From bc0fe0799027fe940845c1f053176b47a8829c61 Mon Sep 17 00:00:00 2001
From: Philippe Pittoli <karchnu@karchnu.fr>
Date: Sat, 24 Dec 2022 18:57:51 +0100
Subject: [PATCH] Add some test/example programs.

---
 zig-impl/src/misc-test.zig     |  27 +++++++++
 zig-impl/src/poll-listener.zig | 104 +++++++++++++++++++++++++++++++++
 2 files changed, 131 insertions(+)
 create mode 100644 zig-impl/src/misc-test.zig
 create mode 100644 zig-impl/src/poll-listener.zig

diff --git a/zig-impl/src/misc-test.zig b/zig-impl/src/misc-test.zig
new file mode 100644
index 0000000..69229d2
--- /dev/null
+++ b/zig-impl/src/misc-test.zig
@@ -0,0 +1,27 @@
+const std = @import("std");
+const hexdump = @import("./hexdump.zig");
+const testing = std.testing;
+const net = std.net;
+const fmt = std.fmt;
+
+const print = std.debug.print;
+const P = std.ArrayList(std.os.pollfd);
+
+fn create_service() !void {
+    const config = .{.safety = true};
+    var gpa = std.heap.GeneralPurposeAllocator(config){};
+    defer _ = gpa.deinit();
+    const allocator = gpa.allocator();
+
+    var p = P.init(allocator);
+    defer p.deinit();
+
+    try p.append(.{.fd = 8, .events = 0, .revents = 0});
+
+    for(p.items) |i| { print("fd: {}\n", .{i.fd}); }
+}
+
+pub fn main() !u8 {
+    try create_service();
+    return 0;
+}
diff --git a/zig-impl/src/poll-listener.zig b/zig-impl/src/poll-listener.zig
new file mode 100644
index 0000000..331095a
--- /dev/null
+++ b/zig-impl/src/poll-listener.zig
@@ -0,0 +1,104 @@
+const std = @import("std");
+const hexdump = @import("./hexdump.zig");
+const testing = std.testing;
+const net = std.net;
+const os = std.os;
+const fmt = std.fmt;
+
+const print = std.debug.print;
+
+// const config = .{.safety = true};
+// var gpa = std.heap.GeneralPurposeAllocator(config){};
+// defer _ = gpa.deinit();
+// const allocator = gpa.allocator();
+
+fn disconnect(stream: *net.StreamServer) void { stream.close(); }
+
+fn server_init() net.StreamServer {
+    // no reuse_address and default kernel_backlog
+    return net.StreamServer.init(.{});
+}
+
+fn remove_unix_socket(path: []const u8) void {
+    std.fs.deleteFileAbsolute(path) catch |err| switch(err) {
+        else => { print("error: {}\n", .{err}); }
+    };
+}
+
+fn waiting_for_connection(stream: *net.StreamServer
+  , path: []const u8) !net.StreamServer.Connection {
+    var address = try net.Address.initUnix(path);
+    try stream.listen(address);
+
+    // const linux = os.linux;
+    // var tfd = try os.timerfd_create(linux.CLOCK.MONOTONIC, linux.TFD.CLOEXEC);
+    // defer os.close(tfd);
+    // // Fire event 10_000_000ns = 10s after the os.timerfd_settime call.
+    // var sit: linux.itimerspec = .{ .it_interval = .{ .tv_sec = 0, .tv_nsec = 0 }
+    //                              , .it_value    = .{ .tv_sec = 0, .tv_nsec = 10 * (1000 * 1000 * 1000) } };
+    // print("before os.timerfd_settime\n", .{});
+    // try os.timerfd_settime(tfd, 0, &sit, null);
+
+    // var fds: [2]os.pollfd =
+    //    .{ .{ .fd = tfd, .events = os.linux.POLL.IN, .revents = 0 }
+    //     , .{ .fd = lfd, .events = os.linux.POLL.IN, .revents = 0 }};
+    // var count = try os.poll(&fds, -1); // -1 => infinite waiting
+
+    var waiting_duration: i32 = 10 * 1000; // in ms
+    print("waiting for 10 seconds, tops\n", .{});
+    var ssockfd = stream.sockfd; // actual listener (server)
+    var lfd: os.socket_t = undefined;
+
+    if (ssockfd) |sfd| { lfd = sfd; }
+    else               { return error.Undefined; }
+
+    print("Let's wait for an event (either stdin or unix socket)\n", .{});
+    var count: usize = undefined;
+    while(true) {
+        var fds: [2]os.pollfd =
+           .{.{ .fd = 0,   .events = os.linux.POLL.IN, .revents = 0 }
+           , .{ .fd = lfd, .events = os.linux.POLL.IN, .revents = 0 }};
+        print("fds: {any}\n", .{fds});
+        count = try os.poll(&fds, waiting_duration);
+        if (count == 0) { print("no client, still waiting\n", .{}); continue; }
+        print("fds NOW: {any}\n", .{fds});
+        break;
+    }
+
+    return stream.accept();
+}
+
+fn receive_msg(stream: net.Stream) !void {
+    var buffer: [1000]u8 = undefined;
+    var fbs = std.io.fixedBufferStream(&buffer);
+    var reader = fbs.reader();
+
+    _ = try stream.read(buffer[0..]);
+
+    const msg_type    = try reader.readByte();
+    const msg_len     = try reader.readIntBig(u32);
+    const msg_payload = buffer[5..5+msg_len];
+    print ("type: {}, len {}, content: {s}\n"
+           , .{msg_type, msg_len, msg_payload});
+}
+
+pub fn main() !u8 {
+    var path = "/tmp/.TEST_USOCK";
+    print("Init UNIX server to {s}...\n", .{path});
+    var stream = server_init();
+    defer stream.deinit();
+    defer remove_unix_socket(path);
+
+    // TODO
+    print("Waiting for a connection...\n", .{});
+    var connection = try waiting_for_connection(&stream, path);
+    print("Someone is connected! Receiving a message...\n", .{});
+    try receive_msg(connection.stream);
+
+    print("Disconnection...\n", .{});
+    disconnect(&stream);
+    print("Disconnected!\n", .{});
+    return 0;
+}
+
+