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authorDaniel Stenberg <daniel@haxx.se>2007-05-31 11:34:32 +0000
committerDaniel Stenberg <daniel@haxx.se>2007-05-31 11:34:32 +0000
commit4c663ba9a8fbb9d58369e613230693b487b18d39 (patch)
treeeefada77f3df989013b628cf3bb52b965795f167 /lib
parent713c9f8602caf53db2159b3db7d863f15174e987 (diff)
When transferring 500 downloads in parallel with a c-ares enabled build only
to find that it crashed miserably, and this was due to some select()isms left in the code. This was due to API restrictions in c-ares 1.3.x, but with the upcoming c-ares 1.4.0 this is no longer the case so now libcurl runs much better with c-ares and the multi interface with > 1024 file descriptors in use.
Diffstat (limited to 'lib')
-rw-r--r--lib/README.ares3
-rw-r--r--lib/easy.c7
-rw-r--r--lib/hostares.c96
-rw-r--r--lib/select.c221
-rw-r--r--lib/select.h4
5 files changed, 74 insertions, 257 deletions
diff --git a/lib/README.ares b/lib/README.ares
index b41b70924..b94a16611 100644
--- a/lib/README.ares
+++ b/lib/README.ares
@@ -12,8 +12,7 @@ c-ares:
http://daniel.haxx.se/projects/c-ares/
NOTE
- The latest libcurl version requires c-ares 1.3.2 or later to work
- flawlessly.
+ The latest libcurl version requires c-ares 1.4.0 or later.
Once upon the time libcurl built fine with the "original" ares. That is no
longer true. You need to use c-ares.
diff --git a/lib/easy.c b/lib/easy.c
index 8f590c97b..d5816bc48 100644
--- a/lib/easy.c
+++ b/lib/easy.c
@@ -420,11 +420,14 @@ CURLcode curl_easy_perform(CURL *easy)
timeout.tv_sec = 1;
timeout.tv_usec = 0;
- /* get file descriptors from the transfers */
+ /* Old deprecated style: get file descriptors from the transfers */
curl_multi_fdset(multi, &fdread, &fdwrite, &fdexcep, &maxfd);
-
rc = Curl_select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
+ /* The way is to extract the sockets and wait for them without using
+ select. This whole alternative version should probably rather use the
+ curl_multi_socket() approach. */
+
if(rc == -1)
/* select error */
break;
diff --git a/lib/hostares.c b/lib/hostares.c
index dae1ca3b7..3aa7782bb 100644
--- a/lib/hostares.c
+++ b/lib/hostares.c
@@ -126,6 +126,69 @@ int Curl_resolv_getsock(struct connectdata *conn,
}
/*
+ * ares_waitperform()
+ *
+ * 1) Ask ares what sockets it currently plays with, then
+ * 2) wait for the timeout period to check for action on ares' sockets.
+ * 3) tell ares to act on all the sockets marked as "with action"
+ *
+ * return number of sockets it worked on
+ */
+
+static int ares_waitperform(struct connectdata *conn, int timeout_ms)
+{
+ struct SessionHandle *data = conn->data;
+ int nfds;
+ int bitmask;
+ int socks[ARES_GETSOCK_MAXNUM];
+ struct pollfd pfd[ARES_GETSOCK_MAXNUM];
+ int m;
+ int i;
+ int num;
+
+ bitmask = ares_getsock(data->state.areschannel, socks, ARES_GETSOCK_MAXNUM);
+
+ for(i=0; i < ARES_GETSOCK_MAXNUM; i++) {
+ pfd[i].events = 0;
+ m=0;
+ if(ARES_GETSOCK_READABLE(bitmask, i)) {
+ pfd[i].fd = socks[i];
+ pfd[i].events |= POLLRDNORM|POLLIN;
+ m=1;
+ }
+ if(ARES_GETSOCK_WRITABLE(bitmask, i)) {
+ pfd[i].fd = socks[i];
+ pfd[i].events |= POLLWRNORM|POLLOUT;
+ m=1;
+ }
+ pfd[i].revents=0;
+ if(!m)
+ break;
+ }
+ num = i;
+
+ if(num)
+ nfds = Curl_poll(pfd, num, timeout_ms);
+ else
+ nfds = 0;
+
+ if(!nfds)
+ /* Call ares_process() unconditonally here, even if we simply timed out
+ above, as otherwise the ares name resolve won't timeout! */
+ ares_process_fd(data->state.areschannel, ARES_SOCKET_BAD, ARES_SOCKET_BAD);
+ else {
+ /* move through the descriptors and ask for processing on them */
+ for(i=0; i < num; i++)
+ ares_process_fd(data->state.areschannel,
+ pfd[i].revents & (POLLRDNORM|POLLIN)?
+ pfd[i].fd:ARES_SOCKET_BAD,
+ pfd[i].revents & (POLLWRNORM|POLLOUT)?
+ pfd[i].fd:ARES_SOCKET_BAD);
+ }
+ return nfds;
+}
+
+/*
* Curl_is_resolved() is called repeatedly to check if a previous name resolve
* request has completed. It should also make sure to time-out if the
* operation seems to take too long.
@@ -135,25 +198,12 @@ int Curl_resolv_getsock(struct connectdata *conn,
CURLcode Curl_is_resolved(struct connectdata *conn,
struct Curl_dns_entry **dns)
{
- fd_set read_fds, write_fds;
- struct timeval tv={0,0};
struct SessionHandle *data = conn->data;
- int nfds;
-
- FD_ZERO(&read_fds);
- FD_ZERO(&write_fds);
-
- nfds = ares_fds(data->state.areschannel, &read_fds, &write_fds);
-
- (void)Curl_select(nfds, &read_fds, &write_fds, NULL,
- (struct timeval *)&tv);
-
- /* Call ares_process() unconditonally here, even if we simply timed out
- above, as otherwise the ares name resolve won't timeout! */
- ares_process(data->state.areschannel, &read_fds, &write_fds);
*dns = NULL;
+ ares_waitperform(conn, 0);
+
if(conn->async.done) {
/* we're done, kill the ares handle */
if(!conn->async.dns) {
@@ -194,28 +244,18 @@ CURLcode Curl_wait_for_resolv(struct connectdata *conn,
/* Wait for the name resolve query to complete. */
while (1) {
- int nfds=0;
- fd_set read_fds, write_fds;
struct timeval *tvp, tv, store;
- int count;
struct timeval now = Curl_tvnow();
long timediff;
store.tv_sec = (int)timeout/1000;
store.tv_usec = (timeout%1000)*1000;
- FD_ZERO(&read_fds);
- FD_ZERO(&write_fds);
- nfds = ares_fds(data->state.areschannel, &read_fds, &write_fds);
- if (nfds == 0)
- /* no file descriptors means we're done waiting */
- break;
tvp = ares_timeout(data->state.areschannel, &store, &tv);
- count = Curl_select(nfds, &read_fds, &write_fds, NULL, tvp);
- if ((count < 0) && (SOCKERRNO != EINVAL))
- break;
- ares_process(data->state.areschannel, &read_fds, &write_fds);
+ if(!ares_waitperform(conn, tv.tv_sec * 1000 + tv.tv_usec/1000))
+ /* no sockets to wait on, get out of the loop */
+ break;
timediff = Curl_tvdiff(Curl_tvnow(), now); /* spent time */
timeout -= timediff?timediff:1; /* always deduct at least 1 */
diff --git a/lib/select.c b/lib/select.c
index daa591eae..28bb141b1 100644
--- a/lib/select.c
+++ b/lib/select.c
@@ -482,227 +482,6 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms)
return r;
}
-/*
- * This is a wrapper around select(). It uses poll() when a fine
- * poll() is available, in order to avoid limits with FD_SETSIZE,
- * otherwise select() is used. An error is returned if select() is
- * being used and a the number of file descriptors is larger than
- * FD_SETSIZE. A NULL timeout pointer makes this function wait
- * indefinitely, unles no valid file descriptor is given, when this
- * happens the NULL timeout is ignored and the function times out
- * immediately. When compiled with CURL_ACKNOWLEDGE_EINTR defined,
- * EINTR condition is honored and function might exit early without
- * awaiting timeout, otherwise EINTR will be ignored.
- *
- * Return values:
- * -1 = system call error or nfds > FD_SETSIZE
- * 0 = timeout
- * N = number of file descriptors kept in file descriptor sets.
- */
-int Curl_select(int nfds,
- fd_set *fds_read, fd_set *fds_write, fd_set *fds_excep,
- struct timeval *timeout)
-{
- struct timeval initial_tv;
- int timeout_ms;
- int pending_ms = 0;
- int error;
- int r;
-#ifdef HAVE_POLL_FINE
- struct pollfd small_fds[SMALL_POLLNFDS];
- struct pollfd *poll_fds;
- int ix;
- int fd;
- int poll_nfds = 0;
-#else
- struct timeval pending_tv;
- struct timeval *ptimeout;
-#endif
- int ret = 0;
-
- if ((nfds < 0) ||
- ((nfds > 0) && (!fds_read && !fds_write && !fds_excep))) {
- SET_SOCKERRNO(EINVAL);
- return -1;
- }
-
- if (timeout) {
- if ((timeout->tv_sec < 0) ||
- (timeout->tv_usec < 0) ||
- (timeout->tv_usec >= 1000000)) {
- SET_SOCKERRNO(EINVAL);
- return -1;
- }
- timeout_ms = (int)(timeout->tv_sec * 1000) +
- (int)(timeout->tv_usec / 1000);
- }
- else {
- timeout_ms = -1;
- }
-
- if ((!nfds) || (!fds_read && !fds_write && !fds_excep)) {
- r = wait_ms(timeout_ms);
- return r;
- }
-
- /* Avoid initial timestamp, avoid gettimeofday() call, when elapsed
- time in this function does not need to be measured. This happens
- when function is called with a zero timeout in the timeval struct
- referenced argument or when a NULL pointer is received as timeval
- reference indicating a blocking call should be performed. */
-
- if (timeout_ms > 0) {
- pending_ms = timeout_ms;
- initial_tv = curlx_tvnow();
- }
-
-#ifdef HAVE_POLL_FINE
-
- if (fds_read || fds_write || fds_excep) {
- fd = nfds;
- while (fd--) {
- if ((fds_read && (0 != FD_ISSET(fd, fds_read))) ||
- (fds_write && (0 != FD_ISSET(fd, fds_write))) ||
- (fds_excep && (0 != FD_ISSET(fd, fds_excep))))
- poll_nfds++;
- }
- }
-
- if (!poll_nfds)
- poll_fds = NULL;
- else if (poll_nfds <= SMALL_POLLNFDS)
- poll_fds = small_fds;
- else {
- poll_fds = malloc(poll_nfds * sizeof(struct pollfd));
- if (!poll_fds) {
- SET_SOCKERRNO(ENOBUFS);
- return -1;
- }
- }
-
- if (poll_fds) {
- int events;
- ix = 0;
- fd = nfds;
- while (fd--) {
- events = 0;
- if (fds_read && (0 != FD_ISSET(fd, fds_read)))
- events |= (POLLRDNORM|POLLIN);
- if (fds_write && (0 != FD_ISSET(fd, fds_write)))
- events |= (POLLWRNORM|POLLOUT);
- if (fds_excep && (0 != FD_ISSET(fd, fds_excep)))
- events |= (POLLRDBAND|POLLPRI);
- if (events) {
- poll_fds[ix].events = events;
- poll_fds[ix].fd = fd;
- poll_fds[ix].revents = 0;
- ix++;
- if(ix == poll_nfds)
- /* since we know this is the total amount of descriptors with
- interesting actions, we can skip the rest of the loop at this
- point */
- break;
- }
- }
- }
-
- do {
- if (timeout_ms < 0)
- pending_ms = -1;
- else if (!timeout_ms)
- pending_ms = 0;
- r = poll(poll_fds, poll_nfds, pending_ms);
- if (r != -1)
- break;
- error = SOCKERRNO;
- if ((error == EINVAL) || error_is_EINTR)
- break;
- if (timeout_ms > 0) {
- pending_ms = timeout_ms - elapsed_ms;
- if (pending_ms <= 0)
- break;
- }
- } while (r == -1);
-
- if (r < 0)
- ret = -1;
-
- if (r > 0) {
- ix = poll_nfds;
- while (ix--) {
- if (poll_fds[ix].revents & POLLNVAL) {
- SET_SOCKERRNO(EBADF);
- ret = -1;
- break;
- }
- }
- }
-
- if (!ret) {
- ix = poll_nfds;
- while (ix--) {
- if (fds_read && (0 != FD_ISSET(poll_fds[ix].fd, fds_read))) {
- if (0 == (poll_fds[ix].revents & (POLLRDNORM|POLLERR|POLLHUP|POLLIN)))
- FD_CLR(poll_fds[ix].fd, fds_read);
- else
- ret++;
- }
- if (fds_write && (0 != FD_ISSET(poll_fds[ix].fd, fds_write))) {
- if (0 == (poll_fds[ix].revents & (POLLWRNORM|POLLERR|POLLHUP|POLLOUT)))
- FD_CLR(poll_fds[ix].fd, fds_write);
- else
- ret++;
- }
- if (fds_excep && (0 != FD_ISSET(poll_fds[ix].fd, fds_excep))) {
- if (0 == (poll_fds[ix].revents & (POLLRDBAND|POLLERR|POLLHUP|POLLPRI)))
- FD_CLR(poll_fds[ix].fd, fds_excep);
- else
- ret++;
- }
- }
- }
-
- if (poll_fds && (poll_nfds > SMALL_POLLNFDS))
- free(poll_fds);
-
-#else /* HAVE_POLL_FINE */
-
- VERIFY_NFDS(nfds);
-
- ptimeout = (timeout_ms < 0) ? NULL : &pending_tv;
-
- do {
- if (timeout_ms > 0) {
- pending_tv.tv_sec = pending_ms / 1000;
- pending_tv.tv_usec = (pending_ms % 1000) * 1000;
- }
- else if (!timeout_ms) {
- pending_tv.tv_sec = 0;
- pending_tv.tv_usec = 0;
- }
- r = select(nfds, fds_read, fds_write, fds_excep, ptimeout);
- if (r != -1)
- break;
- error = SOCKERRNO;
- if ((error == EINVAL) || (error == EBADF) || error_is_EINTR)
- break;
- if (timeout_ms > 0) {
- pending_ms = timeout_ms - elapsed_ms;
- if (pending_ms <= 0)
- break;
- }
- } while (r == -1);
-
- if (r < 0)
- ret = -1;
- else
- ret = r;
-
-#endif /* HAVE_POLL_FINE */
-
- return ret;
-}
-
#ifdef TPF
/*
* This is a replacement for select() on the TPF platform.
diff --git a/lib/select.h b/lib/select.h
index 77b3e915f..ce7b2f897 100644
--- a/lib/select.h
+++ b/lib/select.h
@@ -81,10 +81,6 @@ int Curl_socket_ready(curl_socket_t readfd, curl_socket_t writefd,
int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms);
-int Curl_select(int nfds,
- fd_set *fds_read, fd_set *fds_write, fd_set *fds_excep,
- struct timeval *timeout);
-
#ifdef TPF
int tpf_select_libcurl(int maxfds, fd_set* reads, fd_set* writes,
fd_set* excepts, struct timeval* tv);