From d751dd11ae16fd4e2410d3a32c8e2d951fafc923 Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Sun, 10 Jul 2016 08:20:46 +0000 Subject: hoist out handle_nonblock function for xread and xwrite At least for me, this improves the readability of xread and xwrite; hopefully allowing missing "continue" statements to be spotted more easily. Signed-off-by: Eric Wong Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- wrapper.c | 48 ++++++++++++++++++++---------------------------- 1 file changed, 20 insertions(+), 28 deletions(-) diff --git a/wrapper.c b/wrapper.c index f7ea6c43be..a774ab7d80 100644 --- a/wrapper.c +++ b/wrapper.c @@ -224,6 +224,24 @@ int xopen(const char *path, int oflag, ...) } } +static int handle_nonblock(int fd, short poll_events, int err) +{ + struct pollfd pfd; + + if (err != EAGAIN && err != EWOULDBLOCK) + return 0; + + pfd.fd = fd; + pfd.events = poll_events; + + /* + * no need to check for errors, here; + * a subsequent read/write will detect unrecoverable errors + */ + poll(&pfd, 1, -1); + return 1; +} + /* * xread() is the same a read(), but it automatically restarts read() * operations with a recoverable error (EAGAIN and EINTR). xread() @@ -239,21 +257,8 @@ ssize_t xread(int fd, void *buf, size_t len) if (nr < 0) { if (errno == EINTR) continue; - if (errno == EAGAIN || errno == EWOULDBLOCK) { - struct pollfd pfd; - pfd.events = POLLIN; - pfd.fd = fd; - /* - * it is OK if this poll() failed; we - * want to leave this infinite loop - * only when read() returns with - * success, or an expected failure, - * which would be checked by the next - * call to read(2). - */ - poll(&pfd, 1, -1); + if (handle_nonblock(fd, POLLIN, errno)) continue; - } } return nr; } @@ -274,21 +279,8 @@ ssize_t xwrite(int fd, const void *buf, size_t len) if (nr < 0) { if (errno == EINTR) continue; - if (errno == EAGAIN || errno == EWOULDBLOCK) { - struct pollfd pfd; - pfd.events = POLLOUT; - pfd.fd = fd; - /* - * it is OK if this poll() failed; we - * want to leave this infinite loop - * only when write() returns with - * success, or an expected failure, - * which would be checked by the next - * call to write(2). - */ - poll(&pfd, 1, -1); + if (handle_nonblock(fd, POLLOUT, errno)) continue; - } } return nr; -- cgit v1.2.1