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Lianja

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.

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Lianja
llSuccess = .F.

loSocket = createobject("CkSocket")

//  Connect to the server using TLS.
llBTls = .T.
lnMaxWaitMs = 5000
llSuccess = loSocket.Connect("example.com",5000,llBTls,lnMaxWaitMs)
if (llSuccess = .F.) then
    ? loSocket.LastErrorText
    release loSocket
    return
endif

//  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.
lnWritable = loSocket.CheckWriteable(5000)
if (lnWritable < 0) then
    ? loSocket.LastErrorText
    release loSocket
    return
endif

if (lnWritable <> 1) then
    ? "The socket did not become writable before the timeout."
    release loSocket
    return
endif

? "The socket is writable."


release loSocket