Switching now works with provided bindings.

.gitignore

@@ -1,4 +1,5 @@
 zig-cache
 zig-out
+.zig-cache
 docs
 *.swp

README.md

@@ -24,5 +24,6 @@ See the [dedicated repository][examples].
 
 LibIPC reached a stable state and is usable.
 Performance is fine for most projects, but can be largely improved.
+The `poll` syscall is used instead of more recent and *faster* syscalls (`epoll`, `kqueue`, etc.).
 
 [examples]: https://git.baguette.netlib.re/Baguette/libipc-examples

build.zig

@@ -1,6 +1,6 @@
 const std = @import("std");
 
-const VERSION = "0.1.2";
+const VERSION = "0.2.0";
 
 // Although this function looks imperative, note that its job is to
 // declaratively construct a build graph that will be executed by an external

ipc.pc

@@ -3,6 +3,6 @@ libdir=/usr/local/lib
 
 Name: LibIPC
 Description: The simplest Inter Process Communication library
-Version: 0.1.2
+Version: 0.2.0
 Libs: -L${libdir} -lipc
 Cflags: -I${includedir}

makefile

@@ -48,7 +48,7 @@ serve-doc:
 	darkhttpd docs/ --addr $(DOC_HTTPD_ADDR) --port $(DOC_HTTPD_PORT) --log $(DOC_HTTPD_ACCESS_LOGS)
 
 PACKAGE ?= libipc
-VERSION ?= 0.1.2
+VERSION ?= 0.2.0
 PKG = $(PACKAGE)-$(VERSION)
 dist-dir:
 	[ -d $(PKG) ] || ln -s . $(PKG)

src/bindings.zig

@@ -107,7 +107,10 @@ export fn ipc_wait_event(ctx: *Context, t: *u8, index: *usize, originfd: *i32, n
         var writer = fbs.writer();
         _ = writer.write(m.payload) catch return -4;
         buflen.* = m.payload.len;
-        m.deinit();
+        switch (event.t) {
+            .SWITCH_RX => {},
+            else => m.deinit(),
+        }
     } else {
         buflen.* = 0;
     }

src/context.zig

@@ -1,17 +1,11 @@
 const std = @import("std");
 const testing = std.testing;
-// const DEBUG = @import("./hexdump.zig");
 const net = std.net;
 const os = std.os;
 const fmt = std.fmt;
 const c = std.c;
 const posix = std.posix;
 
-// const print = std.debug.print;
-
-// TODO: to remove once PR https://github.com/ziglang/zig/pull/14639 is accepted.
-pub extern "c" fn umask(mode: c.mode_t) c.mode_t;
-
 const log = std.log.scoped(.libipc_context);
 
 const receive_fd = @import("./exchange-fd.zig").receive_fd;
@@ -35,7 +29,6 @@ pub const PollFD = std.ArrayList(posix.pollfd);
 pub const IPC_HEADER_SIZE = 4; // Size (4 bytes) then content.
 pub const IPC_BASE_SIZE = 100000; // 100 KB, plenty enough space for messages
 pub const IPC_MAX_MESSAGE_SIZE = IPC_BASE_SIZE - IPC_HEADER_SIZE;
-pub const IPC_VERSION = 1;
 
 // Context of the whole networking state.
 pub const Context = struct {
@@ -66,8 +59,8 @@ pub const Context = struct {
         };
 
         // Allow mkdir to create a directory with 0o770 permissions.
-        const previous_mask = umask(0o007);
-        defer _ = umask(previous_mask);
+        const previous_mask = c.umask(0o007);
+        defer _ = c.umask(previous_mask);
 
         // Create the run directory, where all UNIX sockets will be.
         posix.mkdir(rundir, 0o0770) catch |err| switch (err) {
@@ -80,7 +73,12 @@ pub const Context = struct {
             },
         };
 
-        return Self{ .rundir = rundir, .connections = Connections.init(allocator), .pollfd = PollFD.init(allocator), .tx = Messages.init(allocator), .switchdb = SwitchDB.init(allocator), .allocator = allocator };
+        return Self{ .rundir = rundir
+                   , .connections = Connections.init(allocator)
+                   , .pollfd = PollFD.init(allocator)
+                   , .tx = Messages.init(allocator)
+                   , .switchdb = SwitchDB.init(allocator)
+                   , .allocator = allocator };
     }
 
     pub fn deinit(self: *Self) void {
@@ -264,8 +262,8 @@ pub const Context = struct {
 
         // Allow to create a unix socket with the right permissions.
         // Group should include write permissions.
-        const previous_mask = umask(0o117);
-        defer _ = umask(previous_mask);
+        const previous_mask = c.umask(0o117);
+        defer _ = c.umask(previous_mask);
 
         // Remove the old UNIX socket.
         posix.unlink(path) catch |err| switch (err) {
@@ -297,12 +295,6 @@ pub const Context = struct {
         _ = try m.write(writer); // returns paylen
 
         _ = try stream.write(fbs.getWritten());
-
-        // var hexbuf: [2000]u8 = undefined;
-        // var hexfbs = std.io.fixedBufferStream(&hexbuf);
-        // var hexwriter = hexfbs.writer();
-        // try DEBUG.hexdump(hexwriter, "MSG SENT", fbs.getWritten());
-        // print("{s}\n", .{hexfbs.getWritten()});
     }
 
     pub fn schedule(self: *Self, m: Message) !void {

src/hexdump.zig

@@ -72,6 +72,17 @@ pub fn hexdump(stream: anytype, header: []const u8, buffer: []const u8) std.posi
     try stream.writeAll("\n");
 }
 
+/// Debug function: print some bytes' hexdump on standard output.
+pub fn print_hex(title: []const u8, buffer : []const u8) !void
+{
+    const stdout = std.io.getStdOut().writer();
+    var hexbuf: [100_000]u8 = undefined;
+    var hexfbs = std.io.fixedBufferStream(&hexbuf);
+    const hexwriter = hexfbs.writer();
+    try hexdump(hexwriter, title, buffer);
+    try stdout.print("{s}\n", .{hexfbs.getWritten()});
+}
+
 const print = std.debug.print;
 
 test "36-byte hexdump test" {

src/message.zig

@@ -5,6 +5,7 @@ const fmt = std.fmt;
 
 const print_eq = @import("./util.zig").print_eq;
 
+const payload_header_length = 4;
 pub const Messages = std.ArrayList(Message);
 
 pub const Message = struct {
@@ -28,17 +29,17 @@ pub const Message = struct {
         var reader = fbs.reader();
 
         const msg_len = try reader.readInt(u32, .big);
-        if (msg_len > buffer.len - 4) {
+        if (msg_len > buffer.len - payload_header_length) {
             return error.wrongMessageLength;
         }
-        const msg_payload = buffer[4 .. 4 + msg_len];
+        const msg_payload = buffer[payload_header_length .. payload_header_length + msg_len];
 
         return try Message.init(fd, allocator, msg_payload);
     }
 
     pub fn write(self: Self, writer: anytype) !usize {
         try writer.writeInt(u32, @as(u32, @truncate(self.payload.len)), .big);
-        return 4 + try writer.write(self.payload);
+        return payload_header_length + try writer.write(self.payload);
     }
 
     pub fn format(self: Self, comptime _: []const u8, _: fmt.FormatOptions, out_stream: anytype) !void {

src/switch.zig

@@ -40,10 +40,12 @@ pub const SwitchDB = struct {
     const Self = @This();
 
     db: std.AutoArrayHashMap(i32, ManagedConnection),
+    allocator: std.mem.Allocator,
 
     pub fn init(allocator: Allocator) Self {
         return Self{
             .db = std.AutoArrayHashMap(i32, ManagedConnection).init(allocator),
+            .allocator = allocator,
         };
     }
 
@@ -87,9 +89,10 @@ pub const SwitchDB = struct {
             },
             CBEventType.NO_ERROR => {
                 // TODO: read message
-                // TODO: better allocator?
                 // TODO: better errors?
-                const message: Message = Message.read(managedconnection.dest, buffer[0..message_size], std.heap.c_allocator) catch {
+                const message: Message = Message.read(managedconnection.dest
+                                                     , buffer[0..message_size]
+                                                     , self.allocator) catch {
                     return error.generic;
                 };
                 return message;