xread/xwrite: do not worry about EINTR at calling sites.

We had errno==EINTR check after read(2)/write(2) sprinkled all
over the places, always doing continue.  Consolidate them into
xread()/xwrite() wrapper routines.

Credits for suggestion goes to HPA -- bugs are mine.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/apply.c b/apply.c
index 1742ab2..d5e7bfd 100644 (file)
--- a/apply.c
+++ b/apply.c
@@ -84,14 +84,11 @@ static void *read_patch_file(int fd, unsigned long *sizep)
                        buffer = xrealloc(buffer, alloc);
                        nr = alloc - size;
                }
-               nr = read(fd, buffer + size, nr);
+               nr = xread(fd, buffer + size, nr);
                if (!nr)
                        break;
-               if (nr < 0) {
-                       if (errno == EAGAIN)
-                               continue;
+               if (nr < 0)
                        die("git-apply: read returned %s", strerror(errno));
-               }
                size += nr;
        }
        *sizep = size;
@@ -1006,13 +1003,8 @@ static int read_old_data(struct stat *st, const char *path, void *buf, unsigned
                        return error("unable to open %s", path);
                got = 0;
                for (;;) {
-                       int ret = read(fd, buf + got, size - got);
-                       if (ret < 0) {
-                               if (errno == EAGAIN)
-                                       continue;
-                               break;
-                       }
-                       if (!ret)
+                       int ret = xread(fd, buf + got, size - got);
+                       if (ret <= 0)
                                break;
                        got += ret;
                }
@@ -1600,12 +1592,9 @@ static int try_create_file(const char *path, unsigned int mode, const char *buf,
        if (fd < 0)
                return -1;
        while (size) {
-               int written = write(fd, buf, size);
-               if (written < 0) {
-                       if (errno == EINTR || errno == EAGAIN)
-                               continue;
+               int written = xwrite(fd, buf, size);
+               if (written < 0)
                        die("writing file %s: %s", path, strerror(errno));
-               }
                if (!written)
                        die("out of space writing file %s", path);
                buf += written;

diff --git a/cat-file.c b/cat-file.c
index 7594108..96d66b4 100644 (file)
--- a/cat-file.c
+++ b/cat-file.c
@@ -55,10 +55,8 @@ int main(int argc, char **argv)
                die("git-cat-file %s: bad file", argv[2]);
 
        while (size > 0) {
-               long ret = write(1, buf, size);
+               long ret = xwrite(1, buf, size);
                if (ret < 0) {
-                       if (errno == EAGAIN)
-                               continue;
                        /* Ignore epipe */
                        if (errno == EPIPE)
                                break;

diff --git a/copy.c b/copy.c
index e1cd5d0..7100eed 100644 (file)
--- a/copy.c
+++ b/copy.c
@@ -6,32 +6,27 @@ int copy_fd(int ifd, int ofd)
                int len;
                char buffer[8192];
                char *buf = buffer;
-               len = read(ifd, buffer, sizeof(buffer));
+               len = xread(ifd, buffer, sizeof(buffer));
                if (!len)
                        break;
                if (len < 0) {
                        int read_error;
-                       if (errno == EAGAIN)
-                               continue;
                        read_error = errno;
                        close(ifd);
                        return error("copy-fd: read returned %s",
                                     strerror(read_error));
                }
-               while (1) {
-                       int written = write(ofd, buf, len);
+               while (len) {
+                       int written = xwrite(ofd, buf, len);
                        if (written > 0) {
                                buf += written;
                                len -= written;
-                               if (!len)
-                                       break;
                        }
-                       if (!written)
+                       else if (!written)
                                return error("copy-fd: write returned 0");
-                       if (errno == EAGAIN || errno == EINTR)
-                               continue;
-                       return error("copy-fd: write returned %s",
-                                    strerror(errno));
+                       else
+                               return error("copy-fd: write returned %s",
+                                            strerror(errno));
                }
        }
        close(ifd);

diff --git a/csum-file.c b/csum-file.c
index c66b9eb..5f9249a 100644 (file)
--- a/csum-file.c
+++ b/csum-file.c
@@ -15,7 +15,7 @@ static int sha1flush(struct sha1file *f, unsigned int count)
        void *buf = f->buffer;
 
        for (;;) {
-               int ret = write(f->fd, buf, count);
+               int ret = xwrite(f->fd, buf, count);
                if (ret > 0) {
                        buf += ret;
                        count -= ret;
@@ -25,8 +25,6 @@ static int sha1flush(struct sha1file *f, unsigned int count)
                }
                if (!ret)
                        die("sha1 file '%s' write error. Out of diskspace", f->name);
-               if (errno == EAGAIN || errno == EINTR)
-                       continue;
                die("sha1 file '%s' write error (%s)", f->name, strerror(errno));
        }
 }

diff --git a/git-compat-util.h b/git-compat-util.h
index ead0ede..0c98c99 100644 (file)
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -84,6 +84,28 @@ static inline void *xcalloc(size_t nmemb, size_t size)
        return ret;
 }
 
+static inline ssize_t xread(int fd, void *buf, size_t len)
+{
+       ssize_t nr;
+       while (1) {
+               nr = read(fd, buf, len);
+               if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
+                       continue;
+               return nr;
+       }
+}
+
+static inline ssize_t xwrite(int fd, const void *buf, size_t len)
+{
+       ssize_t nr;
+       while (1) {
+               nr = write(fd, buf, len);
+               if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
+                       continue;
+               return nr;
+       }
+}
+
 /* Sane ctype - no locale, and works with signed chars */
 #undef isspace
 #undef isdigit

diff --git a/mktag.c b/mktag.c
index 97e270a..fc6a9bf 100644 (file)
--- a/mktag.c
+++ b/mktag.c
@@ -116,14 +116,9 @@ int main(int argc, char **argv)
        // Read the signature
        size = 0;
        for (;;) {
-               int ret = read(0, buffer + size, MAXSIZE - size);
-               if (!ret)
+               int ret = xread(0, buffer + size, MAXSIZE - size);
+               if (ret <= 0)
                        break;
-               if (ret < 0) {
-                       if (errno == EAGAIN)
-                               continue;
-                       break;
-               }
                size += ret;
        }
 

diff --git a/pkt-line.c b/pkt-line.c
index 6947304..bb3bab0 100644 (file)
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -19,7 +19,7 @@
 static void safe_write(int fd, const void *buf, unsigned n)
 {
        while (n) {
-               int ret = write(fd, buf, n);
+               int ret = xwrite(fd, buf, n);
                if (ret > 0) {
                        buf += ret;
                        n -= ret;
@@ -27,8 +27,6 @@ static void safe_write(int fd, const void *buf, unsigned n)
                }
                if (!ret)
                        die("write error (disk full?)");
-               if (errno == EAGAIN || errno == EINTR)
-                       continue;
                die("write error (%s)", strerror(errno));
        }
 }
@@ -68,12 +66,9 @@ static void safe_read(int fd, void *buffer, unsigned size)
        int n = 0;
 
        while (n < size) {
-               int ret = read(fd, buffer + n, size - n);
-               if (ret < 0) {
-                       if (errno == EINTR || errno == EAGAIN)
-                               continue;
+               int ret = xread(fd, buffer + n, size - n);
+               if (ret < 0)
                        die("read error (%s)", strerror(errno));
-               }
                if (!ret)
                        die("unexpected EOF");
                n += ret;

diff --git a/tar-tree.c b/tar-tree.c
index bacb23a..96bd143 100644 (file)
--- a/tar-tree.c
+++ b/tar-tree.c
@@ -34,10 +34,8 @@ struct path_prefix {
 static void reliable_write(void *buf, unsigned long size)
 {
        while (size > 0) {
-               long ret = write(1, buf, size);
+               long ret = xwrite(1, buf, size);
                if (ret < 0) {
-                       if (errno == EAGAIN)
-                               continue;
                        if (errno == EPIPE)
                                exit(0);
                        die("git-tar-tree: %s", strerror(errno));

diff --git a/unpack-objects.c b/unpack-objects.c
index cfd61ae..5c5cb12 100644 (file)
--- a/unpack-objects.c
+++ b/unpack-objects.c
@@ -31,12 +31,10 @@ static void * fill(int min)
                offset = 0;
        }
        do {
-               int ret = read(0, buffer + len, sizeof(buffer) - len);
+               int ret = xread(0, buffer + len, sizeof(buffer) - len);
                if (ret <= 0) {
                        if (!ret)
                                die("early EOF");
-                       if (errno == EAGAIN || errno == EINTR)
-                               continue;
                        die("read error on input: %s", strerror(errno));
                }
                len += ret;
@@ -299,14 +297,9 @@ int main(int argc, char **argv)
 
        /* Write the last part of the buffer to stdout */
        while (len) {
-               int ret = write(1, buffer + offset, len);
-               if (!ret)
-                       break;
-               if (ret < 0) {
-                       if (errno == EAGAIN || errno == EINTR)
-                               continue;
+               int ret = xwrite(1, buffer + offset, len);
+               if (ret <= 0)
                        break;
-               }
                len -= ret;
                offset += ret;
        }