/* $Id$
 * $URL$
 *
 * thread handling (mutex, shmem, ...)
 *
 * Copyright (C) 2004 Michael Reinelt <michael@reinelt.co.at>
 * Copyright (C) 2004 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
 *
 * parts of this code are based on the old XWindow driver which is
 * Copyright (C) 2000 Herbert Rosmanith <herp@wildsau.idv.uni-linz.ac.at>
 *
 * This file is part of LCD4Linux.
 *
 * LCD4Linux 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, or (at your option)
 * any later version.
 *
 * LCD4Linux 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/* 
 * exported functions:
 * 
 * int  mutex_create  (void);
 *   creates a mutex and treturns its ID
 * 
 * void mutex_lock    (int semid);
 *   try to lock a mutex
 *
 * void mutex_unlock  (int semid);
 *   unlock a mutex
 *
 * void mutex_destroy (int semid);
 *   release a mutex
 *
 *
 * int shm_create    (void **buffer, int size);
 *   create shared memory segment
 *
 * void shm_destroy   (int shmid, void *buffer) ;
 *   release shared memory segment
 *
 * int thread_create (char *name, void (*thread)(void *data), void *data);
 *   create a new thread
 *
 */


#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/shm.h>

#include "debug.h"
#include "thread.h"


#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif


int thread_argc;
char **thread_argv;


/* glibc 2.1 requires defining semun ourselves */
#ifdef _SEM_SEMUN_UNDEFINED
union semun {
    int val;
    struct semid_ds *buf;
    unsigned short int *array;
    struct seminfo *__buf;
};
#endif


int mutex_create(void)
{
    int semid;
    union semun semun;

    semid = semget(IPC_PRIVATE, 1, 0);
    if (semid == -1) {
	error("fatal error: semget() failed: %s", strerror(errno));
	return -1;
    }
    semun.val = 1;
    semctl(semid, 0, SETVAL, semun);

    return semid;
}


void mutex_lock(const int semid)
{
    struct sembuf sembuf;
    sembuf.sem_num = 0;
    sembuf.sem_op = -1;
    sembuf.sem_flg = 0;
    semop(semid, &sembuf, 1);
}


void mutex_unlock(const int semid)
{
    struct sembuf sembuf;
    sembuf.sem_num = 0;
    sembuf.sem_op = 1;
    sembuf.sem_flg = 0;
    semop(semid, &sembuf, 1);
}


void mutex_destroy(const int semid)
{
    union semun arg;
    semctl(semid, 0, IPC_RMID, arg);
}


int shm_create(void **buffer, const int size)
{
    int shmid;

    shmid = shmget(IPC_PRIVATE, size, SHM_R | SHM_W);
    if (shmid == -1) {
	error("fatal error: shmget() failed: %s", strerror(errno));
	return -1;
    }

    *buffer = shmat(shmid, NULL, 0);
    if (*buffer == NULL) {
	error("fatal error: shmat() failed: %s", strerror(errno));
	return -1;
    }

    return shmid;
}


void shm_destroy(const int shmid, const void *buffer)
{
    shmdt(buffer);
    shmctl(shmid, IPC_RMID, NULL);
}


int thread_create(const char *name, void (*thread) (void *data), void *data)
{
    pid_t pid, ppid;

    ppid = getpid();

    switch (pid = fork()) {
    case -1:
	error("fatal error: fork(%s) failed: %s", name, strerror(errno));
	return -1;
    case 0:
	info("thread %s starting...", name);
	if (thread_argc > 0) {
	    strncpy(thread_argv[0], name, strlen(thread_argv[0]));
	}
	thread(data);
	info("thread %s ended.", name);
	exit(0);
    default:
	info("forked process %d for thread %s", pid, name);
    }

    return pid;
}


int thread_destroy(const int pid)
{
    return kill(pid, SIGKILL);
}
b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-12-23 13:28:14 +0000'>2008-12-23</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_LCDLinux.c?id=87b31372d32f6f0a3d90790392b7024823d1cc1e&amp;follow=1'>indent run</a></td><td>michael</td><td>1</td><td><span class='deletions'>-4</span>/<span class='insertions'>+4</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@904 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-11-25 20:38:34 +0000'>2008-11-25</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_LCDLinux.c?id=6ab08ab6c2eb5db99af7d011a9fd8526af3b0aed&amp;follow=1'>fix lcd4linux driver for multible onboard controllers</a></td><td>michux</td><td>1</td><td><span class='deletions'>-4</span>/<span class='insertions'>+4</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@903 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-11-23 00:20:58 +0000'>2008-11-23</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drivers.m4?id=0c9798c9429cabcded458ba127972ea096e69978&amp;follow=1'>fix automake - check for libftdi</a></td><td>michux</td><td>4</td><td><span class='deletions'>-9</span>/<span class='insertions'>+173</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@902 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-11-22 23:46:47 +0000'>2008-11-22</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugin_button_exec.c?id=5162ea943ae34684aacdb8fe29da91e6a974979e&amp;follow=1'>update button_exec plugin - fix segfault</a></td><td>michux</td><td>1</td><td><span class='deletions'>-3</span>/<span class='insertions'>+2</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@901 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-11-22 23:34:20 +0000'>2008-11-22</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugin_fifo.c?id=98870dbee74445b3d7de7468fccdb3ef4d6d2ff2&amp;follow=1'>update fifo plugin - untested</a></td><td>michux</td><td>1</td><td><span class='deletions'>-1</span>/<span class='insertions'>+1</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@900 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-10-07 19:32:42 +0000'>2008-10-07</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_picoLCDGraphic.c?id=3654ca81e0aa3116c24d849336560cc96ff73f11&amp;follow=1'>Replace write to external variable usb_debug by calling usb_set_debug().</a></td><td>bwalle</td><td>7</td><td><span class='deletions'>-16</span>/<span class='insertions'>+7</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
This fixes build on openSUSE Factory.


git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@899 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-10-06 04:29:12 +0000'>2008-10-06</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_picoLCD.c?id=a80978985167df7650209888a5a89ea8089c091d&amp;follow=1'>adding GPI to picoLCD for reading button events  by Igor Mammedov ↵</a></td><td>michael</td><td>1</td><td><span class='deletions'>-1</span>/<span class='insertions'>+22</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
&lt;niallain@gmail.com&gt;

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@898 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-10-06 04:25:14 +0000'>2008-10-06</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugin_time.c?id=c43556a211b45fefe29b73d912c7cc6ff6d8bfdf&amp;follow=1'>properties fixed</a></td><td>michael</td><td>11</td><td><span class='deletions'>-3290</span>/<span class='insertions'>+2675</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@897 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-10-05 16:57:13 +0000'>2008-10-05</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/configure?id=5592dc410563ea62d44ff341a7b12bf564a809f4&amp;follow=1'>Rebuild auto-generated autoconf stuff due to last change in drivers.m4.</a></td><td>bwalle</td><td>3</td><td><span class='deletions'>-2657</span>/<span class='insertions'>+3297</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@896 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-10-05 16:55:26 +0000'>2008-10-05</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drivers.m4?id=7e4ae629678f086951b4ae213bc3dc17c04b27ee&amp;follow=1'>Add 'ULA200' driver when --with-drivers=all is specified</a></td><td>bwalle</td><td>1</td><td><span class='deletions'>-0</span>/<span class='insertions'>+1</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@895 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-09-14 04:00:49 +0000'>2008-09-14</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugin_time.c?id=7695365a0e6ffada25b74e1ac8fa0a54bc5aa32d&amp;follow=1'>strftime_tz patch from Bernhard Walle</a></td><td>michael</td><td>1</td><td><span class='deletions'>-0</span>/<span class='insertions'>+11</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@894 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-09-08 01:52:03 +0000'>2008-09-08</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugin_time.c?id=a97c5c7ecd9800e86882af4476e2dc6098b78cfb&amp;follow=1'>strftime_tz() plugin by Bernhard Walle</a></td><td>michael</td><td>1</td><td><span class='deletions'>-0</span>/<span class='insertions'>+25</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@893 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-09-03 03:28:52 +0000'>2008-09-03</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/smoketest.sh?id=e6f31f6b7949440cd735d0184c846aa2a3330f23&amp;follow=1'>ULA200 driver by Bernhard Walle</a></td><td>michael</td><td>7</td><td><span class='deletions'>-2</span>/<span class='insertions'>+825</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@892 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-09-03 03:26:29 +0000'>2008-09-03</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_D4D.c?id=1285008c5f75c28d6304ba984c432992c450ba3a&amp;follow=1'>indent</a></td><td>michael</td><td>1</td><td><span class='deletions'>-4</span>/<span class='insertions'>+4</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@891 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-08-31 18:27:53 +0000'>2008-08-31</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_generic_serial.c?id=02b0138a4213eff843990f96531cf31918d6dfe2&amp;follow=1'>Increased the maximum bps to 230400, if defined in &lt;termios.h&gt;.</a></td><td>sonic74</td><td>1</td><td><span class='deletions'>-2</span>/<span class='insertions'>+7</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@890 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-08-27 22:32:47 +0000'>2008-08-27</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_D4D.c?id=9e0932674b6e85098e3902f4c3083e80c9590be5&amp;follow=1'>git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@889 ↵</a></td><td>sonic74</td><td>1</td><td><span class='deletions'>-18</span>/<span class='insertions'>+11</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-08-27 03:30:06 +0000'>2008-08-27</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_D4D.c?id=b645e0908429a1ed5c61f2708931bfa026254d52&amp;follow=1'>D4D updates by Sven</a></td><td>michael</td><td>1</td><td><span class='deletions'>-38</span>/<span class='insertions'>+60</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@888 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-08-03 03:10:49 +0000'>2008-08-03</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/smoketest.sh?id=38367abf672c32015cacd8b469c390a048f2c97f&amp;follow=1'>driver for 4D Systems serial displays by Sven Killig</a></td><td>michael</td><td>9</td><td><span class='deletions'>-45</span>/<span class='insertions'>+846</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@887 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-08-03 02:44:22 +0000'>2008-08-03</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/drv_IRLCD.c?id=e91cbd072ab678b68095a5e81fc37df6ae44c975&amp;follow=1'>signed/unsigned mismatch</a></td><td>michael</td><td>1</td><td><span class='deletions'>-3</span>/<span class='insertions'>+3</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@886 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-07-26 14:41:51 +0000'>2008-07-26</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/plugin_mpd.c?id=58d42c80d71e628ddf8fc32cae477f17cb3a3f25&amp;follow=1'>added command functions</a></td><td>michux</td><td>1</td><td><span class='deletions'>-2</span>/<span class='insertions'>+130</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@885 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-07-15 10:22:19 +0000'>2008-07-15</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/svn_version.h?id=b243fddf0754e8d193febc0598941fd1638ff33b&amp;follow=1'>added IRLCD driver by Jean-Philippe Civade</a></td><td>michael</td><td>10</td><td><span class='deletions'>-5</span>/<span class='insertions'>+467</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@884 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>
<tr class='logheader'><td><span title='2008-07-15 09:55:18 +0000'>2008-07-15</span></td><td class='logsubject'><a href='/lcd4linux.git/commit/mkinstalldirs?id=38a69aee81b48e2df7714310c39b5cdf171b9123&amp;follow=1'>'autoreconf -f -i' run &amp; config.rpath added</a></td><td>michael</td><td>8</td><td><span class='deletions'>-370</span>/<span class='insertions'>+1617</span></td></tr>
<tr class='nohover-highlight'><td/><td colspan='5' class='logmsg'>
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@883 3ae390bd-cb1e-0410-b409-cd5a39f66f1f


</td></tr>