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C++

Check Whether a Socket Is Writable

See more Socket/SSL/TLS Examples

Demonstrates Socket.CheckWriteable, which waits for the connected socket to become writable. It returns 1 if writable, 0 if it did not become writable before the timeout, or -1 on error.

Background. A maxWaitMs of 0 performs a nonblocking poll. This is useful for flow control before attempting a large send.

Chilkat C++ Downloads

C++
#include <CkSocket.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkSocket socket;

    //  Connect to the server using TLS.
    bool bTls = true;
    int maxWaitMs = 5000;
    success = socket.Connect("example.com",5000,bTls,maxWaitMs);
    if (success == false) {
        std::cout << socket.lastErrorText() << "\r\n";
        return;
    }

    //  Wait up to 5 seconds for the socket to become writable.  Returns 1 if writable, 0 if it did not
    //  become writable before the timeout, or -1 on error.
    int writable = socket.CheckWriteable(5000);
    if (writable < 0) {
        std::cout << socket.lastErrorText() << "\r\n";
        return;
    }

    if (writable != 1) {
        std::cout << "The socket did not become writable before the timeout." << "\r\n";
        return;
    }

    std::cout << "The socket is writable." << "\r\n";
    }