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Reindent epoll_apply_one_change()

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This commit is contained in:
Nick Mathewson 2010-12-16 14:36:09 -05:00
parent 2d55a190e1
commit d4970d4edd
1 changed files with 92 additions and 95 deletions
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187
epoll.c
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@ -223,6 +223,7 @@ epoll_op_to_string(int op)
the fd, we need to say op="MOD" and set events=the events we want to
remain. But if we want to delete the last event, we say op="DEL" and
set events=(any non-null pointer).
[*1] This MOD is only a guess. MOD might fail with ENOENT if the file was
closed and a new file was opened with the same fd. If so, we'll retry
with ADD.
@ -340,103 +341,99 @@ epoll_apply_one_change(struct event_base *base,
int op, events = 0;
int idx;
if (1) {
idx = INDEX(ch);
op = op_table[idx].op;
events = op_table[idx].events;
idx = INDEX(ch);
op = op_table[idx].op;
events = op_table[idx].events;
if (!events) {
EVUTIL_ASSERT(op == 0);
return 0;
}
if ((ch->read_change|ch->write_change) & EV_CHANGE_ET)
events |= EPOLLET;
memset(&epev, 0, sizeof(epev));
epev.data.fd = ch->fd;
epev.events = events;
if (epoll_ctl(epollop->epfd, op, ch->fd, &epev) == 0) {
event_debug(("Epoll %s(%d) on fd %d okay. [old events were %d; read change was %d; write change was %d]",
epoll_op_to_string(op),
(int)epev.events,
(int)ch->fd,
ch->old_events,
ch->read_change,
ch->write_change));
return 0;
}
switch (op) {
case EPOLL_CTL_MOD:
if (errno == ENOENT) {
/* If a MOD operation fails with ENOENT, the
* fd was probably closed and re-opened. We
* should retry the operation as an ADD.
*/
if (epoll_ctl(epollop->epfd, EPOLL_CTL_ADD, ch->fd, &epev) == -1) {
event_warn("Epoll MOD(%d) on %d retried as ADD; that failed too",
(int)epev.events, ch->fd);
return -1;
} else {
event_debug(("Epoll MOD(%d) on %d retried as ADD; succeeded.",
(int)epev.events,
ch->fd));
return 0;
}
}
break;
case EPOLL_CTL_ADD:
if (errno == EEXIST) {
/* If an ADD operation fails with EEXIST,
* either the operation was redundant (as with a
* precautionary add), or we ran into a fun
* kernel bug where using dup*() to duplicate the
* same file into the same fd gives you the same epitem
* rather than a fresh one. For the second case,
* we must retry with MOD. */
if (epoll_ctl(epollop->epfd, EPOLL_CTL_MOD, ch->fd, &epev) == -1) {
event_warn("Epoll ADD(%d) on %d retried as MOD; that failed too",
(int)epev.events, ch->fd);
return -1;
} else {
event_debug(("Epoll ADD(%d) on %d retried as MOD; succeeded.",
(int)epev.events,
ch->fd));
return 0;
}
}
break;
case EPOLL_CTL_DEL:
if (errno == ENOENT || errno == EBADF ||
errno == EPERM) {
/* If a delete fails with one of these errors,
* that's fine too: we closed the fd before we
* got around to calling epoll_dispatch. */
event_debug(("Epoll DEL(%d) on fd %d gave %s: DEL was unnecessary.",
(int)epev.events,
ch->fd,
strerror(errno)));
return 0;
}
break;
default:
break;
}
if (1) {
event_warn("Epoll %s(%d) on fd %d failed. Old events were %d; read change was %d (%s); write change was %d (%s)",
epoll_op_to_string(op),
(int)epev.events,
ch->fd,
ch->old_events,
ch->read_change,
change_to_string(ch->read_change),
ch->write_change,
change_to_string(ch->write_change));
}
return -1;
if (!events) {
EVUTIL_ASSERT(op == 0);
return 0;
}
if ((ch->read_change|ch->write_change) & EV_CHANGE_ET)
events |= EPOLLET;
memset(&epev, 0, sizeof(epev));
epev.data.fd = ch->fd;
epev.events = events;
if (epoll_ctl(epollop->epfd, op, ch->fd, &epev) == 0) {
event_debug(("Epoll %s(%d) on fd %d okay. [old events were %d; read change was %d; write change was %d]",
epoll_op_to_string(op),
(int)epev.events,
(int)ch->fd,
ch->old_events,
ch->read_change,
ch->write_change));
return 0;
}
switch (op) {
case EPOLL_CTL_MOD:
if (errno == ENOENT) {
/* If a MOD operation fails with ENOENT, the
* fd was probably closed and re-opened. We
* should retry the operation as an ADD.
*/
if (epoll_ctl(epollop->epfd, EPOLL_CTL_ADD, ch->fd, &epev) == -1) {
event_warn("Epoll MOD(%d) on %d retried as ADD; that failed too",
(int)epev.events, ch->fd);
return -1;
} else {
event_debug(("Epoll MOD(%d) on %d retried as ADD; succeeded.",
(int)epev.events,
ch->fd));
return 0;
}
}
break;
case EPOLL_CTL_ADD:
if (errno == EEXIST) {
/* If an ADD operation fails with EEXIST,
* either the operation was redundant (as with a
* precautionary add), or we ran into a fun
* kernel bug where using dup*() to duplicate the
* same file into the same fd gives you the same epitem
* rather than a fresh one. For the second case,
* we must retry with MOD. */
if (epoll_ctl(epollop->epfd, EPOLL_CTL_MOD, ch->fd, &epev) == -1) {
event_warn("Epoll ADD(%d) on %d retried as MOD; that failed too",
(int)epev.events, ch->fd);
return -1;
} else {
event_debug(("Epoll ADD(%d) on %d retried as MOD; succeeded.",
(int)epev.events,
ch->fd));
return 0;
}
}
break;
case EPOLL_CTL_DEL:
if (errno == ENOENT || errno == EBADF || errno == EPERM) {
/* If a delete fails with one of these errors,
* that's fine too: we closed the fd before we
* got around to calling epoll_dispatch. */
event_debug(("Epoll DEL(%d) on fd %d gave %s: DEL was unnecessary.",
(int)epev.events,
ch->fd,
strerror(errno)));
return 0;
}
break;
default:
break;
}
event_warn("Epoll %s(%d) on fd %d failed. Old events were %d; read change was %d (%s); write change was %d (%s)",
epoll_op_to_string(op),
(int)epev.events,
ch->fd,
ch->old_events,
ch->read_change,
change_to_string(ch->read_change),
ch->write_change,
change_to_string(ch->write_change));
return -1;
}
static int