Commit eb9e6938cc83a21d932d0ae9258061287bccecee
2017-10-10T19:44:33
Fixed potentially calling a callback after it has been removed (and userdata possibly deleted)
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diff --git a/src/events/SDL_events.c b/src/events/SDL_events.c
index 9b6fff8..27444d7 100644
--- a/src/events/SDL_events.c
+++ b/src/events/SDL_events.c
@@ -41,12 +41,15 @@
typedef struct SDL_EventWatcher {
SDL_EventFilter callback;
void *userdata;
+ SDL_bool removed;
} SDL_EventWatcher;
static SDL_mutex *SDL_event_watchers_lock;
static SDL_EventWatcher SDL_EventOK;
static SDL_EventWatcher *SDL_event_watchers = NULL;
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 {
Uint32 bits[8];
@@ -370,7 +373,7 @@ SDL_StopEventLoop(void)
SDL_DestroyMutex(SDL_event_watchers_lock);
SDL_event_watchers_lock = NULL;
}
- if (SDL_event_watchers_count > 0) {
+ if (SDL_event_watchers) {
SDL_free(SDL_event_watchers);
SDL_event_watchers = NULL;
SDL_event_watchers_count = 0;
@@ -703,37 +706,42 @@ SDL_PushEvent(SDL_Event * event)
event->common.timestamp = SDL_GetTicks();
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) {
- 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) {
- event_watchers = SDL_stack_alloc(SDL_EventWatcher, SDL_event_watchers_count);
- if (event_watchers) {
- SDL_memcpy(event_watchers, SDL_event_watchers, SDL_event_watchers_count * sizeof(*event_watchers));
- event_watchers_count = SDL_event_watchers_count;
+ /* Make sure we only dispatch the current watcher list */
+ int i, 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) {
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->callback = filter;
watcher->userdata = userdata;
+ watcher->removed = SDL_FALSE;
++SDL_event_watchers_count;
}
@@ -816,9 +825,14 @@ SDL_DelEventWatch(SDL_EventFilter filter, void *userdata)
for (i = 0; i < SDL_event_watchers_count; ++i) {
if (SDL_event_watchers[i].callback == filter && SDL_event_watchers[i].userdata == userdata) {
- --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]));
+ if (SDL_event_watchers_dispatching) {
+ SDL_event_watchers[i].removed = SDL_TRUE;
+ SDL_event_watchers_removed = SDL_TRUE;
+ } else {
+ --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]));
+ }
}
break;
}