1 files changed, 195 insertions, 0 deletions
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 <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);
+}