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Fixed potentially calling a callback after it has been removed (and userdata possibly deleted)

This commit is contained in:
Sam Lantinga 2017-10-10 19:44:33 -07:00
parent 903ff6414e
commit eb9e6938cc
1 changed files with 40 additions and 26 deletions
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60
src/events/SDL_events.c
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@ -41,12 +41,15 @@
typedef struct SDL_EventWatcher { typedef struct SDL_EventWatcher {
SDL_EventFilter callback; SDL_EventFilter callback;
void *userdata; void *userdata;
SDL_bool removed;
} SDL_EventWatcher; } SDL_EventWatcher;
static SDL_mutex *SDL_event_watchers_lock; static SDL_mutex *SDL_event_watchers_lock;
static SDL_EventWatcher SDL_EventOK; static SDL_EventWatcher SDL_EventOK;
static SDL_EventWatcher *SDL_event_watchers = NULL; static SDL_EventWatcher *SDL_event_watchers = NULL;
static int SDL_event_watchers_count = 0; static int SDL_event_watchers_count = 0;
static SDL_bool SDL_event_watchers_dispatching = SDL_FALSE;
static SDL_bool SDL_event_watchers_removed = SDL_FALSE;
typedef struct { typedef struct {
Uint32 bits[8]; Uint32 bits[8];
@ -370,7 +373,7 @@ SDL_StopEventLoop(void)
SDL_DestroyMutex(SDL_event_watchers_lock); SDL_DestroyMutex(SDL_event_watchers_lock);
SDL_event_watchers_lock = NULL; SDL_event_watchers_lock = NULL;
} }
if (SDL_event_watchers_count > 0) { if (SDL_event_watchers) {
SDL_free(SDL_event_watchers); SDL_free(SDL_event_watchers);
SDL_event_watchers = NULL; SDL_event_watchers = NULL;
SDL_event_watchers_count = 0; SDL_event_watchers_count = 0;
@ -703,37 +706,42 @@ SDL_PushEvent(SDL_Event * event)
event->common.timestamp = SDL_GetTicks(); event->common.timestamp = SDL_GetTicks();
if (SDL_EventOK.callback || SDL_event_watchers_count != 0) { if (SDL_EventOK.callback || SDL_event_watchers_count != 0) {
SDL_EventWatcher event_ok;
SDL_EventWatcher *event_watchers = NULL;
int i, event_watchers_count = 0;
if (!SDL_event_watchers_lock || SDL_LockMutex(SDL_event_watchers_lock) == 0) { if (!SDL_event_watchers_lock || SDL_LockMutex(SDL_event_watchers_lock) == 0) {
event_ok = SDL_EventOK; if (SDL_EventOK.callback && !SDL_EventOK.callback(SDL_EventOK.userdata, event)) {
if (SDL_event_watchers_lock) {
SDL_UnlockMutex(SDL_event_watchers_lock);
}
return 0;
}
if (SDL_event_watchers_count > 0) { if (SDL_event_watchers_count > 0) {
event_watchers = SDL_stack_alloc(SDL_EventWatcher, SDL_event_watchers_count); /* Make sure we only dispatch the current watcher list */
if (event_watchers) { int i, event_watchers_count = SDL_event_watchers_count;
SDL_memcpy(event_watchers, SDL_event_watchers, SDL_event_watchers_count * sizeof(*event_watchers));
event_watchers_count = SDL_event_watchers_count; SDL_event_watchers_dispatching = SDL_TRUE;
for (i = 0; i < event_watchers_count; ++i) {
if (!SDL_event_watchers[i].removed) {
SDL_event_watchers[i].callback(SDL_event_watchers[i].userdata, event);
}
}
SDL_event_watchers_dispatching = SDL_FALSE;
if (SDL_event_watchers_removed) {
for (i = SDL_event_watchers_count; i--; ) {
if (SDL_event_watchers[i].removed) {
--SDL_event_watchers_count;
if (i < SDL_event_watchers_count) {
SDL_memcpy(&SDL_event_watchers[i], &SDL_event_watchers[i+1], (SDL_event_watchers_count - i) * sizeof(SDL_event_watchers[i]));
}
}
}
SDL_event_watchers_removed = SDL_FALSE;
} }
} }
if (SDL_event_watchers_lock) { if (SDL_event_watchers_lock) {
SDL_UnlockMutex(SDL_event_watchers_lock); SDL_UnlockMutex(SDL_event_watchers_lock);
} }
} else {
event_ok = SDL_EventOK;
}
if (event_ok.callback && !event_ok.callback(event_ok.userdata, event)) {
return 0;
}
if (event_watchers_count > 0) {
for (i = 0; i < event_watchers_count; ++i) {
event_watchers[i].callback(event_watchers[i].userdata, event);
}
SDL_stack_free(event_watchers);
} }
} }
@ -799,6 +807,7 @@ SDL_AddEventWatch(SDL_EventFilter filter, void *userdata)
watcher = &SDL_event_watchers[SDL_event_watchers_count]; watcher = &SDL_event_watchers[SDL_event_watchers_count];
watcher->callback = filter; watcher->callback = filter;
watcher->userdata = userdata; watcher->userdata = userdata;
watcher->removed = SDL_FALSE;
++SDL_event_watchers_count; ++SDL_event_watchers_count;
} }
@ -816,10 +825,15 @@ SDL_DelEventWatch(SDL_EventFilter filter, void *userdata)
for (i = 0; i < SDL_event_watchers_count; ++i) { for (i = 0; i < SDL_event_watchers_count; ++i) {
if (SDL_event_watchers[i].callback == filter && SDL_event_watchers[i].userdata == userdata) { if (SDL_event_watchers[i].callback == filter && SDL_event_watchers[i].userdata == userdata) {
if (SDL_event_watchers_dispatching) {
SDL_event_watchers[i].removed = SDL_TRUE;
SDL_event_watchers_removed = SDL_TRUE;
} else {
--SDL_event_watchers_count; --SDL_event_watchers_count;
if (i < SDL_event_watchers_count) { if (i < SDL_event_watchers_count) {
SDL_memcpy(&SDL_event_watchers[i], &SDL_event_watchers[i+1], (SDL_event_watchers_count - i) * sizeof(SDL_event_watchers[i])); SDL_memcpy(&SDL_event_watchers[i], &SDL_event_watchers[i+1], (SDL_event_watchers_count - i) * sizeof(SDL_event_watchers[i]));
} }
}
break; break;
} }
} }