channel: Remove old epoll support and fixed max number of file descriptors.

This change removes the old epoll support which has not been used or
maintained in quite some time.

The fixed number of file descriptors on a channel has also been removed.
File descriptors are now contained in a growable vector. This can be
used like before by specifying a specific position to store a file
descriptor at or using a new API call, ast_channel_fd_add, which adds
a file descriptor to the channel and returns its position.

Tests have been added which cover the growing behavior of the vector
and the new API call.

ASTERISK-26885

Change-Id: I1a754b506c009b83dfdeeb08c2d2815db30ef928

1 files changed, 20 insertions, 316 deletions

diff --git a/main/channel.c b/main/channel.c
index 15c7fa406..31f363938 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -78,21 +78,12 @@
 /*** DOCUMENTATION
  ***/
 
-#ifdef HAVE_EPOLL
-#include <sys/epoll.h>
-#endif
-
 #if defined(KEEP_TILL_CHANNEL_PARTY_NUMBER_INFO_NEEDED)
 #if defined(HAVE_PRI)
 #include "libpri.h"
 #endif	/* defined(HAVE_PRI) */
 #endif	/* defined(KEEP_TILL_CHANNEL_PARTY_NUMBER_INFO_NEEDED) */
 
-struct ast_epoll_data {
-	struct ast_channel *chan;
-	int which;
-};
-
 /* uncomment if you have problems with 'monitoring' synchronized files */
 #if 0
 #define MONITOR_CONSTANT_DELAY
@@ -850,10 +841,6 @@ __ast_channel_alloc_ap(int needqueue, int state, const char *cid_num, const char
 	ast_channel_internal_alertpipe_clear(tmp);
 	ast_channel_internal_fd_clear_all(tmp);
 
-#ifdef HAVE_EPOLL
-	ast_channel_epfd_set(tmp, epoll_create(25));
-#endif
-
 	if (!(schedctx = ast_sched_context_create())) {
 		ast_log(LOG_WARNING, "Channel allocation failed: Unable to create schedule context\n");
 		/* See earlier channel creation abort comment above. */
@@ -1058,9 +1045,6 @@ struct ast_channel *__ast_dummy_channel_alloc(const char *file, int line, const
 	ast_channel_timingfd_set(tmp, -1);
 	ast_channel_internal_alertpipe_clear(tmp);
 	ast_channel_internal_fd_clear_all(tmp);
-#ifdef HAVE_EPOLL
-	ast_channel_epfd_set(tmp, -1);
-#endif
 
 	ast_channel_hold_state_set(tmp, AST_CONTROL_UNHOLD);
 
@@ -2223,9 +2207,6 @@ void ast_party_redirecting_free(struct ast_party_redirecting *doomed)
 static void ast_channel_destructor(void *obj)
 {
 	struct ast_channel *chan = obj;
-#ifdef HAVE_EPOLL
-	int i;
-#endif
 	struct ast_var_t *vardata;
 	struct ast_frame *f;
 	struct varshead *headp;
@@ -2323,14 +2304,6 @@ static void ast_channel_destructor(void *obj)
 		ast_timer_close(ast_channel_timer(chan));
 		ast_channel_timer_set(chan, NULL);
 	}
-#ifdef HAVE_EPOLL
-	for (i = 0; i < AST_MAX_FDS; i++) {
-		if (ast_channel_internal_epfd_data(chan, i)) {
-			ast_free(ast_channel_internal_epfd_data(chan, i));
-		}
-	}
-	close(ast_channel_epfd(chan));
-#endif
 	while ((f = AST_LIST_REMOVE_HEAD(ast_channel_readq(chan), frame_list)))
 		ast_frfree(f);
 
@@ -2481,82 +2454,10 @@ struct ast_datastore *ast_channel_datastore_find(struct ast_channel *chan, const
 /*! Set the file descriptor on the channel */
 void ast_channel_set_fd(struct ast_channel *chan, int which, int fd)
 {
-#ifdef HAVE_EPOLL
-	struct epoll_event ev;
-	struct ast_epoll_data *aed = NULL;
-
-	if (ast_channel_fd_isset(chan, which)) {
-		epoll_ctl(ast_channel_epfd(chan), EPOLL_CTL_DEL, ast_channel_fd(chan, which), &ev);
-		aed = ast_channel_internal_epfd_data(chan, which);
-	}
-
-	/* If this new fd is valid, add it to the epoll */
-	if (fd > -1) {
-		if (!aed && (!(aed = ast_calloc(1, sizeof(*aed)))))
-			return;
-
-		ast_channel_internal_epfd_data_set(chan, which, aed);
-		aed->chan = chan;
-		aed->which = which;
-
-		ev.events = EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP;
-		ev.data.ptr = aed;
-		epoll_ctl(ast_channel_epfd(chan), EPOLL_CTL_ADD, fd, &ev);
-	} else if (aed) {
-		/* We don't have to keep around this epoll data structure now */
-		ast_free(aed);
-		ast_channel_epfd_data_set(chan, which, NULL);
-	}
-#endif
 	ast_channel_internal_fd_set(chan, which, fd);
 	return;
 }
 
-/*! Add a channel to an optimized waitfor */
-void ast_poll_channel_add(struct ast_channel *chan0, struct ast_channel *chan1)
-{
-#ifdef HAVE_EPOLL
-	struct epoll_event ev;
-	int i = 0;
-
-	if (ast_channel_epfd(chan0) == -1)
-		return;
-
-	/* Iterate through the file descriptors on chan1, adding them to chan0 */
-	for (i = 0; i < AST_MAX_FDS; i++) {
-		if (!ast_channel_fd_isset(chan1, i)) {
-			continue;
-		}
-		ev.events = EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP;
-		ev.data.ptr = ast_channel_internal_epfd_data(chan1, i);
-		epoll_ctl(ast_channel_epfd(chan0), EPOLL_CTL_ADD, ast_channel_fd(chan1, i), &ev);
-	}
-
-#endif
-	return;
-}
-
-/*! Delete a channel from an optimized waitfor */
-void ast_poll_channel_del(struct ast_channel *chan0, struct ast_channel *chan1)
-{
-#ifdef HAVE_EPOLL
-	struct epoll_event ev;
-	int i = 0;
-
-	if (ast_channel_epfd(chan0) == -1)
-		return;
-
-	for (i = 0; i < AST_MAX_FDS; i++) {
-		if (!ast_channel_fd_isset(chan1, i)) {
-			continue;
-		}
-		epoll_ctl(ast_channel_epfd(chan0), EPOLL_CTL_DEL, ast_channel_fd(chan1, i), &ev);
-	}
-
-#endif
-	return;
-}
-
 void ast_channel_clear_softhangup(struct ast_channel *chan, int flag)
 {
 	ast_channel_lock(chan);
@@ -3061,20 +2962,15 @@ int ast_waitfor_n_fd(int *fds, int n, int *ms, int *exception)
 }
 
 /*! \brief Wait for x amount of time on a file descriptor to have input.  */
-#ifdef HAVE_EPOLL
-static struct ast_channel *ast_waitfor_nandfds_classic(struct ast_channel **c, int n, int *fds, int nfds,
-					int *exception, int *outfd, int *ms)
-#else
 struct ast_channel *ast_waitfor_nandfds(struct ast_channel **c, int n, int *fds, int nfds,
 					int *exception, int *outfd, int *ms)
-#endif
 {
 	struct timeval start = { 0 , 0 };
 	struct pollfd *pfds = NULL;
 	int res;
 	long rms;
 	int x, y, max;
-	int sz;
+	int sz = nfds;
 	struct timeval now = { 0, 0 };
 	struct timeval whentohangup = { 0, 0 }, diff;
 	struct ast_channel *winner = NULL;
@@ -3090,14 +2986,6 @@ struct ast_channel *ast_waitfor_nandfds(struct ast_channel **c, int n, int *fds,
 		*exception = 0;
 	}
 
-	if ((sz = n * AST_MAX_FDS + nfds)) {
-		pfds = ast_alloca(sizeof(*pfds) * sz);
-		fdmap = ast_alloca(sizeof(*fdmap) * sz);
-	} else {
-		/* nothing to allocate and no FDs to check */
-		return NULL;
-	}
-
 	for (x = 0; x < n; x++) {
 		ast_channel_lock(c[x]);
 		if (!ast_tvzero(*ast_channel_whentohangup(c[x]))) {
@@ -3114,8 +3002,17 @@ struct ast_channel *ast_waitfor_nandfds(struct ast_channel **c, int n, int *fds,
 			if (ast_tvzero(whentohangup) || ast_tvcmp(diff, whentohangup) < 0)
 				whentohangup = diff;
 		}
+		sz += ast_channel_fd_count(c[x]);
 		ast_channel_unlock(c[x]);
 	}
+
+	if (!sz) {
+		return NULL;
+	}
+
+	pfds = ast_alloca(sizeof(*pfds) * sz);
+	fdmap = ast_alloca(sizeof(*fdmap) * sz);
+
 	/* Wait full interval */
 	rms = *ms;
 	/* INT_MAX, not LONG_MAX, because it matters on 64-bit */
@@ -3135,12 +3032,12 @@ struct ast_channel *ast_waitfor_nandfds(struct ast_channel **c, int n, int *fds,
 	 */
 	max = 0;
 	for (x = 0; x < n; x++) {
-		for (y = 0; y < AST_MAX_FDS; y++) {
+		ast_channel_lock(c[x]);
+		for (y = 0; y < ast_channel_fd_count(c[x]); y++) {
 			fdmap[max].fdno = y;  /* fd y is linked to this pfds */
 			fdmap[max].chan = x;  /* channel x is linked to this pfds */
 			max += ast_add_fd(&pfds[max], ast_channel_fd(c[x], y));
 		}
-		ast_channel_lock(c[x]);
 		CHECK_BLOCKING(c[x]);
 		ast_channel_unlock(c[x]);
 	}
@@ -3234,205 +3131,6 @@ struct ast_channel *ast_waitfor_nandfds(struct ast_channel **c, int n, int *fds,
 	return winner;
 }
 
-#ifdef HAVE_EPOLL
-static struct ast_channel *ast_waitfor_nandfds_simple(struct ast_channel *chan, int *ms)
-{
-	struct timeval start = { 0 , 0 };
-	int res = 0;
-	struct epoll_event ev[1];
-	long diff, rms = *ms;
-	struct ast_channel *winner = NULL;
-	struct ast_epoll_data *aed = NULL;
-
-	ast_channel_lock(chan);
-	/* Figure out their timeout */
-	if (!ast_tvzero(*ast_channel_whentohangup(chan))) {
-		if ((diff = ast_tvdiff_ms(*ast_channel_whentohangup(chan), ast_tvnow())) < 0) {
-			/* They should already be hungup! */
-			ast_channel_softhangup_internal_flag_add(chan, AST_SOFTHANGUP_TIMEOUT);
-			ast_channel_unlock(chan);
-			return NULL;
-		}
-		/* If this value is smaller then the current one... make it priority */
-		if (rms > diff) {
-			rms = diff;
-		}
-	}
-
-	ast_channel_unlock(chan);
-
-	/* Time to make this channel block... */
-	CHECK_BLOCKING(chan);
-
-	if (*ms > 0) {
-		start = ast_tvnow();
-	}
-
-	/* We don't have to add any file descriptors... they are already added, we just have to wait! */
-	res = epoll_wait(ast_channel_epfd(chan), ev, 1, rms);
-
-	/* Stop blocking */
-	ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING);
-
-	/* Simulate a timeout if we were interrupted */
-	if (res < 0) {
-		if (errno != EINTR) {
-			*ms = -1;
-		}
-		return NULL;
-	}
-
-	/* If this channel has a timeout see if it expired */
-	if (!ast_tvzero(*ast_channel_whentohangup(chan))) {
-		if (ast_tvdiff_ms(ast_tvnow(), *ast_channel_whentohangup(chan)) >= 0) {
-			ast_channel_softhangup_internal_flag_add(chan, AST_SOFTHANGUP_TIMEOUT);
-			winner = chan;
-		}
-	}
-
-	/* No fd ready, reset timeout and be done for now */
-	if (!res) {
-		*ms = 0;
-		return winner;
-	}
-
-	/* See what events are pending */
-	aed = ev[0].data.ptr;
-	ast_channel_fdno_set(chan, aed->which);
-	if (ev[0].events & EPOLLPRI) {
-		ast_set_flag(ast_channel_flags(chan), AST_FLAG_EXCEPTION);
-	} else {
-		ast_clear_flag(ast_channel_flags(chan), AST_FLAG_EXCEPTION);
-	}
-
-	if (*ms > 0) {
-		*ms -= ast_tvdiff_ms(ast_tvnow(), start);
-		if (*ms < 0) {
-			*ms = 0;
-		}
-	}
-
-	return chan;
-}
-
-static struct ast_channel *ast_waitfor_nandfds_complex(struct ast_channel **c, int n, int *ms)
-{
-	struct timeval start = { 0 , 0 };
-	int res = 0, i;
-	struct epoll_event ev[25] = { { 0, } };
-	struct timeval now = { 0, 0 };
-	long whentohangup = 0, diff = 0, rms = *ms;
-	struct ast_channel *winner = NULL;
-
-	for (i = 0; i < n; i++) {
-		ast_channel_lock(c[i]);
-		if (!ast_tvzero(*ast_channel_whentohangup(c[i]))) {
-			if (whentohangup == 0) {
-				now = ast_tvnow();
-			}
-			if ((diff = ast_tvdiff_ms(*ast_channel_whentohangup(c[i]), now)) < 0) {
-				ast_channel_softhangup_internal_flag_add(c[i], AST_SOFTHANGUP_TIMEOUT);
-				ast_channel_unlock(c[i]);
-				return c[i];
-			}
-			if (!whentohangup || whentohangup > diff) {
-				whentohangup = diff;
-			}
-		}
-		ast_channel_unlock(c[i]);
-		CHECK_BLOCKING(c[i]);
-	}
-
-	rms = *ms;
-	if (whentohangup) {
-		rms = whentohangup;
-		if (*ms >= 0 && *ms < rms) {
-			rms = *ms;
-		}
-	}
-
-	if (*ms > 0) {
-		start = ast_tvnow();
-	}
-
-	res = epoll_wait(ast_channel_epfd(c[0]), ev, 25, rms);
-
-	for (i = 0; i < n; i++) {
-		ast_clear_flag(ast_channel_flags(c[i]), AST_FLAG_BLOCKING);
-	}
-
-	if (res < 0) {
-		if (errno != EINTR) {
-			*ms = -1;
-		}
-		return NULL;
-	}
-
-	if (whentohangup) {
-		now = ast_tvnow();
-		for (i = 0; i < n; i++) {
-			if (!ast_tvzero(*ast_channel_whentohangup(c[i])) && ast_tvdiff_ms(now, *ast_channel_whentohangup(c[i])) >= 0) {
-				ast_channel_softhangup_internal_flag_add(c[i], AST_SOFTHANGUP_TIMEOUT);
-				if (!winner) {
-					winner = c[i];
-				}
-			}
-		}
-	}
-
-	if (!res) {
-		*ms = 0;
-		return winner;
-	}
-
-	for (i = 0; i < res; i++) {
-		struct ast_epoll_data *aed = ev[i].data.ptr;
-
-		if (!ev[i].events || !aed) {
-			continue;
-		}
-
-		winner = aed->chan;
-		if (ev[i].events & EPOLLPRI) {
-			ast_set_flag(ast_channel_flags(winner), AST_FLAG_EXCEPTION);
-		} else {
-			ast_clear_flag(ast_channel_flags(winner), AST_FLAG_EXCEPTION);
-		}
-		ast_channel_fdno_set(winner, aed->which);
-	}
-
-	if (*ms > 0) {
-		*ms -= ast_tvdiff_ms(ast_tvnow(), start);
-		if (*ms < 0) {
-			*ms = 0;
-		}
-	}
-
-	return winner;
-}
-
-struct ast_channel *ast_waitfor_nandfds(struct ast_channel **c, int n, int *fds, int nfds,
-					int *exception, int *outfd, int *ms)
-{
-	/* Clear all provided values in one place. */
-	if (outfd) {
-		*outfd = -99999;
-	}
-	if (exception) {
-		*exception = 0;
-	}
-
-	/* If no epoll file descriptor is available resort to classic nandfds */
-	if (!n || nfds || ast_channel_epfd(c[0]) == -1) {
-		return ast_waitfor_nandfds_classic(c, n, fds, nfds, exception, outfd, ms);
-	} else if (!nfds && n == 1) {
-		return ast_waitfor_nandfds_simple(c[0], ms);
-	} else {
-		return ast_waitfor_nandfds_complex(c, n, ms);
-	}
-}
-#endif
-
 struct ast_channel *ast_waitfor_n(struct ast_channel **c, int n, int *ms)
 {
 	return ast_waitfor_nandfds(c, n, NULL, 0, NULL, NULL, ms);
@@ -6852,6 +6550,7 @@ static void channel_do_masquerade(struct ast_channel *original, struct ast_chann
 	int origstate;
 	unsigned int orig_disablestatecache;
 	unsigned int clone_disablestatecache;
+	int generator_fd;
 	int visible_indication;
 	int clone_hold_state;
 	int moh_is_playing;
@@ -7042,8 +6741,13 @@ static void channel_do_masquerade(struct ast_channel *original, struct ast_chann
 	/* Keep the same parkinglot. */
 	ast_channel_parkinglot_set(original, ast_channel_parkinglot(clonechan));
 
-	/* Copy the FD's other than the generator fd */
-	for (x = 0; x < AST_MAX_FDS; x++) {
+	/* Clear all existing file descriptors but retain the generator */
+	generator_fd = ast_channel_fd(original, AST_GENERATOR_FD);
+	ast_channel_internal_fd_clear_all(original);
+	ast_channel_set_fd(original, AST_GENERATOR_FD, generator_fd);
+
+	/* Copy all file descriptors present on clonechan to original, skipping generator */
+	for (x = 0; x < ast_channel_fd_count(clonechan); x++) {
 		if (x != AST_GENERATOR_FD)
 			ast_channel_set_fd(original, x, ast_channel_fd(clonechan, x));
 	}