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Diffstat (limited to 'sanei/sanei_thread.c')
| -rw-r--r-- | sanei/sanei_thread.c | 425 |
1 files changed, 425 insertions, 0 deletions
diff --git a/sanei/sanei_thread.c b/sanei/sanei_thread.c new file mode 100644 index 0000000..0c95fdb --- /dev/null +++ b/sanei/sanei_thread.c @@ -0,0 +1,425 @@ +/* sane - Scanner Access Now Easy. + Copyright (C) 1998-2001 Yuri Dario + Copyright (C) 2003-2004 Gerhard Jaeger (pthread/process support) + This file is part of the SANE package. + + This program 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 2 of the + License, or (at your option) any later version. + + This program 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 this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, + MA 02111-1307, USA. + + As a special exception, the authors of SANE give permission for + additional uses of the libraries contained in this release of SANE. + + The exception is that, if you link a SANE library with other files + to produce an executable, this does not by itself cause the + resulting executable to be covered by the GNU General Public + License. Your use of that executable is in no way restricted on + account of linking the SANE library code into it. + + This exception does not, however, invalidate any other reasons why + the executable file might be covered by the GNU General Public + License. + + If you submit changes to SANE to the maintainers to be included in + a subsequent release, you agree by submitting the changes that + those changes may be distributed with this exception intact. + + If you write modifications of your own for SANE, it is your choice + whether to permit this exception to apply to your modifications. + If you do not wish that, delete this exception notice. + + OS/2 + Helper functions for the OS/2 port (using threads instead of forked + processes). Don't use them in the backends, they are used automatically by + macros. + + Other OS: + use this lib, if you intend to let run your reader function within its own + task (thread or process). Depending on the OS and/or the configure settings + pthread or fork is used to achieve this goal. +*/ + +#include "sane/config.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <signal.h> +#ifdef HAVE_UNISTD_H +# include <unistd.h> +#endif +#ifdef HAVE_OS2_H +# define INCL_DOSPROCESS +# include <os2.h> +#endif +#if !defined USE_PTHREAD && !defined HAVE_OS2_H +# include <sys/wait.h> +#endif +#if defined USE_PTHREAD +# include <pthread.h> +#endif + +#define BACKEND_NAME sanei_thread /**< name of this module for debugging */ + +#include <sane/sane.h> +#include "../include/sane/sanei_debug.h" +#include "../include/sane/sanei_thread.h" + +#ifndef _VAR_NOT_USED +# define _VAR_NOT_USED(x) ((x)=(x)) +#endif + +typedef struct { + + int (*func)( void* ); + SANE_Status status; + void *func_data; + +} ThreadDataDef, *pThreadDataDef; + +static ThreadDataDef td; + +/** for init issues - here only for the debug output + */ +void +sanei_thread_init( void ) +{ + DBG_INIT(); + + memset( &td, 0, sizeof(ThreadDataDef)); + td.status = SANE_STATUS_GOOD; +} + +SANE_Bool +sanei_thread_is_forked( void ) +{ +#if defined USE_PTHREAD || defined HAVE_OS2_H + return SANE_FALSE; +#else + return SANE_TRUE; +#endif +} + +int +sanei_thread_kill( int pid ) +{ + DBG(2, "sanei_thread_kill() will kill %d\n", (int)pid); +#ifdef USE_PTHREAD +#if defined (__APPLE__) && defined (__MACH__) + return pthread_kill((pthread_t)pid, SIGUSR2); +#else + return pthread_cancel((pthread_t)pid); +#endif +#elif defined HAVE_OS2_H + return DosKillThread(pid); +#else + return kill( pid, SIGTERM ); +#endif +} + +#ifdef HAVE_OS2_H + +static void +local_thread( void *arg ) +{ + pThreadDataDef ltd = (pThreadDataDef)arg; + + DBG( 2, "thread started, calling func() now...\n" ); + ltd->status = ltd->func( ltd->func_data ); + + DBG( 2, "func() done - status = %d\n", ltd->status ); + _endthread(); +} + +/* + * starts a new thread or process + * parameters: + * star address of reader function + * args pointer to scanner data structure + * + */ +int +sanei_thread_begin( int (*func)(void *args), void* args ) +{ + int pid; + + td.func = func; + td.func_data = args; + + pid = _beginthread( local_thread, NULL, 1024*1024, (void*)&td ); + if ( pid == -1 ) { + DBG( 1, "_beginthread() failed\n" ); + return -1; + } + + DBG( 2, "_beginthread() created thread %d\n", pid ); + return pid; +} + +int +sanei_thread_waitpid( int pid, int *status ) +{ + if (status) + *status = 0; + return pid; /* DosWaitThread( (TID*) &pid, DCWW_WAIT);*/ +} + +int +sanei_thread_sendsig( int pid, int sig ) +{ + return 0; +} + +#else /* HAVE_OS2_H */ + +#ifdef USE_PTHREAD + +/* seems to be undefined in MacOS X */ +#ifndef PTHREAD_CANCELED +# define PTHREAD_CANCELED ((void *) -1) +#endif + +/** + */ +#if defined (__APPLE__) && defined (__MACH__) +static void +thread_exit_handler( int signo ) +{ + DBG( 2, "signal(%i) caught, calling pthread_exit now...\n", signo ); + pthread_exit( PTHREAD_CANCELED ); +} +#endif + + +static void* +local_thread( void *arg ) +{ + static int status; + pThreadDataDef ltd = (pThreadDataDef)arg; + +#if defined (__APPLE__) && defined (__MACH__) + struct sigaction act; + + sigemptyset(&(act.sa_mask)); + act.sa_flags = 0; + act.sa_handler = thread_exit_handler; + sigaction( SIGUSR2, &act, 0 ); +#else + int old; + + pthread_setcancelstate( PTHREAD_CANCEL_ENABLE, &old ); + pthread_setcanceltype ( PTHREAD_CANCEL_ASYNCHRONOUS, &old ); +#endif + + DBG( 2, "thread started, calling func() now...\n" ); + + status = ltd->func( ltd->func_data ); + + /* so sanei_thread_get_status() will work correctly... */ + ltd->status = status; + + DBG( 2, "func() done - status = %d\n", status ); + + /* return the status, so pthread_join is able to get it*/ + pthread_exit((void*)&status ); +} + +/** + */ +static void +restore_sigpipe( void ) +{ + struct sigaction act; + + if( sigaction( SIGPIPE, NULL, &act ) == 0 ) { + + if( act.sa_handler == SIG_IGN ) { + sigemptyset( &act.sa_mask ); + act.sa_flags = 0; + act.sa_handler = SIG_DFL; + + DBG( 2, "restoring SIGPIPE to SIG_DFL\n" ); + sigaction( SIGPIPE, &act, NULL ); + } + } +} + +#else /* the process stuff */ + +static int +eval_wp_result( int pid, int wpres, int pf ) +{ + int retval = SANE_STATUS_IO_ERROR; + + if( wpres == pid ) { + + if( WIFEXITED(pf)) { + retval = WEXITSTATUS(pf); + } else { + + if( !WIFSIGNALED(pf)) { + retval = SANE_STATUS_GOOD; + } else { + DBG( 1, "Child terminated by signal %d\n", WTERMSIG(pf)); + if( WTERMSIG(pf) == SIGTERM ) + retval = SANE_STATUS_GOOD; + } + } + } + return retval; +} +#endif + +int +sanei_thread_begin( int (func)(void *args), void* args ) +{ + int pid; +#ifdef USE_PTHREAD + struct sigaction act; + pthread_t thread; + + /* if signal handler for SIGPIPE is SIG_DFL, replace by SIG_IGN */ + if( sigaction( SIGPIPE, NULL, &act ) == 0 ) { + + if( act.sa_handler == SIG_DFL ) { + sigemptyset( &act.sa_mask ); + act.sa_flags = 0; + act.sa_handler = SIG_IGN; + + DBG( 2, "setting SIGPIPE to SIG_IGN\n" ); + sigaction( SIGPIPE, &act, NULL ); + } + } + + td.func = func; + td.func_data = args; + + pid = pthread_create( &thread, NULL, local_thread, &td ); + usleep( 1 ); + + if ( pid != 0 ) { + DBG( 1, "pthread_create() failed with %d\n", pid ); + return -1; + } + + DBG( 2, "pthread_create() created thread %d\n", (int)thread ); + return (int)thread; +#else + pid = fork(); + if( pid < 0 ) { + DBG( 1, "fork() failed\n" ); + return -1; + } + + if( pid == 0 ) { + + /* run in child context... */ + int status = func( args ); + + /* don't use exit() since that would run the atexit() handlers */ + _exit( status ); + } + + /* parents return */ + return pid; +#endif +} + +int +sanei_thread_sendsig( int pid, int sig ) +{ +#ifdef USE_PTHREAD + DBG(2, "sanei_thread_sendsig() %d to thread(id=%d)\n", sig, pid); + return pthread_kill((pthread_t)pid, sig ); +#else + DBG(2, "sanei_thread_sendsig() %d to process (id=%d)\n", sig, pid); + return kill( pid, sig ); +#endif +} + +int +sanei_thread_waitpid( int pid, int *status ) +{ +#ifdef USE_PTHREAD + int *ls; +#else + int ls; +#endif + int result, stat; + + stat = 0; + + DBG(2, "sanei_thread_waitpid() - %d\n", pid); +#ifdef USE_PTHREAD + result = pthread_join((pthread_t)pid, (void*)&ls ); + + if( 0 == result ) { + if( PTHREAD_CANCELED == ls ) { + DBG(2, "* thread has been canceled!\n" ); + stat = SANE_STATUS_GOOD; + } else { + stat = *ls; + } + DBG(2, "* result = %d (%p)\n", stat, (void*)status ); + result = pid; + } + /* call detach in any case to make sure that the thread resources + * will be freed, when the thread has terminated + */ + DBG(2, "* detaching thread(%d)\n", pid ); + pthread_detach((pthread_t)pid); + if (status) + *status = stat; + + restore_sigpipe(); +#else + result = waitpid( pid, &ls, 0 ); + if((result < 0) && (errno == ECHILD)) { + stat = SANE_STATUS_GOOD; + result = pid; + } else { + stat = eval_wp_result( pid, result, ls ); + DBG(2, "* result = %d (%p)\n", stat, (void*)status ); + } + if( status ) + *status = stat; +#endif + return result; +} + +#endif /* HAVE_OS2_H */ + +SANE_Status +sanei_thread_get_status( int pid ) +{ +#if defined USE_PTHREAD || defined HAVE_OS2_H + _VAR_NOT_USED( pid ); + + return td.status; +#else + int ls, stat, result; + + stat = SANE_STATUS_IO_ERROR; + if( pid > 0 ) { + + result = waitpid( pid, &ls, WNOHANG ); + + stat = eval_wp_result( pid, result, ls ); + } + return stat; +#endif +} + +/* END sanei_thread.c .......................................................*/ |