minimal-examples/ws-server/minimal-ws-server-threads/protocol_lws_minimal.c - platform/external/libwebsockets - Git at Google

 /*
  * ws protocol handler plugin for "lws-minimal" demonstrating multithread
  *
  * Copyright (C) 2010-2018 Andy Green <andy@warmcat.com>
  *
  * This file is made available under the Creative Commons CC0 1.0
  * Universal Public Domain Dedication.
  */

 #if !defined (LWS_PLUGIN_STATIC)
 #define LWS_DLL
 #define LWS_INTERNAL
 #include <libwebsockets.h>
 #endif

 #include <string.h>

 /* one of these created for each message in the ringbuffer */

 struct msg {
 	void *payload; /* is malloc'd */
 	size_t len;
 };

 /*
  * One of these is created for each client connecting to us.
  *
  * It is ONLY read or written from the lws service thread context.
  */

 struct per_session_data__minimal {
 	struct per_session_data__minimal *pss_list;
 	struct lws *wsi;
 	uint32_t tail;
 };

 /* one of these is created for each vhost our protocol is used with */

 struct per_vhost_data__minimal {
 	struct lws_context *context;
 	struct lws_vhost *vhost;
 	const struct lws_protocols *protocol;

 	struct per_session_data__minimal *pss_list; /* linked-list of live pss*/
 	pthread_t pthread_spam[2];

 	pthread_mutex_t lock_ring; /* serialize access to the ring buffer */
 	struct lws_ring *ring; /* {lock_ring} ringbuffer holding unsent content */

 	const char *config;
 	char finished;
 };

 /*
  * This runs under both lws service and "spam threads" contexts.
  * Access is serialized by vhd->lock_ring.
  */

 static void
 __minimal_destroy_message(void *_msg)
 {
 	struct msg *msg = _msg;

 	free(msg->payload);
 	msg->payload = NULL;
 	msg->len = 0;
 }

 /*
  * This runs under the "spam thread" thread context only.
  *
  * We spawn two threads that generate messages with this.
  *
  */

 static void *
 thread_spam(void *d)
 {
 	struct per_vhost_data__minimal *vhd =
 			(struct per_vhost_data__minimal *)d;
 	struct msg amsg;
 	int len = 128, index = 1, n;

 	do {
 		/* don't generate output if nobody connected */
 		if (!vhd->pss_list)
 			goto wait;

 		pthread_mutex_lock(&vhd->lock_ring); /* --------- ring lock { */

 		/* only create if space in ringbuffer */
 		n = (int)lws_ring_get_count_free_elements(vhd->ring);
 		if (!n) {
 			lwsl_user("dropping!\n");
 			goto wait_unlock;
 		}

 		amsg.payload = malloc(LWS_PRE + len);
 		if (!amsg.payload) {
 			lwsl_user("OOM: dropping\n");
 			goto wait_unlock;
 		}
 		n = lws_snprintf((char *)amsg.payload + LWS_PRE, len,
 			         "%s: tid: %p, msg: %d", vhd->config,
 			         (void *)pthread_self(), index++);
 		amsg.len = n;
 		n = lws_ring_insert(vhd->ring, &amsg, 1);
 		if (n != 1) {
 			__minimal_destroy_message(&amsg);
 			lwsl_user("dropping!\n");
 		} else
 			/*
 			 * This will cause a LWS_CALLBACK_EVENT_WAIT_CANCELLED
 			 * in the lws service thread context.
 			 */
 			lws_cancel_service(vhd->context);

 wait_unlock:
 		pthread_mutex_unlock(&vhd->lock_ring); /* } ring lock ------- */

 wait:
 		usleep(100000);

 	} while (!vhd->finished);

 	lwsl_notice("thread_spam %p exiting\n", (void *)pthread_self());

 	pthread_exit(NULL);
 }

 /* this runs under the lws service thread context only */

 static int
 callback_minimal(struct lws *wsi, enum lws_callback_reasons reason,
 			void *user, void *in, size_t len)
 {
 	struct per_session_data__minimal *pss =
 			(struct per_session_data__minimal *)user;
 	struct per_vhost_data__minimal *vhd =
 			(struct per_vhost_data__minimal *)
 			lws_protocol_vh_priv_get(lws_get_vhost(wsi),
 					lws_get_protocol(wsi));
 	const struct lws_protocol_vhost_options *pvo;
 	const struct msg *pmsg;
 	void *retval;
 	int n, m, r = 0;

 	switch (reason) {
 	case LWS_CALLBACK_PROTOCOL_INIT:
 		/* create our per-vhost struct */
 		vhd = lws_protocol_vh_priv_zalloc(lws_get_vhost(wsi),
 				lws_get_protocol(wsi),
 				sizeof(struct per_vhost_data__minimal));
 		if (!vhd)
 			return 1;

 		pthread_mutex_init(&vhd->lock_ring, NULL);

 		/* recover the pointer to the globals struct */
 		pvo = lws_pvo_search(
 			(const struct lws_protocol_vhost_options *)in,
 			"config");
 		if (!pvo || !pvo->value) {
 			lwsl_err("%s: Can't find \"config\" pvo\n", __func__);
 			return 1;
 		}
 		vhd->config = pvo->value;

 		vhd->context = lws_get_context(wsi);
 		vhd->protocol = lws_get_protocol(wsi);
 		vhd->vhost = lws_get_vhost(wsi);

 		vhd->ring = lws_ring_create(sizeof(struct msg), 8,
 					    __minimal_destroy_message);
 		if (!vhd->ring) {
 			lwsl_err("%s: failed to create ring\n", __func__);
 			return 1;
 		}

 		/* start the content-creating threads */

 		for (n = 0; n < (int)LWS_ARRAY_SIZE(vhd->pthread_spam); n++)
 			if (pthread_create(&vhd->pthread_spam[n], NULL,
 					   thread_spam, vhd)) {
 				lwsl_err("thread creation failed\n");
 				r = 1;
 				goto init_fail;
 			}
 		break;

 	case LWS_CALLBACK_PROTOCOL_DESTROY:
 init_fail:
 		vhd->finished = 1;
 		for (n = 0; n < (int)LWS_ARRAY_SIZE(vhd->pthread_spam); n++)
 			if (vhd->pthread_spam[n])
 				pthread_join(vhd->pthread_spam[n], &retval);

 		if (vhd->ring)
 			lws_ring_destroy(vhd->ring);

 		pthread_mutex_destroy(&vhd->lock_ring);
 		break;

 	case LWS_CALLBACK_ESTABLISHED:
 		/* add ourselves to the list of live pss held in the vhd */
 		lws_ll_fwd_insert(pss, pss_list, vhd->pss_list);
 		pss->tail = lws_ring_get_oldest_tail(vhd->ring);
 		pss->wsi = wsi;
 		break;

 	case LWS_CALLBACK_CLOSED:
 		/* remove our closing pss from the list of live pss */
 		lws_ll_fwd_remove(struct per_session_data__minimal, pss_list,
 				  pss, vhd->pss_list);
 		break;

 	case LWS_CALLBACK_SERVER_WRITEABLE:
 		pthread_mutex_lock(&vhd->lock_ring); /* --------- ring lock { */

 		pmsg = lws_ring_get_element(vhd->ring, &pss->tail);
 		if (!pmsg) {
 			pthread_mutex_unlock(&vhd->lock_ring); /* } ring lock ------- */
 			break;
 		}

 		/* notice we allowed for LWS_PRE in the payload already */
 		m = lws_write(wsi, ((unsigned char *)pmsg->payload) + LWS_PRE,
 			      pmsg->len, LWS_WRITE_TEXT);
 		if (m < (int)pmsg->len) {
 			pthread_mutex_unlock(&vhd->lock_ring); /* } ring lock ------- */
 			lwsl_err("ERROR %d writing to ws socket\n", m);
 			return -1;
 		}

 		lws_ring_consume_and_update_oldest_tail(
 			vhd->ring,	/* lws_ring object */
 			struct per_session_data__minimal, /* type of objects with tails */
 			&pss->tail,	/* tail of guy doing the consuming */
 			1,		/* number of payload objects being consumed */
 			vhd->pss_list,	/* head of list of objects with tails */
 			tail,		/* member name of tail in objects with tails */
 			pss_list	/* member name of next object in objects with tails */
 		);

 		/* more to do? */
 		if (lws_ring_get_element(vhd->ring, &pss->tail))
 			/* come back as soon as we can write more */
 			lws_callback_on_writable(pss->wsi);

 		pthread_mutex_unlock(&vhd->lock_ring); /* } ring lock ------- */
 		break;

 	case LWS_CALLBACK_RECEIVE:
 		break;

 	case LWS_CALLBACK_EVENT_WAIT_CANCELLED:
 		/*
 		 * When the "spam" threads add a message to the ringbuffer,
 		 * they create this event in the lws service thread context
 		 * using lws_cancel_service().
 		 *
 		 * We respond by scheduling a writable callback for all
 		 * connected clients.
 		 */
 		lws_start_foreach_llp(struct per_session_data__minimal **,
 				      ppss, vhd->pss_list) {
 			lws_callback_on_writable((*ppss)->wsi);
 		} lws_end_foreach_llp(ppss, pss_list);
 		break;

 	default:
 		break;
 	}

 	return r;
 }

 #define LWS_PLUGIN_PROTOCOL_MINIMAL \
 	{ \
 		"lws-minimal", \
 		callback_minimal, \
 		sizeof(struct per_session_data__minimal), \
 		128, \
 		0, NULL, 0 \
 	}

 #if !defined (LWS_PLUGIN_STATIC)

 /* boilerplate needed if we are built as a dynamic plugin */

 static const struct lws_protocols protocols[] = {
 	LWS_PLUGIN_PROTOCOL_MINIMAL
 };

 LWS_EXTERN LWS_VISIBLE int
 init_protocol_minimal(struct lws_context *context,
 		      struct lws_plugin_capability *c)
 {
 	if (c->api_magic != LWS_PLUGIN_API_MAGIC) {
 		lwsl_err("Plugin API %d, library API %d", LWS_PLUGIN_API_MAGIC,
 			 c->api_magic);
 		return 1;
 	}

 	c->protocols = protocols;
 	c->count_protocols = LWS_ARRAY_SIZE(protocols);
 	c->extensions = NULL;
 	c->count_extensions = 0;

 	return 0;
 }

 LWS_EXTERN LWS_VISIBLE int
 destroy_protocol_minimal(struct lws_context *context)
 {
 	return 0;
 }
 #endif
	/*
	* ws protocol handler plugin for "lws-minimal" demonstrating multithread
	*
	* Copyright (C) 2010-2018 Andy Green <andy@warmcat.com>
	*
	* This file is made available under the Creative Commons CC0 1.0
	* Universal Public Domain Dedication.
	*/

	#if !defined (LWS_PLUGIN_STATIC)
	#define LWS_DLL
	#define LWS_INTERNAL
	#include <libwebsockets.h>
	#endif

	#include <string.h>

	/* one of these created for each message in the ringbuffer */

	struct msg {
	void payload; / is malloc'd */
	size_t len;
	};

	/*
	* One of these is created for each client connecting to us.
	*
	* It is ONLY read or written from the lws service thread context.
	*/

	struct per_session_data__minimal {
	struct per_session_data__minimal *pss_list;
	struct lws *wsi;
	uint32_t tail;
	};

	/* one of these is created for each vhost our protocol is used with */

	struct per_vhost_data__minimal {
	struct lws_context *context;
	struct lws_vhost *vhost;
	const struct lws_protocols *protocol;

	struct per_session_data__minimal pss_list; / linked-list of live pss*/
	pthread_t pthread_spam[2];

	pthread_mutex_t lock_ring; /* serialize access to the ring buffer */
	struct lws_ring ring; / {lock_ring} ringbuffer holding unsent content */

	const char *config;
	char finished;
	};

	/*
	* This runs under both lws service and "spam threads" contexts.
	* Access is serialized by vhd->lock_ring.
	*/

	static void
	__minimal_destroy_message(void *_msg)
	{
	struct msg *msg = _msg;

	free(msg->payload);
	msg->payload = NULL;
	msg->len = 0;
	}

	/*
	* This runs under the "spam thread" thread context only.
	*
	* We spawn two threads that generate messages with this.
	*
	*/

	static void *
	thread_spam(void *d)
	{
	struct per_vhost_data__minimal *vhd =
	(struct per_vhost_data__minimal *)d;
	struct msg amsg;
	int len = 128, index = 1, n;

	do {
	/* don't generate output if nobody connected */
	if (!vhd->pss_list)
	goto wait;

	pthread_mutex_lock(&vhd->lock_ring); /* --------- ring lock { */

	/* only create if space in ringbuffer */
	n = (int)lws_ring_get_count_free_elements(vhd->ring);
	if (!n) {
	lwsl_user("dropping!\n");
	goto wait_unlock;
	}

	amsg.payload = malloc(LWS_PRE + len);
	if (!amsg.payload) {
	lwsl_user("OOM: dropping\n");
	goto wait_unlock;
	}
	n = lws_snprintf((char *)amsg.payload + LWS_PRE, len,
	"%s: tid: %p, msg: %d", vhd->config,
	(void *)pthread_self(), index++);
	amsg.len = n;
	n = lws_ring_insert(vhd->ring, &amsg, 1);
	if (n != 1) {
	__minimal_destroy_message(&amsg);
	lwsl_user("dropping!\n");
	} else
	/*
	* This will cause a LWS_CALLBACK_EVENT_WAIT_CANCELLED
	* in the lws service thread context.
	*/
	lws_cancel_service(vhd->context);

	wait_unlock:
	pthread_mutex_unlock(&vhd->lock_ring); /* } ring lock ------- */

	wait:
	usleep(100000);

	} while (!vhd->finished);

	lwsl_notice("thread_spam %p exiting\n", (void *)pthread_self());

	pthread_exit(NULL);
	}

	/* this runs under the lws service thread context only */

	static int
	callback_minimal(struct lws *wsi, enum lws_callback_reasons reason,
	void user, void in, size_t len)
	{
	struct per_session_data__minimal *pss =
	(struct per_session_data__minimal *)user;
	struct per_vhost_data__minimal *vhd =
	(struct per_vhost_data__minimal *)
	lws_protocol_vh_priv_get(lws_get_vhost(wsi),
	lws_get_protocol(wsi));
	const struct lws_protocol_vhost_options *pvo;
	const struct msg *pmsg;
	void *retval;
	int n, m, r = 0;

	switch (reason) {
	case LWS_CALLBACK_PROTOCOL_INIT:
	/* create our per-vhost struct */
	vhd = lws_protocol_vh_priv_zalloc(lws_get_vhost(wsi),
	lws_get_protocol(wsi),
	sizeof(struct per_vhost_data__minimal));
	if (!vhd)
	return 1;

	pthread_mutex_init(&vhd->lock_ring, NULL);

	/* recover the pointer to the globals struct */
	pvo = lws_pvo_search(
	(const struct lws_protocol_vhost_options *)in,
	"config");
	if (!pvo \|\| !pvo->value) {
	lwsl_err("%s: Can't find \"config\" pvo\n", __func__);
	return 1;
	}
	vhd->config = pvo->value;

	vhd->context = lws_get_context(wsi);
	vhd->protocol = lws_get_protocol(wsi);
	vhd->vhost = lws_get_vhost(wsi);

	vhd->ring = lws_ring_create(sizeof(struct msg), 8,
	__minimal_destroy_message);
	if (!vhd->ring) {
	lwsl_err("%s: failed to create ring\n", __func__);
	return 1;
	}

	/* start the content-creating threads */

	for (n = 0; n < (int)LWS_ARRAY_SIZE(vhd->pthread_spam); n++)
	if (pthread_create(&vhd->pthread_spam[n], NULL,
	thread_spam, vhd)) {
	lwsl_err("thread creation failed\n");
	r = 1;
	goto init_fail;
	}
	break;

	case LWS_CALLBACK_PROTOCOL_DESTROY:
	init_fail:
	vhd->finished = 1;
	for (n = 0; n < (int)LWS_ARRAY_SIZE(vhd->pthread_spam); n++)
	if (vhd->pthread_spam[n])
	pthread_join(vhd->pthread_spam[n], &retval);

	if (vhd->ring)
	lws_ring_destroy(vhd->ring);

	pthread_mutex_destroy(&vhd->lock_ring);
	break;

	case LWS_CALLBACK_ESTABLISHED:
	/* add ourselves to the list of live pss held in the vhd */
	lws_ll_fwd_insert(pss, pss_list, vhd->pss_list);
	pss->tail = lws_ring_get_oldest_tail(vhd->ring);
	pss->wsi = wsi;
	break;

	case LWS_CALLBACK_CLOSED:
	/* remove our closing pss from the list of live pss */
	lws_ll_fwd_remove(struct per_session_data__minimal, pss_list,
	pss, vhd->pss_list);
	break;

	case LWS_CALLBACK_SERVER_WRITEABLE:
	pthread_mutex_lock(&vhd->lock_ring); /* --------- ring lock { */

	pmsg = lws_ring_get_element(vhd->ring, &pss->tail);
	if (!pmsg) {
	pthread_mutex_unlock(&vhd->lock_ring); /* } ring lock ------- */
	break;
	}

	/* notice we allowed for LWS_PRE in the payload already */
	m = lws_write(wsi, ((unsigned char *)pmsg->payload) + LWS_PRE,
	pmsg->len, LWS_WRITE_TEXT);
	if (m < (int)pmsg->len) {
	pthread_mutex_unlock(&vhd->lock_ring); /* } ring lock ------- */
	lwsl_err("ERROR %d writing to ws socket\n", m);
	return -1;
	}

	lws_ring_consume_and_update_oldest_tail(
	vhd->ring, /* lws_ring object */
	struct per_session_data__minimal, /* type of objects with tails */
	&pss->tail, /* tail of guy doing the consuming */
	1, /* number of payload objects being consumed */
	vhd->pss_list, /* head of list of objects with tails */
	tail, /* member name of tail in objects with tails */
	pss_list /* member name of next object in objects with tails */
	);

	/* more to do? */
	if (lws_ring_get_element(vhd->ring, &pss->tail))
	/* come back as soon as we can write more */
	lws_callback_on_writable(pss->wsi);

	pthread_mutex_unlock(&vhd->lock_ring); /* } ring lock ------- */
	break;

	case LWS_CALLBACK_RECEIVE:
	break;

	case LWS_CALLBACK_EVENT_WAIT_CANCELLED:
	/*
	* When the "spam" threads add a message to the ringbuffer,
	* they create this event in the lws service thread context
	* using lws_cancel_service().
	*
	* We respond by scheduling a writable callback for all
	* connected clients.
	*/
	lws_start_foreach_llp(struct per_session_data__minimal **,
	ppss, vhd->pss_list) {
	lws_callback_on_writable((*ppss)->wsi);
	} lws_end_foreach_llp(ppss, pss_list);
	break;

	default:
	break;
	}

	return r;
	}

	#define LWS_PLUGIN_PROTOCOL_MINIMAL \
	{ \
	"lws-minimal", \
	callback_minimal, \
	sizeof(struct per_session_data__minimal), \
	128, \
	0, NULL, 0 \
	}

	#if !defined (LWS_PLUGIN_STATIC)

	/* boilerplate needed if we are built as a dynamic plugin */

	static const struct lws_protocols protocols[] = {
	LWS_PLUGIN_PROTOCOL_MINIMAL
	};

	LWS_EXTERN LWS_VISIBLE int
	init_protocol_minimal(struct lws_context *context,
	struct lws_plugin_capability *c)
	{
	if (c->api_magic != LWS_PLUGIN_API_MAGIC) {
	lwsl_err("Plugin API %d, library API %d", LWS_PLUGIN_API_MAGIC,
	c->api_magic);
	return 1;
	}

	c->protocols = protocols;
	c->count_protocols = LWS_ARRAY_SIZE(protocols);
	c->extensions = NULL;
	c->count_extensions = 0;

	return 0;
	}

	LWS_EXTERN LWS_VISIBLE int
	destroy_protocol_minimal(struct lws_context *context)
	{
	return 0;
	}
	#endif