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authornormal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2018-11-28 01:10:40 (GMT)
committernormal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2018-11-28 01:10:40 (GMT)
commitdb7338fd7518b068269aa102e821ac388f519cd9 (patch)
tree9a24c11108e985c0ae8ddf704cb3964b34d4cde7 /io.c
parentc5fe904f6ea24a1f38c6a3b33937067f9390ca70 (diff)
io.c (rb_update_max_fd): use F_GETFL if possible
On 64-bit Linux, fstat() needs to fill out a 144 byte struct while F_GETFL only needs to return 8 bytes. Fwiw, F_GETFD requires an additional rcu_read_lock and bitmap check; so it's obviously more expensive than F_GETFL on Linux. Reduce stack usage of rb_update_max_fd from 184 to 24 bytes. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66060 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'io.c')
-rw-r--r--io.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/io.c b/io.c
index 28dfd56..d59bde9 100644
--- a/io.c
+++ b/io.c
@@ -193,14 +193,22 @@ static rb_atomic_t max_file_descriptor = NOFILE;
void
rb_update_max_fd(int fd)
{
- struct stat buf;
rb_atomic_t afd = (rb_atomic_t)fd;
rb_atomic_t max_fd = max_file_descriptor;
+ int err;
if (afd <= max_fd)
return;
- if (fstat(fd, &buf) != 0 && errno == EBADF) {
+#if defined(HAVE_FCNTL) && defined(F_GETFL)
+ err = fcntl(fd, F_GETFL) == -1;
+#else
+ {
+ struct stat buf;
+ err = fstat(fd, &buf) != 0;
+ }
+#endif
+ if (err && errno == EBADF) {
rb_bug("rb_update_max_fd: invalid fd (%d) given.", fd);
}