Example/c pingpong (#650)

src/lava/magma/runtime/_c_message_infrastructure/CMakeLists.txt

@@ -200,3 +200,5 @@ if(CMAKE_BUILD_TYPE STREQUAL "Debug")
 else()
   message("not debug mode and disable cpp unit test")
 endif()
+
+add_subdirectory(examples/c_pingpong)

src/lava/magma/runtime/_c_message_infrastructure/examples/c_pingpong/CMakeLists.txt

@@ -0,0 +1,15 @@
+include_directories(../../csrc)
+
+add_executable(cprocess
+  "cprocess.cc"
+)
+
+target_link_libraries(cprocess PRIVATE
+  message_infrastructure
+)
+
+
+set_target_properties(cprocess
+    PROPERTIES
+    RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+)

src/lava/magma/runtime/_c_message_infrastructure/examples/c_pingpong/README.md

@@ -0,0 +1,25 @@
+# C pingpong
+
+## Run instructions
+One needs to run the `p.py` first, start the `./cprocess` binary once seeing the prompt and hit the enter as indicated.
+
+Two args can be given as the socket file names.
+
+```bash
+# p.py
+$ python3 p.py c2py py2c
+
+# cprocess, in another terminal window
+$ ./cprocess c2py py2c
+```
+
+## Notes on current TempChennel:
+TempChannel uses socket file.
+
+The Recv port will bind the socket file in initialization, listen in `start()` and accept in `recv()`. After established a connection, the port closes it immediately after reading from the socket.
+
+The Send port will connect to the recv port in initialization and write to the socket in send().
+
+Therefore,
+1. The send port can only be initialized after corresponding Recv port called `start()`
+2. In each round, the send port is used one-off. One needs to create a new `TempChannel()` and get the send port from it each time. (The send port will be initialized when accessing the .dst_port property at the first time)

src/lava/magma/runtime/_c_message_infrastructure/examples/c_pingpong/cprocess.cc

@@ -0,0 +1,44 @@
+// Copyright (C) 2023 Intel Corporation
+// SPDX-License-Identifier: BSD-3-Clause
+// See: https://spdx.org/licenses/
+
+#include <core/abstract_channel.h>
+#include <core/channel_factory.h>
+#include <core/abstract_port.h>
+#include <core/utils.h>
+#include <channel/socket/socket_port.h>
+
+using namespace message_infrastructure; // NOLINT
+
+int main(int argc, char *argv[]) {
+    char *c2py = (argc >= 2) ? argv[1] : const_cast<char *>("./c2py");
+    char *py2c = (argc >= 3) ? argv[2] : const_cast<char *>("./py2c");
+
+    std::cout << "socket files: " << c2py << " " << py2c << "\n";
+
+    ChannelFactory &channel_factory = GetChannelFactory();
+
+    AbstractChannelPtr ch = channel_factory.GetTempChannel(py2c);
+    AbstractRecvPortPtr rc = ch->GetRecvPort();
+
+    // order matters
+    rc->Start();
+
+    for (uint _ = 0; _ < 10; ++_) {
+        std::cout << "receiving\n";
+        MetaDataPtr recvd = rc->Recv();
+        std::cout << "received from py, total size: "
+                  << recvd->total_size
+                  << "\n";
+
+        AbstractChannelPtr ch2 = channel_factory.GetTempChannel(c2py);
+        AbstractSendPortPtr sd = ch2->GetSendPort();
+        sd->Start();
+        sd->Send(recvd);
+        sd->Join();
+    }
+
+    rc->Join();
+
+    return 0;
+}

src/lava/magma/runtime/_c_message_infrastructure/examples/c_pingpong/p.py

@@ -0,0 +1,67 @@
+import os
+import sys
+import numpy as np
+
+from lava.magma.runtime.message_infrastructure. \
+    MessageInfrastructurePywrapper import (
+        TempChannel
+    )
+
+
+# float equal
+def f_eq(a, b):
+    return abs(a - b) < 0.001
+
+
+def soc_names_from_args():
+    # default file names
+    C2PY = "./c2py"
+    PY2C = "./py2c"
+
+    socket_file_names = [C2PY, PY2C]
+    filename_args = sys.argv[1:3]
+    if len(filename_args) == 1:
+        socket_file_names[0] = filename_args[0]
+    if len(filename_args) == 2:
+        socket_file_names = filename_args
+
+    return socket_file_names
+
+
+def main():
+    c2py, py2c = soc_names_from_args()
+
+    if os.path.exists(c2py):
+        os.remove(c2py)
+    if os.path.exists(py2c):
+        os.remove(py2c)
+
+    # order matters
+    ch2 = TempChannel(c2py)
+    rc = ch2.dst_port
+    rc.start()
+
+    input("Start the c process, hit enter when you see *receiving*")
+
+    for i in range(10):
+        # send port is one-off
+        ch = TempChannel(py2c)
+        sd = ch.src_port
+        sd.start()
+
+        print("round ", i)
+        rands = np.array([np.random.random() * 100 for __ in range(10)])  # noqa
+        print("Sending array to C: ", rands)
+        sd.send(rands)
+
+        rands2 = rc.recv()
+        print("Got array from C: ", rands2)
+
+        print("Correctness: ", all([f_eq(x, y) for x, y in zip(rands, rands2)]))  # noqa
+        print("========================================")
+        sd.join()
+    rc.join()
+
+
+if __name__ == "__main__":
+    main()