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Diffstat (limited to 'lib/libpthread/thread/thr_select.c')
-rw-r--r--lib/libpthread/thread/thr_select.c184
1 files changed, 101 insertions, 83 deletions
diff --git a/lib/libpthread/thread/thr_select.c b/lib/libpthread/thread/thr_select.c
index 6d7d7dc766ef7..c2f86c5ded477 100644
--- a/lib/libpthread/thread/thr_select.c
+++ b/lib/libpthread/thread/thr_select.c
@@ -29,10 +29,13 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
+ * $Id$
*/
#include <unistd.h>
#include <errno.h>
+#include <poll.h>
#include <string.h>
+#include <sys/param.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/fcntl.h>
@@ -44,12 +47,10 @@ int
select(int numfds, fd_set * readfds, fd_set * writefds,
fd_set * exceptfds, struct timeval * timeout)
{
- fd_set read_locks, write_locks, rdwr_locks;
struct timespec ts;
- struct timeval zero_timeout = {0, 0};
- int i, ret = 0, got_all_locks = 1;
- int f_wait = 1;
- struct pthread_select_data data;
+ int i, ret = 0, f_wait = 1;
+ int pfd_index, got_one = 0, fd_count = 0;
+ struct pthread_poll_data data;
if (numfds > _thread_dtablesize) {
numfds = _thread_dtablesize;
@@ -68,112 +69,129 @@ select(int numfds, fd_set * readfds, fd_set * writefds,
_thread_kern_set_timeout(NULL);
}
- FD_ZERO(&read_locks);
- FD_ZERO(&write_locks);
- FD_ZERO(&rdwr_locks);
-
- /* lock readfds */
+ /* Count the number of file descriptors to be polled: */
if (readfds || writefds || exceptfds) {
for (i = 0; i < numfds; i++) {
- if ((readfds && (FD_ISSET(i, readfds))) || (exceptfds && FD_ISSET(i, exceptfds))) {
- if (writefds && FD_ISSET(i, writefds)) {
- if ((ret = _FD_LOCK(i, FD_RDWR, NULL)) != 0) {
- got_all_locks = 0;
- break;
- }
- FD_SET(i, &rdwr_locks);
- } else {
- if ((ret = _FD_LOCK(i, FD_READ, NULL)) != 0) {
- got_all_locks = 0;
- break;
- }
- FD_SET(i, &read_locks);
- }
- } else {
- if (writefds && FD_ISSET(i, writefds)) {
- if ((ret = _FD_LOCK(i, FD_WRITE, NULL)) != 0) {
- got_all_locks = 0;
- break;
- }
- FD_SET(i, &write_locks);
- }
+ if ((readfds && FD_ISSET(i, readfds)) ||
+ (exceptfds && FD_ISSET(i, exceptfds)) ||
+ (writefds && FD_ISSET(i, writefds))) {
+ fd_count++;
}
}
}
- if (got_all_locks) {
- data.nfds = numfds;
- FD_ZERO(&data.readfds);
- FD_ZERO(&data.writefds);
- FD_ZERO(&data.exceptfds);
- if (readfds != NULL) {
- memcpy(&data.readfds, readfds, sizeof(data.readfds));
- }
- if (writefds != NULL) {
- memcpy(&data.writefds, writefds, sizeof(data.writefds));
+
+ /*
+ * Allocate memory for poll data if it hasn't already been
+ * allocated or if previously allocated memory is insufficient.
+ */
+ if ((_thread_run->poll_data.fds == NULL) ||
+ (_thread_run->poll_data.nfds < fd_count)) {
+ data.fds = (struct pollfd *) realloc(_thread_run->poll_data.fds,
+ sizeof(struct pollfd) * MAX(128, fd_count));
+ if (data.fds == NULL) {
+ errno = ENOMEM;
+ ret = -1;
}
- if (exceptfds != NULL) {
- memcpy(&data.exceptfds, exceptfds, sizeof(data.exceptfds));
+ else {
+ /*
+ * Note that the threads poll data always
+ * indicates what is allocated, not what is
+ * currently being polled.
+ */
+ _thread_run->poll_data.fds = data.fds;
+ _thread_run->poll_data.nfds = MAX(128, fd_count);
}
- if ((ret = _thread_sys_select(data.nfds, &data.readfds, &data.writefds, &data.exceptfds, &zero_timeout)) == 0 && f_wait) {
- data.nfds = numfds;
- FD_ZERO(&data.readfds);
- FD_ZERO(&data.writefds);
- FD_ZERO(&data.exceptfds);
- if (readfds != NULL) {
- memcpy(&data.readfds, readfds, sizeof(data.readfds));
+ }
+ if (ret == 0) {
+ /* Setup the wait data. */
+ data.fds = _thread_run->poll_data.fds;
+ data.nfds = fd_count;
+
+ /*
+ * Setup the array of pollfds. Optimize this by
+ * running the loop in reverse and stopping when
+ * the number of selected file descriptors is reached.
+ */
+ for (i = numfds - 1, pfd_index = fd_count - 1;
+ (i >= 0) && (pfd_index >= 0); i--) {
+ data.fds[pfd_index].events = 0;
+ if (readfds && FD_ISSET(i, readfds)) {
+ data.fds[pfd_index].events = POLLRDNORM;
}
- if (writefds != NULL) {
- memcpy(&data.writefds, writefds, sizeof(data.writefds));
+ if (exceptfds && FD_ISSET(i, exceptfds)) {
+ data.fds[pfd_index].events |= POLLRDBAND;
}
- if (exceptfds != NULL) {
- memcpy(&data.exceptfds, exceptfds, sizeof(data.exceptfds));
+ if (writefds && FD_ISSET(i, writefds)) {
+ data.fds[pfd_index].events |= POLLWRNORM;
+ }
+ if (data.fds[pfd_index].events != 0) {
+ /*
+ * Set the file descriptor to be polled and
+ * clear revents in case of a timeout which
+ * leaves fds unchanged:
+ */
+ data.fds[pfd_index].fd = i;
+ data.fds[pfd_index].revents = 0;
+ pfd_index--;
}
- _thread_run->data.select_data = &data;
+ }
+ if (((ret = _thread_sys_poll(data.fds, data.nfds, 0)) == 0) &&
+ (f_wait != 0)) {
+ _thread_run->data.poll_data = &data;
_thread_run->interrupted = 0;
_thread_kern_sched_state(PS_SELECT_WAIT, __FILE__, __LINE__);
if (_thread_run->interrupted) {
errno = EINTR;
+ data.nfds = 0;
ret = -1;
} else
ret = data.nfds;
}
}
- /* clean up the locks */
- for (i = 0; i < numfds; i++)
- if (FD_ISSET(i, &read_locks))
- _FD_UNLOCK(i, FD_READ);
- for (i = 0; i < numfds; i++)
- if (FD_ISSET(i, &rdwr_locks))
- _FD_UNLOCK(i, FD_RDWR);
- for (i = 0; i < numfds; i++)
- if (FD_ISSET(i, &write_locks))
- _FD_UNLOCK(i, FD_WRITE);
if (ret >= 0) {
- if (readfds != NULL) {
- for (i = 0; i < numfds; i++) {
- if (FD_ISSET(i, readfds) &&
- !FD_ISSET(i, &data.readfds)) {
- FD_CLR(i, readfds);
+ numfds = 0;
+ for (i = 0; i < fd_count; i++) {
+ /*
+ * Check the results of the poll and clear
+ * this file descriptor from the fdset if
+ * the requested event wasn't ready.
+ */
+ got_one = 0;
+ if (readfds != NULL) {
+ if (FD_ISSET(data.fds[i].fd, readfds)) {
+ if (data.fds[i].revents & (POLLIN |
+ POLLRDNORM))
+ got_one = 1;
+ else
+ FD_CLR(data.fds[i].fd, readfds);
}
}
- }
- if (writefds != NULL) {
- for (i = 0; i < numfds; i++) {
- if (FD_ISSET(i, writefds) &&
- !FD_ISSET(i, &data.writefds)) {
- FD_CLR(i, writefds);
+ if (writefds != NULL) {
+ if (FD_ISSET(data.fds[i].fd, writefds)) {
+ if (data.fds[i].revents & (POLLOUT |
+ POLLWRNORM | POLLWRBAND))
+ got_one = 1;
+ else
+ FD_CLR(data.fds[i].fd,
+ writefds);
}
}
- }
- if (exceptfds != NULL) {
- for (i = 0; i < numfds; i++) {
- if (FD_ISSET(i, exceptfds) &&
- !FD_ISSET(i, &data.exceptfds)) {
- FD_CLR(i, exceptfds);
+ if (exceptfds != NULL) {
+ if (FD_ISSET(data.fds[i].fd, exceptfds)) {
+ if (data.fds[i].revents & (POLLRDBAND |
+ POLLPRI | POLLHUP | POLLERR |
+ POLLNVAL))
+ got_one = 1;
+ else
+ FD_CLR(data.fds[i].fd,
+ exceptfds);
}
}
+ if (got_one)
+ numfds++;
}
+ ret = numfds;
}
return (ret);
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-30 04:48:29 +0000