From: Eric Wong <e@80x24.org> To: raindrops-public@bogomips.org Subject: [PATCH] avoid reading errno repeatedly Date: Fri, 17 Mar 2017 01:57:34 +0000 [thread overview] Message-ID: <20170317015734.9783-1-e@80x24.org> (raw) 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); } -- EW
reply other threads:[~2017-03-17 1:57 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style List information: https://yhbt.net/raindrops/ * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20170317015734.9783-1-e@80x24.org \ --to=e@80x24.org \ --cc=raindrops-public@bogomips.org \ --subject='Re: [PATCH] avoid reading errno repeatedly' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Code repositories for project(s) associated with this inbox: ../../raindrops.git This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).