[vlc-devel] commit: LibVLC: per-thread error message API ( Rémi Denis-Courmont )
git version control
git at videolan.org
Sun Aug 9 19:17:40 CEST 2009
vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Sun Aug 9 18:03:57 2009 +0300| [e996cbefaf0f8db55513071b9678242e0a7733da] | committer: Rémi Denis-Courmont
LibVLC: per-thread error message API
> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=e996cbefaf0f8db55513071b9678242e0a7733da
---
include/vlc/libvlc.h | 44 ++++++++++++++
src/Makefile.am | 1 +
src/control/core.c | 18 +++++-
src/control/error.c | 131 +++++++++++++++++++++++++++++++++++++++++
src/control/libvlc_internal.h | 4 +
src/libvlc.sym | 4 +
6 files changed, 200 insertions(+), 2 deletions(-)
diff --git a/include/vlc/libvlc.h b/include/vlc/libvlc.h
index 4f27ad9..f4663eb 100644
--- a/include/vlc/libvlc.h
+++ b/include/vlc/libvlc.h
@@ -58,6 +58,7 @@
extern "C" {
# endif
+#include <stdarg.h>
#include <vlc/libvlc_structures.h>
/*****************************************************************************
@@ -118,6 +119,49 @@ libvlc_exception_get_message( const libvlc_exception_t *p_exception );
/**@} */
/*****************************************************************************
+ * Error handling
+ *****************************************************************************/
+/** \defgroup libvlc_error libvlc_error
+ * \ingroup libvlc_core
+ * LibVLC error handling
+ * @{
+ */
+
+/**
+ * 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).
+ *
+ * @warning
+ * This will be NULL if there was no error.
+ */
+const char *libvlc_errmsg (void);
+
+/**
+ * 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);
+
+/**
+ * Sets the LibVLC error status and message for the current thread.
+ * Any previous error is overriden.
+ * @return a nul terminated string in any case
+ */
+const char *libvlc_vprinterr (const char *fmt, va_list ap);
+
+/**
+ * Sets the LibVLC error status and message for the current thread.
+ * Any previous error is overriden.
+ * @return a nul terminated string in any case
+ */
+const char *libvlc_printerr (const char *fmt, ...);
+
+/**@} */
+
+
+/*****************************************************************************
* Core handling
*****************************************************************************/
diff --git a/src/Makefile.am b/src/Makefile.am
index 30a3da6..bbbe848 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -460,6 +460,7 @@ SOURCES_libvlc_control = \
control/media_list_view_internal.h \
control/media_player_internal.h \
control/core.c \
+ control/error.c \
control/log.c \
control/playlist.c \
control/vlm.c \
diff --git a/src/control/core.c b/src/control/core.c
index a96ff03..3a67a82 100644
--- a/src/control/core.c
+++ b/src/control/core.c
@@ -111,11 +111,22 @@ libvlc_instance_t * libvlc_new( int argc, const char *const *argv,
{
libvlc_instance_t *p_new;
int i_ret;
+
+ libvlc_init_threads ();
+
libvlc_int_t *p_libvlc_int = libvlc_InternalCreate();
- if( !p_libvlc_int ) RAISENULL( "VLC initialization failed" );
+ if( !p_libvlc_int )
+ {
+ libvlc_deinit_threads ();
+ RAISENULL( "VLC initialization failed" );
+ }
p_new = malloc( sizeof( libvlc_instance_t ) );
- if( !p_new ) RAISENULL( "Out of memory" );
+ if( !p_new )
+ {
+ libvlc_deinit_threads ();
+ RAISENULL( "Out of memory" );
+ }
const char *my_argv[argc + 2];
@@ -132,6 +143,8 @@ libvlc_instance_t * libvlc_new( int argc, const char *const *argv,
{
libvlc_InternalDestroy( p_libvlc_int );
free( p_new );
+ libvlc_deinit_threads ();
+
if( i_ret == VLC_EEXITSUCCESS )
return NULL;
else
@@ -181,6 +194,7 @@ void libvlc_release( libvlc_instance_t *p_instance )
libvlc_InternalCleanup( p_instance->p_libvlc_int );
libvlc_InternalDestroy( p_instance->p_libvlc_int );
free( p_instance );
+ libvlc_deinit_threads ();
}
}
diff --git a/src/control/error.c b/src/control/error.c
new file mode 100644
index 0000000..f9a3f69
--- /dev/null
+++ b/src/control/error.c
@@ -0,0 +1,131 @@
+/*****************************************************************************
+ * 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;
+}
+
diff --git a/src/control/libvlc_internal.h b/src/control/libvlc_internal.h
index 6f338ce..8ad972a 100644
--- a/src/control/libvlc_internal.h
+++ b/src/control/libvlc_internal.h
@@ -83,6 +83,10 @@ struct libvlc_instance_t
* Other internal functions
***************************************************************************/
+/* Thread context */
+void libvlc_init_threads (void);
+void libvlc_deinit_threads (void);
+
/* Events */
libvlc_event_manager_t * libvlc_event_manager_new(
void * p_obj, libvlc_instance_t * p_libvlc_inst,
diff --git a/src/libvlc.sym b/src/libvlc.sym
index 7e5cbb8..b41e214 100644
--- a/src/libvlc.sym
+++ b/src/libvlc.sym
@@ -1,3 +1,7 @@
+libvlc_errmsg
+libvlc_clearerr
+libvlc_printerr
+libvlc_vprinterr
libvlc_add_intf
libvlc_audio_output_device_count
libvlc_audio_output_device_id
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