Atlas - SDL_quit.c
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[FILE BEGIN]
1/*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2025 Sam Lantinga <[email protected]>
4
5  This software is provided 'as-is', without any express or implied
6  warranty.  In no event will the authors be held liable for any damages
7  arising from the use of this software.
8
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12
13  1. The origin of this software must not be misrepresented; you must not
14     claim that you wrote the original software. If you use this software
15     in a product, an acknowledgment in the product documentation would be
16     appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18     misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20*/
21#include "SDL_internal.h"
22
23// General quit handling code for SDL
24
25#ifdef HAVE_SIGNAL_H
26#include <signal.h>
27#endif
28
29#include "SDL_events_c.h"
30
31#if defined(HAVE_SIGNAL_H) || defined(HAVE_SIGACTION)
32#define HAVE_SIGNAL_SUPPORT 1
33#endif
34
35#ifdef HAVE_SIGNAL_SUPPORT
36static bool disable_signals = false;
37static bool send_quit_pending = false;
38
39#ifdef SDL_BACKGROUNDING_SIGNAL
40static bool send_backgrounding_pending = false;
41#endif
42
43#ifdef SDL_FOREGROUNDING_SIGNAL
44static bool send_foregrounding_pending = false;
45#endif
46
47static void SDL_HandleSIG(int sig)
48{
49#ifndef HAVE_SIGACTION
50    // Reset the signal handler if it was installed with signal()
51    (void)signal(sig, SDL_HandleSIG);
52#endif
53
54    // Send a quit event next time the event loop pumps.
55    // We can't send it in signal handler; SDL_malloc() might be interrupted!
56    if ((sig == SIGINT) || (sig == SIGTERM)) {
57        send_quit_pending = true;
58    }
59
60#ifdef SDL_BACKGROUNDING_SIGNAL
61    else if (sig == SDL_BACKGROUNDING_SIGNAL) {
62        send_backgrounding_pending = true;
63    }
64#endif
65
66#ifdef SDL_FOREGROUNDING_SIGNAL
67    else if (sig == SDL_FOREGROUNDING_SIGNAL) {
68        send_foregrounding_pending = true;
69    }
70#endif
71}
72
73static void SDL_EventSignal_Init(const int sig)
74{
75#ifdef HAVE_SIGACTION
76    struct sigaction action;
77
78    sigaction(sig, NULL, &action);
79#ifdef HAVE_SA_SIGACTION
80    if (action.sa_handler == SIG_DFL && (void (*)(int))action.sa_sigaction == SIG_DFL) {
81#else
82    if (action.sa_handler == SIG_DFL) {
83#endif
84        action.sa_handler = SDL_HandleSIG;
85        sigaction(sig, &action, NULL);
86    }
87#elif defined(HAVE_SIGNAL_H)
88    void (*ohandler)(int) = signal(sig, SDL_HandleSIG);
89    if (ohandler != SIG_DFL) {
90        signal(sig, ohandler);
91    }
92#endif
93}
94
95static void SDL_EventSignal_Quit(const int sig)
96{
97#ifdef HAVE_SIGACTION
98    struct sigaction action;
99    sigaction(sig, NULL, &action);
100    if (action.sa_handler == SDL_HandleSIG) {
101        action.sa_handler = SIG_DFL;
102        sigaction(sig, &action, NULL);
103    }
104#elif defined(HAVE_SIGNAL_H)
105    void (*ohandler)(int) = signal(sig, SIG_DFL);
106    if (ohandler != SDL_HandleSIG) {
107        signal(sig, ohandler);
108    }
109#endif // HAVE_SIGNAL_H
110}
111
112// Public functions
113static bool SDL_QuitInit_Internal(void)
114{
115    // Both SIGINT and SIGTERM are translated into quit interrupts
116    // and SDL can be built to simulate iOS/Android semantics with arbitrary signals.
117    SDL_EventSignal_Init(SIGINT);
118    SDL_EventSignal_Init(SIGTERM);
119
120#ifdef SDL_BACKGROUNDING_SIGNAL
121    SDL_EventSignal_Init(SDL_BACKGROUNDING_SIGNAL);
122#endif
123
124#ifdef SDL_FOREGROUNDING_SIGNAL
125    SDL_EventSignal_Init(SDL_FOREGROUNDING_SIGNAL);
126#endif
127
128    // That's it!
129    return true;
130}
131
132static void SDL_QuitQuit_Internal(void)
133{
134    SDL_EventSignal_Quit(SIGINT);
135    SDL_EventSignal_Quit(SIGTERM);
136
137#ifdef SDL_BACKGROUNDING_SIGNAL
138    SDL_EventSignal_Quit(SDL_BACKGROUNDING_SIGNAL);
139#endif
140
141#ifdef SDL_FOREGROUNDING_SIGNAL
142    SDL_EventSignal_Quit(SDL_FOREGROUNDING_SIGNAL);
143#endif
144}
145#endif
146
147bool SDL_InitQuit(void)
148{
149#ifdef HAVE_SIGNAL_SUPPORT
150    if (!SDL_GetHintBoolean(SDL_HINT_NO_SIGNAL_HANDLERS, false)) {
151        return SDL_QuitInit_Internal();
152    }
153#endif
154    return true;
155}
156
157void SDL_QuitQuit(void)
158{
159#ifdef HAVE_SIGNAL_SUPPORT
160    if (!disable_signals) {
161        SDL_QuitQuit_Internal();
162    }
163#endif
164}
165
166void SDL_SendPendingSignalEvents(void)
167{
168#ifdef HAVE_SIGNAL_SUPPORT
169    if (send_quit_pending) {
170        SDL_SendQuit();
171        SDL_assert(!send_quit_pending);
172    }
173
174#ifdef SDL_BACKGROUNDING_SIGNAL
175    if (send_backgrounding_pending) {
176        send_backgrounding_pending = false;
177        SDL_OnApplicationWillEnterBackground();
178    }
179#endif
180
181#ifdef SDL_FOREGROUNDING_SIGNAL
182    if (send_foregrounding_pending) {
183        send_foregrounding_pending = false;
184        SDL_OnApplicationDidEnterForeground();
185    }
186#endif
187#endif
188}
189
190void SDL_SendQuit(void)
191{
192#ifdef HAVE_SIGNAL_SUPPORT
193    send_quit_pending = false;
194#endif
195    SDL_SendAppEvent(SDL_EVENT_QUIT);
196}
197
[FILE END]
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