Add -[EDOClientService isServiceAvailableOnPort].

isServiceAvailableOnPort checks if an EDOHostService is running in another process.

PiperOrigin-RevId: 573894398

Author: eDO Team

Service/Sources/EDOClientService.h

@@ -76,6 +76,15 @@ EDOClientErrorHandler EDOSetClientErrorHandler(EDOClientErrorHandler _Nullable e
 
 - (instancetype)init NS_UNAVAILABLE;
 
+/**
+ * Determines if an @c EDOHostService is listening on @c port.
+ *
+ * @param port The port to check if an @c EDOHostService is listening on.
+ * @return @c YES if an @c EDOHostService is listening on @c port and it is safe to connect, @c NO
+ * otherwise.
+ */
++ (BOOL)isServiceAvailableOnPort:(UInt16)port;
+
 #pragma mark - Deprecated APIs
 
 /** Retrieve the root object from the given host port of a service. */

Service/Sources/EDOClientService.m

@@ -146,6 +146,19 @@ + (EDOHostNamingService *)namingServiceWithDeviceSerial:(NSString *)serial error
   return nil;
 }
 
++ (BOOL)isServiceAvailableOnPort:(UInt16)port {
+  EDOHostPort *hostPort = [EDOHostPort hostPortWithLocalPort:port];
+  EDOServiceRequest *classRequest =
+      [EDOClassRequest requestWithClassName:NSStringFromClass([NSObject class]) hostPort:hostPort];
+  EDOHostService *service = [EDOHostService serviceForCurrentExecutingQueue];
+  NSError *error = nil;
+  [self sendSynchronousRequest:classRequest
+                        onPort:hostPort
+                  withExecutor:service.executor
+                         error:&error];
+  return error == nil;
+}
+
 #pragma mark - Private Category
 
 + (NSMapTable *)localDistantObjects {
@@ -235,6 +248,13 @@ + (EDOServiceResponse *)sendSynchronousRequest:(EDOServiceRequest *)request
 + (EDOServiceResponse *)sendSynchronousRequest:(EDOServiceRequest *)request
                                         onPort:(EDOHostPort *)port
                                   withExecutor:(EDOExecutor *)executor {
+  return [self sendSynchronousRequest:request onPort:port withExecutor:executor error:NULL];
+}
+
++ (EDOServiceResponse *)sendSynchronousRequest:(EDOServiceRequest *)request
+                                        onPort:(EDOHostPort *)port
+                                  withExecutor:(EDOExecutor *)executor
+                                         error:(NSError **)errorOut {
   EDOClientServiceStatsCollector *stats = EDOClientServiceStatsCollector.sharedServiceStats;
 
   int maxAttempts = 2;
@@ -257,7 +277,11 @@ + (EDOServiceResponse *)sendSynchronousRequest:(EDOServiceRequest *)request
       NSError *error = [NSError errorWithDomain:EDOServiceErrorDomain
                                            code:EDOServiceErrorCannotConnect
                                        userInfo:userInfo];
-      gEDOClientErrorHandler(error);
+      if (errorOut != NULL) {
+        *errorOut = error;
+      } else {
+        gEDOClientErrorHandler(error);
+      }
       return nil;
     }
 
@@ -327,7 +351,11 @@ + (EDOServiceResponse *)sendSynchronousRequest:(EDOServiceRequest *)request
   NSError *error = [NSError errorWithDomain:EDOServiceErrorDomain
                                        code:EDOServiceErrorConnectTimeout
                                    userInfo:userInfo];
-  gEDOClientErrorHandler(error);
+  if (errorOut != NULL) {
+    *errorOut = error;
+  } else {
+    gEDOClientErrorHandler(error);
+  }
   return nil;
 }
 
@@ -436,4 +464,4 @@ BOOL EDOIsRemoteObject(id object) {
   return objectClass == remoteObjectClass || objectClass == remoteBlockClass;
 }
 
-void EDOExportEDOClientError(NSError *error) { gEDOClientErrorHandler(error); }
+void EDOExportEDOClientError(NSError *error) { gEDOClientErrorHandler(error); }