Initial import of sane-backends version 1.0.24-1.2

1 files changed, 183 insertions, 0 deletions

diff --git a/backend/snapscan-mutex.c b/backend/snapscan-mutex.c
new file mode 100644
index 0000000..0321741
--- /dev/null
+++ b/backend/snapscan-mutex.c
@@ -0,0 +1,183 @@
+/*
+  Mutex implementation for SnapScan backend
+ 
+  Copyright (C) 2000, 2004 Henrik Johansson, Oliver Schwartz
+ 
+  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.*/
+  
+#if defined __BEOS__
+
+#include <OS.h>
+#define snapscan_mutex_t sem_id
+
+static int snapscani_mutex_open(snapscan_mutex_t* a_sem, const char* dev UNUSEDARG)
+{
+    *a_sem = create_sem(1, "snapscan_mutex");
+    return 1;
+}
+
+static void snapscani_mutex_close(snapscan_mutex_t* a_sem)
+{
+    delete_sem(*a_sem);
+}
+
+static void snapscani_mutex_lock(snapscan_mutex_t* a_sem)
+{
+    acquire_sem(*a_sem);
+}
+
+static void snapscani_mutex_unlock(snapscan_mutex_t* a_sem)
+{
+    release_sem(*a_sem);
+}
+
+
+
+#elif defined USE_PTHREAD || defined HAVE_OS2_H
+
+#include <pthread.h>
+#define snapscan_mutex_t pthread_mutex_t
+
+static int snapscani_mutex_open(snapscan_mutex_t* sem_id, const char* dev UNUSEDARG)
+{
+    pthread_mutex_init(sem_id, NULL);
+    return 1;
+}
+
+static void snapscani_mutex_close(snapscan_mutex_t* sem_id)
+{
+    pthread_mutex_destroy(sem_id);
+}
+
+static void snapscani_mutex_lock(snapscan_mutex_t* sem_id)
+{
+    pthread_mutex_lock(sem_id);
+}
+
+static void snapscani_mutex_unlock(snapscan_mutex_t* sem_id)
+{
+    pthread_mutex_unlock(sem_id);
+}
+
+#else /* defined USE_PTHREAD || defined HAVE_OS2_H */
+
+#include <sys/ipc.h>
+#include <sys/sem.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#define snapscan_mutex_t int
+
+/* check for union semun */
+#if defined(HAVE_UNION_SEMUN)
+/* union semun is defined by including <sys/sem.h> */
+#else
+/* according to X/OPEN we have to define it ourselves */
+union semun {
+   int val;                    /* value for SETVAL */
+   struct semid_ds *buf;       /* buffer for IPC_STAT, IPC_SET */
+   unsigned short int *array;  /* array for GETALL, SETALL */
+   struct seminfo *__buf;      /* buffer for IPC_INFO */
+};
+#endif /* defined HAVE_UNION_SEMUN */
+
+static struct sembuf sem_wait = { 0, -1, 0 };
+static struct sembuf sem_signal = { 0, 1, 0 };
+
+static unsigned int snapscani_bernstein(const unsigned char* str)
+{
+    unsigned int hash = 5381; /* some arbitrary number */
+    int c;
+    
+    while (*str)
+    {
+        c = *str++;    
+        hash = ((hash << 5) + hash) + c;
+    }
+    return hash;
+} 
+
+static int snapscani_mutex_open(snapscan_mutex_t* sem_id, const char* dev)
+{
+    static const char *me = "snapscani_mutex_open";
+    key_t ipc_key = -1;
+
+    if (strstr(dev, "libusb:") == dev)
+    {
+        key_t ipc_key = (key_t) snapscani_bernstein((const unsigned char*) dev+7);
+	DBG (DL_INFO, "%s: using IPC key 0x%08x for device %s\n",
+	     me, ipc_key, dev);
+    }
+    else
+    {
+      ipc_key = ftok(dev, 0x12);
+
+	if (ipc_key == -1)
+	{
+	  DBG (DL_MAJOR_ERROR, "%s: could not obtain IPC key for device %s: %s\n", me, dev, strerror(errno));
+	    return 0;
+	}
+    }
+
+    *sem_id = semget( ipc_key, 1, IPC_CREAT | 0660 );
+    if (*sem_id == -1)
+    {
+        DBG (DL_MAJOR_ERROR, "%s: semget failed: %s\n", me, strerror(errno));
+	return 0;
+    }
+
+    semop(*sem_id, &sem_signal, 1);
+    return 1;
+}
+
+static void snapscani_mutex_close(snapscan_mutex_t* sem_id)
+{
+    static union semun dummy_semun_arg;
+    semctl(*sem_id, 0, IPC_RMID, dummy_semun_arg);
+}
+
+static void snapscani_mutex_lock(snapscan_mutex_t* sem_id)
+{
+    semop(*sem_id, &sem_wait, 1);
+}
+
+static void snapscani_mutex_unlock(snapscan_mutex_t* sem_id)
+{
+    semop(*sem_id, &sem_signal, 1);
+}
+
+#endif /* defined USE_PTHREAD || defined HAVE_OS2_H */