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Remove kqueue->pend_changes.

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Since we're no longer writing directly to it from add/del, we don't
need to worry about it changing as kq_dispatch releases the lock.  We
would make it a local variable, except that we wouldn't want to malloc
and free it all the time.
This commit is contained in:
Nick Mathewson 2010-01-14 17:04:08 -05:00
parent 45e5ae3717
commit 3225dfb91d
1 changed files with 11 additions and 25 deletions
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36
kqueue.c
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@ -67,8 +67,6 @@
struct kqop { struct kqop {
struct kevent *changes; struct kevent *changes;
int changes_size; int changes_size;
struct kevent *pend_changes;
int pend_changes_size;
struct kevent *events; struct kevent *events;
int events_size; int events_size;
@ -132,14 +130,10 @@ kq_init(struct event_base *base)
kqueueop->changes = mm_calloc(NEVENT, sizeof(struct kevent)); kqueueop->changes = mm_calloc(NEVENT, sizeof(struct kevent));
if (kqueueop->changes == NULL) if (kqueueop->changes == NULL)
goto err; goto err;
kqueueop->pend_changes = mm_calloc(NEVENT, sizeof(struct kevent));
if (kqueueop->pend_changes == NULL)
goto err;
kqueueop->events = mm_calloc(NEVENT, sizeof(struct kevent)); kqueueop->events = mm_calloc(NEVENT, sizeof(struct kevent));
if (kqueueop->events == NULL) if (kqueueop->events == NULL)
goto err; goto err;
kqueueop->events_size = kqueueop->changes_size = kqueueop->events_size = kqueueop->changes_size = NEVENT;
kqueueop->pend_changes_size = NEVENT;
/* Check for Mac OS X kqueue bug. */ /* Check for Mac OS X kqueue bug. */
memset(&kqueueop->changes[0], 0, sizeof kqueueop->changes[0]); memset(&kqueueop->changes[0], 0, sizeof kqueueop->changes[0]);
@ -198,14 +192,6 @@ kq_setup_kevent(struct kevent *out, evutil_socket_t fd, int filter, short change
} }
} }
#define SWAP(tp,a,b) \
do { \
tp tmp_swap_var = (a); \
a = b; \
b = tmp_swap_var; \
} while (0);
static int static int
kq_build_changes_list(const struct event_changelist *changelist, kq_build_changes_list(const struct event_changelist *changelist,
struct kqop *kqop) struct kqop *kqop)
@ -248,6 +234,7 @@ kq_dispatch(struct event_base *base, struct timeval *tv)
{ {
struct kqop *kqop = base->evbase; struct kqop *kqop = base->evbase;
struct kevent *events = kqop->events; struct kevent *events = kqop->events;
struct kevent *changes;
struct timespec ts, *ts_p = NULL; struct timespec ts, *ts_p = NULL;
int i, n_changes, res; int i, n_changes, res;
@ -257,27 +244,28 @@ kq_dispatch(struct event_base *base, struct timeval *tv)
} }
/* Build "changes" from "base->changes" */ /* Build "changes" from "base->changes" */
EVUTIL_ASSERT(kqop->changes);
n_changes = kq_build_changes_list(&base->changelist, kqop); n_changes = kq_build_changes_list(&base->changelist, kqop);
if (n_changes < 0) if (n_changes < 0)
return -1; return -1;
event_changelist_remove_all(&base->changelist, base); event_changelist_remove_all(&base->changelist, base);
/* We can't hold the lock while we're calling kqueue, so another /* steal the changes array in case some broken code tries to call
* thread might potentially mess with changes before the kernel has a * dispatch twice at once. */
* chance to read it. Therefore, we need to keep the change list changes = kqop->changes;
* we're looking at in pend_changes, and let other threads mess with kqop->changes = NULL;
* changes. */
SWAP(struct kevent *, kqop->changes, kqop->pend_changes);
SWAP(int, kqop->changes_size, kqop->pend_changes_size);
EVBASE_RELEASE_LOCK(base, th_base_lock); EVBASE_RELEASE_LOCK(base, th_base_lock);
res = kevent(kqop->kq, kqop->pend_changes, n_changes, res = kevent(kqop->kq, changes, n_changes,
events, kqop->events_size, ts_p); events, kqop->events_size, ts_p);
EVBASE_ACQUIRE_LOCK(base, th_base_lock); EVBASE_ACQUIRE_LOCK(base, th_base_lock);
EVUTIL_ASSERT(kqop->changes == NULL);
kqop->changes = changes;
if (res == -1) { if (res == -1) {
if (errno != EINTR) { if (errno != EINTR) {
event_warn("kevent"); event_warn("kevent");
@ -353,8 +341,6 @@ kqop_free(struct kqop *kqop)
{ {
if (kqop->changes) if (kqop->changes)
mm_free(kqop->changes); mm_free(kqop->changes);
if (kqop->pend_changes)
mm_free(kqop->pend_changes);
if (kqop->events) if (kqop->events)
mm_free(kqop->events); mm_free(kqop->events);
if (kqop->kq >= 0 && kqop->pid == getpid()) if (kqop->kq >= 0 && kqop->pid == getpid())