[PATCH v8 1/2] Add xpread()
- From
Yiannis Marangos <yiannis.marangos@gmail.com>
- Date
- Apr 10, 2014, 18:54 UTC
- Message-ID
- <1397156052-1247-1-git-send-email-yiannis.marangos@gmail.com>
- In-Reply-To
- <1397081197-14803-1-git-send-email-yiannis.marangos@gmail.com>
xpread() pay attention to EAGAIN/EINTR, so it will resume automatically on interrupted call.
Signed-off-by: Yiannis Marangos <yiannis.marangos@gmail.com> ---
This is actually the 2nd version of this commit but before I emailed it as version 7 because it's a dependency of [PATCH v7 2/2]. Is this the correct way to introduce a new descendant commit? Sorry, It's my first time that I use mailing lists for contribution.
Version 8 removes xpwrite()
builtin/index-pack.c | 2 +- compat/mmap.c | 4 +--- git-compat-util.h | 1 + wrapper.c | 18 ++++++++++++++++++ 4 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/builtin/index-pack.c b/builtin/index-pack.c index b9f6e12..1bac0f5 100644 --- a/builtin/index-pack.c +++ b/builtin/index-pack.c @@ -542,7 +542,7 @@ static void *unpack_data(struct object_entry *obj, do { ssize_t n = (len < 64*1024) ? len : 64*1024; - n = pread(pack_fd, inbuf, n, from); + n = xpread(pack_fd, inbuf, n, from); if (n < 0) die_errno(_("cannot pread pack file")); if (!n) diff --git a/compat/mmap.c b/compat/mmap.c index c9d46d1..7f662fe 100644 --- a/compat/mmap.c +++ b/compat/mmap.c @@ -14,7 +14,7 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of } while (n < length) { - ssize_t count = pread(fd, (char *)start + n, length - n, offset + n); + ssize_t count = xpread(fd, (char *)start + n, length - n, offset + n); if (count == 0) { memset((char *)start+n, 0, length-n); @@ -22,8 +22,6 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of } if (count < 0) { - if (errno == EAGAIN || errno == EINTR) - continue; free(start); errno = EACCES; return MAP_FAILED; diff --git a/git-compat-util.h b/git-compat-util.h index f6d3a46..e6a4159 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -531,6 +531,7 @@ extern void *xcalloc(size_t nmemb, size_t size); extern void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset); extern ssize_t xread(int fd, void *buf, size_t len); extern ssize_t xwrite(int fd, const void *buf, size_t len); +extern ssize_t xpread(int fd, void *buf, size_t len, off_t offset); extern int xdup(int fd); extern FILE *xfdopen(int fd, const char *mode); extern int xmkstemp(char *template); diff --git a/wrapper.c b/wrapper.c index 0cc5636..cf71817 100644 --- a/wrapper.c +++ b/wrapper.c @@ -174,6 +174,24 @@ ssize_t xwrite(int fd, const void *buf, size_t len) } } +/* + * xpread() is the same as pread(), but it automatically restarts pread() + * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES + * NOT GUARANTEE that "len" bytes is read even if the data is available. + */ +ssize_t xpread(int fd, void *buf, size_t len, off_t offset) +{ + ssize_t nr; + if (len > MAX_IO_SIZE) + len = MAX_IO_SIZE; + while (1) { + nr = pread(fd, buf, len, offset); + if ((nr < 0) && (errno == EAGAIN || errno == EINTR)) + continue; + return nr; + } +} + ssize_t read_in_full(int fd, void *buf, size_t count) { char *p = buf;
-- 1.9.1