Merge from camel-mt-branch.

2000-12-24  Not Zed  <NotZed@HelixCode.com>

        * Merge from camel-mt-branch.

svn path=/trunk/; revision=7152

1 files changed, 774 insertions, 0 deletions

diff --git a/e-util/e-msgport.c b/e-util/e-msgport.c
new file mode 100644
index 0000000000..107b889635
--- /dev/null
+++ b/e-util/e-msgport.c
@@ -0,0 +1,774 @@
+
+
+#include <glib.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+#include <stdio.h>
+
+#include "e-msgport.h"
+
+#include <pthread.h>
+
+void e_dlist_init(EDList *v)
+{
+        v->head = (EDListNode *)&v->tail;
+        v->tail = 0;
+        v->tailpred = (EDListNode *)&v->head;
+}
+
+EDListNode *e_dlist_addhead(EDList *l, EDListNode *n)
+{
+        n->next = l->head;
+        n->prev = (EDListNode *)&l->head;
+        l->head->prev = n;
+        l->head = n;
+        return n;
+}
+
+EDListNode *e_dlist_addtail(EDList *l, EDListNode *n)
+{
+        n->next = (EDListNode *)&l->tail;
+        n->prev = l->tailpred;
+        l->tailpred->next = n;
+        l->tailpred = n;
+        return n;
+}
+
+EDListNode *e_dlist_remove(EDListNode *n)
+{
+        n->next->prev = n->prev;
+        n->prev->next = n->next;
+        return n;
+}
+
+EDListNode *e_dlist_remhead(EDList *l)
+{
+	EDListNode *n, *nn;
+
+	n = l->head;
+	nn = n->next;
+	if (nn) {
+		nn->prev = n->prev;
+		l->head = nn;
+		return n;
+	}
+	return NULL;
+}
+
+EDListNode *e_dlist_remtail(EDList *l)
+{
+	EDListNode *n, *np;
+
+	n = l->tailpred;
+	np = n->prev;
+	if (np) {
+		np->next = n->next;
+		l->tailpred = np;
+		return n;
+	}
+	return NULL;
+}
+
+int e_dlist_empty(EDList *l)
+{
+	return (l->head == (EDListNode *)&l->tail);
+}
+
+int e_dlist_length(EDList *l)
+{
+	EDListNode *n, *nn;
+	int count = 0;
+
+	n = l->head;
+	nn = n->next;
+	while (nn) {
+		count++;
+		n = nn;
+		nn = n->next;
+	}
+
+	return 0;
+}
+
+struct _EMsgPort {
+	EDList queue;
+	int condwait;		/* how many waiting in condwait */
+	union {
+		int pipe[2];
+		struct {
+			int read;
+			int write;
+		} fd;
+	} pipe;
+	/* @#@$#$ glib stuff */
+	GCond *cond;
+	GMutex *lock;
+};
+
+#define m(x) 
+
+EMsgPort *e_msgport_new(void)
+{
+	EMsgPort *mp;
+
+	mp = g_malloc(sizeof(*mp));
+	e_dlist_init(&mp->queue);
+	mp->lock = g_mutex_new();
+	mp->cond = g_cond_new();
+	mp->pipe.fd.read = -1;
+	mp->pipe.fd.write = -1;
+	mp->condwait = 0;
+
+	return mp;
+}
+
+void e_msgport_destroy(EMsgPort *mp)
+{
+	g_mutex_free(mp->lock);
+	g_cond_free(mp->cond);
+	if (mp->pipe.fd.read != -1) {
+		close(mp->pipe.fd.read);
+		close(mp->pipe.fd.write);
+	}
+	g_free(mp);
+}
+
+/* get a fd that can be used to wait on the port asynchronously */
+int e_msgport_fd(EMsgPort *mp)
+{
+	int fd;
+
+	g_mutex_lock(mp->lock);
+	fd = mp->pipe.fd.read;
+	if (fd == -1) {
+		pipe(mp->pipe.pipe);
+		fd = mp->pipe.fd.read;
+	}
+	g_mutex_unlock(mp->lock);
+
+	return fd;
+}
+
+void e_msgport_put(EMsgPort *mp, EMsg *msg)
+{
+	m(printf("put:\n"));
+	g_mutex_lock(mp->lock);
+	e_dlist_addtail(&mp->queue, &msg->ln);
+	if (mp->condwait > 0) {
+		m(printf("put: condwait > 0, waking up\n"));
+		g_cond_signal(mp->cond);
+	}
+	if (mp->pipe.fd.write != -1) {
+		m(printf("put: have pipe, writing notification to it\n"));
+		write(mp->pipe.fd.write, "", 1);
+	}
+	g_mutex_unlock(mp->lock);
+	m(printf("put: done\n"));
+}
+
+EMsg *e_msgport_wait(EMsgPort *mp)
+{
+	EMsg *msg;
+
+	m(printf("wait:\n"));
+	g_mutex_lock(mp->lock);
+	while (e_dlist_empty(&mp->queue)) {
+		if (mp->pipe.fd.read == -1) {
+			m(printf("wait: waiting on condition\n"));
+			mp->condwait++;
+			g_cond_wait(mp->cond, mp->lock);
+			m(printf("wait: got condition\n"));
+			mp->condwait--;
+		} else {
+			fd_set rfds;
+
+			m(printf("wait: waitng on pipe\n"));
+			FD_ZERO(&rfds);
+			FD_SET(mp->pipe.fd.read, &rfds);
+			g_mutex_unlock(mp->lock);
+			select(mp->pipe.fd.read+1, &rfds, NULL, NULL, NULL);
+			pthread_testcancel();
+			g_mutex_lock(mp->lock);
+			m(printf("wait: got pipe\n"));
+		}
+	}
+	msg = (EMsg *)mp->queue.head;
+	m(printf("wait: message = %p\n", msg));
+	g_mutex_unlock(mp->lock);
+	m(printf("wait: done\n"));
+	return msg;
+}
+
+EMsg *e_msgport_get(EMsgPort *mp)
+{
+	EMsg *msg;
+	char dummy[1];
+
+	g_mutex_lock(mp->lock);
+	msg = (EMsg *)e_dlist_remhead(&mp->queue);
+	if (msg && mp->pipe.fd.read != -1)
+		read(mp->pipe.fd.read, dummy, 1);
+	m(printf("get: message = %p\n", msg));
+	g_mutex_unlock(mp->lock);
+
+	return msg;
+}
+
+void e_msgport_reply(EMsg *msg)
+{
+	if (msg->reply_port) {
+		e_msgport_put(msg->reply_port, msg);
+	}
+	/* else lost? */
+}
+
+struct _EThread {
+	EMsgPort *server_port;
+	EMsgPort *reply_port;
+	pthread_mutex_t mutex;
+	e_thread_t type;
+	int queue_limit;
+
+	int waiting;		/* if we are waiting for a new message */
+	pthread_t id;		/* id of our running child thread */
+	GList *id_list;		/* if THREAD_NEW, then a list of our child threads */
+
+	EThreadFunc destroy;
+	void *destroy_data;
+
+	EThreadFunc received;
+	void *received_data;
+
+	EThreadFunc lost;
+	void *lost_data;
+};
+
+static void thread_destroy_msg(EThread *e, EMsg *m);
+
+EThread *e_thread_new(e_thread_t type)
+{
+	EThread *e;
+
+	e = g_malloc0(sizeof(*e));
+	pthread_mutex_init(&e->mutex, 0);
+	e->type = type;
+	e->server_port = e_msgport_new();
+	e->id = ~0;
+	e->queue_limit = INT_MAX;
+
+	return e;
+}
+
+/* close down the threads & resources etc */
+void e_thread_destroy(EThread *e)
+{
+	int tries = 0;
+	int busy = FALSE;
+	EMsg *msg;
+
+	/* make sure we soak up all the messages first */
+	while ( (msg = e_msgport_get(e->server_port)) ) {
+		thread_destroy_msg(e, msg);
+	}
+
+	pthread_mutex_lock(&e->mutex);
+
+	switch(e->type) {
+	case E_THREAD_QUEUE:
+	case E_THREAD_DROP:
+		/* if we have a thread, 'kill' it */
+		while (e->id != ~0 && tries < 5) {
+			if (e->waiting == 1) {
+				pthread_t id = e->id;
+				e->id = ~0;
+				pthread_mutex_unlock(&e->mutex);
+				if (pthread_cancel(id) == 0)
+					pthread_join(id, 0);
+				pthread_mutex_lock(&e->mutex);
+			} else {
+				printf("thread still active, waiting for it to finish\n");
+				pthread_mutex_unlock(&e->mutex);
+				sleep(1);
+				pthread_mutex_lock(&e->mutex);
+			}
+			tries++;
+		}
+		busy = e->id != ~0;
+		break;
+	case E_THREAD_NEW:
+		while (g_list_length(e->id_list) && tries < 5) {
+			printf("thread(s) still active, waiting for them to finish\n");
+			pthread_mutex_unlock(&e->mutex);
+			sleep(1);
+			pthread_mutex_lock(&e->mutex);
+		}
+		busy = g_list_length(e->id_list) != 0;
+		break;
+	}
+
+	pthread_mutex_unlock(&e->mutex);
+
+	/* and clean up, if we can */
+	if (busy) {
+		g_warning("threads were busy, leaked EThread");
+		return;
+	}
+
+	e_msgport_destroy(e->server_port);
+	g_free(e);
+}
+
+/* set the queue maximum depth, what happens when the queue
+   fills up depends on the queue type */
+void e_thread_set_queue_limit(EThread *e, int limit)
+{
+	e->queue_limit = limit;
+}
+
+/* set a msg destroy callback, this can not call any e_thread functions on @e */
+void e_thread_set_msg_destroy(EThread *e, EThreadFunc destroy, void *data)
+{
+	pthread_mutex_lock(&e->mutex);
+	e->destroy = destroy;
+	e->destroy_data = data;
+	pthread_mutex_unlock(&e->mutex);
+}
+
+/* set a message lost callback, called if any message is discarded */
+void e_thread_set_msg_lost(EThread *e, EThreadFunc lost, void *data)
+{
+	pthread_mutex_lock(&e->mutex);
+	e->lost = lost;
+	e->lost_data = lost;
+	pthread_mutex_unlock(&e->mutex);
+}
+
+/* set a reply port, if set, then send messages back once finished */
+void e_thread_set_reply_port(EThread *e, EMsgPort *reply_port)
+{
+	e->reply_port = reply_port;
+}
+
+/* set a received data callback */
+void e_thread_set_msg_received(EThread *e, EThreadFunc received, void *data)
+{
+	pthread_mutex_lock(&e->mutex);
+	e->received = received;
+	e->received_data = data;
+	pthread_mutex_unlock(&e->mutex);
+}
+
+static void
+thread_destroy_msg(EThread *e, EMsg *m)
+{
+	EThreadFunc func;
+	void *func_data;
+
+	/* we do this so we never get an incomplete/unmatched callback + data */
+	pthread_mutex_lock(&e->mutex);
+	func = e->destroy;
+	func_data = e->destroy_data;
+	pthread_mutex_unlock(&e->mutex);
+	
+	if (func)
+		func(e, m, func_data);
+}
+
+static void
+thread_received_msg(EThread *e, EMsg *m)
+{
+	EThreadFunc func;
+	void *func_data;
+
+	/* we do this so we never get an incomplete/unmatched callback + data */
+	pthread_mutex_lock(&e->mutex);
+	func = e->received;
+	func_data = e->received_data;
+	pthread_mutex_unlock(&e->mutex);
+	
+	if (func)
+		func(e, m, func_data);
+	else
+		g_warning("No processing callback for EThread, message unprocessed");
+}
+
+static void
+thread_lost_msg(EThread *e, EMsg *m)
+{
+	EThreadFunc func;
+	void *func_data;
+
+	/* we do this so we never get an incomplete/unmatched callback + data */
+	pthread_mutex_lock(&e->mutex);
+	func = e->lost;
+	func_data = e->lost_data;
+	pthread_mutex_unlock(&e->mutex);
+	
+	if (func)
+		func(e, m, func_data);
+}
+
+/* the actual thread dispatcher */
+static void *
+thread_dispatch(void *din)
+{
+	EThread *e = din;
+	EMsg *m;
+
+	printf("dispatch thread started: %ld\n", pthread_self());
+
+	while (1) {
+		pthread_mutex_lock(&e->mutex);
+		m = e_msgport_get(e->server_port);
+		if (m == NULL) {
+			/* nothing to do?  If we are a 'new' type thread, just quit.
+			   Otherwise, go into waiting (can be cancelled here) */
+			switch (e->type) {
+			case E_THREAD_QUEUE:
+			case E_THREAD_DROP:
+				e->waiting = 1;
+				pthread_mutex_unlock(&e->mutex);
+				e_msgport_wait(e->server_port);
+				e->waiting = 0;
+				break;
+			case E_THREAD_NEW:
+				e->id_list = g_list_remove(e->id_list, (void *)pthread_self());
+				pthread_mutex_unlock(&e->mutex);
+				return 0;
+			}
+
+			continue;
+		}
+		pthread_mutex_unlock(&e->mutex);
+
+		printf("got message in dispatch thread\n");
+
+		/* process it */
+		thread_received_msg(e, m);
+
+		/* if we have a reply port, send it back, otherwise, lose it */
+		if (m->reply_port) {
+			e_msgport_reply(m);
+		} else {
+			thread_destroy_msg(e, m);
+		}
+	}
+
+	/* if we run out of things to process we could conceivably 'hang around' for a bit,
+	   but to do this we need to use the fd interface of the msgport, and its utility
+	   is probably debatable anyway */
+
+	/* signify we are no longer running */
+	/* This code isn't used yet, but would be if we ever had a 'quit now' message implemented */
+	pthread_mutex_lock(&e->mutex);
+	switch (e->type) {
+	case E_THREAD_QUEUE:
+	case E_THREAD_DROP:
+		e->id = ~0;
+		break;
+	case E_THREAD_NEW:
+		e->id_list = g_list_remove(e->id_list, (void *)pthread_self());
+		break;
+	}
+	pthread_mutex_unlock(&e->mutex);
+
+	return 0;
+}
+
+/* send a message to the thread, start thread if necessary */
+void e_thread_put(EThread *e, EMsg *msg)
+{
+	pthread_t id;
+	EMsg *dmsg = NULL;
+
+	pthread_mutex_lock(&e->mutex);
+
+	/* the caller forgot to tell us what to do, well, we can't do anything can we */
+	if (e->received == NULL) {
+		pthread_mutex_unlock(&e->mutex);
+		g_warning("EThread called with no receiver function, no work to do!");
+		thread_destroy_msg(e, msg);
+		return;
+	}
+
+	msg->reply_port = e->reply_port;
+
+	switch(e->type) {
+	case E_THREAD_QUEUE:
+		/* if the queue is full, lose this new addition */
+		if (e_dlist_length(&e->server_port->queue) < e->queue_limit) {
+			e_msgport_put(e->server_port, msg);
+		} else {
+			printf("queue limit reached, dropping new message\n");
+			dmsg = msg;
+		}
+		break;
+	case E_THREAD_DROP:
+		/* if the queue is full, lose the oldest (unprocessed) message */
+		if (e_dlist_length(&e->server_port->queue) < e->queue_limit) {
+			e_msgport_put(e->server_port, msg);
+		} else {
+			printf("queue limit reached, dropping old message\n");
+			e_msgport_put(e->server_port, msg);
+			dmsg = e_msgport_get(e->server_port);
+		}
+		break;
+	case E_THREAD_NEW:
+		/* it is possible that an existing thread can catch this message, so
+		   we might create a thread with no work to do.
+		   but that doesn't matter, the other alternative that it be lost is worse */
+		e_msgport_put(e->server_port, msg);
+		if (g_list_length(e->id_list) < e->queue_limit
+		    && pthread_create(&id, NULL, thread_dispatch, e) == 0) {
+			e->id_list = g_list_append(e->id_list, (void *)id);
+		}
+		pthread_mutex_unlock(&e->mutex);
+		return;
+	}
+
+	/* create the thread, if there is none to receive it yet */
+	if (e->id == ~0) {
+		if (pthread_create(&e->id, NULL, thread_dispatch, e) == -1) {
+			g_warning("Could not create dispatcher thread, message queued?: %s", strerror(errno));
+			e->id = ~0;
+		}
+	}
+
+	pthread_mutex_unlock(&e->mutex);
+
+	if (dmsg) {
+		thread_lost_msg(e, dmsg);
+		thread_destroy_msg(e, dmsg);
+	}
+}
+
+/* yet-another-mutex interface */
+struct _EMutex {
+	int type;
+	pthread_t owner;
+	short waiters;
+	short depth;
+	pthread_mutex_t mutex;
+	pthread_cond_t cond;
+};
+
+/* sigh, this is just painful to have to need, but recursive
+   read/write, etc mutexes just aren't very common in thread
+   implementations */
+/* TODO: Just make it use recursive mutexes if they are available */
+EMutex *e_mutex_new(e_mutex_t type)
+{
+	struct _EMutex *m;
+
+	m = g_malloc(sizeof(*m));
+	m->type = type;
+	m->waiters = 0;
+	m->depth = 0;
+	m->owner = ~0;
+
+	switch (type) {
+	case E_MUTEX_SIMPLE:
+		pthread_mutex_init(&m->mutex, 0);
+		break;
+	case E_MUTEX_REC:
+		pthread_mutex_init(&m->mutex, 0);
+		pthread_cond_init(&m->cond, 0);
+		break;
+		/* read / write ?  flags for same? */
+	}
+
+	return m;
+}
+
+int e_mutex_destroy(EMutex *m)
+{
+	int ret = 0;
+
+	switch (m->type) {
+	case E_MUTEX_SIMPLE:
+		ret = pthread_mutex_destroy(&m->mutex);
+		if (ret == -1)
+			g_warning("EMutex destroy failed: %s", strerror(errno));
+		g_free(m);
+		break;
+	case E_MUTEX_REC:
+		ret = pthread_mutex_destroy(&m->mutex);
+		if (ret == -1)
+			g_warning("EMutex destroy failed: %s", strerror(errno));
+		ret = pthread_cond_destroy(&m->cond);
+		if (ret == -1)
+			g_warning("EMutex destroy failed: %s", strerror(errno));
+		g_free(m);
+
+	}
+	return ret;
+}
+
+int e_mutex_lock(EMutex *m)
+{
+	pthread_t id;
+
+	switch (m->type) {
+	case E_MUTEX_SIMPLE:
+		return pthread_mutex_lock(&m->mutex);
+	case E_MUTEX_REC:
+		id = pthread_self();
+		if (pthread_mutex_lock(&m->mutex) == -1)
+			return -1;
+		while (1) {
+			if (m->owner == ~0) {
+				m->owner = id;
+				m->depth = 1;
+				break;
+			} else if (id == m->owner) {
+				m->depth++;
+				break;
+			} else {
+				m->waiters++;
+				if (pthread_cond_wait(&m->cond, &m->mutex) == -1)
+					return -1;
+				m->waiters--;
+			}
+		}
+		return pthread_mutex_unlock(&m->mutex);
+	}
+
+	errno = EINVAL;
+	return -1;
+}
+
+int e_mutex_unlock(EMutex *m)
+{
+	switch (m->type) {
+	case E_MUTEX_SIMPLE:
+		return pthread_mutex_unlock(&m->mutex);
+	case E_MUTEX_REC:
+		if (pthread_mutex_lock(&m->mutex) == -1)
+			return -1;
+		g_assert(m->owner == pthread_self());
+
+		m->depth--;
+		if (m->depth == 0) {
+			m->owner = ~0;
+			if (m->waiters > 0)
+				pthread_cond_signal(&m->cond);
+		}
+		return pthread_mutex_unlock(&m->mutex);
+	}
+
+	errno = EINVAL;
+	return -1;
+}
+
+#ifdef STANDALONE
+EMsgPort *server_port;
+
+
+void *fdserver(void *data)
+{
+	int fd;
+	EMsg *msg;
+	int id = (int)data;
+	fd_set rfds;
+
+	fd = e_msgport_fd(server_port);
+
+	while (1) {
+		int count = 0;
+
+		printf("server %d: waiting on fd %d\n", id, fd);
+		FD_ZERO(&rfds);
+		FD_SET(fd, &rfds);
+		select(fd+1, &rfds, NULL, NULL, NULL);
+		printf("server %d: Got async notification, checking for messages\n", id);
+		while ((msg = e_msgport_get(server_port))) {
+			printf("server %d: got message\n", id);
+			sleep(1);
+			printf("server %d: replying\n", id);
+			e_msgport_reply(msg);
+			count++;
+		}
+		printf("server %d: got %d messages\n", id, count);
+	}
+}
+
+void *server(void *data)
+{
+	EMsg *msg;
+	int id = (int)data;
+
+	while (1) {
+		printf("server %d: waiting\n", id);
+		msg = e_msgport_wait(server_port);
+		msg = e_msgport_get(server_port);
+		if (msg) {
+			printf("server %d: got message\n", id);
+			sleep(1);
+			printf("server %d: replying\n", id);
+			e_msgport_reply(msg);
+		} else {
+			printf("server %d: didn't get message\n", id);
+		}
+	}
+}
+
+void *client(void *data)
+{
+	EMsg *msg;
+	EMsgPort *replyport;
+	int i;
+
+	replyport = e_msgport_new();
+	msg = g_malloc0(sizeof(*msg));
+	msg->reply_port = replyport;
+	for (i=0;i<10;i++) {
+		/* synchronous operation */
+		printf("client: sending\n");
+		e_msgport_put(server_port, msg);
+		printf("client: waiting for reply\n");
+		e_msgport_wait(replyport);
+		e_msgport_get(replyport);
+		printf("client: got reply\n");
+	}
+
+	printf("client: sleeping ...\n");
+	sleep(2);
+	printf("client: sending multiple\n");
+
+	for (i=0;i<10;i++) {
+		msg = g_malloc0(sizeof(*msg));
+		msg->reply_port = replyport;
+		e_msgport_put(server_port, msg);
+	}
+
+	printf("client: receiving multiple\n");
+	for (i=0;i<10;i++) {
+		e_msgport_wait(replyport);
+		msg = e_msgport_get(replyport);
+		g_free(msg);
+	}
+
+	printf("client: done\n");
+}
+
+int main(int argc, char **argv)
+{
+	pthread_t serverid, clientid;
+
+	g_thread_init(NULL);
+
+	server_port = e_msgport_new();
+
+	/*pthread_create(&serverid, NULL, server, (void *)1);*/
+	pthread_create(&serverid, NULL, fdserver, (void *)1);
+	pthread_create(&clientid, NULL, client, NULL);
+
+	sleep(60);
+
+	return 0;
+}
+#endif