Rename LSUUID and checkLuaSkinInstance to variations of 'GCCanary'

LuaSkin/LuaSkin/Skin.h

@@ -50,9 +50,9 @@ extern int luaopen_luaskin_internal(lua_State* L) ; // entry vector to luaskin.m
 typedef int LSRefTable;
 
 #define LSUUIDLen 37
-typedef struct LSUUID {
+typedef struct LSGCCanary {
     char uuid[LSUUIDLen];
-} LSUUID;
+} LSGCCanary;
 
 // Define some bits for masking operations in the argument checker
 /*!
@@ -283,9 +283,9 @@ NSString *specMaskToString(int spec);
  */
 - (void)resetLuaState;
 
-- (BOOL)checkLuaSkinInstance:(LSUUID)lsUUID;
-- (LSUUID)getLuaSkinUUID;
-- (void)gcLuaSkinUUID:(LSUUID *)lsUUID;
+- (BOOL)checkGCCanary:(LSGCCanary)canary;
+- (LSGCCanary)createGCCanary;
+- (void)destroyGCCanary:(LSGCCanary *)canary;
 
 #pragma mark - Methods for calling into Lua from C
 

LuaSkin/LuaSkin/Skin.m

@@ -333,37 +333,37 @@ - (void)resetLuaState {
     [self createLuaState];
 }
 
-- (BOOL)checkLuaSkinInstance:(LSUUID)lsUUID {
+- (BOOL)checkGCCanary:(LSGCCanary)canary {
     if (!self.L) {
         [self logBreadcrumb:@"LuaSkin nil lua_State detected"];
         return NO;
     }
 
-    NSString *NSlsUUID = [NSString stringWithCString:lsUUID.uuid encoding:NSUTF8StringEncoding];
-    if (!NSlsUUID || ![self.uuid.UUIDString isEqualToString:NSlsUUID]) {
-        [self logKnownBug:[NSString stringWithFormat:@"LuaSkin UUID mismatch detected: %s from the callback, %@ from the current LuaSkin instance", lsUUID.uuid, self.uuid.UUIDString]];
+    NSString *NSlsCanary = [NSString stringWithCString:canary.uuid encoding:NSUTF8StringEncoding];
+    if (!NSlsCanary || ![self.uuid.UUIDString isEqualToString:NSlsCanary]) {
+        [self logWarn:@"LuaSkin has caught an attempt to operate on an object that has been garbage collected."];
         return NO;
     }
 
     return YES;
 }
 
-- (LSUUID)getLuaSkinUUID {
-    LSUUID lsUUID;
-    memset(lsUUID.uuid, 0, LSUUIDLen);
-    strncpy(lsUUID.uuid, "UNINITIALISED", 13);
+- (LSGCCanary)createGCCanary {
+    LSGCCanary canary;
+    memset(canary.uuid, 0, LSUUIDLen);
+    strncpy(canary.uuid, "UNINITIALISED", 13);
 
     const char *tmpUUID = [self.uuid.UUIDString cStringUsingEncoding:NSUTF8StringEncoding];
     if (tmpUUID) {
-        strncpy(lsUUID.uuid, tmpUUID, LSUUIDLen);
+        strncpy(canary.uuid, tmpUUID, LSUUIDLen);
     }
 
-    return lsUUID;
+    return canary;
 }
 
-- (void)gcLuaSkinUUID:(LSUUID *)lsUUID {
-    memset(lsUUID->uuid, 0, LSUUIDLen);
-    strncpy(lsUUID->uuid, "GC", 2);
+- (void)destroyGCCanary:(LSGCCanary *)canary {
+    memset(canary->uuid, 0, LSUUIDLen);
+    strncpy(canary->uuid, "GC", 2);
 }
 
 #pragma mark - Methods for calling into Lua from C

extensions/audiodevice/internal.m

@@ -19,7 +19,7 @@
     AudioDeviceID deviceId;
     int callback;
     BOOL watcherRunning;
-    LSUUID luaSkinUUID;
+    LSGCCanary lsCanary;
 } audioDeviceUserData;
 
 // Define a datatype for hs.audiodevice.datasource objects
@@ -82,7 +82,7 @@ OSStatus audiodevice_callback(AudioDeviceID deviceID, UInt32 numAddresses, const
 
         audioDeviceUserData *userData = (audioDeviceUserData *)clientData;
         LuaSkin *skin = [LuaSkin sharedWithState:NULL];
-        if (![skin checkLuaSkinInstance:userData->luaSkinUUID]) {
+        if (![skin checkGCCanary:userData->lsCanary]) {
             return;
         }
 
@@ -145,7 +145,7 @@ void new_device(lua_State* L, AudioDeviceID deviceId) {
     audioDevice->watcherRunning = NO;
 
     LuaSkin *skin = [LuaSkin sharedWithState:L];
-    audioDevice->luaSkinUUID = [skin getLuaSkinUUID];
+    audioDevice->lsCanary = [skin createGCCanary];
 
     luaL_getmetatable(L, USERDATA_TAG);
     lua_setmetatable(L, -2);
@@ -1711,7 +1711,7 @@ static int audiodevice_gc(lua_State* L) {
     audiodevice_watcherStop(L);
 
     audioDevice->callback = [skin luaUnref:refTable ref:audioDevice->callback];
-    [skin gcLuaSkinUUID:&(audioDevice->luaSkinUUID)];
+    [skin destroyGCCanary:&(audioDevice->lsCanary)];
 
     return 0;
 }

extensions/battery/watcher.m

@@ -21,15 +21,15 @@
     CFRunLoopSourceRef t;
     int fn;
     bool started;
-    LSUUID luaSkinUUID;
+    LSGCCanary lsCanary;
 } battery_watcher_t;
 
 static void callback(void *info) {
     LuaSkin *skin = [LuaSkin sharedWithState:NULL];
 
     battery_watcher_t* t = info;
 
-    if (![skin checkLuaSkinInstance:t->luaSkinUUID]) {
+    if (![skin checkGCCanary:t->lsCanary]) {
         return;
     }
 
@@ -69,7 +69,7 @@ static int battery_watcher_new(lua_State* L) {
 
     watcher->t = IOPSNotificationCreateRunLoopSource(callback, watcher);
     watcher->started = false;
-    watcher->luaSkinUUID = [skin getLuaSkinUUID];
+    watcher->lsCanary = [skin createGCCanary];
     return 1;
 }
 
@@ -123,7 +123,7 @@ static int battery_watcher_gc(lua_State* L) {
     lua_pushcfunction(L, battery_watcher_stop) ; lua_pushvalue(L,1); lua_call(L, 1, 1);
 
     watcher->fn = [skin luaUnref:refTable ref:watcher->fn];
-    [skin gcLuaSkinUUID:&(watcher->luaSkinUUID)];
+    [skin destroyGCCanary:&(watcher->lsCanary)];
     CFRunLoopSourceInvalidate(watcher->t);
     CFRelease(watcher->t);
     return 0;

extensions/caffeinate/watcher.m

@@ -70,7 +70,7 @@
     bool running;
     int fn;
     void* obj;
-    LSUUID luaSkinUUID;
+    LSGCCanary lsCanary;
 } caffeinatewatcher_t;
 
 typedef enum _event_t {
@@ -105,7 +105,7 @@ - (id)initWithObject:(caffeinatewatcher_t*)object {
 - (void)callback:(NSDictionary* __unused)dict withEvent:(event_t)event {
     if (self.object->fn != LUA_NOREF) {
         LuaSkin *skin = [LuaSkin sharedWithState:NULL];
-        [skin checkLuaSkinInstance:self.object->luaSkinUUID];
+        [skin checkGCCanary:self.object->lsCanary];
         lua_State *L = skin.L;
         _lua_stackguard_entry(L);
 
@@ -188,7 +188,7 @@ static int caffeinate_watcher_new(lua_State* L) {
     caffeinateWatcher->fn = [skin luaRef:refTable];
     caffeinateWatcher->running = NO;
     caffeinateWatcher->obj = (__bridge_retained void*) [[CaffeinateWatcher alloc] initWithObject:caffeinateWatcher];
-    caffeinateWatcher->luaSkinUUID = [skin getLuaSkinUUID];
+    caffeinateWatcher->lsCanary = [skin createGCCanary];
 
     luaL_getmetatable(L, USERDATA_TAG);
     lua_setmetatable(L, -2);
@@ -331,7 +331,7 @@ static int caffeinate_watcher_gc(lua_State* L) {
     caffeinate_watcher_stop(L);
 
     caffeinateWatcher->fn = [skin luaUnref:refTable ref:caffeinateWatcher->fn];
-    [skin gcLuaSkinUUID:&(caffeinateWatcher->luaSkinUUID)];
+    [skin destroyGCCanary:&(caffeinateWatcher->lsCanary)];
 
     CaffeinateWatcher* object = (__bridge_transfer CaffeinateWatcher*)caffeinateWatcher->obj;
     object = nil;

extensions/eventtap/internal.m

@@ -9,7 +9,7 @@
     CGEventMask mask;
     CFMachPortRef tap;
     CFRunLoopSourceRef runloopsrc;
-    LSUUID luaSkinUUID;
+    LSGCCanary lsCanary;
 } eventtap_t;
 
 CGEventRef eventtap_callback(CGEventTapProxy proxy, CGEventType type, CGEventRef event, void *refcon) {
@@ -19,7 +19,7 @@ CGEventRef eventtap_callback(CGEventTapProxy proxy, CGEventType type, CGEventRef
     eventtap_t* e = refcon;
 
     // Guard against this callback being delivered at a point where LuaSkin has been reset and our references wouldn't make sense anymore
-    if (![skin checkLuaSkinInstance:e->luaSkinUUID]) {
+    if (![skin checkGCCanary:e->lsCanary]) {
         return event; // Allow the event to pass through unmodified
     }
 
@@ -166,7 +166,7 @@ static int eventtap_new(lua_State* L) {
     memset(eventtap, 0, sizeof(eventtap_t));
 
     eventtap->tap = NULL ;
-    eventtap->luaSkinUUID = [skin getLuaSkinUUID];
+    eventtap->lsCanary = [skin createGCCanary];
 
     lua_pushnil(L);
     while (lua_next(L, 1) != 0) {
@@ -447,7 +447,7 @@ static int eventtap_gc(lua_State* L) {
     }
 
     eventtap->fn = [skin luaUnref:refTable ref:eventtap->fn];
-    [skin gcLuaSkinUUID:&(eventtap->luaSkinUUID)];
+    [skin destroyGCCanary:&(eventtap->lsCanary)];
 
     return 0;
 }

extensions/hotkey/internal.m

@@ -99,7 +99,7 @@ static int remove_hotkey(lua_State* L, int x) {
     int repeatfn;
     BOOL enabled;
     EventHotKeyRef carbonHotKey;
-    LSUUID luaSkinUUID;
+    LSGCCanary lsCanary;
 } hotkey_t;
 
 
@@ -135,7 +135,7 @@ static int hotkey_new(lua_State* L) {
     hotkey_t* hotkey = lua_newuserdata(L, sizeof(hotkey_t));
     memset(hotkey, 0, sizeof(hotkey_t));
 
-    hotkey->luaSkinUUID = [skin getLuaSkinUUID];
+    hotkey->lsCanary = [skin createGCCanary];
     hotkey->carbonHotKey = nil;
     hotkey->keycode = keycode;
 
@@ -308,7 +308,7 @@ static int hotkey_gc(lua_State* L) {
     hotkey->pressedfn = [skin luaUnref:refTable ref:hotkey->pressedfn];
     hotkey->releasedfn = [skin luaUnref:refTable ref:hotkey->releasedfn];
     hotkey->repeatfn = [skin luaUnref:refTable ref:hotkey->repeatfn];
-    [skin gcLuaSkinUUID:&(hotkey->luaSkinUUID)];
+    [skin destroyGCCanary:&(hotkey->lsCanary)];
 
     return 0;
 }
@@ -343,7 +343,7 @@ static OSStatus trigger_hotkey_callback(int eventUID, int eventKind, BOOL isRepe
     hotkey_t* hotkey = push_hotkey(L, eventUID);
     lua_pop(L, 1);
 
-    if (![skin checkLuaSkinInstance:hotkey->luaSkinUUID]) {
+    if (![skin checkGCCanary:hotkey->lsCanary]) {
         return noErr;
     }
 

extensions/network/configurationinternal.m

@@ -16,7 +16,7 @@
     int               callbackRef ;
     int               selfRef ;
     BOOL              watcherEnabled ;
-    LSUUID            luaSkinUUID;
+    LSGCCanary            lsCanary;
 } dynamicstore_t;
 
 static void doDynamicStoreCallback(__unused SCDynamicStoreRef store, CFArrayRef changedKeys, void *info) {
@@ -26,7 +26,7 @@ static void doDynamicStoreCallback(__unused SCDynamicStoreRef store, CFArrayRef
         if ((thePtr->callbackRef != LUA_NOREF) && (thePtr->selfRef != LUA_NOREF)) {
             LuaSkin   *skin = [LuaSkin sharedWithState:NULL] ;
             lua_State *L    = [skin L] ;
-            if (![skin checkLuaSkinInstance:thePtr->luaSkinUUID]) {
+            if (![skin checkGCCanary:thePtr->lsCanary]) {
                 return;
             }
             _lua_stackguard_entry(L);
@@ -69,7 +69,7 @@ static int newStoreObject(lua_State *L) {
         thePtr->callbackRef    = LUA_NOREF ;
         thePtr->selfRef        = LUA_NOREF ;
         thePtr->watcherEnabled = NO ;
-        thePtr->luaSkinUUID = [skin getLuaSkinUUID];
+        thePtr->lsCanary = [skin createGCCanary];
 
         luaL_getmetatable(L, USERDATA_TAG) ;
         lua_setmetatable(L, -2) ;
@@ -654,7 +654,7 @@ static int userdata_gc(lua_State* L) {
         }
     }
     thePtr->selfRef = [skin luaUnref:refTable ref:thePtr->selfRef] ;
-    [skin gcLuaSkinUUID:&(thePtr->luaSkinUUID)];
+    [skin destroyGCCanary:&(thePtr->lsCanary)];
 
     CFRelease(thePtr->storeObject) ;
     lua_pushnil(L) ;

extensions/network/hostinternal.m

@@ -19,7 +19,7 @@
     CFHostInfoType resolveType ;
     int            selfRef ;
     BOOL           running ;
-    LSUUID         luaSkinUUID;
+    LSGCCanary         lsCanary;
 } hshost_t;
 
 static int pushCFHost(lua_State *L, CFHostRef theHost, CFHostInfoType resolveType) {
@@ -38,7 +38,7 @@ static int pushCFHost(lua_State *L, CFHostRef theHost, CFHostInfoType resolveTyp
     thePtr->resolveType = resolveType ;
     thePtr->selfRef     = LUA_NOREF ;
     thePtr->running     = NO ;
-    thePtr->luaSkinUUID = [skin getLuaSkinUUID];
+    thePtr->lsCanary = [skin createGCCanary];
 
     luaL_getmetatable(L, USERDATA_TAG) ;
     lua_setmetatable(L, -2) ;
@@ -151,7 +151,7 @@ void handleCallback(__unused CFHostRef theHost, __unused CFHostInfoType typeInfo
         LuaSkin *skin = [LuaSkin sharedWithState:NULL] ;
         if (theRef->callbackRef != LUA_NOREF) {
             lua_State *L = [skin L] ;
-            if (![skin checkLuaSkinInstance:theRef->luaSkinUUID]) {
+            if (![skin checkGCCanary:theRef->lsCanary]) {
                 return;
             }
             _lua_stackguard_entry(L);
@@ -421,7 +421,7 @@ static int userdata_gc(lua_State* L) {
     theRef->callbackRef = [skin luaUnref:refTable ref:theRef->callbackRef] ;
     // in case __gc forced by reload
     theRef->selfRef = [skin luaUnref:refTable ref:theRef->selfRef] ;
-    [skin gcLuaSkinUUID:&(theRef->luaSkinUUID)];
+    [skin destroyGCCanary:&(theRef->lsCanary)];
 
     lua_pushcfunction(L, cancelResolution) ;
     lua_pushvalue(L, 1) ;

extensions/network/reachabilityinternal.m

@@ -19,7 +19,7 @@
     int                      callbackRef ;
     int                      selfRef ;
     BOOL                     watcherEnabled ;
-    LSUUID                   luaSkinUUID;
+    LSGCCanary                   lsCanary;
 } reachability_t;
 
 static int pushSCNetworkReachability(lua_State *L, SCNetworkReachabilityRef theRef) {
@@ -31,7 +31,7 @@ static int pushSCNetworkReachability(lua_State *L, SCNetworkReachabilityRef theR
     thePtr->callbackRef     = LUA_NOREF ;
     thePtr->selfRef         = LUA_NOREF ;
     thePtr->watcherEnabled  = NO ;
-    thePtr->luaSkinUUID     = [skin getLuaSkinUUID];
+    thePtr->lsCanary     = [skin createGCCanary];
 
     luaL_getmetatable(L, USERDATA_TAG) ;
     lua_setmetatable(L, -2) ;
@@ -44,7 +44,7 @@ static void doReachabilityCallback(__unused SCNetworkReachabilityRef target, SCN
         if ((theRef->callbackRef != LUA_NOREF) && (theRef->selfRef != LUA_NOREF)) {
             LuaSkin   *skin = [LuaSkin sharedWithState:NULL] ;
             lua_State *L    = [skin L] ;
-            if (![skin checkLuaSkinInstance:theRef->luaSkinUUID]) {
+            if (![skin checkGCCanary:theRef->lsCanary]) {
                 return;
             }
             _lua_stackguard_entry(L);
@@ -386,7 +386,7 @@ static int userdata_gc(lua_State* L) {
         SCNetworkReachabilitySetDispatchQueue(theRef->reachabilityObj, NULL);
     }
     theRef->selfRef = [skin luaUnref:refTable ref:theRef->selfRef] ;
-    [skin gcLuaSkinUUID:&(theRef->luaSkinUUID)];
+    [skin destroyGCCanary:&(theRef->lsCanary)];
 
     CFRelease(theRef->reachabilityObj) ;
     lua_pushnil(L) ;

extensions/pathwatcher/internal.m

@@ -12,7 +12,7 @@
     int closureref;
     FSEventStreamRef stream;
     bool started;
-    LSUUID luaSkinUUID;
+    LSGCCanary lsCanary;
 } watcher_path_t;
 
 #if MAC_OS_X_VERSION_MAX_ALLOWED < 1090
@@ -55,7 +55,7 @@ void event_callback(ConstFSEventStreamRef __unused streamRef, void *clientCallBa
     LuaSkin *skin = [LuaSkin sharedWithState:NULL];
     lua_State *L = skin.L;
 
-    if (![skin checkLuaSkinInstance:pw->luaSkinUUID]) {
+    if (![skin checkGCCanary:pw->lsCanary]) {
         return;
     }
 
@@ -125,7 +125,7 @@ static int watcher_path_new(lua_State* L) {
 
     watcher_path_t* watcher_path = lua_newuserdata(L, sizeof(watcher_path_t));
     watcher_path->started = NO;
-    watcher_path->luaSkinUUID = [skin getLuaSkinUUID];
+    watcher_path->lsCanary = [skin createGCCanary];
 
     luaL_getmetatable(L, USERDATA_TAG);
     lua_setmetatable(L, -2);
@@ -205,7 +205,7 @@ static int watcher_path_gc(lua_State* L) {
     FSEventStreamRelease(watcher_path->stream);
 
     watcher_path->closureref = [skin luaUnref:refTable ref:watcher_path->closureref];
-    [skin gcLuaSkinUUID:&(watcher_path->luaSkinUUID)];
+    [skin destroyGCCanary:&(watcher_path->lsCanary)];
 
     return 0;
 }