)
{
    VncJobQueue *queue = arg;

    qemu_thread_get_self(&queue->thread);

    while (!vnc_worker_thread_loop(queue)) ;
    vnc_queue_clear(queue);
    return NULL;
}

static bool vnc_worker_thread_running(void)
{
    return queue; /* Check global queue */
}

void vnc_start_worker_thread(void)
{
    VncJobQueue *q;

    if (vnc_worker_thread_running())
        return ;

    q = vnc_queue_init();
    qemu_thread_create(&q->thread, "vnc_worker", vnc_worker_thread, q,
                       QEMU_THREAD_DETACHED);
    queue = q; /* Set global queue */
}
Commit	Line	Data
bd023f95 CC	1	/*
	2	* QEMU VNC display driver
	3	*
	4	* Copyright (C) 2006 Anthony Liguori <[email protected]>
	5	* Copyright (C) 2006 Fabrice Bellard
	6	* Copyright (C) 2009 Red Hat, Inc
	7	* Copyright (C) 2010 Corentin Chary <[email protected]>
	8	*
	9	* Permission is hereby granted, free of charge, to any person obtaining a copy
	10	* of this software and associated documentation files (the "Software"), to deal
	11	* in the Software without restriction, including without limitation the rights
	12	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	13	* copies of the Software, and to permit persons to whom the Software is
	14	* furnished to do so, subject to the following conditions:
	15	*
	16	* The above copyright notice and this permission notice shall be included in
	17	* all copies or substantial portions of the Software.
	18	*
	19	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	20	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	21	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	22	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	23	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	24	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	25	* THE SOFTWARE.
	26	*/
	27
	28
	29	#include "vnc.h"
	30	#include "vnc-jobs.h"
1de7afc9	31	#include "qemu/sockets.h"
a0b1a66e	32	#include "block/aio.h"
bd023f95 CC	33
	34	/*
	35	* Locking:
	36	*
11f66978	37	* There are three levels of locking:
bd023f95 CC	38	* - jobs queue lock: for each operation on the queue (push, pop, isEmpty?)
	39	* - VncDisplay global lock: mainly used for framebuffer updates to avoid
	40	* screen corruption if the framebuffer is updated
11f66978	41	* while the worker is doing something.
bd023f95	42	* - VncState::output lock: used to make sure the output buffer is not corrupted
11f66978	43	* if two threads try to write on it at the same time
bd023f95	44	*
11f66978 PM	45	* While the VNC worker thread is working, the VncDisplay global lock is held
	46	* to avoid screen corruption (this does not block vnc_refresh() because it
	47	* uses trylock()) but the output lock is not held because the thread works on
bd023f95 CC	48	* its own output buffer.
	49	* When the encoding job is done, the worker thread will hold the output lock
	50	* and copy its output buffer in vs->output.
11f66978	51	*/
bd023f95 CC	52
	53	struct VncJobQueue {
	54	QemuCond cond;
	55	QemuMutex mutex;
	56	QemuThread thread;
	57	Buffer buffer;
	58	bool exit;
	59	QTAILQ_HEAD(, VncJob) jobs;
	60	};
	61
	62	typedef struct VncJobQueue VncJobQueue;
	63
	64	/*
	65	* We use a single global queue, but most of the functions are
11f66978	66	* already reentrant, so we can easily add more than one encoding thread
bd023f95 CC	67	*/
	68	static VncJobQueue *queue;
	69
	70	static void vnc_lock_queue(VncJobQueue *queue)
	71	{
	72	qemu_mutex_lock(&queue->mutex);
	73	}
	74
	75	static void vnc_unlock_queue(VncJobQueue *queue)
	76	{
	77	qemu_mutex_unlock(&queue->mutex);
	78	}
	79
	80	VncJob vnc_job_new(VncState vs)
	81	{
7267c094	82	VncJob *job = g_malloc0(sizeof(VncJob));
bd023f95 CC	83
	84	job->vs = vs;
	85	vnc_lock_queue(queue);
	86	QLIST_INIT(&job->rectangles);
	87	vnc_unlock_queue(queue);
	88	return job;
	89	}
	90
	91	int vnc_job_add_rect(VncJob *job, int x, int y, int w, int h)
	92	{
7267c094	93	VncRectEntry *entry = g_malloc0(sizeof(VncRectEntry));
bd023f95 CC	94
	95	entry->rect.x = x;
	96	entry->rect.y = y;
	97	entry->rect.w = w;
	98	entry->rect.h = h;
	99
	100	vnc_lock_queue(queue);
	101	QLIST_INSERT_HEAD(&job->rectangles, entry, next);
	102	vnc_unlock_queue(queue);
	103	return 1;
	104	}
	105
	106	void vnc_job_push(VncJob *job)
	107	{
	108	vnc_lock_queue(queue);
	109	if (queue->exit \|\| QLIST_EMPTY(&job->rectangles)) {
7267c094	110	g_free(job);
bd023f95 CC	111	} else {
	112	QTAILQ_INSERT_TAIL(&queue->jobs, job, next);
	113	qemu_cond_broadcast(&queue->cond);
	114	}
	115	vnc_unlock_queue(queue);
	116	}
	117
	118	static bool vnc_has_job_locked(VncState *vs)
	119	{
	120	VncJob *job;
	121
	122	QTAILQ_FOREACH(job, &queue->jobs, next) {
	123	if (job->vs == vs \|\| !vs) {
	124	return true;
	125	}
	126	}
	127	return false;
	128	}
	129
	130	bool vnc_has_job(VncState *vs)
	131	{
	132	bool ret;
	133
	134	vnc_lock_queue(queue);
	135	ret = vnc_has_job_locked(vs);
	136	vnc_unlock_queue(queue);
	137	return ret;
	138	}
	139
	140	void vnc_jobs_clear(VncState *vs)
	141	{
	142	VncJob job, tmp;
	143
	144	vnc_lock_queue(queue);
	145	QTAILQ_FOREACH_SAFE(job, &queue->jobs, next, tmp) {
	146	if (job->vs == vs \|\| !vs) {
	147	QTAILQ_REMOVE(&queue->jobs, job, next);
	148	}
	149	}
	150	vnc_unlock_queue(queue);
	151	}
	152
	153	void vnc_jobs_join(VncState *vs)
	154	{
	155	vnc_lock_queue(queue);
	156	while (vnc_has_job_locked(vs)) {
	157	qemu_cond_wait(&queue->cond, &queue->mutex);
	158	}
	159	vnc_unlock_queue(queue);
175b2a6e CC	160	vnc_jobs_consume_buffer(vs);
	161	}
	162
	163	void vnc_jobs_consume_buffer(VncState *vs)
	164	{
	165	bool flush;
	166
	167	vnc_lock_output(vs);
	168	if (vs->jobs_buffer.offset) {
	169	vnc_write(vs, vs->jobs_buffer.buffer, vs->jobs_buffer.offset);
	170	buffer_reset(&vs->jobs_buffer);
	171	}
	172	flush = vs->csock != -1 && vs->abort != true;
	173	vnc_unlock_output(vs);
	174
	175	if (flush) {
	176	vnc_flush(vs);
	177	}
bd023f95 CC	178	}
	179
	180	/*
	181	* Copy data for local use
	182	*/
	183	static void vnc_async_encoding_start(VncState orig, VncState local)
	184	{
	185	local->vnc_encoding = orig->vnc_encoding;
	186	local->features = orig->features;
bd023f95	187	local->vd = orig->vd;
7d964c9d	188	local->lossy_rect = orig->lossy_rect;
bd023f95	189	local->write_pixels = orig->write_pixels;
9f64916d GH	190	local->client_pf = orig->client_pf;
9f64916d GH	191	local->client_be = orig->client_be;
bd023f95 CC	192	local->tight = orig->tight;
	193	local->zlib = orig->zlib;
	194	local->hextile = orig->hextile;
148954fa	195	local->zrle = orig->zrle;
bd023f95 CC	196	local->output = queue->buffer;
	197	local->csock = -1; /* Don't do any network work on this thread */
	198
	199	buffer_reset(&local->output);
	200	}
	201
	202	static void vnc_async_encoding_end(VncState orig, VncState local)
	203	{
	204	orig->tight = local->tight;
	205	orig->zlib = local->zlib;
	206	orig->hextile = local->hextile;
148954fa	207	orig->zrle = local->zrle;
7d964c9d	208	orig->lossy_rect = local->lossy_rect;
c53af37f CC	209
c53af37f CC	210	queue->buffer = local->output;
bd023f95 CC	211	}
	212
	213	static int vnc_worker_thread_loop(VncJobQueue *queue)
	214	{
	215	VncJob *job;
	216	VncRectEntry entry, tmp;
	217	VncState vs;
	218	int n_rectangles;
	219	int saved_offset;
bd023f95 CC	220
	221	vnc_lock_queue(queue);
	222	while (QTAILQ_EMPTY(&queue->jobs) && !queue->exit) {
	223	qemu_cond_wait(&queue->cond, &queue->mutex);
	224	}
	225	/* Here job can only be NULL if queue->exit is true */
	226	job = QTAILQ_FIRST(&queue->jobs);
	227	vnc_unlock_queue(queue);
	228
	229	if (queue->exit) {
	230	return -1;
	231	}
	232
	233	vnc_lock_output(job->vs);
	234	if (job->vs->csock == -1 \|\| job->vs->abort == true) {
175b2a6e	235	vnc_unlock_output(job->vs);
bd023f95 CC	236	goto disconnected;
	237	}
	238	vnc_unlock_output(job->vs);
	239
	240	/* Make a local copy of vs and switch output buffers */
	241	vnc_async_encoding_start(job->vs, &vs);
	242
	243	/* Start sending rectangles */
	244	n_rectangles = 0;
	245	vnc_write_u8(&vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
	246	vnc_write_u8(&vs, 0);
	247	saved_offset = vs.output.offset;
	248	vnc_write_u16(&vs, 0);
	249
	250	vnc_lock_display(job->vs->vd);
	251	QLIST_FOREACH_SAFE(entry, &job->rectangles, next, tmp) {
	252	int n;
	253
	254	if (job->vs->csock == -1) {
	255	vnc_unlock_display(job->vs->vd);
e3c1adf1 GA	256	/* Copy persistent encoding data */
e3c1adf1 GA	257	vnc_async_encoding_end(job->vs, &vs);
bd023f95 CC	258	goto disconnected;
	259	}
	260
	261	n = vnc_send_framebuffer_update(&vs, entry->rect.x, entry->rect.y,
	262	entry->rect.w, entry->rect.h);
	263
	264	if (n >= 0) {
	265	n_rectangles += n;
	266	}
7267c094	267	g_free(entry);
bd023f95 CC	268	}
	269	vnc_unlock_display(job->vs->vd);
	270
	271	/* Put n_rectangles at the beginning of the message */
	272	vs.output.buffer[saved_offset] = (n_rectangles >> 8) & 0xFF;
	273	vs.output.buffer[saved_offset + 1] = n_rectangles & 0xFF;
	274
bd023f95	275	vnc_lock_output(job->vs);
175b2a6e CC	276	if (job->vs->csock != -1) {
	277	buffer_reserve(&job->vs->jobs_buffer, vs.output.offset);
	278	buffer_append(&job->vs->jobs_buffer, vs.output.buffer,
	279	vs.output.offset);
	280	/* Copy persistent encoding data */
	281	vnc_async_encoding_end(job->vs, &vs);
	282
	283	qemu_bh_schedule(job->vs->bh);
e3c1adf1 GA	284	} else {
	285	/* Copy persistent encoding data */
	286	vnc_async_encoding_end(job->vs, &vs);
bd023f95	287	}
bd023f95 CC	288	vnc_unlock_output(job->vs);
bd023f95 CC	289
175b2a6e	290	disconnected:
bd023f95 CC	291	vnc_lock_queue(queue);
	292	QTAILQ_REMOVE(&queue->jobs, job, next);
	293	vnc_unlock_queue(queue);
	294	qemu_cond_broadcast(&queue->cond);
7267c094	295	g_free(job);
bd023f95 CC	296	return 0;
	297	}
	298
	299	static VncJobQueue *vnc_queue_init(void)
	300	{
7267c094	301	VncJobQueue *queue = g_malloc0(sizeof(VncJobQueue));
bd023f95 CC	302
	303	qemu_cond_init(&queue->cond);
	304	qemu_mutex_init(&queue->mutex);
	305	QTAILQ_INIT(&queue->jobs);
	306	return queue;
	307	}
	308
	309	static void vnc_queue_clear(VncJobQueue *q)
	310	{
	311	qemu_cond_destroy(&queue->cond);
	312	qemu_mutex_destroy(&queue->mutex);
	313	buffer_free(&queue->buffer);
7267c094	314	g_free(q);
bd023f95 CC	315	queue = NULL; /* Unset global queue */
	316	}
	317
	318	static void vnc_worker_thread(void arg)
	319	{
	320	VncJobQueue *queue = arg;
	321
b7680cb6	322	qemu_thread_get_self(&queue->thread);
bd023f95 CC	323
	324	while (!vnc_worker_thread_loop(queue)) ;
	325	vnc_queue_clear(queue);
	326	return NULL;
	327	}
	328
71a8cdec BS	329	static bool vnc_worker_thread_running(void)
	330	{
	331	return queue; /* Check global queue */
	332	}
	333
bd023f95 CC	334	void vnc_start_worker_thread(void)
	335	{
	336	VncJobQueue *q;
	337
	338	if (vnc_worker_thread_running())
	339	return ;
	340
	341	q = vnc_queue_init();
4900116e DDAG	342	qemu_thread_create(&q->thread, "vnc_worker", vnc_worker_thread, q,
4900116e DDAG	343	QEMU_THREAD_DETACHED);
bd023f95 CC	344	queue = q; /* Set global queue */
bd023f95 CC	345	}