From 181cec4348da40331b3e8ab365732c025ec149b2 Mon Sep 17 00:00:00 2001 From: Reinhard Tartler Date: Wed, 27 Apr 2011 19:24:15 +0200 Subject: Import upstream version 0.11.0~svn1143 --- thread.c | 195 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100644 thread.c (limited to 'thread.c') diff --git a/thread.c b/thread.c new file mode 100644 index 0000000..5e5897b --- /dev/null +++ b/thread.c @@ -0,0 +1,195 @@ +/* $Id: thread.c 840 2007-09-09 12:17:42Z michael $ + * $URL: https://ssl.bulix.org/svn/lcd4linux/trunk/thread.c $ + * + * thread handling (mutex, shmem, ...) + * + * Copyright (C) 2004 Michael Reinelt + * Copyright (C) 2004 The LCD4Linux Team + * + * parts of this code are based on the old XWindow driver which is + * Copyright (C) 2000 Herbert Rosmanith + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "debug.h" +#include "thread.h" + + +#ifdef WITH_DMALLOC +#include +#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); +} -- cgit v1.2.3