How to cancel socket block operation

[AndrewY]

Hi All,

One of the classics problems in Unix/Linux socket programming,
is to force cancel block operation (accept, recv ...).
Here is description of my problem:

I have thread which is blocked with socket function recv (I am waiting for data from client). But it is situation when I need to cancel
recv blocking, and send data to client using this socket.

Question: how to cancel recv operation, to have ability to use this socket for sending data (so we can/t close socket).

Mutlithreading implemented using POSIX threads.

One of the ways how to deal with this problem, is to use pthread_kill.

Second way - using non-blocking sockets and select function, but I would like to avoid this way.

If somebody know other ways to resolve this problem, I will be very thankful for your help.

[Rubberman]

Typically you set a timer which will raise a signal. When you return from the signal handler, recv will return an EINTR error if there was no data to process. Since you are using pthreads, then you will want to use pthread_kill in order to deliver the signal to the thread in question. The thread receiving the signal can handle it as appropriate - it doesn't need to die.

[AndrewY]

Thanks guys,
I also found other methods of resolving this problem, but I should try it first, to be sure.
Will try all known solutions, and will report you about results.

Thanks!