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Reindent epoll_apply_one_change()
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@nmathewson
nmathewson committed Dec 16, 2010
1 parent 2d55a19 commit d4970d4
Showing 1 changed file with 86 additions and 89 deletions.
175 changes: 86 additions & 89 deletions epoll.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand Down Expand Up @@ -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;
if (!events) {
EVUTIL_ASSERT(op == 0);
return 0;
}

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;
}
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.",
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,
strerror(errno)));
ch->fd));
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));
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;
}
return -1;
}
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
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