1 /*
2  * This file is part of gtkD.
3  *
4  * gtkD is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU Lesser General Public License
6  * as published by the Free Software Foundation; either version 3
7  * of the License, or (at your option) any later version, with
8  * some exceptions, please read the COPYING file.
9  *
10  * gtkD is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public License
16  * along with gtkD; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
18  */
19  
20 // generated automatically - do not change
21 // find conversion definition on APILookup.txt
22 // implement new conversion functionalities on the wrap.utils pakage
23 
24 /*
25  * Conversion parameters:
26  * inFile  = 
27  * outPack = gthread
28  * outFile = Once
29  * strct   = GOnce
30  * realStrct=
31  * ctorStrct=
32  * clss    = Once
33  * interf  = 
34  * class Code: No
35  * interface Code: No
36  * template for:
37  * extend  = 
38  * implements:
39  * prefixes:
40  * 	- g_once_
41  * omit structs:
42  * omit prefixes:
43  * omit code:
44  * omit signals:
45  * imports:
46  * structWrap:
47  * module aliases:
48  * local aliases:
49  * overrides:
50  */
51 
52 module gthread.Once;
53 
54 public  import gtkc.gthreadtypes;
55 
56 private import gtkc.gthread;
57 private import glib.ConstructionException;
58 
59 
60 
61 
62 /**
63  * Threads act almost like processes, but unlike processes all threads
64  * of one process share the same memory. This is good, as it provides
65  * easy communication between the involved threads via this shared
66  * memory, and it is bad, because strange things (so called
67  * "Heisenbugs") might happen if the program is not carefully designed.
68  * In particular, due to the concurrent nature of threads, no
69  * assumptions on the order of execution of code running in different
70  * threads can be made, unless order is explicitly forced by the
71  * programmer through synchronization primitives.
72  *
73  * The aim of the thread-related functions in GLib is to provide a
74  * portable means for writing multi-threaded software. There are
75  * primitives for mutexes to protect the access to portions of memory
76  * (GMutex, GRecMutex and GRWLock). There is a facility to use
77  * individual bits for locks (g_bit_lock()). There are primitives
78  * for condition variables to allow synchronization of threads (GCond).
79  * There are primitives for thread-private data - data that every
80  * thread has a private instance of (GPrivate). There are facilities
81  * for one-time initialization (GOnce, g_once_init_enter()). Finally,
82  * there are primitives to create and manage threads (GThread).
83  *
84  * The GLib threading system used to be initialized with g_thread_init().
85  * This is no longer necessary. Since version 2.32, the GLib threading
86  * system is automatically initialized at the start of your program,
87  * and all thread-creation functions and synchronization primitives
88  * are available right away.
89  *
90  * Note that it is not safe to assume that your program has no threads
91  * even if you don't call g_thread_new() yourself. GLib and GIO can
92  * and will create threads for their own purposes in some cases, such
93  * as when using g_unix_signal_source_new() or when using GDBus.
94  *
95  * Originally, UNIX did not have threads, and therefore some traditional
96  * UNIX APIs are problematic in threaded programs. Some notable examples
97  * are
98  *
99  *  C library functions that return data in statically allocated
100  *  buffers, such as strtok() or strerror(). For many of these,
101  *  there are thread-safe variants with a _r suffix, or you can
102  *  look at corresponding GLib APIs (like g_strsplit() or g_strerror()).
103  *
104  * setenv() and unsetenv() manipulate the process environment in
105  *  a not thread-safe way, and may interfere with getenv() calls
106  *  in other threads. Note that getenv() calls may be
107  *  “hidden” behind other APIs. For example, GNU gettext()
108  *  calls getenv() under the covers. In general, it is best to treat
109  *  the environment as readonly. If you absolutely have to modify the
110  *  environment, do it early in main(), when no other threads are around yet.
111  *
112  * setlocale() changes the locale for the entire process, affecting
113  *  all threads. Temporary changes to the locale are often made to
114  *  change the behavior of string scanning or formatting functions
115  *  like scanf() or printf(). GLib offers a number of string APIs
116  *  (like g_ascii_formatd() or g_ascii_strtod()) that can often be
117  *  used as an alternative. Or you can use the uselocale() function
118  *  to change the locale only for the current thread.
119  *
120  * fork() only takes the calling thread into the child's copy of the
121  *  process image. If other threads were executing in critical
122  *  sections they could have left mutexes locked which could easily
123  *  cause deadlocks in the new child. For this reason, you should
124  *  call exit() or exec() as soon as possible in the child and only
125  *  make signal-safe library calls before that.
126  *
127  * daemon() uses fork() in a way contrary to what is described
128  *  above. It should not be used with GLib programs.
129  *
130  * GLib itself is internally completely thread-safe (all global data is
131  * automatically locked), but individual data structure instances are
132  * not automatically locked for performance reasons. For example,
133  * you must coordinate accesses to the same GHashTable from multiple
134  * threads. The two notable exceptions from this rule are GMainLoop
135  * and GAsyncQueue, which are thread-safe and
136  * need no further application-level locking to be accessed from
137  * multiple threads. Most refcounting functions such as g_object_ref()
138  * are also thread-safe.
139  */
140 public class Once
141 {
142 	
143 	/** the main Gtk struct */
144 	protected GOnce* gOnce;
145 	
146 	
147 	/** Get the main Gtk struct */
148 	public GOnce* getOnceStruct()
149 	{
150 		return gOnce;
151 	}
152 	
153 	
154 	/** the main Gtk struct as a void* */
155 	protected void* getStruct()
156 	{
157 		return cast(void*)gOnce;
158 	}
159 	
160 	/**
161 	 * Sets our main struct and passes it to the parent class
162 	 */
163 	public this (GOnce* gOnce)
164 	{
165 		this.gOnce = gOnce;
166 	}
167 	
168 	/**
169 	 */
170 	
171 	/**
172 	 * Function to be called when starting a critical initialization
173 	 * section. The argument location must point to a static
174 	 * 0-initialized variable that will be set to a value other than 0 at
175 	 * the end of the initialization section. In combination with
176 	 * g_once_init_leave() and the unique address value_location, it can
177 	 * be ensured that an initialization section will be executed only once
178 	 * during a program's life time, and that concurrent threads are
179 	 * blocked until initialization completed. To be used in constructs
180 	 * Since 2.14
181 	 * Params:
182 	 * location = location of a static initializable variable containing 0
183 	 * Returns: TRUE if the initialization section should be entered, FALSE and blocks otherwise
184 	 */
185 	public static int initEnter(void* location)
186 	{
187 		// gboolean g_once_init_enter (volatile void *location);
188 		return g_once_init_enter(location);
189 	}
190 	
191 	/**
192 	 * Counterpart to g_once_init_enter(). Expects a location of a static
193 	 * 0-initialized initialization variable, and an initialization value
194 	 * other than 0. Sets the variable to the initialization value, and
195 	 * releases concurrent threads blocking in g_once_init_enter() on this
196 	 * initialization variable.
197 	 * Since 2.14
198 	 * Params:
199 	 * location = location of a static initializable variable containing 0
200 	 * result = new non-0 value for *value_location
201 	 */
202 	public static void initLeave(void* location, gsize result)
203 	{
204 		// void g_once_init_leave (volatile void *location,  gsize result);
205 		g_once_init_leave(location, result);
206 	}
207 }