/* 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" #include "gioalias.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(). 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 propegated 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 if available. * 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. **/ 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; 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->context) 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_get_thread_default (); if (simple->context) g_main_context_ref (simple->context); } /** * g_simple_async_result_new: * @source_object: a #GObject the asynchronous function was called with, * or %NULL. * @callback: a #GAsyncReadyCallback. * @user_data: user data passed to @callback. * @source_tag: the asynchronous function. * * Creates a #GSimpleAsyncResult. * * 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: a #GObject, or %NULL. * @callback: a #GAsyncReadyCallback. * @user_data: user data passed to @callback. * @error: a #GError location. * * 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, 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_error: * @source_object: a #GObject, or %NULL. * @callback: a #GAsyncReadyCallback. * @user_data: 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. * **/ 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: * @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: a location to propegate the error to. * * Propagates an error from within the simple asynchronous result to * a given destination. * * Returns: %TRUE if the error was propegated 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 (simple->failed) { g_propagate_error (dest, simple->error); simple->error = NULL; return TRUE; } return FALSE; } /** * g_simple_async_result_set_op_res_gpointer: * @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: * @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, 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_set_error_va: * @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: * @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(). **/ 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) { current_context = g_source_get_context (current_source); if (current_context == g_main_context_default ()) current_context = NULL; if (simple->context != current_context) g_warning ("g_simple_async_result_complete() called from wrong context!"); } else g_warning ("g_simple_async_result_complete() called from outside main loop!"); #endif if (simple->callback) simple->callback (simple->source_object, G_ASYNC_RESULT (simple), simple->user_data); } 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. **/ 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: * @simple: a #GSimpleAsyncResult. * @func: a #GSimpleAsyncThreadFunc. * @io_priority: the io priority of the request. * @cancellable: 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. **/ 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 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. **/ 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) { g_object_unref (cmp_source); return FALSE; } g_object_unref (cmp_source); return source_tag == g_simple_async_result_get_source_tag (simple); } /** * g_simple_async_report_error_in_idle: * @object: a #GObject. * @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 (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: a #GObject. * @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_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, GError *error) { GSimpleAsyncResult *simple; g_return_if_fail (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); } #define __G_SIMPLE_ASYNC_RESULT_C__ #include "gioaliasdef.c"