Skip to content

Latest commit

 

History

History
77 lines (58 loc) · 3.78 KB

README.md

File metadata and controls

77 lines (58 loc) · 3.78 KB
Raw

Non-blocking TCP Sockets

This namespace defines interfaces for creating non-blocking Cpl::Io streams using TCP/IP connections. This provides an alternative non-blocking approach vs. traditional BSD Sockets. The interfaces are designed to be compatible with the Cpl::System::PeriodicScheduler and/or runnable objects/threads that support periodic scheduling.

The are three primary interfaces:

The motivation for the non-blocking TCP support comes from wanting to use the Raspberry PI PicoW's native WIFI without an RTOS. However, the interfaces are not specific to the PicoW (e.g. there is a Win32 implementation).

PicoW Implementation

The PicoW implementation is built on top of the Pico C/C++ SDK and its integration with the lwIP networking stack. In addition, the implementation is thread1/multi-core safe. The required build options/switches are:

  • LIB_PICO_CYW43_ARCH=1
  • CYW43_LWIP=1
  • PICO_CYW43_ARCH_THREADSAFE_BACKGROUND=1 or PICO_CYW43_ARCH_POLL=1

Note: The above settings sets the lwIP configuration to NO_SYS=1

The implementation is located in the src/Cpl/Io/Tcp/lwIP/Picow directory.

Win32 Implementation

The Win32 implementation use the Winsock DLL to implement the interface. The implementation uses WSA sockets configured for non-blocking operation.

The implementation is located in the src/Cpl/Io/Tcp/Win32 directory.

Test Applications

There are two test applications used to verify the implementations. One of the applications is a TCP server/listener that accepting incoming connection requests. The second one is client/connector that connects to a remote host. The test code is located in the src/Cpl/Io/Tcp/_0test directory. The test applications are built under the tests/Cpl/Io/Tcp/_0test/ directory tree.

The applications are meant to be used as a pair. The server application echoes back the input it receives from the client application. The client application verifies that the data it sends is the data it receives. Note: The server application can be used as a stand alone TCP echo server.

Testing Examples

  1. To test the PicoW AsyncListener implementation
    • Build the tests/Cpl/Io/Tcp/_0test/server/lwip/picow-uart/windows/gcc test project
      • Flash the tcp-server image onto the PicoW
    • Build the tests/Cpl/Io/Tcp/_test/client/win32/vc12 test project.
      • Run the _win32\bb.exe to connect to the PicoW test client application
  2. To test the PicoW AsyncConnector implementation
    • Build the tests/Cpl/Io/Tcp/_test/server/win32/vc12 test project.
      • Run the _win32\bb.exe to begin listening for a connection.
    • Build the tests/Cpl/Io/Tcp/_0test/client/lwip/picow-uart/windows/gcc test project
      • Flash the tcp-client image onto the PicoW

Notes:

  1. When building the PicoW projects the following configuration is set via the build scripts (i.e. edit the mytoolchain.py file in the build directory)
  • WIFI_SSID=<my network's SSID>
  • WIFI_PASSWORD=<my wifi password>
  1. When building a client/connector application the IP address of the remote host is specified in the colony_config.h file (located in the build directory)
    • #define OPTION_REMOTE_HOST_ADDRESS "192.168.1.72"

Footnotes

  1. In this context threads are the Cpl::System::Thread instances and when built with PICO_CYW43_ARCH_THREADSAFE_BACKGROUND=1. ↩