* Wrapper around the accept system call.
*
* \param fd The listening socket.
+ * \param rfds An optional fd_set pointer.
* \param addr Structure which is filled in with the address of the peer socket.
* \param size Should contain the size of the structure pointed to by \a addr.
+ * \param new_fd Result pointer.
*
- * Accept incoming connections on \a addr. Retry if interrupted.
+ * Accept incoming connections on \a addr, retry if interrupted. If \a rfds is
+ * not \p NULL, return 0 if \a fd is not set in \a rfds without calling accept().
*
- * \return The new file descriptor on success, negative on errors.
+ * \return Negative on errors, zero if no connections are present to be accepted,
+ * one otherwise.
*
* \sa accept(2).
*/
-int para_accept(int fd, void *addr, socklen_t size)
+int para_accept(int fd, fd_set *rfds, void *addr, socklen_t size, int *new_fd)
{
- int new_fd;
+ int ret;
+ if (rfds && !FD_ISSET(fd, rfds))
+ return 0;
do
- new_fd = accept(fd, (struct sockaddr *) addr, &size);
- while (new_fd < 0 && errno == EINTR);
- return new_fd < 0? -ERRNO_TO_PARA_ERROR(errno) : new_fd;
+ ret = accept(fd, (struct sockaddr *) addr, &size);
+ while (ret < 0 && errno == EINTR);
+
+ if (ret >= 0) {
+ *new_fd = ret;
+ return 1;
+ }
+ if (errno == EAGAIN || errno == EWOULDBLOCK)
+ return 0;
+ return -ERRNO_TO_PARA_ERROR(errno);
}
/**