(PHP Extension) Bidirectional Sockets (TLS or non-TLS, simultaneous reading and writing a connection)

This example demonstrates how to simultaneously read/write on a single socket connection.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

$tlsRead = new CkSocket();

// We'll just use an HTTPS server for this example...
$bUseTls = true;
$maxWaitMs = 5000;
$success = $tlsRead->Connect('www.chilkatsoft.com',443,$bUseTls,$maxWaitMs);
if ($success != true) {
    print $tlsRead->lastErrorText() . "\n";
    exit;
}

// Chilkat classes are thread-safe.  This means that only one method call can be active
// at a time for a given object instance.  It would seem that this would prevent the possibility
// to simultaneously read/write a given connection because it would require two method calls
// to be simultaneously active: one for reading and one for writing.
// 
// There's a trick to doing it...
// 
// The CloneSocket method is provided to get a new object instance that shares the same socket
// connection.  This allows for the coarse-grained object-level thread safety to be maintained, 
// while finer-grained thread-safety mechanisms keep things kosher internally.

// One object will be used for reading, and the cloned socket is used for writing.
// It doesn't matter which --  you can use the cloned socket for reading or the original for writing.
// However.. if you try to read simultneously from both the original and cloned objects at the same
// time, then one will block until the other finishes.  (This is because of the finer-grained thread
// safety internally.)  The same is true if you try to write both socket objects simultaneously.

// tlsWrite is a CkSocket
$tlsWrite = $tlsRead->CloneSocket();

// Let's start an async read on the socket.  Nothing will be arriving until we actually send the GET
// request and the server responds.  This will read until the end of the HTTP response header.
// task is a CkTask
$task = $tlsRead->ReceiveUntilMatchAsync('\r\n\r\n');
$task->Run();

// Now send the request.  This should not block because the read is happening on the tlsRead object.
$httpGetReq = 'GET / HTTP/1.1\r\nHost: www.chilkatsoft.com\r\n\r\n';
$success = $tlsWrite->SendString($httpGetReq);
// Assuming success for the example...

// Wait for the read task to finish.
// The true/false returned by Wait applies to the Wait method call, not the task.
$maxWaitMs = 5000;
$success = $task->Wait($maxWaitMs);
if (!$success or ($task->get_StatusInt() != 7) or ($task->get_TaskSuccess() != true)) {
    if (!$success) {
        // The task.LastErrorText applies to the Wait method call.
        print $task->lastErrorText() . "\n";
    }
    else {
        // The ResultErrorText applies to the underlying task method call (i.e. the Connect)
        print $task->status() . "\n";
        print $task->resultErrorText() . "\n";
    }

    exit;
}

// Examine the received HTTP response header:
print 'HTTP response header:' . "\n";
print $task->getResultString() . "\n";

// We should get a response that looks like this:
// 	HTTP response header:
// 	HTTP/1.1 200 OK
// 	Cache-Control: private
// 	Content-Length: 7477
// 	Content-Type: text/html
// 	Server: Microsoft-IIS/8.5
// 	Set-Cookie: ASPSESSIONIDSWDSTRTQ=BBNMIKGCHFJNILFFPLDIOGDE; secure; path=/
// 	X-Powered-By: ASP.NET
// 	X-Powered-By-Plesk: PleskWin
// 	Date: Thu, 06 Apr 2017 12:03:30 GMT

// Forget about the remainder of the HTTP response... The example was only to demonstrate
// simultaneous reading/writing..
$maxWaitMs = 20;
$tlsRead->Close($maxWaitMs);

?>