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When building high-performance network applications, especially in scenarios where shared sockets are required across processes, network programming under the Windows platform provides a series of unique functions to support these advanced features. socket_wsaprotocol_info_import is one of the important functions. This article will analyze its role in depth and explore its typical application scenarios.
socket_wsaprotocol_info_import is a Windows platform-specific socket function provided by PHP, which is used to import a socket handle from the received WSAPROTOCOL_INFO structure. This process enables the sharing of an established socket connection between the two processes, enabling more efficient communication and resource reuse.
$info = /* Through other ways（like socket_wsaprotocol_info_export）Obtained WSAPROTOCOL_INFO String */;
$socket = socket_wsaprotocol_info_import($info);
if ($socket === false) {
echo "Failed to import socket: " . socket_strerror(socket_last_error());
exit;
}
The essence of this function is to reconstruct a SOCKET object through the known WSAPROTOCOL_INFO string, and is usually used by the server to pass the established connection socket to the child process or other services for use.
The function prototype of this function is as follows:
resource socket_wsaprotocol_info_import(string $info)
Parameter $info : is a string exported through the socket_wsaprotocol_info_export() function, representing a WSAPROTOCOL_INFO structure.
Return value : Returns an available socket resource on success; returns false on failure.
Under the Windows platform, PHP's socket_wsaprotocol_info_export() and socket_wsaprotocol_info_import() functions are used in combination to realize socket sharing between parent and child processes. For example:
The parent process creates a listening socket;
The parent process accepts the connection and exports the information of the connection socket through socket_wsaprotocol_info_export() ;
Send this information to the child process through a named pipe or other IPC;
The child process reconstructs the socket through socket_wsaprotocol_info_import() and continues the communication processing.
This type of design is very useful in high-performance servers, such as a PHP background service system that requires multiple subprocesses to handle a large number of concurrent requests.
When building a custom WebSocket service, if the server framework implements itself using PHP (such as through extensions or FFI), it can migrate WebSocket-connected sockets between multiple processes. For example, when a child process has reached its upper limit, the connection can be migrated to another child process to continue processing.
// Export connection
$info = socket_wsaprotocol_info_export($socket, $target_pid);
file_put_contents("C:/tmp/pipe_to_{$target_pid}.txt", $info);
// Subprocess import connection
$info = file_get_contents("C:/tmp/pipe_to_{$mypid}.txt");
$socket = socket_wsaprotocol_info_import($info);
Since WSAPROTOCOL_INFO is the underlying structure, PHP uses the socket_wsaprotocol_info_import() function to collaborate with high-performance network services written in C/C++ to achieve the effect of mixed language development. This not only takes advantage of the high performance of C/C++, but also maintains the flexibility of PHP development and the advantages of rapid iteration.
For example, connections can be passed from C++ services to PHP subsystem for back-end business logic processing, greatly improving system performance and scalability.
This function is only available on Windows systems;
Before using it, you need to confirm that sockets extension is enabled during PHP compilation;
When transferring sockets across processes, you need to pay attention to synchronization and permission issues;
Only used for sockets based on Windows socket model (i.e. Winsock supports);
socket_wsaprotocol_info_export() and socket_wsaprotocol_info_import() usually need to be used together, and do not support direct serialization of cross-platform delivery.
socket_wsaprotocol_info_import() is a high-level function in network programming in PHP on the Windows platform, mainly used to support cross-process shared sockets. It has extremely high practical value in high-performance multi-process servers, WebSocket services, multi-language collaborative development and other scenarios.
By rationally designing the inter-process communication and resource sharing mechanism, this function can be used to build a more efficient and scalable network service system.
To learn more about the relevant implementation of socket_wsaprotocol_info_export() , you can refer to the example code and documentation: https://gitbox.net/docs/php-sockets/ .
