From 83e805a41554a9e69ab7d2d75e56c30f3147ffa6 Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Fri, 7 Jan 2011 13:18:09 -0500 Subject: [PATCH] Handle resize failures in the select backend better. --- select.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/select.c b/select.c index 993a4e60..8327518e 100644 --- a/select.c +++ b/select.c @@ -100,7 +100,9 @@ select_init(struct event_base *base) return (NULL); if (select_resize(sop, howmany(32 + 1, NFDBITS)*sizeof(fd_mask))) { - mm_free(sop); + /* select_resize might have left this around. */ + if (sop->event_readset_in) + mm_free(sop->event_readset_in); return (NULL); } @@ -131,11 +133,14 @@ select_dispatch(struct event_base *base, struct timeval *tv) size_t sz = sop->event_fdsz; if (!(readset_out = mm_realloc(sop->event_readset_out, sz))) return (-1); + sop->event_readset_out = readset_out; if (!(writeset_out = mm_realloc(sop->event_writeset_out, sz))) { - mm_free(readset_out); + /* We don't free readset_out here, since it was + * already successfully reallocated. The next time + * we call select_dispatch, the realloc will be a + * no-op. */ return (-1); } - sop->event_readset_out = readset_out; sop->event_writeset_out = writeset_out; sop->resize_out_sets = 0; } @@ -188,7 +193,6 @@ select_dispatch(struct event_base *base, struct timeval *tv) return (0); } - static int select_resize(struct selectop *sop, int fdsz) { @@ -202,7 +206,12 @@ select_resize(struct selectop *sop, int fdsz) goto error; sop->event_readset_in = readset_in; if ((writeset_in = mm_realloc(sop->event_writeset_in, fdsz)) == NULL) { - mm_free(readset_in); + /* Note that this will leave event_readset_in expanded. + * That's okay; we wouldn't want to free it, since that would + * change the semantics of select_resize from "expand the + * readset_in and writeset_in, or return -1" to "expand the + * *set_in members, or trash them and return -1." + */ goto error; } sop->event_writeset_in = writeset_in; -- 2.50.1