Version 0.1.0 from FTP

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@2 65c4cc65-6c06-0410-ace0-fbb531ad65f3

doc/model.txt

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+Description of call model:
+
+Incoming Call:
+
+	Channel backend waits for a RING or equivalent on some sort of
+interface. Typically this is done in its own thread.  When a RING is
+detected, the backend should create a channel structure and then call
+ast_pbx_start() on that channel, which will create a thread to monitor
+that interface.  At this point, the PBX and/or applications it launches
+will manage the interface, and it need not be montored by the
+aforementioned thread.  When the applications are finished, the requisite
+hangup function will be called, at which the channel can be considered to
+be no longer valid, and the thread that controls it will immenantly be
+terminated. 
+

io.c

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+/*
+ * Asterisk
+ * 
+ * Mark Spencer <markster@marko.net>
+ *
+ * Copyright(C) 1999, Adtran, Inc.
+ * 
+ * Distributed under the terms of the GNU General Public License (GPL) Version 2
+ *
+ * I/O Managment (Derived from Cheops-NG)
+ *
+ */
+
+#include <stdio.h>
+#include <sys/poll.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <asterisk/io.h>
+#include <asterisk/logger.h>
+
+#ifdef DEBUG_IO
+#define DEBUG DEBUG_M
+#else
+#define DEBUG(a) 
+#endif
+
+/* 
+ * Kept for each file descriptor
+ */
+struct io_rec {
+	ast_io_cb callback;		/* What is to be called */
+	void *data; 				/* Data to be passed */
+	int *id; 					/* ID number */
+};
+
+/* These two arrays are keyed with
+   the same index.  it's too bad that
+   pollfd doesn't have a callback field
+   or something like that.  They grow as
+   needed, by GROW_SHRINK_AMOUNT structures
+   at once */
+
+#define GROW_SHRINK_SIZE 512
+
+/* Global variables are now in a struct in order to be
+   made threadsafe */
+struct io_context {
+	/* Poll structure */
+	struct pollfd *fds;
+	/* Associated I/O records */
+	struct io_rec *ior;
+	/* First available fd */
+	unsigned int fdcnt;
+	/* Maximum available fd */
+	unsigned int maxfdcnt;
+	/* Currently used io callback */
+	int current_ioc;
+};
+
+
+struct io_context *io_context_create()
+{
+	/* Create an I/O context */
+	struct io_context *tmp;
+	tmp = malloc(sizeof(struct io_context));
+	if (tmp) {
+		tmp->fds = NULL;
+		tmp->ior =  NULL;
+		tmp->fdcnt = 0;
+		tmp->maxfdcnt = -1;
+		tmp->current_ioc = -1;
+	}
+	return tmp;
+}
+
+void io_context_destroy(struct io_context *ioc)
+{
+	/* Free associated memory with an I/O context */
+	if (ioc->fds)
+		free(ioc->fds);
+	if (ioc->ior)
+		free(ioc->ior);
+	free(ioc);
+}
+
+static int io_grow(struct io_context *ioc)
+{
+	/* 
+	 * Grow the size of our arrays.  Return 0 on success or
+	 * -1 on failure
+	 */
+	void *tmp;
+	DEBUG(ast_log(LOG_DEBUG, "io_grow()\n"));
+	ioc->maxfdcnt += GROW_SHRINK_SIZE;
+	tmp = realloc(ioc->ior, (ioc->maxfdcnt + 1) * sizeof(struct io_rec));
+	if (tmp) {
+		ioc->ior = (struct io_rec *)tmp;
+		tmp = realloc(ioc->fds, (ioc->maxfdcnt + 1) * sizeof(struct pollfd));
+		if (tmp) {
+			ioc->fds = tmp;
+		} else {
+			/*
+			 * Not enough memory for the pollfd.  Not really any need
+			 * to shrink back the iorec's as we'll probably want to
+			 * grow them again soon when more memory is available, and
+			 * then they'll already be the right size
+			 */
+			ioc->maxfdcnt -= GROW_SHRINK_SIZE;
+			return -1;
+		}
+		
+	} else {
+		/*
+		 * Out of memory.  We return to the old size, and return a failure
+		 */
+		ioc->maxfdcnt -= GROW_SHRINK_SIZE;
+		return -1;
+	}
+	return 0;
+}
+
+int *ast_io_add(struct io_context *ioc, int fd, ast_io_cb callback, short events, void *data)
+{
+	/*
+	 * Add a new I/O entry for this file descriptor
+	 * with the given event mask, to call callback with
+	 * data as an argument.  Returns NULL on failure.
+	 */
+	DEBUG(ast_log(LOG_DEBUG, "ast_io_add()\n"));
+	if (ioc->fdcnt < ioc->maxfdcnt) {
+		/* 
+		 * We don't have enough space for this entry.  We need to
+		 * reallocate maxfdcnt poll fd's and io_rec's, or back out now.
+		 */
+		if (io_grow(ioc))
+			return NULL;
+	}
+
+	/*
+	 * At this point, we've got sufficiently large arrays going
+	 * and we can make an entry for it in the pollfd and io_r
+	 * structures.
+	 */
+	ioc->fds[ioc->fdcnt].fd = fd;
+	ioc->fds[ioc->fdcnt].events = events;
+	ioc->ior[ioc->fdcnt].callback = callback;
+	ioc->ior[ioc->fdcnt].data = data;
+	ioc->ior[ioc->fdcnt].id = (int *)malloc(sizeof(int));
+	/* Bonk if we couldn't allocate an int */
+	if (!ioc->ior[ioc->fdcnt].id)
+		return NULL;
+	*ioc->ior[ioc->fdcnt].id = ioc->fdcnt;
+	return ioc->ior[ioc->fdcnt++].id;
+}
+
+int *ast_io_change(struct io_context *ioc, int *id, int fd, ast_io_cb callback, short events, void *data)
+{
+	if (*id < ioc->fdcnt) {
+		if (fd > -1)
+			ioc->fds[*id].fd = fd;
+		if (callback)
+			ioc->ior[*id].callback = callback;
+		if (events)
+			ioc->fds[*id].events = events;
+		if (data)
+			ioc->ior[*id].data = data;
+		return id;
+	} else return NULL;
+}
+
+static int io_shrink(struct io_context *ioc, int which)
+{
+	/* 
+	 * Bring the fields from the very last entry to cover over
+	 * the entry we are removing, then decrease the size of the 
+	 * arrays by one.
+	 */
+	ioc->fdcnt--;
+
+	/* Free the int */
+	free(ioc->ior[which].id);
+	
+	/* If we're not deleting the last one, move the last one to
+	   the current position */
+	if (which != ioc->fdcnt) {
+		ioc->fds[which] = ioc->fds[ioc->fdcnt];
+		ioc->ior[which] = ioc->ior[ioc->fdcnt];
+		*ioc->ior[which].id = which;
+	}
+	/* FIXME: We should free some memory if we have lots of unused
+	   io structs */
+	return 0;
+}
+
+int ast_io_remove(struct io_context *ioc, int *id)
+{
+	if (ioc->current_ioc == *id) {
+		ast_log(LOG_NOTICE, "Callback for %d tried to remove itself\n", *id);
+	} else
+	
+	if (*id < ioc->fdcnt) {
+		return io_shrink(ioc, *id);
+	} else 
+		ast_log(LOG_NOTICE, "Unable to remove unknown id %d\n", *id);
+
+	return -1;
+}
+
+int ast_io_wait(struct io_context *ioc, int howlong)
+{
+	/*
+	 * Make the poll call, and call
+	 * the callbacks for anything that needs
+	 * to be handled
+	 */
+	int res;
+	int x;
+	DEBUG(ast_log(LOG_DEBUG, "ast_io_wait()\n"));
+	res = poll(ioc->fds, ioc->fdcnt, howlong);
+	if (res > 0) {
+		/*
+		 * At least one event
+		 */
+		for(x=0;x<ioc->fdcnt;x++) {
+			if (ioc->fds[x].revents) {
+				/* There's an event waiting */
+				ioc->current_ioc = *ioc->ior[x].id;
+				if (!ioc->ior[x].callback(ioc->ior[x].id, ioc->fds[x].fd, ioc->fds[x].revents, ioc->ior[x].data)) {
+					/* Time to delete them since they returned a 0 */
+					io_shrink(ioc, x);
+				}
+				ioc->current_ioc = -1;
+			}
+		}
+	}
+	return res;
+}
+
+void ast_io_dump(struct io_context *ioc)
+{
+	/*
+	 * Print some debugging information via
+	 * the logger interface
+	 */
+	int x;
+	ast_log(LOG_DEBUG, "Asterisk IO Dump: %d entries, %d max entries\n", ioc->fdcnt, ioc->maxfdcnt);
+	ast_log(LOG_DEBUG, "================================================\n");
+	ast_log(LOG_DEBUG, "| ID    FD     Callback    Data        Events  |\n");
+	ast_log(LOG_DEBUG, "+------+------+-----------+-----------+--------+\n");
+	for (x=0;x<ioc->fdcnt;x++) {
+		ast_log(LOG_DEBUG, "| %.4d | %.4d | %p | %p | %.6x |\n", 
+				*ioc->ior[x].id,
+				ioc->fds[x].fd,
+				ioc->ior[x].callback,
+				ioc->ior[x].data,
+				ioc->fds[x].events);
+	}
+	ast_log(LOG_DEBUG, "================================================\n");
+}