From 33a2540fb12cec9052f9b92810f2a9aa5b395911 Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Fri, 17 Mar 2017 01:57:34 +0000 Subject: avoid reading errno repeatedly errno is in the thread-specific section and it is slightly cheaper to read it once rather than twice. Recent versions of mainline Ruby itself follows the same pattern. --- ext/raindrops/raindrops.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/ext/raindrops/raindrops.c b/ext/raindrops/raindrops.c index 390b8b8..9090839 100644 --- a/ext/raindrops/raindrops.c +++ b/ext/raindrops/raindrops.c @@ -117,7 +117,9 @@ retry: r->drops = mmap(NULL, tmp, PROT_READ|PROT_WRITE, MAP_ANON|MAP_SHARED, -1, 0); if (r->drops == MAP_FAILED) { - if ((errno == EAGAIN || errno == ENOMEM) && tries-- > 0) { + int err = errno; + + if ((err == EAGAIN || err == ENOMEM) && tries-- > 0) { rb_gc(); goto retry; } @@ -153,7 +155,9 @@ static void resize(struct raindrops *r, size_t new_rd_size) rv = mremap(old_address, old_size, new_size, MREMAP_MAYMOVE); if (rv == MAP_FAILED) { - if (errno == EAGAIN || errno == ENOMEM) { + int err = errno; + + if (err == EAGAIN || err == ENOMEM) { rb_gc(); rv = mremap(old_address, old_size, new_size, 0); } -- cgit v1.2.3-24-ge0c7