[asterisk-commits] russell: trunk r166282 - in /trunk: include/asterisk/ main/
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Mon Dec 22 11:09:36 CST 2008
Author: russell
Date: Mon Dec 22 11:09:36 2008
New Revision: 166282
URL: http://svn.digium.com/view/asterisk?view=rev&rev=166282
Log:
Introduce ast_careful_fwrite() and use in AMI to prevent partial writes.
This patch introduces a function to do careful writes on a file stream which
will handle timeouts and partial writes. It is currently used in AMI to
address the issue that has been reported. However, there are probably a few
other places where this could be used.
(closes issue #13546)
Reported by: srt
Tested by: russell
http://reviewboard.digium.com/r/104/
Modified:
trunk/include/asterisk/utils.h
trunk/main/manager.c
trunk/main/utils.c
Modified: trunk/include/asterisk/utils.h
URL: http://svn.digium.com/view/asterisk/trunk/include/asterisk/utils.h?view=diff&rev=166282&r1=166281&r2=166282
==============================================================================
--- trunk/include/asterisk/utils.h (original)
+++ trunk/include/asterisk/utils.h Mon Dec 22 11:09:36 2008
@@ -325,6 +325,25 @@
have a need to wait. This way, we get better performance.
*/
int ast_carefulwrite(int fd, char *s, int len, int timeoutms);
+
+/*!
+ * \brief Write data to a file stream with a timeout
+ *
+ * \param f the file stream to write to
+ * \param fd the file description to poll on to know when the file stream can
+ * be written to without blocking.
+ * \param s the buffer to write from
+ * \param len the number of bytes to write
+ * \param timeoutms The maximum amount of time to block in this function trying
+ * to write, specified in milliseconds.
+ *
+ * \note This function assumes that the associated file stream has been set up
+ * as non-blocking.
+ *
+ * \retval 0 success
+ * \retval -1 error
+ */
+int ast_careful_fwrite(FILE *f, int fd, const char *s, size_t len, int timeoutms);
/*
* Thread management support (should be moved to lock.h or a different header)
Modified: trunk/main/manager.c
URL: http://svn.digium.com/view/asterisk/trunk/main/manager.c?view=diff&rev=166282&r1=166281&r2=166282
==============================================================================
--- trunk/main/manager.c (original)
+++ trunk/main/manager.c Mon Dec 22 11:09:36 2008
@@ -899,30 +899,7 @@
*/
static int send_string(struct mansession *s, char *string)
{
- int len = strlen(string); /* residual length */
- char *src = string;
- struct timeval start = ast_tvnow();
- int n = 0;
-
- for (;;) {
- int elapsed;
- struct pollfd fd;
- n = fwrite(src, 1, len, s->f); /* try to write the string, non blocking */
- if (n == len /* ok */ || n < 0 /* error */)
- break;
- len -= n; /* skip already written data */
- src += n;
- fd.fd = s->fd;
- fd.events = POLLOUT;
- n = -1; /* error marker */
- elapsed = ast_tvdiff_ms(ast_tvnow(), start);
- if (elapsed > s->writetimeout)
- break;
- if (poll(&fd, 1, s->writetimeout - elapsed) < 1)
- break;
- }
- fflush(s->f);
- return n < 0 ? -1 : 0;
+ return ast_careful_fwrite(s->f, s->fd, string, strlen(string), s->writetimeout);
}
/*!
Modified: trunk/main/utils.c
URL: http://svn.digium.com/view/asterisk/trunk/main/utils.c?view=diff&rev=166282&r1=166281&r2=166282
==============================================================================
--- trunk/main/utils.c (original)
+++ trunk/main/utils.c Mon Dec 22 11:09:36 2008
@@ -1057,6 +1057,38 @@
return poll(pfd, 1, ms);
}
+static int ast_wait_for_output(int fd, int timeoutms)
+{
+ struct pollfd pfd = {
+ .fd = fd,
+ .events = POLLOUT,
+ };
+ int res;
+
+ /* poll() until the fd is writable without blocking */
+ while ((res = poll(&pfd, 1, timeoutms)) <= 0) {
+ if (res == 0) {
+ /* timed out. */
+ ast_log(LOG_NOTICE, "Timed out trying to write\n");
+ return -1;
+ } else if (res == -1) {
+ /* poll() returned an error, check to see if it was fatal */
+
+ if (errno == EINTR || errno == EAGAIN) {
+ /* This was an acceptable error, go back into poll() */
+ continue;
+ }
+
+ /* Fatal error, bail. */
+ ast_log(LOG_ERROR, "poll returned error: %s\n", strerror(errno));
+
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
/*!
* Try to write string, but wait no more than ms milliseconds before timing out.
*
@@ -1077,30 +1109,8 @@
int res = 0;
while (len) {
- struct pollfd pfd = {
- .fd = fd,
- .events = POLLOUT,
- };
-
- /* poll() until the fd is writable without blocking */
- while ((res = poll(&pfd, 1, timeoutms)) <= 0) {
- if (res == 0) {
- /* timed out. */
- ast_log(LOG_NOTICE, "Timed out trying to write\n");
- return -1;
- } else if (res == -1) {
- /* poll() returned an error, check to see if it was fatal */
-
- if (errno == EINTR || errno == EAGAIN) {
- /* This was an acceptable error, go back into poll() */
- continue;
- }
-
- /* Fatal error, bail. */
- ast_log(LOG_ERROR, "poll returned error: %s\n", strerror(errno));
-
- return -1;
- }
+ if (ast_wait_for_output(fd, timeoutms)) {
+ return -1;
}
res = write(fd, s, len);
@@ -1123,6 +1133,62 @@
}
return res;
+}
+
+int ast_careful_fwrite(FILE *f, int fd, const char *src, size_t len, int timeoutms)
+{
+ struct timeval start = ast_tvnow();
+ int n = 0;
+
+ while (len) {
+ int elapsed;
+
+ if (ast_wait_for_output(fd, timeoutms)) {
+ /* poll returned a fatal error, so bail out immediately. */
+ return -1;
+ }
+
+ /* Clear any errors from a previous write */
+ clearerr(f);
+
+ n = fwrite(src, 1, len, f);
+
+ if (ferror(f) && errno != EINTR && errno != EAGAIN) {
+ /* fatal error from fwrite() */
+ if (!feof(f)) {
+ /* Don't spam the logs if it was just that the connection is closed. */
+ ast_log(LOG_ERROR, "fwrite() returned error: %s\n", strerror(errno));
+ }
+ n = -1;
+ break;
+ }
+
+ /* Update for data already written to the socket */
+ len -= n;
+ src += n;
+
+ elapsed = ast_tvdiff_ms(ast_tvnow(), start);
+ if (elapsed > timeoutms) {
+ /* We've taken too long to write
+ * This is only an error condition if we haven't finished writing. */
+ n = len ? -1 : 0;
+ break;
+ }
+ }
+
+ while (fflush(f)) {
+ if (errno == EAGAIN || errno == EINTR) {
+ continue;
+ }
+ if (!feof(f)) {
+ /* Don't spam the logs if it was just that the connection is closed. */
+ ast_log(LOG_ERROR, "fflush() returned error: %s\n", strerror(errno));
+ }
+ n = -1;
+ break;
+ }
+
+ return n < 0 ? -1 : 0;
}
char *ast_strip_quoted(char *s, const char *beg_quotes, const char *end_quotes)
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