diff options
| -rw-r--r-- | ChangeLog | 8 | ||||
| -rw-r--r-- | nscd/nscd_helper.c | 103 |
2 files changed, 76 insertions, 35 deletions
@@ -1,3 +1,11 @@ +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. + 2007-10-13 Bruno Haible <bruno@clisp.org> * intl/dcigettext.c (_nl_find_msg): Unlock the conversions_lock diff --git a/nscd/nscd_helper.c b/nscd/nscd_helper.c index 6718d922f3..b499f9cf99 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)); |