From: Roy Marples <roy@marples.name>
Date: Fri, 12 Nov 2021 16:24:32 +0000 (+0000)
Subject: Revert "eloop: Allow eloop to process all fds returned from poll(2)"
X-Git-Tag: v9.5.0~38
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2b4fe4c12b5d4366ff21fabf3a6c3799f8e4fa53;p=thirdparty%2Fdhcpcd.git

Revert "eloop: Allow eloop to process all fds returned from poll(2)"

This stops dumping leases when privsep is compiled out.
This change works fine on master, but we also have eloop using
more of a native poll(2) style interface.
Easier for now to just revert this on the dhcpcd-9 branch.

This reverts commit fe2b82eec25da908c3a1a71c2dc2402d9ff70e31.
---

diff --git a/src/eloop.c b/src/eloop.c
index a6ab43fb..c3330817 100644
--- a/src/eloop.c
+++ b/src/eloop.c
@@ -32,7 +32,6 @@
 #include <errno.h>
 #include <limits.h>
 #include <poll.h>
-#include <stdbool.h>
 #include <signal.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -137,7 +136,6 @@ struct eloop {
 	TAILQ_HEAD (event_head, eloop_event) events;
 	size_t nevents;
 	struct event_head free_events;
-	bool events_need_setup;
 
 	struct timespec now;
 	TAILQ_HEAD (timeout_head, eloop_timeout) timeouts;
@@ -284,16 +282,11 @@ eloop_reduce_timers(struct eloop *eloop)
 static void
 eloop_event_setup_fds(struct eloop *eloop)
 {
-	struct eloop_event *e, *ne;
+	struct eloop_event *e;
 	struct pollfd *pfd;
 
 	pfd = eloop->fds;
-	TAILQ_FOREACH_SAFE(e, &eloop->events, next, ne) {
-		if (e->fd == -1) {
-			TAILQ_REMOVE(&eloop->events, e, next);
-			TAILQ_INSERT_TAIL(&eloop->free_events, e, next);
-			continue;
-		}
+	TAILQ_FOREACH(e, &eloop->events, next) {
 #ifdef ELOOP_DEBUG
 		fprintf(stderr, "%s(%d) fd=%d, rcb=%p, wcb=%p\n",
 		    __func__, getpid(), e->fd, e->read_cb, e->write_cb);
@@ -308,7 +301,6 @@ eloop_event_setup_fds(struct eloop *eloop)
 		pfd->revents = 0;
 		pfd++;
 	}
-	eloop->events_need_setup = false;
 }
 
 size_t
@@ -376,8 +368,7 @@ eloop_event_add_rw(struct eloop *eloop, int fd,
 	}
 
 setup:
-	e->pollfd = NULL;
-	eloop->events_need_setup = true;
+	eloop_event_setup_fds(eloop);
 	return 0;
 }
 
@@ -403,10 +394,6 @@ eloop_event_delete_write(struct eloop *eloop, int fd, int write_only)
 	struct eloop_event *e;
 
 	assert(eloop != NULL);
-	if (fd == -1) {
-		errno = EINVAL;
-		return -1;
-	}
 
 	TAILQ_FOREACH(e, &eloop->events, next) {
 		if (e->fd == fd)
@@ -422,17 +409,16 @@ eloop_event_delete_write(struct eloop *eloop, int fd, int write_only)
 			goto remove;
 		e->write_cb = NULL;
 		e->write_cb_arg = NULL;
-		if (e->pollfd != NULL) {
-			e->pollfd->events &= ~POLLOUT;
-			e->pollfd->revents &= ~POLLOUT;
-		}
-		return 1;
+		goto done;
 	}
 
 remove:
-	e->fd = -1;
+	TAILQ_REMOVE(&eloop->events, e, next);
+	TAILQ_INSERT_TAIL(&eloop->free_events, e, next);
 	eloop->nevents--;
-	eloop->events_need_setup = true;
+
+done:
+	eloop_event_setup_fds(eloop);
 	return 1;
 }
 
@@ -750,9 +736,6 @@ eloop_start(struct eloop *eloop, sigset_t *signals)
 		} else
 			tsp = NULL;
 
-		if (eloop->events_need_setup)
-			eloop_event_setup_fds(eloop);
-
 		n = ppoll(eloop->fds, (nfds_t)eloop->nevents, tsp, signals);
 		if (n == -1) {
 			if (errno == EINTR)
@@ -763,23 +746,18 @@ eloop_start(struct eloop *eloop, sigset_t *signals)
 			continue;
 
 		TAILQ_FOREACH(e, &eloop->events, next) {
-			/* Skip freshly added events */
-			if (e->pollfd == NULL)
-				continue;
-			if (e->pollfd->revents)
-				n--;
-			if (e->fd != -1 && e->pollfd->revents & POLLOUT) {
-				if (e->write_cb != NULL)
+			if (e->pollfd->revents & POLLOUT) {
+				if (e->write_cb != NULL) {
 					e->write_cb(e->write_cb_arg);
+					break;
+				}
 			}
-			if (e->fd != -1 &&
-			    e->pollfd != NULL && e->pollfd->revents)
-			{
-				if (e->read_cb != NULL)
+			if (e->pollfd->revents) {
+				if (e->read_cb != NULL) {
 					e->read_cb(e->read_cb_arg);
+					break;
+				}
 			}
-			if (n == 0)
-				break;
 		}
 	}