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weston/libweston/weston-log.c

905 lines
26 KiB

/*
* Copyright © 2017 Pekka Paalanen <pq@iki.fi>
* Copyright © 2018 Zodiac Inflight Innovations
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "config.h"
#include <libweston/weston-log.h>
#include "shared/helpers.h"
#include <libweston/libweston.h>
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
#include "weston-log-internal.h"
#include "weston-debug-server-protocol.h"
#include <assert.h>
#include <unistd.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <sys/time.h>
/**
* @defgroup log Public Logging/Debugging API
* @defgroup internal-log Private/Internal Logging/Debugging API
* @defgroup debug-protocol weston-debug protocol specific
*/
/** Main weston-log context
*
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
* One per weston_compositor. Stores list of scopes created and a list pending
* subscriptions.
*
* A pending subscription is a subscription to a scope which hasn't been
* created. When the scope is finally created the pending subscription will be
* removed from the pending subscription list, but not before was added in the
* scope's subscription list and that of the subscriber list.
*
* Pending subscriptions only make sense for other types of streams, other than
* those created by weston-debug protocol. In the case of the weston-debug
* protocol, the subscription processes is done automatically whenever a client
* connects and subscribes to a scope which was previously advertised by the
* compositor.
*
* @ingroup internal-log
*/
struct weston_log_context {
struct wl_global *global;
struct wl_list scope_list; /**< weston_log_scope::compositor_link */
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
struct wl_list pending_subscription_list; /**< weston_log_subscription::source_link */
};
/** weston-log message scope
*
* This is used for scoping logging/debugging messages. Clients can subscribe
* to only the scopes they are interested in. A scope is identified by its name
* (also referred to as debug stream name).
*
* @ingroup log
*/
struct weston_log_scope {
char *name;
char *desc;
weston_log_scope_cb new_subscriber;
void *user_data;
struct wl_list compositor_link;
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
struct wl_list subscription_list; /**< weston_log_subscription::source_link */
};
/** Ties a subscriber to a scope
*
* A subscription is created each time we'd want to subscribe to a scope. From
* the stream type we can retrieve the subscriber and from the subscriber we
* reach each of the streams callbacks. See also weston_log_subscriber object.
*
* When a subscription has been created we store it in the scope's subscription
* list and in the subscriber's subscription list. The subscription might be a
* pending subscription until the scope for which there's was a subscribe has
* been created. The scope creation will take of looking through the pending
* subscription list.
*
* A subscription can reached from a subscriber subscription list by using the
* streams base class.
*
* @ingroup internal-log
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
*/
struct weston_log_subscription {
struct weston_log_subscriber *owner;
struct wl_list owner_link; /**< weston_log_subscriber::subscription_list */
char *scope_name;
struct weston_log_scope *source;
struct wl_list source_link; /**< weston_log_scope::subscription_list or
weston_log_context::pending_subscription_list */
};
static struct weston_log_subscription *
find_pending_subscription(struct weston_log_context *log_ctx,
const char *scope_name)
{
struct weston_log_subscription *sub;
wl_list_for_each(sub, &log_ctx->pending_subscription_list, source_link)
if (!strncmp(sub->scope_name, scope_name, strlen(scope_name)))
return sub;
return NULL;
}
/** Create a pending subscription and add it the list of pending subscriptions
*
* @param owner a subscriber represented by weston_log_subscriber object
* @param scope_name the name of the scope (which we don't have in the list of scopes)
* @param log_ctx the logging context used to add the pending subscription
*
* @memberof weston_log_subscription
*/
static void
weston_log_subscription_create_pending(struct weston_log_subscriber *owner,
const char *scope_name,
struct weston_log_context *log_ctx)
{
assert(owner);
assert(scope_name);
struct weston_log_subscription *sub = zalloc(sizeof(*sub));
if (!sub)
return;
sub->scope_name = strdup(scope_name);
sub->owner = owner;
wl_list_insert(&log_ctx->pending_subscription_list, &sub->source_link);
}
/** Destroys the pending subscription created previously with
* weston_log_subscription_create_pending()
*
* @param sub the weston_log_subscription object to remove from the list
* of subscriptions and to destroy the subscription
*
* @memberof weston_log_subscription
*/
static void
weston_log_subscription_destroy_pending(struct weston_log_subscription *sub)
{
assert(sub);
/* pending subsriptions do not have a source */
wl_list_remove(&sub->source_link);
free(sub->scope_name);
free(sub);
}
/** Write to the stream's subscription
*
* @memberof weston_log_subscription
*/
static void
weston_log_subscription_write(struct weston_log_subscription *sub,
const char *data, size_t len)
{
if (sub->owner && sub->owner->write)
sub->owner->write(sub->owner, data, len);
}
/** Write a formatted string to the stream's subscription
*
* @memberof weston_log_subscription
*/
static void
weston_log_subscription_vprintf(struct weston_log_subscription *sub,
const char *fmt, va_list ap)
{
static const char oom[] = "Out of memory";
char *str;
int len;
if (!weston_log_scope_is_enabled(sub->source))
return;
len = vasprintf(&str, fmt, ap);
if (len >= 0) {
weston_log_subscription_write(sub, str, len);
free(str);
} else {
weston_log_subscription_write(sub, oom, sizeof oom - 1);
}
}
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
/** Creates a new subscription using the subscriber by \c owner.
*
* The subscription created is added to the \c owner subscription list.
* Destroying the subscription using weston_log_subscription_destroy() will
* remove the link from the subscription list and free storage alloc'ed.
*
* Note that this adds the subscription to the scope's subscription list
* hence the \c scope required argument.
*
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
* @param owner the subscriber owner, must be created before creating a
* subscription
* @param scope the scope in order to add the subscription to the scope's
* subscription list
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
* @returns a weston_log_subscription object in case of success, or NULL
* otherwise
*
* @sa weston_log_subscription_destroy, weston_log_subscription_remove,
* weston_log_subscription_add
* @memberof weston_log_subscription
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
*/
void
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
weston_log_subscription_create(struct weston_log_subscriber *owner,
struct weston_log_scope *scope)
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
{
struct weston_log_subscription *sub;
assert(owner);
assert(scope);
assert(scope->name);
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
sub = zalloc(sizeof(*sub));
if (!sub)
return;
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
sub->owner = owner;
sub->scope_name = strdup(scope->name);
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
wl_list_insert(&sub->owner->subscription_list, &sub->owner_link);
weston_log_subscription_add(scope, sub);
weston_log_run_cb_new_subscriber(sub);
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
}
/** Destroys the subscription
*
* Removes the subscription from the scopes subscription list and from
* subscriber's subscription list. It destroys the subscription afterwads.
*
* @memberof weston_log_subscription
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
*/
void
weston_log_subscription_destroy(struct weston_log_subscription *sub)
{
assert(sub);
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
if (sub->owner)
wl_list_remove(&sub->owner_link);
weston_log_subscription_remove(sub);
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
free(sub->scope_name);
free(sub);
}
/** Retrieve a subscription by using the subscriber
*
* This is useful when trying to find a subscription from the subscriber by
* having only access to the stream.
*
* @param subscriber the subscriber in question
* @returns a weston_log_subscription object
*
* @memberof weston_log_subscription
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
*/
struct weston_log_subscription *
weston_log_subscriber_get_only_subscription(struct weston_log_subscriber *subscriber)
{
struct weston_log_subscription *sub;
/* unlikely, but can happen */
if (wl_list_length(&subscriber->subscription_list) == 0)
return NULL;
assert(wl_list_length(&subscriber->subscription_list) == 1);
return wl_container_of(subscriber->subscription_list.prev,
sub, owner_link);
}
/** Adds the subscription \c sub to the subscription list of the
* scope.
*
* This should used when the scope has been created, and the subscription \c
* sub has be created before calling this function.
*
* @param scope the scope
* @param sub the subscription, it must be created before, see
* weston_log_subscription_create()
*
* @memberof weston_log_subscription
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
*/
void
weston_log_subscription_add(struct weston_log_scope *scope,
struct weston_log_subscription *sub)
{
assert(scope);
assert(sub);
/* don't allow subscriptions to have a source already! */
assert(!sub->source);
sub->source = scope;
wl_list_insert(&scope->subscription_list, &sub->source_link);
}
/** Removes the subscription from the scope's subscription list
*
* @memberof weston_log_subscription
weston-debug: Introduce weston_log_subscription and weston_log_subscriber objects Adds a minimalistic API for managing the subscription object. The subscribe functionality will be brought in once we re-organize a bit weston-debug-stream and split it properly. It extends the logging context with a linked list of potential subscription and adds a linked list of subscriptions in the log scope. This patch represents the start of a logging framework for weston. It's being built around weston-debug, with the intent to superseded it, and make weston-debug a client of the framework. Further more the logging framework should replace current logging handler and allow other types of streams to be used. Currently present in libweston under weston-debug we have log scopes, debug streams and a logging context. With this patch, two (internal) objects are being added: the concept of a subscriber and the concept of subscription. The subscription object is a ephemeral object, implicitly managed which is created each time one would want to a subscribe to a scope. The scope will maintain a list of subscriptions and will continue to be explicitly managed. The streams will use the subscriber object as a base class to extend upon. By doing so it allows to customize the stream with specific functions that manipulate the underlaying storage. The subscriber object will require a subscribe function and specific stream functions and like the scope, will be explicitly managed. Signed-off-by: Marius Vlad <marius.vlad@collabora.com> Suggested-by: Pekka Paalanen <pekka.paalanen@collabora.com>
5 years ago
*/
void
weston_log_subscription_remove(struct weston_log_subscription *sub)
{
assert(sub);
if (sub->source)
wl_list_remove(&sub->source_link);
sub->source = NULL;
}
/** Look-up the scope from the scope list stored in the log context, by
* matching against the \c name.
*
* @param log_ctx
* @param name the scope name, see weston_compositor_add_log_scope()
* @returns NULL if none found, or a pointer to a weston_log_scope
*
* @ingroup internal-log
*/
struct weston_log_scope *
weston_log_get_scope(struct weston_log_context *log_ctx, const char *name)
{
struct weston_log_scope *scope;
wl_list_for_each(scope, &log_ctx->scope_list, compositor_link)
if (strcmp(name, scope->name) == 0)
return scope;
return NULL;
}
/** Wrapper to invoke the weston_log_scope_cb. Allows to call the cb new_subscriber of
* a log scope.
*
* @ingroup internal-log
*/
void
weston_log_run_cb_new_subscriber(struct weston_log_subscription *sub)
{
if (sub->source->new_subscriber)
sub->source->new_subscriber(sub, sub->source->user_data);
}
/** Advertise the log scope name and the log scope description
*
* This is only used by the weston-debug protocol!
*
* @ingroup internal-log
*/
void
weston_debug_protocol_advertise_scopes(struct weston_log_context *log_ctx,
struct wl_resource *res)
{
struct weston_log_scope *scope;
wl_list_for_each(scope, &log_ctx->scope_list, compositor_link)
weston_debug_v1_send_available(res, scope->name, scope->desc);
}
/**
* Connect weston_compositor structure to weston_log_context structure.
*
* \param compositor
* \param log_ctx
* \return 0 on success, -1 on failure
*
* Sets weston_compositor::weston_log_ctx.
*
* @ingroup log
*/
int
weston_log_ctx_compositor_setup(struct weston_compositor *compositor,
struct weston_log_context *log_ctx)
{
assert(!compositor->weston_log_ctx);
assert(log_ctx);
compositor->weston_log_ctx = log_ctx;
return 0;
}
/** Creates weston_log_context structure
*
* \return NULL in case of failure, or a weston_log_context object in case of
* success
*
* weston_log_context is a singleton for each weston_compositor.
* @ingroup log
*
*/
WL_EXPORT struct weston_log_context *
weston_log_ctx_compositor_create(void)
{
struct weston_log_context *log_ctx;
log_ctx = zalloc(sizeof *log_ctx);
if (!log_ctx)
return NULL;
wl_list_init(&log_ctx->scope_list);
wl_list_init(&log_ctx->pending_subscription_list);
return log_ctx;
}
/** Destroy weston_log_context structure
*
* \param compositor The libweston compositor whose weston-debug to tear down.
*
* Clears weston_compositor::weston_log_ctx.
* @ingroup log
*
*/
WL_EXPORT void
weston_log_ctx_compositor_destroy(struct weston_compositor *compositor)
{
struct weston_log_context *log_ctx = compositor->weston_log_ctx;
struct weston_log_scope *scope;
struct weston_log_subscription *pending_sub, *pending_sub_tmp;
if (log_ctx->global)
wl_global_destroy(log_ctx->global);
wl_list_for_each(scope, &log_ctx->scope_list, compositor_link)
fprintf(stderr, "Internal warning: debug scope '%s' has not been destroyed.\n",
scope->name);
/* Remove head to not crash if scope removed later. */
wl_list_remove(&log_ctx->scope_list);
/* Remove any pending subscription(s) which nobody subscribed to */
wl_list_for_each_safe(pending_sub, pending_sub_tmp,
&log_ctx->pending_subscription_list, source_link) {
weston_log_subscription_destroy_pending(pending_sub);
}
/* pending_subscription_list should be empty at this point */
free(log_ctx);
compositor->weston_log_ctx = NULL;
}
/** Enable weston-debug protocol extension
*
* \param compositor The libweston compositor where to enable.
*
* This enables the weston_debug_v1 Wayland protocol extension which any client
* can use to get debug messages from the compositor.
*
* WARNING: This feature should not be used in production. If a client
* provides a file descriptor that blocks writes, it will block the whole
* compositor indefinitely.
*
* There is no control on which client is allowed to subscribe to debug
* messages. Any and all clients are allowed.
*
* The debug extension is disabled by default, and once enabled, cannot be
* disabled again.
*
* @ingroup debug-protocol
*/
WL_EXPORT void
weston_compositor_enable_debug_protocol(struct weston_compositor *compositor)
{
struct weston_log_context *log_ctx = compositor->weston_log_ctx;
assert(log_ctx);
if (log_ctx->global)
return;
log_ctx->global = wl_global_create(compositor->wl_display,
&weston_debug_v1_interface, 1,
log_ctx, weston_log_bind_weston_debug);
if (!log_ctx->global)
return;
fprintf(stderr, "WARNING: debug protocol has been enabled. "
"This is a potential denial-of-service attack vector and "
"information leak.\n");
}
/** Determine if the debug protocol has been enabled
*
* \param wc The libweston compositor to verify if debug protocol has been
* enabled
*
* @ingroup debug-protocol
*/
WL_EXPORT bool
weston_compositor_is_debug_protocol_enabled(struct weston_compositor *wc)
{
return wc->weston_log_ctx->global != NULL;
}
/** Register a new stream name, creating a log scope.
*
* @param log_ctx The weston_log_context where to add.
* @param name The debug stream/scope name; must not be NULL.
* @param description The log scope description for humans; must not be NULL.
* @param new_subscriber Optional callback when a client subscribes to this
* scope.
* @param user_data Optional user data pointer for the callback.
* @returns A valid pointer on success, NULL on failure.
*
* This function is used to create a log scope. All debug message printing
* happens for a scope, which allows clients to subscribe to the kind of debug
* messages they want by \c name. For the weston-debug protocol,
* subscription for the scope will happen automatically but for other types of
* streams, weston_log_subscribe() should be called as to create a subscription
* and tie it to the scope created by this function.
*
* \p name must be unique in the weston_compositor instance. \p name
* and \p description must both be provided. In case of the weston-debug
* protocol, the description is printed when a client asks for a list of
* supported log scopes.
*
* \p new_subscriber, if not NULL, is called when a client subscribes to the log
* scope creating a debug stream. This is for log scopes that need to print
* messages as a response to a client appearing, e.g. printing a list of
* windows on demand or a static preamble. The argument \p user_data is
* passed in to the callback and is otherwise unused.
*
* For one-shot debug streams, \c new_subscriber should finally call
* weston_log_subscription_complete() to close the stream and tell the client
* the printing is complete. Otherwise the client expects more data to be
* written. The complete callback in weston_log_subscriber should be installed
* to trigger it and it is set-up automatically for the weston-debug protocol.
*
* As subscription can take place before creating the scope, any pending
* subscriptions to scope added by weston_log_subscribe(), will be checked
* against the scope being created and if found will be added to the scope's
* subscription list.
*
* The log scope must be destroyed using weston_compositor_log_scope_destroy()
* before destroying the weston_compositor.
*
* @memberof weston_log_scope
* @sa weston_log_scope_cb, weston_log_subscribe
*/
WL_EXPORT struct weston_log_scope *
weston_compositor_add_log_scope(struct weston_log_context *log_ctx,
const char *name,
const char *description,
weston_log_scope_cb new_subscriber,
void *user_data)
{
struct weston_log_scope *scope;
struct weston_log_subscription *pending_sub = NULL;
if (!name || !description) {
fprintf(stderr, "Error: cannot add a debug scope without name or description.\n");
return NULL;
}
if (!log_ctx) {
fprintf(stderr, "Error: cannot add debug scope '%s', infra not initialized.\n",
name);
return NULL;
}
if (weston_log_get_scope(log_ctx, name)){
fprintf(stderr, "Error: debug scope named '%s' is already registered.\n",
name);
return NULL;
}
scope = zalloc(sizeof *scope);
if (!scope) {
fprintf(stderr, "Error adding debug scope '%s': out of memory.\n",
name);
return NULL;
}
scope->name = strdup(name);
scope->desc = strdup(description);
scope->new_subscriber = new_subscriber;
scope->user_data = user_data;
wl_list_init(&scope->subscription_list);
if (!scope->name || !scope->desc) {
fprintf(stderr, "Error adding debug scope '%s': out of memory.\n",
name);
free(scope->name);
free(scope->desc);
free(scope);
return NULL;
}
wl_list_insert(log_ctx->scope_list.prev, &scope->compositor_link);
/* check if there are any pending subscriptions to this scope */
while ((pending_sub = find_pending_subscription(log_ctx, scope->name)) != NULL) {
weston_log_subscription_create(pending_sub->owner, scope);
/* remove it from pending */
weston_log_subscription_destroy_pending(pending_sub);
}
return scope;
}
/** Destroy a log scope
*
* @param scope The log scope to destroy; may be NULL.
*
* Destroys the log scope, calling each stream's destroy callback if one was
* installed/created.
*
* @memberof weston_log_scope
*/
WL_EXPORT void
weston_compositor_log_scope_destroy(struct weston_log_scope *scope)
{
struct weston_log_subscription *sub, *sub_tmp;
if (!scope)
return;
wl_list_for_each_safe(sub, sub_tmp, &scope->subscription_list, source_link) {
/* destroy each subscription */
if (sub->owner->destroy)
sub->owner->destroy(sub->owner);
weston_log_subscription_destroy(sub);
}
wl_list_remove(&scope->compositor_link);
free(scope->name);
free(scope->desc);
free(scope);
}
/** Are there any active subscriptions to the scope?
*
* \param scope The log scope to check; may be NULL.
* \return True if any streams are open for this scope, false otherwise.
*
* As printing some debugging messages may be relatively expensive, one
* can use this function to determine if there is a need to gather the
* debugging information at all. If this function returns false, all
* printing for this scope is dropped, so gathering the information is
* pointless.
*
* The return value of this function should not be stored, as new clients
* may subscribe to the debug scope later.
*
* If the given scope is NULL, this function will always return false,
* making it safe to use in teardown or destroy code, provided the
* scope is initialized to NULL before creation and set to NULL after
* destruction.
*
* \memberof weston_log_scope
*/
WL_EXPORT bool
weston_log_scope_is_enabled(struct weston_log_scope *scope)
{
if (!scope)
return false;
return !wl_list_empty(&scope->subscription_list);
}
/** Close the stream's complete callback if one was installed/created.
*
* @ingroup log
*/
WL_EXPORT void
weston_log_subscription_complete(struct weston_log_subscription *sub)
{
if (sub->owner && sub->owner->complete)
sub->owner->complete(sub->owner);
}
/** Close the log scope.
*
* @param scope The log scope to complete; may be NULL.
*
* Complete the log scope, calling each stream's complete callback if one was
* installed/created. This can be useful to signal the reading end that the
* data has been transmited and should no longer expect that written over the
* stream. Particularly useful for the weston-debug protocol.
*
* @memberof weston_log_scope
* @sa weston_compositor_add_log_scope, weston_compositor_log_scope_destroy
*/
WL_EXPORT void
weston_log_scope_complete(struct weston_log_scope *scope)
{
struct weston_log_subscription *sub;
if (!scope)
return;
wl_list_for_each(sub, &scope->subscription_list, source_link)
weston_log_subscription_complete(sub);
}
/** Write log data for a scope
*
* \param scope The debug scope to write for; may be NULL, in which case
* nothing will be written.
* \param[in] data Pointer to the data to write.
* \param len Number of bytes to write.
*
* Writes the given data to all subscribed clients' streams.
*
* \memberof weston_log_scope
*/
WL_EXPORT void
weston_log_scope_write(struct weston_log_scope *scope,
const char *data, size_t len)
{
struct weston_log_subscription *sub;
if (!scope)
return;
wl_list_for_each(sub, &scope->subscription_list, source_link)
weston_log_subscription_write(sub, data, len);
}
/** Write a formatted string for a scope (varargs)
*
* \param scope The log scope to write for; may be NULL, in which case
* nothing will be written.
* \param fmt Printf-style format string.
* \param ap Formatting arguments.
*
* Writes to formatted string to all subscribed clients' streams.
*
* The behavioral details for each stream are the same as for
* weston_debug_stream_write().
*
* \memberof weston_log_scope
*/
WL_EXPORT int
weston_log_scope_vprintf(struct weston_log_scope *scope,
const char *fmt, va_list ap)
{
static const char oom[] = "Out of memory";
char *str;
int len = 0;
if (!weston_log_scope_is_enabled(scope))
return len;
len = vasprintf(&str, fmt, ap);
if (len >= 0) {
weston_log_scope_write(scope, str, len);
free(str);
} else {
weston_log_scope_write(scope, oom, sizeof oom - 1);
}
return len;
}
/** Write a formatted string for a scope
*
* \param scope The log scope to write for; may be NULL, in which case
* nothing will be written.
* \param fmt Printf-style format string and arguments.
*
* Writes to formatted string to all subscribed clients' streams.
*
* The behavioral details for each stream are the same as for
* weston_debug_stream_write().
*
* \memberof weston_log_scope
*/
WL_EXPORT int
weston_log_scope_printf(struct weston_log_scope *scope,
const char *fmt, ...)
{
va_list ap;
int len;
va_start(ap, fmt);
len = weston_log_scope_vprintf(scope, fmt, ap);
va_end(ap);
return len;
}
/** Write a formatted string for a subscription
*
* \param sub The subscription to write for; may be NULL, in which case
* nothing will be written.
* \param fmt Printf-style format string and arguments.
*
* Writes to formatted string to the stream that created the subscription.
*
* @ingroup log
*/
WL_EXPORT void
weston_log_subscription_printf(struct weston_log_subscription *sub,
const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
weston_log_subscription_vprintf(sub, fmt, ap);
va_end(ap);
}
/** Write debug scope name and current time into string
*
* \param[in] scope debug scope; may be NULL
* \param[out] buf Buffer to store the string.
* \param len Available size in the buffer in bytes.
* \return \c buf
*
* Reads the current local wall-clock time and formats it into a string.
* and append the debug scope name to it, if a scope is available.
* The string is NUL-terminated, even if truncated.
*
* @memberof weston_log_scope
*/
WL_EXPORT char *
weston_log_scope_timestamp(struct weston_log_scope *scope,
char *buf, size_t len)
{
struct timeval tv;
struct tm *bdt;
char string[128];
size_t ret = 0;
gettimeofday(&tv, NULL);
bdt = localtime(&tv.tv_sec);
if (bdt)
ret = strftime(string, sizeof string,
"%Y-%m-%d %H:%M:%S", bdt);
if (ret > 0) {
snprintf(buf, len, "[%s.%03ld][%s]", string,
tv.tv_usec / 1000,
(scope) ? scope->name : "no scope");
} else {
snprintf(buf, len, "[?][%s]",
(scope) ? scope->name : "no scope");
}
return buf;
}
/** Subscribe to a scope
*
* Creates a subscription which is used to subscribe the \p subscriber
* to the scope \c scope_name.
*
* If \c scope_name has already been created (using
* weston_compositor_add_log_scope) the subscription will take place
* immediately, otherwise we store the subscription into a pending list. See
* also weston_compositor_add_log_scope().
*
* @param log_ctx the log context, used for accessing pending list
* @param subscriber the subscriber, which has to be created before
* @param scope_name the scope name. In case the scope is not created
* we temporarily store the subscription in the pending list.
*
* @ingroup log
*/
WL_EXPORT void
weston_log_subscribe(struct weston_log_context *log_ctx,
struct weston_log_subscriber *subscriber,
const char *scope_name)
{
assert(log_ctx);
assert(subscriber);
assert(scope_name);
struct weston_log_scope *scope;
scope = weston_log_get_scope(log_ctx, scope_name);
if (scope)
weston_log_subscription_create(subscriber, scope);
else
/*
* if we don't have already as scope for it, add it to pending
* subscription list
*/
weston_log_subscription_create_pending(subscriber, scope_name, log_ctx);
}