From 711c36558f50943c8342f25ad210281134887a3d Mon Sep 17 00:00:00 2001 From: "Brian M. Clapper" Date: Mon, 11 Jul 2016 18:30:05 -0400 Subject: os: Add poll emulation for mingw [v2] v2: rename as 'xserver_poll' to avoid potential library name collisions. Provide 'xserver_poll.h' which uses the system poll where available and falls back to this emulation otherwise. Autodetects when this is required, building the emulation only then Source: https://github.com/bmc/poll Signed-off-by: Adam Jackson --- os/Makefile.am | 7 ++ os/xserver_poll.c | 277 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 284 insertions(+) create mode 100644 os/xserver_poll.c (limited to 'os') diff --git a/os/Makefile.am b/os/Makefile.am index fc49a73e3..c449076f8 100644 --- a/os/Makefile.am +++ b/os/Makefile.am @@ -7,6 +7,8 @@ XDMCP_SRCS = xdmcp.c XORG_SRCS = log.c BUSFAULT_SRCS = busfault.c +XSERVER_POLL_SRCS=xserver_poll.c + libos_la_SOURCES = \ WaitFor.c \ access.c \ @@ -32,6 +34,11 @@ if SECURE_RPC libos_la_SOURCES += $(SECURERPC_SRCS) endif +if POLL +else +libos_la_SOURCES += $(XSERVER_POLL_SRCS) +endif + if XDMCP libos_la_SOURCES += $(XDMCP_SRCS) endif diff --git a/os/xserver_poll.c b/os/xserver_poll.c new file mode 100644 index 000000000..f152cda21 --- /dev/null +++ b/os/xserver_poll.c @@ -0,0 +1,277 @@ +/*---------------------------------------------------------------------------*\ + $Id$ + + NAME + + poll - select(2)-based poll() emulation function for BSD systems. + + SYNOPSIS + #include "poll.h" + + struct pollfd + { + int fd; + short events; + short revents; + } + + int poll (struct pollfd *pArray, unsigned long n_fds, int timeout) + + DESCRIPTION + + This file, and the accompanying "poll.h", implement the System V + poll(2) system call for BSD systems (which typically do not provide + poll()). Poll() provides a method for multiplexing input and output + on multiple open file descriptors; in traditional BSD systems, that + capability is provided by select(). While the semantics of select() + differ from those of poll(), poll() can be readily emulated in terms + of select() -- which is how this function is implemented. + + REFERENCES + Stevens, W. Richard. Unix Network Programming. Prentice-Hall, 1990. + + NOTES + 1. This software requires an ANSI C compiler. + + LICENSE + + This software is released under the following BSD license, adapted from + http://opensource.org/licenses/bsd-license.php + + Copyright (c) 1995-2011, Brian M. Clapper + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + * Neither the name of the clapper.org nor the names of its contributors + may be used to endorse or promote products derived from this software + without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS + IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR + CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +\*---------------------------------------------------------------------------*/ + + +/*---------------------------------------------------------------------------*\ + Includes +\*---------------------------------------------------------------------------*/ + +#ifdef HAVE_DIX_CONFIG_H +#include +#endif + +#include /* standard Unix definitions */ +#include /* system types */ +#include /* time definitions */ +#include /* assertion macros */ +#include /* string functions */ +#include "xserver_poll.h" + +/*---------------------------------------------------------------------------*\ + Macros +\*---------------------------------------------------------------------------*/ + +#ifndef MAX +#define MAX(a,b) ((a) > (b) ? (a) : (b)) +#endif + +/*---------------------------------------------------------------------------*\ + Private Functions +\*---------------------------------------------------------------------------*/ + +static int map_poll_spec + (struct pollfd *pArray, + nfds_t n_fds, + fd_set *pReadSet, + fd_set *pWriteSet, + fd_set *pExceptSet) +{ + register nfds_t i; /* loop control */ + register struct pollfd *pCur; /* current array element */ + register int max_fd = -1; /* return value */ + + /* + Map the poll() structures into the file descriptor sets required + by select(). + */ + for (i = 0, pCur = pArray; i < n_fds; i++, pCur++) + { + /* Skip any bad FDs in the array. */ + + if (pCur->fd < 0) + continue; + + if (pCur->events & POLLIN) + { + /* "Input Ready" notification desired. */ + FD_SET (pCur->fd, pReadSet); + } + + if (pCur->events & POLLOUT) + { + /* "Output Possible" notification desired. */ + FD_SET (pCur->fd, pWriteSet); + } + + if (pCur->events & POLLPRI) + { + /* + "Exception Occurred" notification desired. (Exceptions + include out of band data. + */ + FD_SET (pCur->fd, pExceptSet); + } + + max_fd = MAX (max_fd, pCur->fd); + } + + return max_fd; +} + +static struct timeval *map_timeout + (int poll_timeout, struct timeval *pSelTimeout) +{ + struct timeval *pResult; + + /* + Map the poll() timeout value into a select() timeout. The possible + values of the poll() timeout value, and their meanings, are: + + VALUE MEANING + + -1 wait indefinitely (until signal occurs) + 0 return immediately, don't block + >0 wait specified number of milliseconds + + select() uses a "struct timeval", which specifies the timeout in + seconds and microseconds, so the milliseconds value has to be mapped + accordingly. + */ + + assert (pSelTimeout != (struct timeval *) NULL); + + switch (poll_timeout) + { + case -1: + /* + A NULL timeout structure tells select() to wait indefinitely. + */ + pResult = (struct timeval *) NULL; + break; + + case 0: + /* + "Return immediately" (test) is specified by all zeros in + a timeval structure. + */ + pSelTimeout->tv_sec = 0; + pSelTimeout->tv_usec = 0; + pResult = pSelTimeout; + break; + + default: + /* Wait the specified number of milliseconds. */ + pSelTimeout->tv_sec = poll_timeout / 1000; /* get seconds */ + poll_timeout %= 1000; /* remove seconds */ + pSelTimeout->tv_usec = poll_timeout * 1000; /* get microseconds */ + pResult = pSelTimeout; + break; + } + + + return pResult; +} + +static void map_select_results + (struct pollfd *pArray, + unsigned long n_fds, + fd_set *pReadSet, + fd_set *pWriteSet, + fd_set *pExceptSet) +{ + register unsigned long i; /* loop control */ + register struct pollfd *pCur; /* current array element */ + + for (i = 0, pCur = pArray; i < n_fds; i++, pCur++) + { + /* Skip any bad FDs in the array. */ + + if (pCur->fd < 0) + continue; + + /* Exception events take priority over input events. */ + + pCur->revents = 0; + if (FD_ISSET (pCur->fd, pExceptSet)) + pCur->revents |= POLLPRI; + + else if (FD_ISSET (pCur->fd, pReadSet)) + pCur->revents |= POLLIN; + + if (FD_ISSET (pCur->fd, pWriteSet)) + pCur->revents |= POLLOUT; + } + + return; +} + +/*---------------------------------------------------------------------------*\ + Public Functions +\*---------------------------------------------------------------------------*/ + +int xserver_poll + (struct pollfd *pArray, unsigned long n_fds, int timeout) +{ + fd_set read_descs; /* input file descs */ + fd_set write_descs; /* output file descs */ + fd_set except_descs; /* exception descs */ + struct timeval stime; /* select() timeout value */ + int ready_descriptors; /* function result */ + int max_fd; /* maximum fd value */ + struct timeval *pTimeout; /* actually passed */ + + FD_ZERO (&read_descs); + FD_ZERO (&write_descs); + FD_ZERO (&except_descs); + + assert (pArray != (struct pollfd *) NULL); + + /* Map the poll() file descriptor list in the select() data structures. */ + + max_fd = map_poll_spec (pArray, n_fds, + &read_descs, &write_descs, &except_descs); + + /* Map the poll() timeout value in the select() timeout structure. */ + + pTimeout = map_timeout (timeout, &stime); + + /* Make the select() call. */ + + ready_descriptors = select (max_fd + 1, &read_descs, &write_descs, + &except_descs, pTimeout); + + if (ready_descriptors >= 0) + { + map_select_results (pArray, n_fds, + &read_descs, &write_descs, &except_descs); + } + + return ready_descriptors; +} -- cgit v1.2.3