+/*****************************************************************************
+ * error.c: Error handling for libvlc
+ *****************************************************************************
+ * Copyright (C) 2009 Rémi Denis-Courmont
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#include "libvlc_internal.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <assert.h>
+#include <vlc/libvlc.h>
+
+
+static const char oom[] = "Out of memory";
+/* TODO: use only one thread-specific key for whole libvlc */
+static vlc_threadvar_t context;
+
+static void libvlc_setup_threads (bool init)
+{
+ static vlc_mutex_t lock = VLC_STATIC_MUTEX;
+ static uintptr_t refs = 0;
+
+ vlc_mutex_lock (&lock);
+ if (init)
+ {
+ if (refs++ == 0)
+ vlc_threadvar_create (&context, free);
+ }
+ else
+ {
+ assert (refs > 0);
+ if (--refs == 0)
+ vlc_threadvar_delete (&context);
+ }
+ vlc_mutex_unlock (&lock);
+}
+
+void libvlc_init_threads (void)
+{
+ libvlc_setup_threads (true);
+}
+
+void libvlc_deinit_threads (void)
+{
+ libvlc_setup_threads (false);
+}
+
+static char *get_error (void)
+{
+ return vlc_threadvar_get (context);
+}
+
+static void free_error (void)
+{
+ char *msg = get_error ();
+ if (msg != oom)
+ free (msg);
+}
+
+/**
+ * Gets a human-readable error message for the last LibVLC error in the calling
+ * thread. The resulting string is valid until another error occurs (at least
+ * until the next LibVLC call).
+ *
+ * @return NULL if there was no error, a nul-terminated string otherwise.
+ */
+const char *libvlc_errmsg (void)
+{
+ return get_error ();
+}
+
+/**
+ * Clears the LibVLC error status for the current thread. This is optional.
+ * By default, the error status is automatically overriden when a new error
+ * occurs, and destroyed when the thread exits.
+ */
+void libvlc_clearerr (void)
+{
+ free_error ();
+ vlc_threadvar_set (context, NULL);
+}
+
+/**
+ * Sets the LibVLC error status and message for the current thread.
+ * Any previous error is overriden.
+ * @return a nul terminated string (always)
+ */
+const char *libvlc_vprinterr (const char *fmt, va_list ap)
+{
+ char *msg;
+
+ assert (fmt != NULL);
+ if (vasprintf (&msg, fmt, ap) == -1)
+ msg = (char *)oom;
+
+ free_error ();
+ vlc_threadvar_set (context, msg);
+ return msg;
+}
+
+/**
+ * Sets the LibVLC error status and message for the current thread.
+ * Any previous error is overriden.
+ * @return a nul terminated string (always)
+ */
+const char *libvlc_printerr (const char *fmt, ...)
+{
+ va_list ap;
+ const char *msg;
+
+ va_start (ap, fmt);
+ msg = libvlc_vprinterr (fmt, ap);
+ va_end (ap);
+ return msg;
+}
+