Restrict NSTimeInterval parameters to non-negative

src/objective-c/GRPCClient/GRPCCallOptions.h

@@ -120,15 +120,15 @@ typedef NS_ENUM(NSInteger, GRPCTransportType) {
  */
 @property(readonly) BOOL enableRetry;
 
-/**
- * HTTP/2 keep-alive feature. The parameter \a keepaliveInterval specifies the interval between two
- * PING frames. The parameter \a keepaliveTimeout specifies the length of the period for which the
- * call should wait for PING ACK. If PING ACK is not received after this period, the call fails.
- */
+// HTTP/2 keep-alive feature. The parameter \a keepaliveInterval specifies the interval between two
+// PING frames. The parameter \a keepaliveTimeout specifies the length of the period for which the
+// call should wait for PING ACK. If PING ACK is not received after this period, the call fails.
+// Negative values are not allowed.
 @property(readonly) NSTimeInterval keepaliveInterval;
 @property(readonly) NSTimeInterval keepaliveTimeout;
 
-// Parameters for connection backoff. For details of gRPC's backoff behavior, refer to
+// Parameters for connection backoff. Negative values are not allowed.
+// For details of gRPC's backoff behavior, refer to
 // https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md
 @property(readonly) NSTimeInterval connectMinTimeout;
 @property(readonly) NSTimeInterval connectInitialBackoff;
@@ -203,7 +203,8 @@ typedef NS_ENUM(NSInteger, GRPCTransportType) {
 /**
  * The timeout for the RPC call in seconds. If set to 0, the call will not timeout. If set to
  * positive, the gRPC call returns with status GRPCErrorCodeDeadlineExceeded if it is not completed
- * within \a timeout seconds. A negative value is not allowed.
+ * within \a timeout seconds. Negative value is invalid; setting the parameter to negative value
+ * will reset the parameter to 0.
  */
 @property(readwrite) NSTimeInterval timeout;
 
@@ -249,15 +250,17 @@ typedef NS_ENUM(NSInteger, GRPCTransportType) {
  */
 @property(readwrite) BOOL enableRetry;
 
-/**
- * HTTP/2 keep-alive feature. The parameter \a keepaliveInterval specifies the interval between two
- * PING frames. The parameter \a keepaliveTimeout specifies the length of the period for which the
- * call should wait for PING ACK. If PING ACK is not received after this period, the call fails.
- */
+// HTTP/2 keep-alive feature. The parameter \a keepaliveInterval specifies the interval between two
+// PING frames. The parameter \a keepaliveTimeout specifies the length of the period for which the
+// call should wait for PING ACK. If PING ACK is not received after this period, the call fails.
+// Negative values are invalid; setting these parameters to negative value will reset the
+// corresponding parameter to 0.
 @property(readwrite) NSTimeInterval keepaliveInterval;
 @property(readwrite) NSTimeInterval keepaliveTimeout;
 
-// Parameters for connection backoff. For details of gRPC's backoff behavior, refer to
+// Parameters for connection backoff. Negative value is invalid; setting the parameters to negative
+// value will reset corresponding parameter to 0.
+// For details of gRPC's backoff behavior, refer to
 // https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md
 @property(readwrite) NSTimeInterval connectMinTimeout;
 @property(readwrite) NSTimeInterval connectInitialBackoff;

src/objective-c/GRPCClient/GRPCCallOptions.m

@@ -342,7 +342,11 @@ static NSUInteger kDefaultChannelId = 0;
 }
 
 - (void)setTimeout:(NSTimeInterval)timeout {
-  _timeout = timeout;
+  if (timeout < 0) {
+    _timeout = 0;
+  } else {
+    _timeout = timeout;
+  }
 }
 
 - (void)setOauth2AccessToken:(NSString *)oauth2AccessToken {
@@ -374,23 +378,43 @@ static NSUInteger kDefaultChannelId = 0;
 }
 
 - (void)setKeepaliveInterval:(NSTimeInterval)keepaliveInterval {
-  _keepaliveInterval = keepaliveInterval;
+  if (keepaliveInterval < 0) {
+    _keepaliveInterval = 0;
+  } else {
+    _keepaliveInterval = keepaliveInterval;
+  }
 }
 
 - (void)setKeepaliveTimeout:(NSTimeInterval)keepaliveTimeout {
-  _keepaliveTimeout = keepaliveTimeout;
+  if (keepaliveTimeout < 0) {
+    _keepaliveTimeout = 0;
+  } else {
+    _keepaliveTimeout = keepaliveTimeout;
+  }
 }
 
 - (void)setConnectMinTimeout:(NSTimeInterval)connectMinTimeout {
-  _connectMinTimeout = connectMinTimeout;
+  if (connectMinTimeout < 0) {
+    connectMinTimeout = 0;
+  } else {
+    _connectMinTimeout = connectMinTimeout;
+  }
 }
 
 - (void)setConnectInitialBackoff:(NSTimeInterval)connectInitialBackoff {
-  _connectInitialBackoff = connectInitialBackoff;
+  if (connectInitialBackoff < 0) {
+    _connectInitialBackoff = 0;
+  } else {
+    _connectInitialBackoff = connectInitialBackoff;
+  }
 }
 
 - (void)setConnectMaxBackoff:(NSTimeInterval)connectMaxBackoff {
-  _connectMaxBackoff = connectMaxBackoff;
+  if (connectMaxBackoff < 0) {
+    _connectMaxBackoff = 0;
+  } else {
+    _connectMaxBackoff = connectMaxBackoff;
+  }
 }
 
 - (void)setAdditionalChannelArgs:(NSDictionary *)additionalChannelArgs {