romenskiy2012/curl
1
0
Fork 0
mirror of https://github.com/curl/curl.git synced 2026-08-24 23:43:40 +03:00
Code Issues Projects Releases Packages Wiki Activity

When transferring 500 downloads in parallel with a c-ares enabled build only

Browse source 
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.
This commit is contained in:
Daniel Stenberg 2007-05-31 11:34:32 +00:00
parent 713c9f8602
commit 4c663ba9a8
8 changed files with 92 additions and 263 deletions
Download patch file Download diff file Expand all files Collapse all files

221
lib/select.c
View file

@ -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.