/*
This file is part of libmicrohttpd
Copyright (C) 2016 Karlson2k (Evgeny Grin)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file microhttpd/mhd_itc.h
* @brief Header for platform-independent inter-thread communication
* @author Karlson2k (Evgeny Grin)
* @author Christian Grothoff
*
* Provides basic abstraction for inter-thread communication.
* Any functions can be implemented as macro on some platforms
* unless explicitly marked otherwise.
* Any function argument can be skipped in macro, so avoid
* variable modification in function parameters.
*/
#ifndef MHD_ITC_H
#define MHD_ITC_H 1
#include "mhd_itc_types.h"
#include <fcntl.h>
#ifndef MHD_PANIC
# include <stdio.h>
# include <stdlib.h>
/* Simple implementation of MHD_PANIC, to be used outside lib */
# define MHD_PANIC(msg) do { fprintf (stderr, \
"Abnormal termination at %d line in file %s: %s\n", \
(int)__LINE__, __FILE__, msg); abort();} while(0)
#endif /* ! MHD_PANIC */
#if defined(_MHD_ITC_EVENTFD)
/* **************** Optimized GNU/Linux ITC implementation by eventfd ********** */
#include <sys/eventfd.h>
#include <stdint.h> /* for uint64_t */
#ifdef HAVE_UNISTD_H
#include <unistd.h> /* for read(), write(), errno */
#endif /* HAVE_UNISTD_H */
#ifdef HAVE_STRING_H
#include <string.h> /* for strerror() */
#endif
/**
* Initialise ITC by generating eventFD
* @param itc the itc to initialise
* @return non-zero if succeeded, zero otherwise
*/
#define MHD_itc_init_(itc) (-1 != ((itc).fd = eventfd (0, EFD_CLOEXEC | EFD_NONBLOCK)))
/**
* Get description string of last errno for itc operations.
*/
#define MHD_itc_last_strerror_() strerror(errno)
/**
* Internal static const helper for MHD_itc_activate_()
*/
static const uint64_t _MHD_itc_wr_data = 1;
/**
* Activate signal on @a itc
* @param itc the itc to use
* @param str ignored
* @return non-zero if succeeded, zero otherwise
*/
#define MHD_itc_activate_(itc, str) \
((write((itc).fd, (const void*)&_MHD_itc_wr_data, 8) > 0) || (EAGAIN == errno))
/**
* Return read FD of @a itc which can be used for poll(), select() etc.
* @param itc the itc to get FD
* @return FD of read side
*/
#define MHD_itc_r_fd_(itc) ((itc).fd)
/**
* Return write FD of @a itc
* @param itc the itc to get FD
* @return FD of write side
*/
#define MHD_itc_w_fd_(itc) ((itc).fd)
/**
* Clear signaled state on @a itc
* @param itc the itc to clear
*/
#define MHD_itc_clear_(itc) \
do { uint64_t __b; int __r; \
__r = read((itc).fd, &__b, sizeof(__b)); \
(void)__r; } while(0)
/**
* Destroy previously initialised ITC
* @param itc the itc to destroy
* @return non-zero if succeeded, zero otherwise
*/
#define MHD_itc_destroy_(itc) ((0 != close ((itc).fd)) || (EBADF != errno))
/**
* Check whether ITC has valid value.
*
* Macro check whether @a itc value is valid (allowed),
* macro does not check whether @a itc was really initialised.
* @param itc the itc to check
* @return boolean true if @a itc has valid value,
* boolean false otherwise.
*/
#define MHD_ITC_IS_VALID_(itc) (-1 != ((itc).fd))
/**
* Set @a itc to invalid value.
* @param itc the itc to set
*/
#define MHD_itc_set_invalid_(itc) ((itc).fd = -1)
#elif defined(_MHD_ITC_PIPE)
/* **************** Standard UNIX ITC implementation by pipe ********** */
#if defined(HAVE_PIPE2_FUNC) && defined(HAVE_FCNTL_H)
# include <fcntl.h> /* for O_CLOEXEC, O_NONBLOCK */
#endif /* HAVE_PIPE2_FUNC && HAVE_FCNTL_H */
#ifdef HAVE_UNISTD_H
#include <unistd.h> /* for read(), write(), errno */
#endif /* HAVE_UNISTD_H */
#ifdef HAVE_STRING_H
#include <string.h> /* for strerror() */
#endif
/**
* Initialise ITC by generating pipe
* @param itc the itc to initialise
* @return non-zero if succeeded, zero otherwise
*/
#ifdef HAVE_PIPE2_FUNC
# define MHD_itc_init_(itc) (!pipe2((itc).fd, O_CLOEXEC | O_NONBLOCK))
#else /* ! HAVE_PIPE2_FUNC */
# define MHD_itc_init_(itc) \
( (!pipe((itc).fd)) ? \
(MHD_itc_nonblocking_((itc)) ? \
(!0) : \
(MHD_itc_destroy_((itc)), 0) ) \
: (0) )
#endif /* ! HAVE_PIPE2_FUNC */
/**
* Get description string of last errno for itc operations.
*/
#define MHD_itc_last_strerror_() strerror(errno)
/**
* Activate signal on @a itc
* @param itc the itc to use
* @param str one-symbol string, useful only for strace debug
* @return non-zero if succeeded, zero otherwise
*/
#define MHD_itc_activate_(itc, str) \
((write((itc).fd[1], (const void*)(str), 1) > 0) || (EAGAIN == errno))
/**
* Return read FD of @a itc which can be used for poll(), select() etc.
* @param itc the itc to get FD
* @return FD of read side
*/
#define MHD_itc_r_fd_(itc) ((itc).fd[0])
/**
* Return write FD of @a itc
* @param itc the itc to get FD
* @return FD of write side
*/
#define MHD_itc_w_fd_(itc) ((itc).fd[1])
/**
* Clear signaled state on @a itc
* @param itc the itc to clear
*/
#define MHD_itc_clear_(itc) do \
{ long __b; \
while(0 < read((itc).fd[0], &__b, sizeof(__b))) \
{} } while(0)
/**
* Destroy previously initialised ITC
* @param itc the itc to destroy
* @return non-zero if succeeded, zero otherwise
*/
#define MHD_itc_destroy_(itc) \
( (0 == close ((itc).fd[0])) ? \
(0 == close ((itc).fd[1])) : \
((close ((itc).fd[1])), 0) )
/**
* Check whether ITC has valid value.
*
* Macro check whether @a itc value is valid (allowed),
* macro does not check whether @a itc was really initialised.
* @param itc the itc to check
* @return boolean true if @a itc has valid value,
* boolean false otherwise.
*/
#define MHD_ITC_IS_VALID_(itc) (-1 != (itc).fd[0])
/**
* Set @a itc to invalid value.
* @param itc the itc to set
*/
#define MHD_itc_set_invalid_(itc) ((itc).fd[0] = (itc).fd[1] = -1)
#ifndef HAVE_PIPE2_FUNC
/**
* Change itc FD options to be non-blocking.
*
* @param fd the FD to manipulate
* @return non-zero if succeeded, zero otherwise
*/
int
MHD_itc_nonblocking_ (struct MHD_itc_ itc);
#endif /* ! HAVE_PIPE2_FUNC */
#elif defined(_MHD_ITC_SOCKETPAIR)
/* **************** ITC implementation by socket pair ********** */
#include "mhd_sockets.h"
/**
* Initialise ITC by generating socketpair
* @param itc the itc to initialise
* @return non-zero if succeeded, zero otherwise
*/
#ifdef MHD_socket_pair_nblk_
# define MHD_itc_init_(itc) MHD_socket_pair_nblk_((itc).sk)
#else /* ! MHD_socket_pair_nblk_ */
# define MHD_itc_init_(itc) \
(MHD_socket_pair_((itc).sk) ? \
(MHD_itc_nonblocking_((itc)) ? \
(!0) : \
(MHD_itc_destroy_((itc)), 0) ) \
: (0))
#endif /* ! MHD_socket_pair_nblk_ */
/**
* Get description string of last error for itc operations.
*/
#define MHD_itc_last_strerror_() MHD_socket_last_strerr_()
/**
* Activate signal on @a itc
* @param itc the itc to use
* @param str one-symbol string, useful only for strace debug
* @return non-zero if succeeded, zero otherwise
*/
#define MHD_itc_activate_(itc, str) \
((MHD_send_((itc).sk[1], (str), 1) > 0) || \
(MHD_SCKT_ERR_IS_EAGAIN_(MHD_socket_get_error_())))
/**
* Return read FD of @a itc which can be used for poll(), select() etc.
* @param itc the itc to get FD
* @return FD of read side
*/
#define MHD_itc_r_fd_(itc) ((itc).sk[0])
/**
* Return write FD of @a itc
* @param itc the itc to get FD
* @return FD of write side
*/
#define MHD_itc_w_fd_(itc) ((itc).sk[1])
/**
* Clear signaled state on @a itc
* @param itc the itc to clear
*/
#define MHD_itc_clear_(itc) do \
{ long __b; \
while(0 < recv((itc).sk[0], \
(char*)&__b, \
sizeof(__b), 0)) \
{} } while(0)
/**
* Destroy previously initialised ITC
* @param itc the itc to destroy
* @return non-zero if succeeded, zero otherwise
*/
#define MHD_itc_destroy_(itc) \
( MHD_socket_close_((itc).sk[0]) ? \
MHD_socket_close_((itc).sk[1]) : \
((void)MHD_socket_close_((itc).sk[1]), 0) )
/**
* Check whether ITC has valid value.
*
* Macro check whether @a itc value is valid (allowed),
* macro does not check whether @a itc was really initialised.
* @param itc the itc to check
* @return boolean true if @a itc has valid value,
* boolean false otherwise.
*/
#define MHD_ITC_IS_VALID_(itc) (MHD_INVALID_SOCKET != (itc).sk[0])
/**
* Set @a itc to invalid value.
* @param itc the itc to set
*/
#define MHD_itc_set_invalid_(itc) ((itc).sk[0] = (itc).sk[1] = MHD_INVALID_SOCKET)
#ifndef MHD_socket_pair_nblk_
# define MHD_itc_nonblocking_(pip) (MHD_socket_nonblocking_((pip).sk[0]) && MHD_socket_nonblocking_((pip).sk[1]))
#endif /* ! MHD_socket_pair_nblk_ */
#endif /* _MHD_ITC_SOCKETPAIR */
/**
* Destroy previously initialised ITC and abort execution
* if error is detected.
* @param itc the itc to destroy
*/
#define MHD_itc_destroy_chk_(itc) do { \
if (!MHD_itc_destroy_(itc)) \
MHD_PANIC(_("Failed to destroy ITC.\n")); \
} while(0)
/**
* Check whether ITC has invalid value.
*
* Macro check whether @a itc value is invalid,
* macro does not check whether @a itc was destroyed.
* @param itc the itc to check
* @return boolean true if @a itc has invalid value,
* boolean false otherwise.
*/
#define MHD_ITC_IS_INVALID_(itc) (! MHD_ITC_IS_VALID_(itc))
#endif /* MHD_ITC_H */