diff --git a/doric-iOS/Devkit/Classes/DoricDev.m b/doric-iOS/Devkit/Classes/DoricDev.m
index 9c4e5f07..f39d98ec 100644
--- a/doric-iOS/Devkit/Classes/DoricDev.m
+++ b/doric-iOS/Devkit/Classes/DoricDev.m
@@ -111,8 +111,7 @@ - (void)onConnectExceptionEvent {
 - (void)onStartDebugEvent:(NSNotification *)notification {
     NSString *contextId = notification.object;
     ShowToast(contextId, DoricGravityBottom);
-    for (NSValue *value in  [[DoricContextManager instance] aliveContexts]) {
-        DoricContext *context = value.nonretainedObjectValue;
+    for (DoricContext *context in  [[DoricContextManager instance] aliveContexts]) {
         BOOL result = [context.contextId compare:contextId] == NSOrderedSame;
         if (result) {
             _context = context;
diff --git a/doric-iOS/Devkit/Classes/DoricDevViewController.m b/doric-iOS/Devkit/Classes/DoricDevViewController.m
index 91fde21b..fe877fd1 100644
--- a/doric-iOS/Devkit/Classes/DoricDevViewController.m
+++ b/doric-iOS/Devkit/Classes/DoricDevViewController.m
@@ -58,17 +58,18 @@ - (void)viewDidLoad {
         [self.navigationController pushViewController:[QRScanViewController new] animated:NO];
     }
 }
+
 - (void)onClose {
     [[DoricDev instance] closeDevMode];
     [self.navigationController popViewControllerAnimated:YES];
 }
+
 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
     return [DoricContextManager.instance aliveContexts].count;
 }
 
 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
-    NSValue *value = [DoricContextManager.instance aliveContexts][(NSUInteger) indexPath.row];
-    DoricContext *context = value.nonretainedObjectValue;
+    DoricContext *context = [DoricContextManager.instance aliveContexts][(NSUInteger) indexPath.row];
     NSString *path = context.source;
     UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];
     if (cell == nil) {
@@ -84,8 +85,7 @@ - (BOOL)isSimulator {
 }
 
 - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
-    NSValue *value = [DoricContextManager.instance aliveContexts][(NSUInteger) indexPath.row];
-    DoricContext *context = value.nonretainedObjectValue;
+    DoricContext *context = [DoricContextManager.instance aliveContexts][(NSUInteger) indexPath.row];
     [[NSNotificationCenter defaultCenter] postNotificationName:@"StartDebugEvent" object:context.contextId];
     NSDictionary *jsonDic = @{
             @"cmd": @"DEBUG",
diff --git a/doric-iOS/Devkit/Classes/DoricWSClient.m b/doric-iOS/Devkit/Classes/DoricWSClient.m
index 9b74b5a8..47702d1b 100644
--- a/doric-iOS/Devkit/Classes/DoricWSClient.m
+++ b/doric-iOS/Devkit/Classes/DoricWSClient.m
@@ -64,8 +64,7 @@ - (void)webSocket:(SRWebSocket *)webSocket didReceiveMessage:(id)message {
     } else if ([cmd compare:@"RELOAD"] == NSOrderedSame) {
         NSString *source = [[dic valueForKey:@"source"] mutableCopy];
         NSString *script = [dic valueForKey:@"script"];
-        for (NSValue *value in  [[DoricContextManager instance] aliveContexts]) {
-            DoricContext *context = value.nonretainedObjectValue;
+        for (DoricContext *context in  [[DoricContextManager instance] aliveContexts]) {
             if ([source containsString:context.source] || [context.source isEqualToString:@"__dev__"]) {
                 [context reload:script];
             }
diff --git a/doric-iOS/Pod/Classes/DoricContextManager.h b/doric-iOS/Pod/Classes/DoricContextManager.h
index d8927542..7b6faf05 100644
--- a/doric-iOS/Pod/Classes/DoricContextManager.h
+++ b/doric-iOS/Pod/Classes/DoricContextManager.h
@@ -34,7 +34,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (DoricContext *)getContext:(NSString *)contextId;
 
-- (NSArray *)aliveContexts;
+- (NSArray <DoricContext *> *)aliveContexts;
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/doric-iOS/Pod/Classes/DoricContextManager.m b/doric-iOS/Pod/Classes/DoricContextManager.m
index fdf2d39f..1a23d2ad 100644
--- a/doric-iOS/Pod/Classes/DoricContextManager.m
+++ b/doric-iOS/Pod/Classes/DoricContextManager.m
@@ -25,7 +25,7 @@
 @interface DoricContextManager ()
 
 @property(nonatomic) NSInteger counter;
-@property(nonatomic, strong) NSMutableDictionary <NSString *, NSValue *> *doricContextMap;
+@property(nonatomic, strong) NSMapTable <NSString *, DoricContext *> *contextMapTable;
 @property(nonatomic, strong) dispatch_queue_t mapQueue;
 @end
 
@@ -33,9 +33,11 @@ @implementation DoricContextManager
 
 - (instancetype)init {
     if (self = [super init]) {
-        _doricContextMap = [[NSMutableDictionary alloc] init];
         _counter = 0;
         _mapQueue = dispatch_queue_create("doric.contextmap", DISPATCH_QUEUE_SERIAL);
+        _contextMapTable = [[NSMapTable alloc] initWithKeyOptions:NSPointerFunctionsCopyIn
+                                                     valueOptions:NSPointerFunctionsWeakMemory
+                                                         capacity:0];
     }
     return self;
 }
@@ -52,8 +54,7 @@ + (instancetype)instance {
 - (void)createContext:(DoricContext *)context script:(NSString *)script source:(NSString *)source {
     context.contextId = [NSString stringWithFormat:@"%ld", (long) ++self.counter];
     dispatch_sync(self.mapQueue, ^() {
-        NSValue *value = [NSValue valueWithNonretainedObject:context];
-        self.doricContextMap[context.contextId] = value;
+        [self.contextMapTable setObject:context forKey:context.contextId];
     });
     [context.driver createContext:context.contextId script:script source:source];
 }
@@ -61,8 +62,7 @@ - (void)createContext:(DoricContext *)context script:(NSString *)script source:(
 - (DoricContext *)getContext:(NSString *)contextId {
     __block DoricContext *context;
     dispatch_sync(self.mapQueue, ^{
-        NSValue *value = self.doricContextMap[contextId];
-        context = value.nonretainedObjectValue;
+        context = [self.contextMapTable objectForKey:contextId];
     });
     return context;
 }
@@ -70,12 +70,18 @@ - (DoricContext *)getContext:(NSString *)contextId {
 - (void)destroyContext:(DoricContext *)context {
     NSString *contextId = context.contextId;
     dispatch_sync(self.mapQueue, ^() {
-        [self.doricContextMap removeObjectForKey:contextId];
+        [self.contextMapTable removeObjectForKey:contextId];
     });
 }
 
-- (NSArray *)aliveContexts {
-    return [self.doricContextMap allValues];
+- (NSArray <DoricContext *> *)aliveContexts {
+    NSEnumerator *enumerator = [self.contextMapTable objectEnumerator];
+    NSMutableArray *ret = [NSMutableArray new];
+    DoricContext *context;
+    while ((context = [enumerator nextObject])) {
+        [ret addObject:context];
+    }
+    return ret;
 }
 
 @end
diff --git a/doric-iOS/Pod/Classes/Extension/DoricBridgeExtension.m b/doric-iOS/Pod/Classes/Extension/DoricBridgeExtension.m
index 86369d01..4c996108 100644
--- a/doric-iOS/Pod/Classes/Extension/DoricBridgeExtension.m
+++ b/doric-iOS/Pod/Classes/Extension/DoricBridgeExtension.m
@@ -34,7 +34,7 @@ @implementation DoricBridgeExtension
 
 - (id)callNativeWithContextId:(NSString *)contextId module:(NSString *)module method:(NSString *)method callbackId:(NSString *)callbackId argument:(id)argument {
     __strong DoricContext *context = [[DoricContextManager instance] getContext:contextId];
-    if (context.destroyed) {
+    if (!context || context.destroyed) {
         return nil;
     }
     Class pluginClass = [self.registry acquireNativePlugin:module];