sync: Upgrade from SCNetworkReachability -> nw_path_monitor

Source/santasyncservice/BUILD

@@ -22,7 +22,7 @@ objc_library(
     name = "FCM_lib",
     srcs = ["SNTSyncFCM.m"],
     hdrs = ["SNTSyncFCM.h"],
-    sdk_frameworks = ["SystemConfiguration"],
+    sdk_frameworks = ["Network"],
     deps = [
         "@MOLAuthenticatingURLSession",
     ],
@@ -55,6 +55,7 @@ objc_library(
     ],
     hdrs = ["SNTSyncManager.h"],
     sdk_dylibs = ["libz"],
+    sdk_frameworks = ["Network"],
     deps = [
         ":FCM_lib",
         ":broadcaster_lib",

Source/santasyncservice/SNTSyncFCM.m

@@ -14,7 +14,7 @@
 
 #import "Source/santasyncservice/SNTSyncFCM.h"
 
-#import <SystemConfiguration/SystemConfiguration.h>
+#import <Network/Network.h>
 
 #import <MOLAuthenticatingURLSession/MOLAuthenticatingURLSession.h>
 
@@ -80,7 +80,7 @@ @interface SNTSyncFCM () {
 @property(copy, nonatomic) SNTSyncFCMMessageHandler messageHandler;
 
 /**  Is used throughout the class to reconnect to FCM after a connection loss. */
-@property SCNetworkReachabilityRef reachability;
+@property nw_path_monitor_t pathMonitor;
 
 /**  FCM client identities. */
 @property(nonatomic, readonly) NSString *project;
@@ -97,21 +97,6 @@ - (void)reachabilityRestored;
 
 @end
 
-#pragma mark SCNetworkReachabilityCallBack
-
-/**  Called when the network state changes. */
-static void reachabilityHandler(SCNetworkReachabilityRef target, SCNetworkReachabilityFlags flags,
-                                void *info) {
-  dispatch_async(dispatch_get_main_queue(), ^{
-    if (flags & kSCNetworkReachabilityFlagsReachable) {
-      SNTSyncFCM *FCMClient = (__bridge SNTSyncFCM *)info;
-      SEL s = @selector(reachabilityRestored);
-      [NSObject cancelPreviousPerformRequestsWithTarget:FCMClient selector:s object:nil];
-      [FCMClient performSelector:s withObject:nil afterDelay:1];
-    }
-  });
-}
-
 @implementation SNTSyncFCM
 
 #pragma mark init/dealloc methods
@@ -184,11 +169,6 @@ - (instancetype)initWithProject:(NSString *)project
                 messageHandler:messageHandler];
 }
 
-/**  Before this object is released ensure reachability release. */
-- (void)dealloc {
-  [self stopReachability];
-}
-
 #pragma mark property methods
 
 - (BOOL)isConnected {
@@ -212,24 +192,27 @@ - (void)reachabilityRestored {
 
 /**  Start listening for network state changes on a background thread. */
 - (void)startReachability {
-  if (self.reachability) return;
+  if (!self.pathMonitor) return;
+  self.pathMonitor = nw_path_monitor_create();
+  nw_path_monitor_set_queue(self.pathMonitor, dispatch_get_main_queue());
+  nw_path_monitor_set_update_handler(self.pathMonitor, ^(nw_path_t path) {
+    if (nw_path_get_status(path) == nw_path_status_satisfied) {
+      SEL s = @selector(reachabilityRestored);
+      [NSObject cancelPreviousPerformRequestsWithTarget:self selector:s object:nil];
+      [self performSelector:s withObject:nil afterDelay:1];
+    }
+  });
+  nw_path_monitor_set_cancel_handler(self.pathMonitor, ^{
+    self.pathMonitor = nil;
+  });
+  nw_path_monitor_start(self.pathMonitor);
   LOGD(@"Reachability started.");
-  self.reachability =
-    SCNetworkReachabilityCreateWithName(kCFAllocatorDefault, _connectComponents.host.UTF8String);
-  SCNetworkReachabilityContext context = {.info = (__bridge void *)self};
-  if (SCNetworkReachabilitySetCallback(self.reachability, reachabilityHandler, &context)) {
-    SCNetworkReachabilitySetDispatchQueue(
-      self.reachability, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0));
-  }
 }
 
 /**  Stop listening for network state changes. */
 - (void)stopReachability {
-  if (self.reachability) {
-    SCNetworkReachabilitySetDispatchQueue(self.reachability, NULL);
-    if (self.reachability) CFRelease(self.reachability);
-    self.reachability = NULL;
-  }
+  if (!self.pathMonitor) return;
+  nw_path_monitor_cancel(self.pathMonitor);
 }
 
 #pragma mark message methods

Source/santasyncservice/SNTSyncManager.m

@@ -16,7 +16,7 @@
 
 #import <MOLAuthenticatingURLSession/MOLAuthenticatingURLSession.h>
 #import <MOLXPCConnection/MOLXPCConnection.h>
-#import <SystemConfiguration/SystemConfiguration.h>
+#import <Network/Network.h>
 
 #import "Source/common/SNTCommonEnums.h"
 #import "Source/common/SNTConfigurator.h"
@@ -35,9 +35,7 @@
 
 static const uint8_t kMaxEnqueuedSyncs = 2;
 
-@interface SNTSyncManager () <SNTPushNotificationsDelegate> {
-  SCNetworkReachabilityRef _reachability;
-}
+@interface SNTSyncManager () <SNTPushNotificationsDelegate>
 
 @property(nonatomic) dispatch_source_t fullSyncTimer;
 @property(nonatomic) dispatch_source_t ruleSyncTimer;
@@ -48,6 +46,7 @@ @interface SNTSyncManager () <SNTPushNotificationsDelegate> {
 @property(nonatomic) MOLXPCConnection *daemonConn;
 
 @property(nonatomic) BOOL reachable;
+@property nw_path_monitor_t pathMonitor;
 
 @property SNTPushNotifications *pushNotifications;
 
@@ -58,22 +57,6 @@ @interface SNTSyncManager () <SNTPushNotificationsDelegate> {
 
 @end
 
-// Called when the network state changes
-static void reachabilityHandler(SCNetworkReachabilityRef target, SCNetworkReachabilityFlags flags,
-                                void *info) {
-  // Put this check and set on the main thread to ensure serial access.
-  dispatch_async(dispatch_get_main_queue(), ^{
-    SNTSyncManager *commandSyncManager = (__bridge SNTSyncManager *)info;
-    // Only call the setter when there is a change. This will filter out the redundant calls to this
-    // callback whenever the network interface states change.
-    int reachable =
-      (flags & kSCNetworkReachabilityFlagsReachable) == kSCNetworkReachabilityFlagsReachable;
-    if (commandSyncManager.reachable != reachable) {
-      commandSyncManager.reachable = reachable;
-    }
-  });
-}
-
 @implementation SNTSyncManager
 
 #pragma mark init
@@ -102,11 +85,6 @@ - (instancetype)initWithDaemonConnection:(MOLXPCConnection *)daemonConn {
   return self;
 }
 
-- (void)dealloc {
-  // Ensure reachability is always stopped
-  [self stopReachability];
-}
-
 #pragma mark SNTSyncServiceXPC methods
 
 - (void)postEventsToSyncServer:(NSArray<SNTStoredEvent *> *)events fromBundle:(BOOL)isFromBundle {
@@ -413,34 +391,29 @@ - (void)setReachable:(BOOL)reachable {
   }
 }
 
-// Start listening for network state changes on a background thread
+// Start listening for network state changes.
 - (void)startReachability {
-  dispatch_async(dispatch_get_main_queue(), ^{
-    if (self->_reachability) return;
-    const char *nodename = [[SNTConfigurator configurator] syncBaseURL].host.UTF8String;
-    self->_reachability = SCNetworkReachabilityCreateWithName(kCFAllocatorDefault, nodename);
-    SCNetworkReachabilityContext context = {
-      .info = (__bridge_retained void *)self,
-      .release = (void (*)(const void *))CFBridgingRelease,
-    };
-    if (SCNetworkReachabilitySetCallback(self->_reachability, reachabilityHandler, &context)) {
-      SCNetworkReachabilitySetDispatchQueue(
-        self->_reachability, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0));
-    } else {
-      [self stopReachability];
+  self.pathMonitor = nw_path_monitor_create();
+  // Put the callback on the main thread to ensure serial access.
+  nw_path_monitor_set_queue(self.pathMonitor, dispatch_get_main_queue());
+  nw_path_monitor_set_update_handler(self.pathMonitor, ^(nw_path_t path) {
+    // Only call the setter when there is a change. This will filter out the redundant calls to
+    // this callback whenever the network interface states change.
+    int reachable = nw_path_get_status(path) == nw_path_status_satisfied;
+    if (self.reachable != reachable) {
+      self.reachable = reachable;
     }
   });
+  nw_path_monitor_set_cancel_handler(self.pathMonitor, ^{
+    self.pathMonitor = nil;
+  });
+  nw_path_monitor_start(self.pathMonitor);
 }
 
 // Stop listening for network state changes
 - (void)stopReachability {
-  dispatch_async(dispatch_get_main_queue(), ^{
-    if (self->_reachability) {
-      SCNetworkReachabilitySetDispatchQueue(self->_reachability, NULL);
-      if (self->_reachability) CFRelease(self->_reachability);
-      self->_reachability = NULL;
-    }
-  });
+  if (!self.pathMonitor) return;
+  nw_path_monitor_cancel(self.pathMonitor);
 }
 
 @end