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New Internal wrapper function Curl_select() around select (2), it

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uses poll() when a fine poll() is available, so now libcurl can be
built without select() support at all if a fine poll() is available.
This commit is contained in:
Yang Tse
2007-03-27 18:15:26 +00:00
parent 59eaae42b8
commit eed47311f8
6 changed files with 222 additions and 10 deletions
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197
lib/select.c
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@@ -32,8 +32,8 @@
#include <sys/time.h>
#endif
#ifndef HAVE_SELECT
#error "We can't compile without select() support!"
#if !defined(HAVE_SELECT) && !defined(HAVE_POLL_FINE)
#error "We can't compile without select() or poll() support."
#endif
#ifdef __BEOS__
@@ -64,6 +64,7 @@
#if defined(USE_WINSOCK) || defined(TPF)
#define VERIFY_SOCK(x) do { } while (0)
#define VERIFY_NFDS(x) do { } while (0)
#else
#define VALID_SOCK(s) (((s) >= 0) && ((s) < FD_SETSIZE))
#define VERIFY_SOCK(x) do { \
@@ -72,6 +73,13 @@
return -1; \
} \
} while(0)
#define VALID_NFDS(n) (((n) >= 0) && ((n) <= FD_SETSIZE))
#define VERIFY_NFDS(x) do { \
if(!VALID_NFDS(x)) { \
SET_SOCKERRNO(EINVAL); \
return -1; \
} \
} while(0)
#endif
/* Convenience local macros */
@@ -84,6 +92,8 @@
#define error_not_EINTR (1)
#endif
#define SMALL_POLLNFDS 0X20
/*
* Internal function used for waiting a specific amount of ms
* in Curl_socket_ready() and Curl_poll() when no file descriptor
@@ -424,6 +434,189 @@ 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;
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 = (timeout->tv_sec * 1000) + (timeout->tv_usec / 1000);
}
else {
timeout_ms = -1;
}
if ((!nfds) || (!fds_read && !fds_write && !fds_excep)) {
r = wait_ms(timeout_ms);
return r;
}
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 = calloc((size_t)poll_nfds, sizeof(struct pollfd));
if (!poll_fds) {
SET_SOCKERRNO(ENOBUFS);
return -1;
}
}
if (poll_fds) {
ix = 0;
fd = nfds;
while (fd--) {
poll_fds[ix].events = 0;
if (fds_read && (0 != FD_ISSET(fd, fds_read)))
poll_fds[ix].events |= (POLLRDNORM|POLLIN);
if (fds_write && (0 != FD_ISSET(fd, fds_write)))
poll_fds[ix].events |= (POLLWRNORM|POLLOUT);
if (fds_excep && (0 != FD_ISSET(fd, fds_excep)))
poll_fds[ix].events |= (POLLRDBAND|POLLPRI);
if (poll_fds[ix].events) {
poll_fds[ix].fd = fd;
poll_fds[ix].revents = 0;
ix++;
}
}
}
do {
if (timeout_ms < 0)
pending_ms = -1;
r = poll(poll_fds, poll_nfds, pending_ms);
} while ((r == -1) && (error = SOCKERRNO) &&
(error != EINVAL) && error_not_EINTR &&
((timeout_ms < 0) || ((pending_ms = timeout_ms - elapsed_ms) > 0)));
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 (ptimeout) {
pending_tv.tv_sec = pending_ms / 1000;
pending_tv.tv_usec = (pending_ms % 1000) * 1000;
}
r = select(nfds, fds_read, fds_write, fds_excep, ptimeout);
} while ((r == -1) && (error = SOCKERRNO) &&
(error != EINVAL) && (error != EBADF) && error_not_EINTR &&
((timeout_ms < 0) || ((pending_ms = timeout_ms - elapsed_ms) > 0)));
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.