tor-android/tor-android-binary/src/main/jni/pdnsd/src/thread.h

144 lines
4.5 KiB
C

/* thread.h - Threading helpers
Copyright (C) 2000 Thomas Moestl
Copyright (C) 2002, 2003, 2005 Paul A. Rombouts
This file is part of the pdnsd package.
pdnsd is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
pdnsd 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with pdnsd; see the file COPYING. If not, see
<http://www.gnu.org/licenses/>.
*/
#ifndef _THREAD_H_
#define _THREAD_H_
#include <config.h>
#include <pthread.h>
#include <signal.h>
/* --- from main.c */
extern sigset_t sigs_msk;
/* --- */
#if (TARGET==TARGET_LINUX) && !defined(THREADLIB_NPTL)
extern volatile short int waiting;
void thread_sig(int sig);
#endif
/* These are macros for setting up the signal handling of a new thread. They
* are needed because the LinuxThreads implementation obviously has some
* problems in signal handling, which makes the recommended solution (doing
* sigwait() in one thread and blocking the signals in all threads) impossible.
* So, for Linux, we have to install the fatal_sig handler.
* It seems to me that signal handlers in fact aren't shared between threads
* under Linux. Also, sigwait() does not seem to work as indicated in the docs */
/* Note added by Paul Rombouts: In the new Native POSIX Thread Library for Linux (NPTL)
signal handling has changed from per-thread signal handling to POSIX process signal handling,
which makes the recommended solution mentioned by Thomas Moestl possible.
In this case I can simply define THREAD_SIGINIT to be empty.
The signals are blocked in main() before any threads are created,
and we simply never unblock them except by calling sigwait() in main(). */
#if (TARGET==TARGET_LINUX)
# ifdef THREADLIB_NPTL
# define THREAD_SIGINIT
# else
# ifdef THREADLIB_LINUXTHREADS2
# define THREAD_SIGINIT { \
struct sigaction action; \
pthread_sigmask(SIG_UNBLOCK,&sigs_msk,NULL); \
action.sa_handler = thread_sig; \
action.sa_mask = sigs_msk; \
action.sa_flags = 0; \
sigaction(SIGINT,&action,NULL); \
sigaction(SIGILL,&action,NULL); \
sigaction(SIGABRT,&action,NULL); \
sigaction(SIGFPE,&action,NULL); \
sigaction(SIGSEGV,&action,NULL); \
sigaction(SIGTSTP,&action,NULL); \
sigaction(SIGTTOU,&action,NULL); \
sigaction(SIGTTIN,&action,NULL); \
sigaction(SIGTERM,&action,NULL); \
action.sa_handler = SIG_IGN; \
sigemptyset(&action.sa_mask); \
action.sa_flags = 0; \
sigaction(SIGPIPE,&action,NULL); \
}
# else
# define THREAD_SIGINIT { \
struct sigaction action; \
pthread_sigmask(SIG_UNBLOCK,&sigs_msk,NULL); \
action.sa_handler = thread_sig; \
action.sa_mask = sigs_msk; \
action.sa_flags = 0; \
sigaction(SIGILL,&action,NULL); \
sigaction(SIGABRT,&action,NULL); \
sigaction(SIGFPE,&action,NULL); \
sigaction(SIGSEGV,&action,NULL); \
sigaction(SIGTSTP,&action,NULL); \
sigaction(SIGTTOU,&action,NULL); \
sigaction(SIGTTIN,&action,NULL); \
action.sa_handler = SIG_IGN; \
sigemptyset(&action.sa_mask); \
action.sa_flags = 0; \
sigaction(SIGPIPE,&action,NULL); \
}
# endif
# endif
#elif (TARGET==TARGET_BSD) || (TARGET==TARGET_CYGWIN)
#define THREAD_SIGINIT pthread_sigmask(SIG_BLOCK,&sigs_msk,NULL)
#else
# error Unsupported platform!
#endif
/* This is a thread-safe usleep().
Implementation of the BSD usleep function using nanosleep.
*/
inline static int usleep_r(unsigned long useconds)
__attribute__((always_inline));
inline static int usleep_r(unsigned long useconds)
{
struct timespec ts = { tv_sec: (useconds / 1000000),
tv_nsec: (useconds % 1000000) * 1000ul };
return nanosleep(&ts, NULL);
}
/* This is a thread-safe sleep().
The semantics are somewhat different from the POSIX sleep function,
but it suits our purposes.
*/
inline static int sleep_r (unsigned int seconds)
__attribute__((always_inline));
inline static int sleep_r (unsigned int seconds)
{
struct timespec ts = { tv_sec: seconds, tv_nsec: 0 };
return nanosleep(&ts, NULL);
}
/* Used for creating detached threads */
extern pthread_attr_t attr_detached;
#if DEBUG>0
/* Key for storing private thread ID's */
extern pthread_key_t thrid_key;
#endif
#endif