Doing a little Jeopardy style Q&A here.
I'm developing an app in Flutter that uses the udp package for broadcasting on the local network. This has worked fine on Android, Windows, macOS and iOS until I tried on an iOS 14.6 device.
The code flow is mainly like this:
var endPoint = Endpoint.broadcast(port: Port(6000));
var udpFuture = UDP.bind(Endpoint.any(port: Port(6000)));
udpFuture.then((udp) {
udp.listen((datagram) {
handleMessage(datagram.data);
});
udp.send(bytesToSend, endPoint);
}
The error message I'm getting is this: Unhandled Exception: OS Error: Bad file descriptor, errno = 9
Starting from iOS 14 your app needs the Multicast networking entitlement com.apple.developer.networking.multicast to be able to send or receive IP multicast traffic.
To get the entitlement you need to apply using Apple's request form. It took me 4-5 days before I got the request approved.
Then you can follow the instructions on Apple's forums to get up and running.
I have been working with HFC SDK for Node.js and it used to work, but since last night I am having some problems.
When running helloblockchain.js only few times works, most time I get this error when it tries to enroll a new user:
E0113 11:56:05.983919636 5288 handshake.c:128] Security handshake failed: {"created":"#1484304965.983872199","description":"Handshake read failed","file":"../src/core/lib/security/transport/handshake.c","file_line":237,"referenced_errors":[{"created":"#1484304965.983866102","description":"FD shutdown","file":"../src/core/lib/iomgr/ev_epoll_linux.c","file_line":948}]}
Error: Failed to register and enroll JohnDoe: Error
Other times, the enroll works and the failure appears deploying the chaincode:
Enrolled and registered JohnDoe successfully
Deploying chaincode ...
E0113 12:14:27.341527043 5455 handshake.c:128] Security handshake failed: {"created":"#1484306067.341430168","description":"Handshake read failed","file":"../src/core/lib/security/transport/handshake.c","file_line":237,"referenced_errors":[{"created":"#1484306067.341421859","description":"FD shutdown","file":"../src/core/lib/iomgr/ev_epoll_linux.c","file_line":948}]}
Failed to deploy chaincode: request={"fcn":"init","args":["a","100","b","200"],"chaincodePath":"chaincode","certificatePath":"/certs/peer/cert.pem"}, error={"error":{"code":14,"metadata":{"_internal_repr":{}}},"msg":"Error"}
Or:
Enrolled and registered JohnDoe successfully
Deploying chaincode ...
E0113 12:15:27.448867739 5483 handshake.c:128] Security handshake failed: {"created":"#1484306127.448692244","description":"Handshake read failed","file":"../src/core/lib/security/transport/handshake.c","file_line":237,"referenced_errors":[{"created":"#1484306127.448668047","description":"FD shutdown","file":"../src/core/lib/iomgr/ev_epoll_linux.c","file_line":948}]}
events.js:160
throw er; // Unhandled 'error' event
^
Error
at ClientDuplexStream._emitStatusIfDone (/usr/lib/node_modules/hfc/node_modules/grpc/src/node/src/client.js:189:19)
at ClientDuplexStream._readsDone (/usr/lib/node_modules/hfc/node_modules/grpc/src/node/src/client.js:158:8)
at readCallback (/usr/lib/node_modules/hfc/node_modules/grpc/src/node/src/client.js:217:12)
E0113 12:15:27.563487641 5483 handshake.c:128] Security handshake failed: {"created":"#1484306127.563437122","description":"Handshake read failed","file":"../src/core/lib/security/transport/handshake.c","file_line":237,"referenced_errors":[{"created":"#1484306127.563429661","description":"FD shutdown","file":"../src/core/lib/iomgr/ev_epoll_linux.c","file_line":948}]}
This code worked yesterday, so I don't know what could be happening.
Does anybody know how can I fix it?
Thanks,
Javier.
ibm-bluemix
blockchain
These types of intermittent issues are usually related to GRPC. An initial suggestion is to ensure that you are using at least GRPC version 1.0.0.
If you are using a Mac, then the maximum number of open file descriptors should be checked (using ulimit -n). Sometimes this is initially set to a low value such as 256, so increasing the value could help.
There are a couple of GRPC issues with similar symptoms.
https://github.com/grpc/grpc/issues/8732
https://github.com/grpc/grpc/issues/8839
https://github.com/grpc/grpc/issues/8382
There is a grpc.initial_reconnect_backoff_ms property that is mentioned in some of these issues. Increasing the value past the 1000 ms level might help reduce the frequency of issues. Below are instructions for how the helloblockchain.js file can be modified to set this property to a higher value.
Open the helloblockchain.js file in the Hyperledger Fabric Client example and find the enrollAndRegisterUsers function.
Add “grpc.initial_reconnect_backoff_ms": 5000 to the setMemberServicesUrl call.
chain.setMemberServicesUrl(ca_url, {
pem: cert, "grpc.initial_reconnect_backoff_ms": 5000
});
Add “grpc.initial_reconnect_backoff_ms": 5000 to the addPeer call.
chain.addPeer("grpcs://" + peers[i].discovery_host + ":" + peers[i].discovery_port,
{pem: cert, "grpc.initial_reconnect_backoff_ms": 5000
});
Note that setting the grpc.initial_reconnect_backoff_ms property may reduce the frequency of issues, but it will not necessarily eliminate all issues.
The connection to the eventhub that is made in the helloblockchain.js file can also be a factor. There is an earlier version of the Hyperledger Fabric Client that does not utilize the eventhub. This earlier version could be tried to determine if this makes a difference. After running git clone https://github.com/IBM-Blockchain/SDK-Demo.git, run git checkout b7d5195 to use this prior level. Before running node helloblockchain.js from a Node.js command window, the git status command can be used to check the code level that is being used.
I imported the MessageUI.h class and implemented the function in MFMailComposeViewControllerDelegate.
I was following the tutorial on : http://www.appcoda.com/ios-programming-101-send-email-iphone-app/
I am currently using Xcode 6.0.1 and iOS SDK 8.0 to build and run the app on the simulator. The issue is:
On running the app in the simulator, I get the following error
2014-09-26 03:39:07.687 SendMessage[44465:2674263] Mail cancelled
2014-09-26 03:39:07.743 SendMessage[44465:2673753] viewServiceDidTerminateWithError: Error Domain=_UIViewServiceInterfaceErrorDomain Code=3 "The operation couldn’t be completed. (_UIViewServiceInterfaceErrorDomain error 3.)" UserInfo=0x7fe873e01d30 {Message=Service Connection Interrupted}
2014-09-26 03:39:25.172 SendMessage[44465:2674263] <MFMailComposeRemoteViewController: 0x7fe873c389e0> timed out waiting for fence barrier from com.apple.MailCompositionService
Any suggestions on what should be done to get this working?
This is a known error in the simulator. It does not appear when you run on a device. So, try it on a device and if it runs normally, then you should be ok.
I have a problem in my C client, where I implemented a client gsoap program to invoke a web service.
Everything works fine on a Windows PC, but when I publish my code on a linux-based POS device, I receive the following error:
"setsockopt SO_SNDBUF failed in tcp_connect()"
Where should I start to debug this error, what could be the cause?
the errornum returned is 2
The code section that generates the error : (in stdsoap2.c)
if (setsockopt(sk, SOL_SOCKET, SO_SNDBUF, (char*)&len, sizeof(int))){
soap->errnum = soap_socket_errno(sk);
soap_set_sender_error(soap,
tcp_error(soap),
"setsockopt SO_SNDBUF failed in tcp_connect()",
SOAP_TCP_ERROR);
soap->fclosesocket(soap, sk);
#ifdef WITH_IPV6
freeaddrinfo(ressave);
#endif
return SOAP_INVALID_SOCKET;
}
How big is the len argument? It's possible that the value works on Windows, but is rejected by linux for some reason. Take a look at the actual values being submitted and see if they look reasonable.
You can also try reducing this down to a very small program that just sets up a socket and tries to replicate the call to setsockopt() and see if it still fails with the SO_SNDBUF size the main program is trying to use.
well it turned out to be very simple one!!
i just had to build the c/c++ files using the binaries dedicated for linux....
gsoap(wsdl2h,soapcpp2)
windows build uses winsock and linux build uses standard sockets
and the sockets on the 2 systems are differentes!
thats why i was receiving the socket error.
hope this help others, getting this socket error msg..
A week ago I started to notice a problem with the php sdk file - facebook_base.php
sometimes when connected facebook member visit the site and the auto-login trigger I get 2 errors and sometimes only the first error (that is why I used it in my problem title)+ the site shows up but without showing that user is connected.
after a refresh no error is shown and the site for connected member shows up.
I've tried new version of php API and also old ones that worked and still problem remained.
any ideas what can cause the problem?
UPDATE: similar problem spotted here: https://developers.facebook.com/bugs/207087046099691?browse=search_512a0e37e7ecf6136191651
this is the errors:
Warning: curl_setopt() [function.curl-setopt]: Invalid curl configuration option in /home/admin/domains/mydomain.com/public_html/includes/base_facebook.php on line 970
Warning: curl_setopt_array() [function.curl-setopt-array]: Array keys must be CURLOPT constants or equivalent integer values in /home/admin/domains/mydomain.com/public_html/includes/base_facebook.php on line 946