1 files changed, 124 insertions, 0 deletions
diff --git a/gpgme/mutex.h b/gpgme/mutex.h
new file mode 100644
index 00000000..a1cf868b
--- /dev/null
+++ b/gpgme/mutex.h
@@ -0,0 +1,124 @@
+/* mutex.h -  Portable mutual exclusion, independent from any thread library.
+ *      Copyright (C) 2002 g10 Code GmbH
+ *
+ * This file is part of GPGME.
+ *
+ * GPGME 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.
+ *
+ * GPGME 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
+ */
+
+#ifndef MUTEX_H
+#define MUTEX_H
+
+/* Define MUTEX_FAKE before including the file to get stubs that don't
+   provide any locking at all.  Define MUTEX_PTHREAD if you can link
+   against the posix thread library.  */
+
+#if defined(MUTEX_FAKE)
+
+typedef char mutex_t;
+#define mutex_init(x) (0)
+#define mutex_destroy(x)
+#define mutex_lock(x) (0)
+#define mutex_unlock(x) (0)
+
+#elif defined(MUTEX_PTHREAD)
+
+#include <pthread.h>
+
+#define mutex_t pthread_mutex_t
+#define mutex_init(x) pthread_mutex_init (&(x), 0)
+#define mutex_destroy(x) pthread_mutex_destroy(&(x))
+#define mutex_lock(x) pthread_mutex_lock (&(x))
+#define mutex_unlock(x) pthread_mutex_unlock (&(x))
+
+#else
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+/* The type of a mutex.  */
+typedef int mutex_t[2];
+
+inline static int
+set_close_on_exec (int fd)
+{
+  int flags = fcntl (fd, F_GETFD, 0);
+  if (flags == -1)
+    return errno;
+  flags |= FD_CLOEXEC;
+  if (fcntl (fd, F_SETFD, flags) == -1)
+    return errno;
+  return 0;
+}
+
+/* Initialize the mutex variable MUTEX.  */
+inline int
+mutex_init (mutex_t mutex)
+{
+  ssize_t amount;
+  int err = 0;
+
+  if (pipe (mutex))
+    return errno;
+
+  err = set_close_on_exec (mutex[0]);
+  if (!err)
+    err = set_close_on_exec (mutex[1]);
+  if (!err)
+    while ((amount = write (mutex[1], " ", 1)) < 0 && errno == EINTR)
+      ;
+  if (!err && amount != 1)
+    err = errno;
+
+  if (err)
+    {
+      close (mutex[0]);
+      close (mutex[1]);
+    }
+  return err;
+}
+
+/* Destroy the mutex variable MUTEX.  */
+inline void
+mutex_destroy (mutex_t mutex)
+{
+  close (mutex[0]);
+  close (mutex[1]);
+}
+
+/* Take the mutex variable MUTEX.  */
+inline int
+mutex_lock (mutex_t mutex)
+{
+  char data;
+  int amount;
+  while ((amount = read (mutex[0], &data, 1)) < 0 && errno == EINTR)
+    ;
+  return (amount != 1) ? errno : 0;
+}
+
+/* Release the mutex variable MUTEX.  */
+inline int
+mutex_unlock (mutex_t mutex)
+{
+  int amount;
+  while ((amount = write (mutex[1], " ", 1)) < 0 && errno == EINTR)
+    ;
+  return (amount != 1) ? errno : 0;
+}
+
+#endif	/* MUTEX_FAKE */
+#endif	/* MUTEX_H */