[ios, macos] 7955 fix MGLMapView leaks MGLReachability objects (and threads) (#7956)

* fix MGLMapView leaks MGLReachability objects (and threads)

* fix leak of MGLReachability objects and threads in MGLMapView.commonInit

* update changelogs

4 files changed, 19 insertions, 6 deletions

diff --git a/platform/ios/CHANGELOG.md b/platform/ios/CHANGELOG.md
index 9f0bc3af1c..e654f1d720 100644
--- a/platform/ios/CHANGELOG.md
+++ b/platform/ios/CHANGELOG.md
@@ -102,6 +102,7 @@ Mapbox welcomes participation and contributions from everyone. Please read [CONT
 
 ### Networking and offline maps
 
+* Fixed a leak of MGLReachability objects and threads in MGLMapView. ([#7956](https://github.com/mapbox/mapbox-gl-native/pull/7956))
 * Fixed an issue preventing an MGLMapView from loading tiles while an offline pack is downloading. ([#6446](https://github.com/mapbox/mapbox-gl-native/pull/6446))
 * Fixed a crash that could occur when the device is disconnected while downloading an offline pack. ([#6293](https://github.com/mapbox/mapbox-gl-native/pull/6293))
 * Fixed a crash that occurred when encountering a rate-limit error in response to a network request. ([#6223](https://github.com/mapbox/mapbox-gl-native/pull/6223))
diff --git a/platform/ios/src/MGLMapView.mm b/platform/ios/src/MGLMapView.mm
index 35ad583081..0c438d5606 100644
--- a/platform/ios/src/MGLMapView.mm
+++ b/platform/ios/src/MGLMapView.mm
@@ -314,6 +314,8 @@ public:
     MGLCompassDirectionFormatter *_accessibilityCompassFormatter;
 
     NS_ARRAY_OF(MGLAttributionInfo *) *_attributionInfos;
+
+    MGLReachability *_reachability;
 }
 
 #pragma mark - Setup & Teardown -
@@ -440,12 +442,12 @@ public:
                                                  name:kMGLReachabilityChangedNotification
                                                object:nil];
 
-    MGLReachability* reachability = [MGLReachability reachabilityForInternetConnection];
-    if ([reachability isReachable])
+    _reachability = [MGLReachability reachabilityForInternetConnection];
+    if ([_reachability isReachable])
     {
         _isWaitingForRedundantReachableNotification = YES;
     }
-    [reachability startNotifier];
+    [_reachability startNotifier];
 
     // Set up annotation management and selection state.
     _annotationImagesByIdentifier = [NSMutableDictionary dictionary];
@@ -664,6 +666,8 @@ public:
 
 - (void)dealloc
 {
+    [_reachability stopNotifier];
+
     [[UIDevice currentDevice] endGeneratingDeviceOrientationNotifications];
     [[NSNotificationCenter defaultCenter] removeObserver:self];
     [_attributionButton removeObserver:self forKeyPath:@"hidden"];
diff --git a/platform/macos/CHANGELOG.md b/platform/macos/CHANGELOG.md
index 0e68a50e21..638b249cba 100644
--- a/platform/macos/CHANGELOG.md
+++ b/platform/macos/CHANGELOG.md
@@ -84,6 +84,7 @@ This version of the Mapbox macOS SDK corresponds to version 3.4.0 of the Mapbox
 
 ### Networking and offline maps
 
+* Fixed a leak of MGLReachability objects and threads in MGLMapView. ([#7956](https://github.com/mapbox/mapbox-gl-native/pull/7956))
 * Fixed an issue preventing an MGLMapView from loading tiles while an offline pack is downloading. ([#6446](https://github.com/mapbox/mapbox-gl-native/pull/6446))
 * Fixed an issue causing an MGLOfflinePack’s progress to continue to update after calling `-suspend`. ([#6186](https://github.com/mapbox/mapbox-gl-native/pull/6186))
 * Fixed an issue preventing cached annotation images from displaying while the device is offline. ([#6358](https://github.com/mapbox/mapbox-gl-native/pull/6358))
diff --git a/platform/macos/src/MGLMapView.mm b/platform/macos/src/MGLMapView.mm
index 86d74d768d..d687a19aed 100644
--- a/platform/macos/src/MGLMapView.mm
+++ b/platform/macos/src/MGLMapView.mm
@@ -193,6 +193,9 @@ public:
 
     /// True if the view is currently printing itself.
     BOOL _isPrinting;
+
+    /// reachability instance
+    MGLReachability *_reachability;
 }
 
 #pragma mark Lifecycle
@@ -273,11 +276,11 @@ public:
     self.layer = _isTargetingInterfaceBuilder ? [CALayer layer] : [MGLOpenGLLayer layer];
 
     // Notify map object when network reachability status changes.
-    MGLReachability *reachability = [MGLReachability reachabilityForInternetConnection];
-    reachability.reachableBlock = ^(MGLReachability *) {
+    _reachability = [MGLReachability reachabilityForInternetConnection];
+    _reachability.reachableBlock = ^(MGLReachability *) {
         mbgl::NetworkStatus::Reachable();
     };
-    [reachability startNotifier];
+    [_reachability startNotifier];
 
     // Install ornaments and gesture recognizers.
     [self installZoomControls];
@@ -497,6 +500,10 @@ public:
 }
 
 - (void)dealloc {
+
+    [_reachability stopNotifier];
+
+
     [self.window removeObserver:self forKeyPath:@"contentLayoutRect"];
     [self.window removeObserver:self forKeyPath:@"titlebarAppearsTransparent"];