/usr/include/giomm-2.4/giomm/cancellable.h is in libglibmm-2.4-dev 2.42.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 | // -*- c++ -*-
// Generated by gmmproc 2.42.0 -- DO NOT MODIFY!
#ifndef _GIOMM_CANCELLABLE_H
#define _GIOMM_CANCELLABLE_H
#include <glibmm/ustring.h>
#include <sigc++/sigc++.h>
// -*- Mode: C++; indent-tabs-mode: nil; c-basic-offset: 2 -*-
/* Copyright (C) 2007 The gtkmm Development Team
*
* 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 2.1 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <glibmm/object.h>
#ifndef DOXYGEN_SHOULD_SKIP_THIS
typedef struct _GCancellable GCancellable;
typedef struct _GCancellableClass GCancellableClass;
#endif /* DOXYGEN_SHOULD_SKIP_THIS */
namespace Gio
{ class Cancellable_Class; } // namespace Gio
namespace Gio
{
/** Allows actions to be cancelled.
* Cancellable is a thread-safe operation cancellation stack used throughout GIO to allow for cancellation of synchronous and asynchronous operations.
*
* @newin{2,16}
*/
class Cancellable : public Glib::Object
{
#ifndef DOXYGEN_SHOULD_SKIP_THIS
public:
typedef Cancellable CppObjectType;
typedef Cancellable_Class CppClassType;
typedef GCancellable BaseObjectType;
typedef GCancellableClass BaseClassType;
private: friend class Cancellable_Class;
static CppClassType cancellable_class_;
private:
// noncopyable
Cancellable(const Cancellable&);
Cancellable& operator=(const Cancellable&);
protected:
explicit Cancellable(const Glib::ConstructParams& construct_params);
explicit Cancellable(GCancellable* castitem);
#endif /* DOXYGEN_SHOULD_SKIP_THIS */
public:
virtual ~Cancellable();
/** Get the GType for this class, for use with the underlying GObject type system.
*/
static GType get_type() G_GNUC_CONST;
#ifndef DOXYGEN_SHOULD_SKIP_THIS
static GType get_base_type() G_GNUC_CONST;
#endif
///Provides access to the underlying C GObject.
GCancellable* gobj() { return reinterpret_cast<GCancellable*>(gobject_); }
///Provides access to the underlying C GObject.
const GCancellable* gobj() const { return reinterpret_cast<GCancellable*>(gobject_); }
///Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
GCancellable* gobj_copy();
private:
protected:
Cancellable();
public:
typedef sigc::slot<void> SlotCancelledCallback;
static Glib::RefPtr<Cancellable> create();
/** Checks if a cancellable job has been cancelled.
*
* @return <tt>true</tt> if @a cancellable is cancelled,
* <tt>false</tt> if called with <tt>0</tt> or if item is not cancelled.
*/
bool is_cancelled() const;
//May return -1 if fds not supported, or on errors .
/** Gets the file descriptor for a cancellable job. This can be used to
* implement cancellable operations on Unix systems. The returned fd will
* turn readable when @a cancellable is cancelled.
*
* You are not supposed to read from the fd yourself, just check for
* readable status. Reading to unset the readable status is done
* with g_cancellable_reset().
*
* After a successful return from this function, you should use
* g_cancellable_release_fd() to free up resources allocated for
* the returned file descriptor.
*
* See also g_cancellable_make_pollfd().
*
* @return A valid file descriptor. %-1 if the file descriptor
* is not supported, or on errors.
*/
int get_fd() const;
/** Creates a PollFD corresponding to @a cancellable; this can be passed
* to Glib::poll() and used to poll for cancellation. This is useful both
* for unix systems without a native poll and for portability to
* windows.
*
* When this function returns <tt>true</tt>, you should use
* g_cancellable_release_fd() to free up resources allocated for the
* @a pollfd. After a <tt>false</tt> return, do not call g_cancellable_release_fd().
*
* If this function returns <tt>false</tt>, either no @a cancellable was given or
* resource limits prevent this function from allocating the necessary
* structures for polling. (On Linux, you will likely have reached
* the maximum number of file descriptors.) The suggested way to handle
* these cases is to ignore the @a cancellable.
*
* You are not supposed to read from the fd yourself, just check for
* readable status. Reading to unset the readable status is done
* with g_cancellable_reset().
*
* @newin{2,22}
*
* @param pollfd A pointer to a PollFD.
* @return <tt>true</tt> if @a pollfd was successfully initialized, <tt>false</tt> on
* failure to prepare the cancellable.
*/
bool make_pollfd(GPollFD* pollfd);
/** Releases a resources previously allocated by g_cancellable_get_fd()
* or g_cancellable_make_pollfd().
*
* For compatibility reasons with older releases, calling this function
* is not strictly required, the resources will be automatically freed
* when the @a cancellable is finalized. However, the @a cancellable will
* block scarce file descriptors until it is finalized if this function
* is not called. This can cause the application to run out of file
* descriptors when many Cancellables are used at the same time.
*
* @newin{2,22}
*
*/
void release_fd();
//This is safe to call from another thread.
/** Will set @a cancellable to cancelled, and will emit the
* Cancellable::signal_cancelled() signal. (However, see the warning about
* race conditions in the documentation for that signal if you are
* planning to connect to it.)
*
* This function is thread-safe. In other words, you can safely call
* it from a thread other than the one running the operation that was
* passed the @a cancellable.
*
* The convention within gio is that cancelling an asynchronous
* operation causes it to complete asynchronously. That is, if you
* cancel the operation from the same thread in which it is running,
* then the operation's SlotAsyncReady will not be invoked until
* the application returns to the main loop.
*
*/
void cancel();
/** Gets the top cancellable from the stack.
*
* @return A Cancellable from the top
* of the stack, or <tt>0</tt> if the stack is empty.
*/
static Glib::RefPtr<Cancellable> get_current();
/** Pushes @a cancellable onto the cancellable stack. The current
* cancellable can then be received using g_cancellable_get_current().
*
* This is useful when implementing cancellable operations in
* code that does not allow you to pass down the cancellable object.
*
* This is typically called automatically by e.g. File operations,
* so you rarely have to call this yourself.
*
*/
void push_current();
/** Pops @a cancellable off the cancellable stack (verifying that @a cancellable
* is on the top of the stack).
*
*/
void pop_current();
/** Resets @a cancellable to its uncancelled state.
*
* If cancellable is currently in use by any cancellable operation
* then the behavior of this function is undefined.
*
*/
void reset();
/** Convenience function to connect to the Cancellable::signal_cancelled()
* signal. Also handles the race condition that may happen
* if the cancellable is cancelled right before connecting.
*
* @a slot is called at most once, either directly at the
* time of the connect if @a cancellable is already cancelled,
* or when @a cancellable is cancelled in some thread.
*
* See Cancellable::signal_cancelled() for details on how to use this.
*
* @newin{2,22}
* @param slot The slot to connect.
* @return The id of the signal handler or 0 if @a cancellable has already
* been cancelled.
*/
gulong connect(const SlotCancelledCallback& slot);
/** Disconnects a handler from a cancellable instance similar to
* Glib::signal_handler_disconnect(). Additionally, in the event that a
* signal handler is currently running, this call will block until the
* handler has finished. Calling this function from a
* Cancellable::signal_cancelled() signal handler will therefore result in a
* deadlock.
*
* This avoids a race condition where a thread cancels at the
* same time as the cancellable operation is finished and the
* signal handler is removed. See Cancellable::signal_cancelled() for
* details on how to use this.
*
* If @a cancellable is <tt>0</tt> or @a handler_id is %0 this function does
* nothing.
*
* @newin{2,22}
*
* @param handler_id Handler id of the handler to be disconnected, or %0.
*/
void disconnect(gulong handler_id);
/**
* @par Slot Prototype:
* <tt>void on_my_%cancelled()</tt>
*
* Emitted when the operation has been cancelled.
*
* Can be used by implementations of cancellable operations. If the
* operation is cancelled from another thread, the signal will be
* emitted in the thread that cancelled the operation, not the
* thread that is running the operation.
*
* Note that disconnecting from this signal (or any signal) in a
* multi-threaded program is prone to race conditions. For instance
* it is possible that a signal handler may be invoked even after
* a call to Glib::signal_handler_disconnect() for that handler has
* already returned.
*
* There is also a problem when cancellation happens right before
* connecting to the signal. If this happens the signal will
* unexpectedly not be emitted, and checking before connecting to
* the signal leaves a race condition where this is still happening.
*
* In order to make it safe and easy to connect handlers there
* are two helper functions: g_cancellable_connect() and
* g_cancellable_disconnect() which protect against problems
* like this.
*
* An example of how to us this:
*
* [C example ellipted]
*
* Note that the cancelled signal is emitted in the thread that
* the user cancelled from, which may be the main thread. So, the
* cancellable signal should not do something that can block.
*
*/
Glib::SignalProxy0< void > signal_cancelled();
public:
public:
//C++ methods used to invoke GTK+ virtual functions:
protected:
//GTK+ Virtual Functions (override these to change behaviour):
//Default Signal Handlers::
/// This is a default handler for the signal signal_cancelled().
virtual void on_cancelled();
};
} // namespace Gio
namespace Glib
{
/** A Glib::wrap() method for this object.
*
* @param object The C instance.
* @param take_copy False if the result should take ownership of the C instance. True if it should take a new copy or ref.
* @result A C++ instance that wraps this C instance.
*
* @relates Gio::Cancellable
*/
Glib::RefPtr<Gio::Cancellable> wrap(GCancellable* object, bool take_copy = false);
}
#endif /* _GIOMM_CANCELLABLE_H */
|