/* GIO - GLib Input, Output and Streaming Library * * Copyright (C) 2006-2007 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General * Public License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307, USA. * * Author: Alexander Larsson */ #include "config.h" #include #include #include #include #include #ifdef HAVE_UNISTD_H #include #endif #include "gsimpleasyncresult.h" #include "gasyncresult.h" #include "gcancellable.h" #include "gioscheduler.h" #include #include "glibintl.h" /** * SECTION:gsimpleasyncresult * @short_description: Simple asynchronous results implementation * @include: gio/gio.h * @see_also: #GAsyncResult * * Implements #GAsyncResult for simple cases. Most of the time, this * will be all an application needs, and will be used transparently. * Because of this, #GSimpleAsyncResult is used throughout GIO for * handling asynchronous functions. * * GSimpleAsyncResult handles #GAsyncReadyCallbacks, error * reporting, operation cancellation and the final state of an operation, * completely transparent to the application. Results can be returned * as a pointer e.g. for functions that return data that is collected * asynchronously, a boolean value for checking the success or failure * of an operation, or a #gssize for operations which return the number * of bytes modified by the operation; all of the simple return cases * are covered. * * Most of the time, an application will not need to know of the details * of this API; it is handled transparently, and any necessary operations * are handled by #GAsyncResult's interface. However, if implementing a * new GIO module, for writing language bindings, or for complex * applications that need better control of how asynchronous operations * are completed, it is important to understand this functionality. * * GSimpleAsyncResults are tagged with the calling function to ensure * that asynchronous functions and their finishing functions are used * together correctly. * * To create a new #GSimpleAsyncResult, call g_simple_async_result_new(). * If the result needs to be created for a #GError, use * g_simple_async_result_new_from_error() or * g_simple_async_result_new_take_error(). If a #GError is not available * (e.g. the asynchronous operation's doesn't take a #GError argument), * but the result still needs to be created for an error condition, use * g_simple_async_result_new_error() (or g_simple_async_result_set_error_va() * if your application or binding requires passing a variable argument list * directly), and the error can then be propagated through the use of * g_simple_async_result_propagate_error(). * * An asynchronous operation can be made to ignore a cancellation event by * calling g_simple_async_result_set_handle_cancellation() with a * #GSimpleAsyncResult for the operation and %FALSE. This is useful for * operations that are dangerous to cancel, such as close (which would * cause a leak if cancelled before being run). * * GSimpleAsyncResult can integrate into GLib's event loop, #GMainLoop, * or it can use #GThreads. * g_simple_async_result_complete() will finish an I/O task directly * from the point where it is called. g_simple_async_result_complete_in_idle() * will finish it from an idle handler in the thread-default main * context. g_simple_async_result_run_in_thread() will run the * job in a separate thread and then deliver the result to the * thread-default main context. * * To set the results of an asynchronous function, * g_simple_async_result_set_op_res_gpointer(), * g_simple_async_result_set_op_res_gboolean(), and * g_simple_async_result_set_op_res_gssize() * are provided, setting the operation's result to a gpointer, gboolean, or * gssize, respectively. * * Likewise, to get the result of an asynchronous function, * g_simple_async_result_get_op_res_gpointer(), * g_simple_async_result_get_op_res_gboolean(), and * g_simple_async_result_get_op_res_gssize() are * provided, getting the operation's result as a gpointer, gboolean, and * gssize, respectively. * * For the details of the requirements implementations must respect, see * #GAsyncResult. A typical implementation of an asynchronous operation * using GSimpleAsyncResult looks something like this: * * |[ * static void * baked_cb (Cake *cake, * gpointer user_data) * { * /* In this example, this callback is not given a reference to the cake, so * * the GSimpleAsyncResult has to take a reference to it. * */ * GSimpleAsyncResult *result = user_data; * * if (cake == NULL) * g_simple_async_result_set_error (result, * BAKER_ERRORS, * BAKER_ERROR_NO_FLOUR, * "Go to the supermarket"); * else * g_simple_async_result_set_op_res_gpointer (result, * g_object_ref (cake), * g_object_unref); * * * /* In this example, we assume that baked_cb is called as a callback from * * the mainloop, so it's safe to complete the operation synchronously here. * * If, however, _baker_prepare_cake () might call its callback without * * first returning to the mainloop — inadvisable, but some APIs do so — * * we would need to use g_simple_async_result_complete_in_idle(). * */ * g_simple_async_result_complete (result); * g_object_unref (result); * } * * void * baker_bake_cake_async (Baker *self, * guint radius, * GAsyncReadyCallback callback, * gpointer user_data) * { * GSimpleAsyncResult *simple; * Cake *cake; * * if (radius < 3) * { * g_simple_async_report_error_in_idle (G_OBJECT (self), * callback, * user_data, * BAKER_ERRORS, * BAKER_ERROR_TOO_SMALL, * "%ucm radius cakes are silly", * radius); * return; * } * * simple = g_simple_async_result_new (G_OBJECT (self), * callback, * user_data, * baker_bake_cake_async); * cake = _baker_get_cached_cake (self, radius); * * if (cake != NULL) * { * g_simple_async_result_set_op_res_gpointer (simple, * g_object_ref (cake), * g_object_unref); * g_simple_async_result_complete_in_idle (simple); * g_object_unref (simple); * /* Drop the reference returned by _baker_get_cached_cake(); the * * GSimpleAsyncResult has taken its own reference. * */ * g_object_unref (cake); * return; * } * * _baker_prepare_cake (self, radius, baked_cb, simple); * } * * Cake * * baker_bake_cake_finish (Baker *self, * GAsyncResult *result, * GError **error) * { * GSimpleAsyncResult *simple; * Cake *cake; * * g_return_val_if_fail (g_simple_async_result_is_valid (result, * G_OBJECT (self), * baker_bake_cake_async), * NULL); * * simple = (GSimpleAsyncResult *) result; * * if (g_simple_async_result_propagate_error (simple, error)) * return NULL; * * cake = CAKE (g_simple_async_result_get_op_res_gpointer (simple)); * return g_object_ref (cake); * } * ]| */ static void g_simple_async_result_async_result_iface_init (GAsyncResultIface *iface); struct _GSimpleAsyncResult { GObject parent_instance; GObject *source_object; GAsyncReadyCallback callback; gpointer user_data; GMainContext *context; GError *error; gboolean failed; gboolean handle_cancellation; GCancellable *check_cancellable; gpointer source_tag; union { gpointer v_pointer; gboolean v_boolean; gssize v_ssize; } op_res; GDestroyNotify destroy_op_res; }; struct _GSimpleAsyncResultClass { GObjectClass parent_class; }; G_DEFINE_TYPE_WITH_CODE (GSimpleAsyncResult, g_simple_async_result, G_TYPE_OBJECT, G_IMPLEMENT_INTERFACE (G_TYPE_ASYNC_RESULT, g_simple_async_result_async_result_iface_init)) static void clear_op_res (GSimpleAsyncResult *simple) { if (simple->destroy_op_res) simple->destroy_op_res (simple->op_res.v_pointer); simple->destroy_op_res = NULL; simple->op_res.v_ssize = 0; } static void g_simple_async_result_finalize (GObject *object) { GSimpleAsyncResult *simple; simple = G_SIMPLE_ASYNC_RESULT (object); if (simple->source_object) g_object_unref (simple->source_object); if (simple->check_cancellable) g_object_unref (simple->check_cancellable); g_main_context_unref (simple->context); clear_op_res (simple); if (simple->error) g_error_free (simple->error); G_OBJECT_CLASS (g_simple_async_result_parent_class)->finalize (object); } static void g_simple_async_result_class_init (GSimpleAsyncResultClass *klass) { GObjectClass *gobject_class = G_OBJECT_CLASS (klass); gobject_class->finalize = g_simple_async_result_finalize; } static void g_simple_async_result_init (GSimpleAsyncResult *simple) { simple->handle_cancellation = TRUE; simple->context = g_main_context_ref_thread_default (); } /** * g_simple_async_result_new: * @source_object: (allow-none): a #GObject, or %NULL. * @callback: (scope async): a #GAsyncReadyCallback. * @user_data: (closure): user data passed to @callback. * @source_tag: the asynchronous function. * * Creates a #GSimpleAsyncResult. * * The common convention is to create the #GSimpleAsyncResult in the * function that starts the asynchronous operation and use that same * function as the @source_tag. * * If your operation supports cancellation with #GCancellable (which it * probably should) then you should provide the user's cancellable to * g_simple_async_result_set_check_cancellable() immediately after * this function returns. * * Returns: a #GSimpleAsyncResult. **/ GSimpleAsyncResult * g_simple_async_result_new (GObject *source_object, GAsyncReadyCallback callback, gpointer user_data, gpointer source_tag) { GSimpleAsyncResult *simple; g_return_val_if_fail (!source_object || G_IS_OBJECT (source_object), NULL); simple = g_object_new (G_TYPE_SIMPLE_ASYNC_RESULT, NULL); simple->callback = callback; if (source_object) simple->source_object = g_object_ref (source_object); else simple->source_object = NULL; simple->user_data = user_data; simple->source_tag = source_tag; return simple; } /** * g_simple_async_result_new_from_error: * @source_object: (allow-none): a #GObject, or %NULL. * @callback: (scope async): a #GAsyncReadyCallback. * @user_data: (closure): user data passed to @callback. * @error: a #GError * * Creates a #GSimpleAsyncResult from an error condition. * * Returns: a #GSimpleAsyncResult. **/ GSimpleAsyncResult * g_simple_async_result_new_from_error (GObject *source_object, GAsyncReadyCallback callback, gpointer user_data, const GError *error) { GSimpleAsyncResult *simple; g_return_val_if_fail (!source_object || G_IS_OBJECT (source_object), NULL); simple = g_simple_async_result_new (source_object, callback, user_data, NULL); g_simple_async_result_set_from_error (simple, error); return simple; } /** * g_simple_async_result_new_take_error: (skip) * @source_object: (allow-none): a #GObject, or %NULL * @callback: (scope async): a #GAsyncReadyCallback * @user_data: (closure): user data passed to @callback * @error: a #GError * * Creates a #GSimpleAsyncResult from an error condition, and takes over the * caller's ownership of @error, so the caller does not need to free it anymore. * * Returns: a #GSimpleAsyncResult * * Since: 2.28 **/ GSimpleAsyncResult * g_simple_async_result_new_take_error (GObject *source_object, GAsyncReadyCallback callback, gpointer user_data, GError *error) { GSimpleAsyncResult *simple; g_return_val_if_fail (!source_object || G_IS_OBJECT (source_object), NULL); simple = g_simple_async_result_new (source_object, callback, user_data, NULL); g_simple_async_result_take_error (simple, error); return simple; } /** * g_simple_async_result_new_error: * @source_object: (allow-none): a #GObject, or %NULL. * @callback: (scope async): a #GAsyncReadyCallback. * @user_data: (closure): user data passed to @callback. * @domain: a #GQuark. * @code: an error code. * @format: a string with format characters. * @...: a list of values to insert into @format. * * Creates a new #GSimpleAsyncResult with a set error. * * Returns: a #GSimpleAsyncResult. **/ GSimpleAsyncResult * g_simple_async_result_new_error (GObject *source_object, GAsyncReadyCallback callback, gpointer user_data, GQuark domain, gint code, const char *format, ...) { GSimpleAsyncResult *simple; va_list args; g_return_val_if_fail (!source_object || G_IS_OBJECT (source_object), NULL); g_return_val_if_fail (domain != 0, NULL); g_return_val_if_fail (format != NULL, NULL); simple = g_simple_async_result_new (source_object, callback, user_data, NULL); va_start (args, format); g_simple_async_result_set_error_va (simple, domain, code, format, args); va_end (args); return simple; } static gpointer g_simple_async_result_get_user_data (GAsyncResult *res) { return G_SIMPLE_ASYNC_RESULT (res)->user_data; } static GObject * g_simple_async_result_get_source_object (GAsyncResult *res) { if (G_SIMPLE_ASYNC_RESULT (res)->source_object) return g_object_ref (G_SIMPLE_ASYNC_RESULT (res)->source_object); return NULL; } static void g_simple_async_result_async_result_iface_init (GAsyncResultIface *iface) { iface->get_user_data = g_simple_async_result_get_user_data; iface->get_source_object = g_simple_async_result_get_source_object; } /** * g_simple_async_result_set_handle_cancellation: * @simple: a #GSimpleAsyncResult. * @handle_cancellation: a #gboolean. * * Sets whether to handle cancellation within the asynchronous operation. * * This function has nothing to do with * g_simple_async_result_set_check_cancellable(). It only refers to the * #GCancellable passed to g_simple_async_result_run_in_thread(). **/ void g_simple_async_result_set_handle_cancellation (GSimpleAsyncResult *simple, gboolean handle_cancellation) { g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); simple->handle_cancellation = handle_cancellation; } /** * g_simple_async_result_get_source_tag: (skip) * @simple: a #GSimpleAsyncResult. * * Gets the source tag for the #GSimpleAsyncResult. * * Returns: a #gpointer to the source object for the #GSimpleAsyncResult. **/ gpointer g_simple_async_result_get_source_tag (GSimpleAsyncResult *simple) { g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), NULL); return simple->source_tag; } /** * g_simple_async_result_propagate_error: * @simple: a #GSimpleAsyncResult. * @dest: (out): a location to propagate the error to. * * Propagates an error from within the simple asynchronous result to * a given destination. * * If the #GCancellable given to a prior call to * g_simple_async_result_set_check_cancellable() is cancelled then this * function will return %TRUE with @dest set appropriately. * * Returns: %TRUE if the error was propagated to @dest. %FALSE otherwise. **/ gboolean g_simple_async_result_propagate_error (GSimpleAsyncResult *simple, GError **dest) { g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), FALSE); if (g_cancellable_set_error_if_cancelled (simple->check_cancellable, dest)) return TRUE; if (simple->failed) { g_propagate_error (dest, simple->error); simple->error = NULL; return TRUE; } return FALSE; } /** * g_simple_async_result_set_op_res_gpointer: (skip) * @simple: a #GSimpleAsyncResult. * @op_res: a pointer result from an asynchronous function. * @destroy_op_res: a #GDestroyNotify function. * * Sets the operation result within the asynchronous result to a pointer. **/ void g_simple_async_result_set_op_res_gpointer (GSimpleAsyncResult *simple, gpointer op_res, GDestroyNotify destroy_op_res) { g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); clear_op_res (simple); simple->op_res.v_pointer = op_res; simple->destroy_op_res = destroy_op_res; } /** * g_simple_async_result_get_op_res_gpointer: (skip) * @simple: a #GSimpleAsyncResult. * * Gets a pointer result as returned by the asynchronous function. * * Returns: a pointer from the result. **/ gpointer g_simple_async_result_get_op_res_gpointer (GSimpleAsyncResult *simple) { g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), NULL); return simple->op_res.v_pointer; } /** * g_simple_async_result_set_op_res_gssize: * @simple: a #GSimpleAsyncResult. * @op_res: a #gssize. * * Sets the operation result within the asynchronous result to * the given @op_res. **/ void g_simple_async_result_set_op_res_gssize (GSimpleAsyncResult *simple, gssize op_res) { g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); clear_op_res (simple); simple->op_res.v_ssize = op_res; } /** * g_simple_async_result_get_op_res_gssize: * @simple: a #GSimpleAsyncResult. * * Gets a gssize from the asynchronous result. * * Returns: a gssize returned from the asynchronous function. **/ gssize g_simple_async_result_get_op_res_gssize (GSimpleAsyncResult *simple) { g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), 0); return simple->op_res.v_ssize; } /** * g_simple_async_result_set_op_res_gboolean: * @simple: a #GSimpleAsyncResult. * @op_res: a #gboolean. * * Sets the operation result to a boolean within the asynchronous result. **/ void g_simple_async_result_set_op_res_gboolean (GSimpleAsyncResult *simple, gboolean op_res) { g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); clear_op_res (simple); simple->op_res.v_boolean = !!op_res; } /** * g_simple_async_result_get_op_res_gboolean: * @simple: a #GSimpleAsyncResult. * * Gets the operation result boolean from within the asynchronous result. * * Returns: %TRUE if the operation's result was %TRUE, %FALSE * if the operation's result was %FALSE. **/ gboolean g_simple_async_result_get_op_res_gboolean (GSimpleAsyncResult *simple) { g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), FALSE); return simple->op_res.v_boolean; } /** * g_simple_async_result_set_from_error: * @simple: a #GSimpleAsyncResult. * @error: #GError. * * Sets the result from a #GError. **/ void g_simple_async_result_set_from_error (GSimpleAsyncResult *simple, const GError *error) { g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); g_return_if_fail (error != NULL); if (simple->error) g_error_free (simple->error); simple->error = g_error_copy (error); simple->failed = TRUE; } /** * g_simple_async_result_take_error: (skip) * @simple: a #GSimpleAsyncResult * @error: a #GError * * Sets the result from @error, and takes over the caller's ownership * of @error, so the caller does not need to free it any more. * * Since: 2.28 **/ void g_simple_async_result_take_error (GSimpleAsyncResult *simple, GError *error) { g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); g_return_if_fail (error != NULL); if (simple->error) g_error_free (simple->error); simple->error = error; simple->failed = TRUE; } /** * g_simple_async_result_set_error_va: (skip) * @simple: a #GSimpleAsyncResult. * @domain: a #GQuark (usually #G_IO_ERROR). * @code: an error code. * @format: a formatted error reporting string. * @args: va_list of arguments. * * Sets an error within the asynchronous result without a #GError. * Unless writing a binding, see g_simple_async_result_set_error(). **/ void g_simple_async_result_set_error_va (GSimpleAsyncResult *simple, GQuark domain, gint code, const char *format, va_list args) { g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); g_return_if_fail (domain != 0); g_return_if_fail (format != NULL); if (simple->error) g_error_free (simple->error); simple->error = g_error_new_valist (domain, code, format, args); simple->failed = TRUE; } /** * g_simple_async_result_set_error: (skip) * @simple: a #GSimpleAsyncResult. * @domain: a #GQuark (usually #G_IO_ERROR). * @code: an error code. * @format: a formatted error reporting string. * @...: a list of variables to fill in @format. * * Sets an error within the asynchronous result without a #GError. **/ void g_simple_async_result_set_error (GSimpleAsyncResult *simple, GQuark domain, gint code, const char *format, ...) { va_list args; g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); g_return_if_fail (domain != 0); g_return_if_fail (format != NULL); va_start (args, format); g_simple_async_result_set_error_va (simple, domain, code, format, args); va_end (args); } /** * g_simple_async_result_complete: * @simple: a #GSimpleAsyncResult. * * Completes an asynchronous I/O job immediately. Must be called in * the thread where the asynchronous result was to be delivered, as it * invokes the callback directly. If you are in a different thread use * g_simple_async_result_complete_in_idle(). * * Calling this function takes a reference to @simple for as long as * is needed to complete the call. **/ void g_simple_async_result_complete (GSimpleAsyncResult *simple) { #ifndef G_DISABLE_CHECKS GSource *current_source; GMainContext *current_context; #endif g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); #ifndef G_DISABLE_CHECKS current_source = g_main_current_source (); if (current_source && !g_source_is_destroyed (current_source)) { current_context = g_source_get_context (current_source); if (simple->context != current_context) g_warning ("g_simple_async_result_complete() called from wrong context!"); } #endif if (simple->callback) { g_main_context_push_thread_default (simple->context); simple->callback (simple->source_object, G_ASYNC_RESULT (simple), simple->user_data); g_main_context_pop_thread_default (simple->context); } } static gboolean complete_in_idle_cb (gpointer data) { GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (data); g_simple_async_result_complete (simple); return FALSE; } /** * g_simple_async_result_complete_in_idle: * @simple: a #GSimpleAsyncResult. * * Completes an asynchronous function in an idle handler in the thread-default main * loop of the thread that @simple was initially created in * (and re-pushes that context around the invocation of the callback). * * Calling this function takes a reference to @simple for as long as * is needed to complete the call. */ void g_simple_async_result_complete_in_idle (GSimpleAsyncResult *simple) { GSource *source; g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); g_object_ref (simple); source = g_idle_source_new (); g_source_set_priority (source, G_PRIORITY_DEFAULT); g_source_set_callback (source, complete_in_idle_cb, simple, g_object_unref); g_source_attach (source, simple->context); g_source_unref (source); } typedef struct { GSimpleAsyncResult *simple; GCancellable *cancellable; GSimpleAsyncThreadFunc func; } RunInThreadData; static gboolean complete_in_idle_cb_for_thread (gpointer _data) { RunInThreadData *data = _data; GSimpleAsyncResult *simple; simple = data->simple; if (simple->handle_cancellation && g_cancellable_is_cancelled (data->cancellable)) g_simple_async_result_set_error (simple, G_IO_ERROR, G_IO_ERROR_CANCELLED, "%s", _("Operation was cancelled")); g_simple_async_result_complete (simple); if (data->cancellable) g_object_unref (data->cancellable); g_object_unref (data->simple); g_free (data); return FALSE; } static gboolean run_in_thread (GIOSchedulerJob *job, GCancellable *c, gpointer _data) { RunInThreadData *data = _data; GSimpleAsyncResult *simple = data->simple; GSource *source; if (simple->handle_cancellation && g_cancellable_is_cancelled (c)) g_simple_async_result_set_error (simple, G_IO_ERROR, G_IO_ERROR_CANCELLED, "%s", _("Operation was cancelled")); else data->func (simple, simple->source_object, c); source = g_idle_source_new (); g_source_set_priority (source, G_PRIORITY_DEFAULT); g_source_set_callback (source, complete_in_idle_cb_for_thread, data, NULL); g_source_attach (source, simple->context); g_source_unref (source); return FALSE; } /** * g_simple_async_result_run_in_thread: (skip) * @simple: a #GSimpleAsyncResult. * @func: a #GSimpleAsyncThreadFunc. * @io_priority: the io priority of the request. * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore. * * Runs the asynchronous job in a separate thread and then calls * g_simple_async_result_complete_in_idle() on @simple to return * the result to the appropriate main loop. * * Calling this function takes a reference to @simple for as long as * is needed to run the job and report its completion. */ void g_simple_async_result_run_in_thread (GSimpleAsyncResult *simple, GSimpleAsyncThreadFunc func, int io_priority, GCancellable *cancellable) { RunInThreadData *data; g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); g_return_if_fail (func != NULL); data = g_new (RunInThreadData, 1); data->func = func; data->simple = g_object_ref (simple); data->cancellable = cancellable; if (cancellable) g_object_ref (cancellable); g_io_scheduler_push_job (run_in_thread, data, NULL, io_priority, cancellable); } /** * g_simple_async_result_is_valid: * @result: the #GAsyncResult passed to the _finish function. * @source: the #GObject passed to the _finish function. * @source_tag: the asynchronous function. * * Ensures that the data passed to the _finish function of an async * operation is consistent. Three checks are performed. * * First, @result is checked to ensure that it is really a * #GSimpleAsyncResult. Second, @source is checked to ensure that it * matches the source object of @result. Third, @source_tag is * checked to ensure that it is either %NULL (as it is when the result was * created by g_simple_async_report_error_in_idle() or * g_simple_async_report_gerror_in_idle()) or equal to the * @source_tag argument given to g_simple_async_result_new() (which, by * convention, is a pointer to the _async function corresponding to the * _finish function from which this function is called). * * Returns: #TRUE if all checks passed or #FALSE if any failed. * * Since: 2.20 **/ gboolean g_simple_async_result_is_valid (GAsyncResult *result, GObject *source, gpointer source_tag) { GSimpleAsyncResult *simple; GObject *cmp_source; if (!G_IS_SIMPLE_ASYNC_RESULT (result)) return FALSE; simple = (GSimpleAsyncResult *)result; cmp_source = g_async_result_get_source_object (result); if (cmp_source != source) { if (cmp_source != NULL) g_object_unref (cmp_source); return FALSE; } if (cmp_source != NULL) g_object_unref (cmp_source); return source_tag == NULL || source_tag == g_simple_async_result_get_source_tag (simple); } /** * g_simple_async_report_error_in_idle: (skip) * @object: (allow-none): a #GObject, or %NULL. * @callback: a #GAsyncReadyCallback. * @user_data: user data passed to @callback. * @domain: a #GQuark containing the error domain (usually #G_IO_ERROR). * @code: a specific error code. * @format: a formatted error reporting string. * @...: a list of variables to fill in @format. * * Reports an error in an asynchronous function in an idle function by * directly setting the contents of the #GAsyncResult with the given error * information. **/ void g_simple_async_report_error_in_idle (GObject *object, GAsyncReadyCallback callback, gpointer user_data, GQuark domain, gint code, const char *format, ...) { GSimpleAsyncResult *simple; va_list args; g_return_if_fail (!object || G_IS_OBJECT (object)); g_return_if_fail (domain != 0); g_return_if_fail (format != NULL); simple = g_simple_async_result_new (object, callback, user_data, NULL); va_start (args, format); g_simple_async_result_set_error_va (simple, domain, code, format, args); va_end (args); g_simple_async_result_complete_in_idle (simple); g_object_unref (simple); } /** * g_simple_async_report_gerror_in_idle: * @object: (allow-none): a #GObject, or %NULL * @callback: (scope async): a #GAsyncReadyCallback. * @user_data: (closure): user data passed to @callback. * @error: the #GError to report * * Reports an error in an idle function. Similar to * g_simple_async_report_error_in_idle(), but takes a #GError rather * than building a new one. **/ void g_simple_async_report_gerror_in_idle (GObject *object, GAsyncReadyCallback callback, gpointer user_data, const GError *error) { GSimpleAsyncResult *simple; g_return_if_fail (!object || G_IS_OBJECT (object)); g_return_if_fail (error != NULL); simple = g_simple_async_result_new_from_error (object, callback, user_data, error); g_simple_async_result_complete_in_idle (simple); g_object_unref (simple); } /** * g_simple_async_report_take_gerror_in_idle: (skip) * @object: (allow-none): a #GObject, or %NULL * @callback: a #GAsyncReadyCallback. * @user_data: user data passed to @callback. * @error: the #GError to report * * Reports an error in an idle function. Similar to * g_simple_async_report_gerror_in_idle(), but takes over the caller's * ownership of @error, so the caller does not have to free it any more. * * Since: 2.28 **/ void g_simple_async_report_take_gerror_in_idle (GObject *object, GAsyncReadyCallback callback, gpointer user_data, GError *error) { GSimpleAsyncResult *simple; g_return_if_fail (!object || G_IS_OBJECT (object)); g_return_if_fail (error != NULL); simple = g_simple_async_result_new_take_error (object, callback, user_data, error); g_simple_async_result_complete_in_idle (simple); g_object_unref (simple); } /** * g_simple_async_result_set_check_cancellable: * @simple: a #GSimpleAsyncResult * @check_cancellable: (allow-none): a #GCancellable to check, or %NULL to unset * * Sets a #GCancellable to check before dispatching results. * * This function has one very specific purpose: the provided cancellable * is checked at the time of g_simple_async_result_propagate_error() If * it is cancelled, these functions will return an "Operation was * cancelled" error (%G_IO_ERROR_CANCELLED). * * Implementors of cancellable asynchronous functions should use this in * order to provide a guarantee to their callers that cancelling an * async operation will reliably result in an error being returned for * that operation (even if a positive result for the operation has * already been sent as an idle to the main context to be dispatched). * * The checking described above is done regardless of any call to the * unrelated g_simple_async_result_set_handle_cancellation() function. * * Since: 2.32 **/ void g_simple_async_result_set_check_cancellable (GSimpleAsyncResult *simple, GCancellable *check_cancellable) { g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple)); g_return_if_fail (check_cancellable == NULL || G_IS_CANCELLABLE (check_cancellable)); g_clear_object (&simple->check_cancellable); if (check_cancellable) simple->check_cancellable = g_object_ref (check_cancellable); }