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authorUlrich Drepper <drepper@redhat.com>2007-10-13 18:02:24 +0000
committerUlrich Drepper <drepper@redhat.com>2007-10-13 18:02:24 +0000
commitf7140274a410838336adca1acb40f5a862e6cac9 (patch)
tree609c375a589fa62136d4cc021363d03bfa7ffa8c /nscd
parent656f02ce5b080fa4dfdd7c6f0ee52aa30b94c880 (diff)
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[BZ #3242]
2007-10-13 Ulrich Drepper <drepper@redhat.com> [BZ #3242] * nscd/nscd_helper.c (wait_on_socket): Take timeout as parameter. (__readall): If reading failed due to EAGAIN error wait a bit and possibly try again. (__readvall): Likewise.
Diffstat (limited to 'nscd')
-rw-r--r--nscd/nscd_helper.c103
1 files changed, 68 insertions, 35 deletions
diff --git a/nscd/nscd_helper.c b/nscd/nscd_helper.c
index 6718d92..b499f9c 100644
--- a/nscd/nscd_helper.c
+++ b/nscd/nscd_helper.c
@@ -38,6 +38,45 @@
#include "nscd-client.h"
+/* Extra time we wait if the socket is still receiving data. This
+ value is in microseconds. Note that the other side is nscd on the
+ local machine and it is already transmitting data. So the wait
+ time need not be long. */
+#define EXTRA_RECEIVE_TIME 200
+
+
+static int
+wait_on_socket (int sock, long int usectmo)
+{
+ struct pollfd fds[1];
+ fds[0].fd = sock;
+ fds[0].events = POLLIN | POLLERR | POLLHUP;
+ int n = __poll (fds, 1, usectmo);
+ if (n == -1 && __builtin_expect (errno == EINTR, 0))
+ {
+ /* Handle the case where the poll() call is interrupted by a
+ signal. We cannot just use TEMP_FAILURE_RETRY since it might
+ lead to infinite loops. */
+ struct timeval now;
+ (void) __gettimeofday (&now, NULL);
+ long int end = now.tv_sec * 1000 + usectmo + (now.tv_usec + 500) / 1000;
+ long int timeout = usectmo;
+ while (1)
+ {
+ n = __poll (fds, 1, timeout);
+ if (n != -1 || errno != EINTR)
+ break;
+
+ /* Recompute the timeout time. */
+ (void) __gettimeofday (&now, NULL);
+ timeout = end - (now.tv_sec * 1000 + (now.tv_usec + 500) / 1000);
+ }
+ }
+
+ return n;
+}
+
+
ssize_t
__readall (int fd, void *buf, size_t len)
{
@@ -45,9 +84,17 @@ __readall (int fd, void *buf, size_t len)
ssize_t ret;
do
{
+ again:
ret = TEMP_FAILURE_RETRY (__read (fd, buf, n));
if (ret <= 0)
- break;
+ {
+ if (__builtin_expect (ret < 0 && errno == EAGAIN, 0)
+ /* The socket is still receiving data. Wait a bit more. */
+ && wait_on_socket (fd, EXTRA_RECEIVE_TIME) > 0)
+ goto again;
+
+ break;
+ }
buf = (char *) buf + ret;
n -= ret;
}
@@ -61,7 +108,15 @@ __readvall (int fd, const struct iovec *iov, int iovcnt)
{
ssize_t ret = TEMP_FAILURE_RETRY (__readv (fd, iov, iovcnt));
if (ret <= 0)
- return ret;
+ {
+ if (__builtin_expect (ret == 0 || errno != EAGAIN, 1))
+ /* A genuine error or no data to read. */
+ return ret;
+
+ /* The data has not all yet been received. Do as if we have not
+ read anything yet. */
+ ret = 0;
+ }
size_t total = 0;
for (int i = 0; i < iovcnt; ++i)
@@ -83,9 +138,17 @@ __readvall (int fd, const struct iovec *iov, int iovcnt)
}
iovp->iov_base = (char *) iovp->iov_base + r;
iovp->iov_len -= r;
+ again:
r = TEMP_FAILURE_RETRY (__readv (fd, iovp, iovcnt));
if (r <= 0)
- break;
+ {
+ if (__builtin_expect (r < 0 && errno == EAGAIN, 0)
+ /* The socket is still receiving data. Wait a bit more. */
+ && wait_on_socket (fd, EXTRA_RECEIVE_TIME) > 0)
+ goto again;
+
+ break;
+ }
ret += r;
}
while (ret < total);
@@ -187,36 +250,6 @@ __nscd_unmap (struct mapped_database *mapped)
}
-static int
-wait_on_socket (int sock)
-{
- struct pollfd fds[1];
- fds[0].fd = sock;
- fds[0].events = POLLIN | POLLERR | POLLHUP;
- int n = __poll (fds, 1, 5 * 1000);
- if (n == -1 && __builtin_expect (errno == EINTR, 0))
- {
- /* Handle the case where the poll() call is interrupted by a
- signal. We cannot just use TEMP_FAILURE_RETRY since it might
- lead to infinite loops. */
- struct timeval now;
- (void) __gettimeofday (&now, NULL);
- long int end = (now.tv_sec + 5) * 1000 + (now.tv_usec + 500) / 1000;
- while (1)
- {
- long int timeout = end - (now.tv_sec * 1000
- + (now.tv_usec + 500) / 1000);
- n = __poll (fds, 1, timeout);
- if (n != -1 || errno != EINTR)
- break;
- (void) __gettimeofday (&now, NULL);
- }
- }
-
- return n;
-}
-
-
/* Try to get a file descriptor for the shared meory segment
containing the database. */
static struct mapped_database *
@@ -265,7 +298,7 @@ get_mapping (request_type type, const char *key,
msg.msg_controllen = cmsg->cmsg_len;
- if (wait_on_socket (sock) <= 0)
+ if (wait_on_socket (sock, 5 * 1000) <= 0)
goto out_close2;
# ifndef MSG_CMSG_CLOEXEC
@@ -497,7 +530,7 @@ __nscd_open_socket (const char *key, size_t keylen, request_type type,
if (sock >= 0)
{
/* Wait for data. */
- if (wait_on_socket (sock) > 0)
+ if (wait_on_socket (sock, 5 * 1000) > 0)
{
ssize_t nbytes = TEMP_FAILURE_RETRY (__read (sock, response,
responselen));