mirror of
https://github.com/moparisthebest/curl
synced 2024-10-31 15:45:12 -04:00
fb4937a311
"Any two of the parameters, readfds, writefds, or exceptfds, can be given as null. At least one must be non-null, and any non-null descriptor set must contain at least one handle to a socket." http://msdn.microsoft.com/en-ca/library/windows/desktop/ms740141(v=vs.85).aspx When using select(), cURL doesn't adhere to this (WinSock-specific) rule, and can ask to monitor empty fd_sets, which leads to select() returning WSAEINVAL (i.e. EINVAL) and connections failing in mysterious ways as a result (at least when using the curl_multi_socket_action() interface). Bug: http://curl.haxx.se/mail/lib-2014-05/0278.html
569 lines
15 KiB
C
569 lines
15 KiB
C
/***************************************************************************
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* _ _ ____ _
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* Project ___| | | | _ \| |
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* / __| | | | |_) | |
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* | (__| |_| | _ <| |___
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* \___|\___/|_| \_\_____|
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*
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* Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
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*
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* This software is licensed as described in the file COPYING, which
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* you should have received as part of this distribution. The terms
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* are also available at http://curl.haxx.se/docs/copyright.html.
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*
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* You may opt to use, copy, modify, merge, publish, distribute and/or sell
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* copies of the Software, and permit persons to whom the Software is
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* furnished to do so, under the terms of the COPYING file.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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***************************************************************************/
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#include "curl_setup.h"
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#ifdef HAVE_SYS_SELECT_H
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#include <sys/select.h>
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#endif
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#if !defined(HAVE_SELECT) && !defined(HAVE_POLL_FINE)
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#error "We can't compile without select() or poll() support."
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#endif
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#if defined(__BEOS__) && !defined(__HAIKU__)
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/* BeOS has FD_SET defined in socket.h */
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#include <socket.h>
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#endif
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#ifdef MSDOS
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#include <dos.h> /* delay() */
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#endif
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#include <curl/curl.h>
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#include "urldata.h"
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#include "connect.h"
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#include "select.h"
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#include "warnless.h"
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/* Convenience local macros */
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#define elapsed_ms (int)curlx_tvdiff(curlx_tvnow(), initial_tv)
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int Curl_ack_eintr = 0;
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#define error_not_EINTR (Curl_ack_eintr || error != EINTR)
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/*
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* Internal function used for waiting a specific amount of ms
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* in Curl_socket_ready() and Curl_poll() when no file descriptor
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* is provided to wait on, just being used to delay execution.
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* WinSock select() and poll() timeout mechanisms need a valid
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* socket descriptor in a not null file descriptor set to work.
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* Waiting indefinitely with this function is not allowed, a
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* zero or negative timeout value will return immediately.
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* Timeout resolution, accuracy, as well as maximum supported
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* value is system dependent, neither factor is a citical issue
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* for the intended use of this function in the library.
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*
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* Return values:
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* -1 = system call error, invalid timeout value, or interrupted
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* 0 = specified timeout has elapsed
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*/
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int Curl_wait_ms(int timeout_ms)
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{
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#if !defined(MSDOS) && !defined(USE_WINSOCK)
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#ifndef HAVE_POLL_FINE
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struct timeval pending_tv;
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#endif
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struct timeval initial_tv;
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int pending_ms;
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int error;
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#endif
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int r = 0;
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if(!timeout_ms)
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return 0;
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if(timeout_ms < 0) {
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SET_SOCKERRNO(EINVAL);
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return -1;
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}
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#if defined(MSDOS)
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delay(timeout_ms);
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#elif defined(USE_WINSOCK)
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Sleep(timeout_ms);
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#else
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pending_ms = timeout_ms;
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initial_tv = curlx_tvnow();
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do {
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#if defined(HAVE_POLL_FINE)
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r = poll(NULL, 0, pending_ms);
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#else
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pending_tv.tv_sec = pending_ms / 1000;
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pending_tv.tv_usec = (pending_ms % 1000) * 1000;
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r = select(0, NULL, NULL, NULL, &pending_tv);
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#endif /* HAVE_POLL_FINE */
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if(r != -1)
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break;
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error = SOCKERRNO;
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if(error && error_not_EINTR)
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break;
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pending_ms = timeout_ms - elapsed_ms;
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if(pending_ms <= 0)
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break;
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} while(r == -1);
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#endif /* USE_WINSOCK */
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if(r)
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r = -1;
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return r;
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}
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/*
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* Wait for read or write events on a set of file descriptors. It uses poll()
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* when a fine poll() is available, in order to avoid limits with FD_SETSIZE,
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* otherwise select() is used. An error is returned if select() is being used
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* and a file descriptor is too large for FD_SETSIZE.
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*
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* A negative timeout value makes this function wait indefinitely,
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* unles no valid file descriptor is given, when this happens the
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* negative timeout is ignored and the function times out immediately.
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*
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* Return values:
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* -1 = system call error or fd >= FD_SETSIZE
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* 0 = timeout
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* [bitmask] = action as described below
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*
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* CURL_CSELECT_IN - first socket is readable
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* CURL_CSELECT_IN2 - second socket is readable
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* CURL_CSELECT_OUT - write socket is writable
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* CURL_CSELECT_ERR - an error condition occurred
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*/
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int Curl_socket_check(curl_socket_t readfd0, /* two sockets to read from */
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curl_socket_t readfd1,
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curl_socket_t writefd, /* socket to write to */
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long timeout_ms) /* milliseconds to wait */
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{
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#ifdef HAVE_POLL_FINE
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struct pollfd pfd[3];
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int num;
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#else
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struct timeval pending_tv;
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struct timeval *ptimeout;
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fd_set fds_read;
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fd_set fds_write;
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fd_set fds_err;
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curl_socket_t maxfd;
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#endif
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struct timeval initial_tv = {0,0};
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int pending_ms = 0;
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int error;
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int r;
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int ret;
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if((readfd0 == CURL_SOCKET_BAD) && (readfd1 == CURL_SOCKET_BAD) &&
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(writefd == CURL_SOCKET_BAD)) {
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/* no sockets, just wait */
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r = Curl_wait_ms((int)timeout_ms);
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return r;
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}
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/* Avoid initial timestamp, avoid curlx_tvnow() call, when elapsed
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time in this function does not need to be measured. This happens
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when function is called with a zero timeout or a negative timeout
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value indicating a blocking call should be performed. */
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if(timeout_ms > 0) {
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pending_ms = (int)timeout_ms;
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initial_tv = curlx_tvnow();
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}
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#ifdef HAVE_POLL_FINE
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num = 0;
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if(readfd0 != CURL_SOCKET_BAD) {
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pfd[num].fd = readfd0;
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pfd[num].events = POLLRDNORM|POLLIN|POLLRDBAND|POLLPRI;
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pfd[num].revents = 0;
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num++;
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}
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if(readfd1 != CURL_SOCKET_BAD) {
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pfd[num].fd = readfd1;
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pfd[num].events = POLLRDNORM|POLLIN|POLLRDBAND|POLLPRI;
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pfd[num].revents = 0;
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num++;
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}
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if(writefd != CURL_SOCKET_BAD) {
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pfd[num].fd = writefd;
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pfd[num].events = POLLWRNORM|POLLOUT;
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pfd[num].revents = 0;
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num++;
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}
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do {
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if(timeout_ms < 0)
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pending_ms = -1;
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else if(!timeout_ms)
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pending_ms = 0;
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r = poll(pfd, num, pending_ms);
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if(r != -1)
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break;
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error = SOCKERRNO;
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if(error && error_not_EINTR)
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break;
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if(timeout_ms > 0) {
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pending_ms = (int)(timeout_ms - elapsed_ms);
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if(pending_ms <= 0) {
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r = 0; /* Simulate a "call timed out" case */
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break;
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}
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}
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} while(r == -1);
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if(r < 0)
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return -1;
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if(r == 0)
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return 0;
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ret = 0;
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num = 0;
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if(readfd0 != CURL_SOCKET_BAD) {
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if(pfd[num].revents & (POLLRDNORM|POLLIN|POLLERR|POLLHUP))
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ret |= CURL_CSELECT_IN;
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if(pfd[num].revents & (POLLRDBAND|POLLPRI|POLLNVAL))
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ret |= CURL_CSELECT_ERR;
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num++;
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}
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if(readfd1 != CURL_SOCKET_BAD) {
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if(pfd[num].revents & (POLLRDNORM|POLLIN|POLLERR|POLLHUP))
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ret |= CURL_CSELECT_IN2;
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if(pfd[num].revents & (POLLRDBAND|POLLPRI|POLLNVAL))
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ret |= CURL_CSELECT_ERR;
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num++;
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}
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if(writefd != CURL_SOCKET_BAD) {
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if(pfd[num].revents & (POLLWRNORM|POLLOUT))
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ret |= CURL_CSELECT_OUT;
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if(pfd[num].revents & (POLLERR|POLLHUP|POLLNVAL))
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ret |= CURL_CSELECT_ERR;
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}
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return ret;
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#else /* HAVE_POLL_FINE */
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FD_ZERO(&fds_err);
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maxfd = (curl_socket_t)-1;
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FD_ZERO(&fds_read);
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if(readfd0 != CURL_SOCKET_BAD) {
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VERIFY_SOCK(readfd0);
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FD_SET(readfd0, &fds_read);
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FD_SET(readfd0, &fds_err);
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maxfd = readfd0;
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}
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if(readfd1 != CURL_SOCKET_BAD) {
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VERIFY_SOCK(readfd1);
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FD_SET(readfd1, &fds_read);
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FD_SET(readfd1, &fds_err);
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if(readfd1 > maxfd)
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maxfd = readfd1;
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}
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FD_ZERO(&fds_write);
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if(writefd != CURL_SOCKET_BAD) {
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VERIFY_SOCK(writefd);
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FD_SET(writefd, &fds_write);
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FD_SET(writefd, &fds_err);
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if(writefd > maxfd)
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maxfd = writefd;
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}
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ptimeout = (timeout_ms < 0) ? NULL : &pending_tv;
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do {
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if(timeout_ms > 0) {
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pending_tv.tv_sec = pending_ms / 1000;
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pending_tv.tv_usec = (pending_ms % 1000) * 1000;
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}
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else if(!timeout_ms) {
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pending_tv.tv_sec = 0;
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pending_tv.tv_usec = 0;
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}
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/* WinSock select() must not be called with an fd_set that contains zero
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fd flags, or it will return WSAEINVAL. But, it also can't be called
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with no fd_sets at all! From the documentation:
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Any two of the parameters, readfds, writefds, or exceptfds, can be
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given as null. At least one must be non-null, and any non-null
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descriptor set must contain at least one handle to a socket.
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We know that we have at least one bit set in at least two fd_sets in
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this case, but we may have no bits set in either fds_read or fd_write,
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so check for that and handle it. Luckily, with WinSock, we can _also_
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ask how many bits are set on an fd_set.
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It is unclear why WinSock doesn't just handle this for us instead of
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calling this an error.
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Note also that WinSock ignores the first argument, so we don't worry
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about the fact that maxfd is computed incorrectly with WinSock (since
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curl_socket_t is unsigned in such cases and thus -1 is the largest
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value).
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*/
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r = select((int)maxfd + 1,
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#ifndef USE_WINSOCK
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&fds_read,
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&fds_write,
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#else
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fds_read.fd_count ? &fds_read : NULL,
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fds_write.fd_count ? &fds_write : NULL,
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#endif
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&fds_err, ptimeout);
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if(r != -1)
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break;
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error = SOCKERRNO;
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if(error && error_not_EINTR)
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break;
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if(timeout_ms > 0) {
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pending_ms = timeout_ms - elapsed_ms;
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if(pending_ms <= 0) {
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r = 0; /* Simulate a "call timed out" case */
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break;
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}
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}
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} while(r == -1);
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if(r < 0)
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return -1;
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if(r == 0)
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return 0;
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ret = 0;
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if(readfd0 != CURL_SOCKET_BAD) {
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if(FD_ISSET(readfd0, &fds_read))
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ret |= CURL_CSELECT_IN;
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if(FD_ISSET(readfd0, &fds_err))
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ret |= CURL_CSELECT_ERR;
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}
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if(readfd1 != CURL_SOCKET_BAD) {
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if(FD_ISSET(readfd1, &fds_read))
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ret |= CURL_CSELECT_IN2;
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if(FD_ISSET(readfd1, &fds_err))
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ret |= CURL_CSELECT_ERR;
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}
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if(writefd != CURL_SOCKET_BAD) {
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if(FD_ISSET(writefd, &fds_write))
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ret |= CURL_CSELECT_OUT;
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if(FD_ISSET(writefd, &fds_err))
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ret |= CURL_CSELECT_ERR;
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}
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return ret;
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#endif /* HAVE_POLL_FINE */
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}
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/*
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* This is a wrapper around poll(). If poll() does not exist, then
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* select() is used instead. An error is returned if select() is
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* being used and a file descriptor is too large for FD_SETSIZE.
|
|
* A negative timeout value makes this function wait indefinitely,
|
|
* unles no valid file descriptor is given, when this happens the
|
|
* negative timeout is ignored and the function times out immediately.
|
|
*
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* Return values:
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* -1 = system call error or fd >= FD_SETSIZE
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* 0 = timeout
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* N = number of structures with non zero revent fields
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*/
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int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms)
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{
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#ifndef HAVE_POLL_FINE
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struct timeval pending_tv;
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struct timeval *ptimeout;
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fd_set fds_read;
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fd_set fds_write;
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fd_set fds_err;
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curl_socket_t maxfd;
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#endif
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struct timeval initial_tv = {0,0};
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bool fds_none = TRUE;
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unsigned int i;
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int pending_ms = 0;
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int error;
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int r;
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if(ufds) {
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for(i = 0; i < nfds; i++) {
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if(ufds[i].fd != CURL_SOCKET_BAD) {
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fds_none = FALSE;
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break;
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}
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}
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}
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if(fds_none) {
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r = Curl_wait_ms(timeout_ms);
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return r;
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}
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|
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/* Avoid initial timestamp, avoid curlx_tvnow() call, when elapsed
|
|
time in this function does not need to be measured. This happens
|
|
when function is called with a zero timeout or a negative timeout
|
|
value indicating a blocking call should be performed. */
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|
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if(timeout_ms > 0) {
|
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pending_ms = timeout_ms;
|
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initial_tv = curlx_tvnow();
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}
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|
|
#ifdef HAVE_POLL_FINE
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|
|
do {
|
|
if(timeout_ms < 0)
|
|
pending_ms = -1;
|
|
else if(!timeout_ms)
|
|
pending_ms = 0;
|
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r = poll(ufds, nfds, pending_ms);
|
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if(r != -1)
|
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break;
|
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error = SOCKERRNO;
|
|
if(error && error_not_EINTR)
|
|
break;
|
|
if(timeout_ms > 0) {
|
|
pending_ms = timeout_ms - elapsed_ms;
|
|
if(pending_ms <= 0)
|
|
break;
|
|
}
|
|
} while(r == -1);
|
|
|
|
if(r < 0)
|
|
return -1;
|
|
if(r == 0)
|
|
return 0;
|
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|
|
for(i = 0; i < nfds; i++) {
|
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if(ufds[i].fd == CURL_SOCKET_BAD)
|
|
continue;
|
|
if(ufds[i].revents & POLLHUP)
|
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ufds[i].revents |= POLLIN;
|
|
if(ufds[i].revents & POLLERR)
|
|
ufds[i].revents |= (POLLIN|POLLOUT);
|
|
}
|
|
|
|
#else /* HAVE_POLL_FINE */
|
|
|
|
FD_ZERO(&fds_read);
|
|
FD_ZERO(&fds_write);
|
|
FD_ZERO(&fds_err);
|
|
maxfd = (curl_socket_t)-1;
|
|
|
|
for(i = 0; i < nfds; i++) {
|
|
ufds[i].revents = 0;
|
|
if(ufds[i].fd == CURL_SOCKET_BAD)
|
|
continue;
|
|
VERIFY_SOCK(ufds[i].fd);
|
|
if(ufds[i].events & (POLLIN|POLLOUT|POLLPRI|
|
|
POLLRDNORM|POLLWRNORM|POLLRDBAND)) {
|
|
if(ufds[i].fd > maxfd)
|
|
maxfd = ufds[i].fd;
|
|
if(ufds[i].events & (POLLRDNORM|POLLIN))
|
|
FD_SET(ufds[i].fd, &fds_read);
|
|
if(ufds[i].events & (POLLWRNORM|POLLOUT))
|
|
FD_SET(ufds[i].fd, &fds_write);
|
|
if(ufds[i].events & (POLLRDBAND|POLLPRI))
|
|
FD_SET(ufds[i].fd, &fds_err);
|
|
}
|
|
}
|
|
|
|
#ifdef USE_WINSOCK
|
|
/* WinSock select() can't handle zero events. See the comment about this in
|
|
Curl_check_socket(). */
|
|
if(fds_read.fd_count == 0 && fds_write.fd_count == 0
|
|
&& fds_err.fd_count == 0) {
|
|
r = Curl_wait_ms(timeout_ms);
|
|
return r;
|
|
}
|
|
#endif
|
|
|
|
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((int)maxfd + 1,
|
|
#ifndef USE_WINSOCK
|
|
&fds_read, &fds_write, &fds_err,
|
|
#else
|
|
/* WinSock select() can't handle fd_sets with zero bits set, so
|
|
don't give it such arguments. See the comment about this in
|
|
Curl_check_socket().
|
|
*/
|
|
fds_read.fd_count ? &fds_read : NULL,
|
|
fds_write.fd_count ? &fds_write : NULL,
|
|
fds_err.fd_count ? &fds_err : NULL,
|
|
#endif
|
|
ptimeout);
|
|
if(r != -1)
|
|
break;
|
|
error = SOCKERRNO;
|
|
if(error && error_not_EINTR)
|
|
break;
|
|
if(timeout_ms > 0) {
|
|
pending_ms = timeout_ms - elapsed_ms;
|
|
if(pending_ms <= 0)
|
|
break;
|
|
}
|
|
} while(r == -1);
|
|
|
|
if(r < 0)
|
|
return -1;
|
|
if(r == 0)
|
|
return 0;
|
|
|
|
r = 0;
|
|
for(i = 0; i < nfds; i++) {
|
|
ufds[i].revents = 0;
|
|
if(ufds[i].fd == CURL_SOCKET_BAD)
|
|
continue;
|
|
if(FD_ISSET(ufds[i].fd, &fds_read))
|
|
ufds[i].revents |= POLLIN;
|
|
if(FD_ISSET(ufds[i].fd, &fds_write))
|
|
ufds[i].revents |= POLLOUT;
|
|
if(FD_ISSET(ufds[i].fd, &fds_err))
|
|
ufds[i].revents |= POLLPRI;
|
|
if(ufds[i].revents != 0)
|
|
r++;
|
|
}
|
|
|
|
#endif /* HAVE_POLL_FINE */
|
|
|
|
return r;
|
|
}
|
|
|
|
#ifdef TPF
|
|
/*
|
|
* This is a replacement for select() on the TPF platform.
|
|
* It is used whenever libcurl calls select().
|
|
* The call below to tpf_process_signals() is required because
|
|
* TPF's select calls are not signal interruptible.
|
|
*
|
|
* Return values are the same as select's.
|
|
*/
|
|
int tpf_select_libcurl(int maxfds, fd_set* reads, fd_set* writes,
|
|
fd_set* excepts, struct timeval* tv)
|
|
{
|
|
int rc;
|
|
|
|
rc = tpf_select_bsd(maxfds, reads, writes, excepts, tv);
|
|
tpf_process_signals();
|
|
return(rc);
|
|
}
|
|
#endif /* TPF */
|