channel: Allow anonymous transmissions

2 files changed, 7 insertions, 6 deletions

diff --git a/src/channel.zig b/src/channel.zig
index b3084b8..061331e 100644
--- a/src/channel.zig
+++ b/src/channel.zig
@@ -57,14 +57,14 @@ pub fn leave(pid: u16, id: usize) void {
 }
 
 // The channel takes ownership of `bytes`.
-pub fn pass(pid: u16, id: usize, receiver: u16, bytes: []const u8) !void {
+pub fn pass(pid: u16, id: usize, receiver: u16, identify: bool, bytes: []const u8) !void {
     const message = try alloc.create(Message);
     defer message.dropReference();
 
     message.* = .{
         .bytes = bytes,
         .process_filter = receiver,
-        .sender = pid,
+        .sender = if (identify) pid else 0,
     };
 
     var it = joined.iterator();
diff --git a/src/syscall.zig b/src/syscall.zig
index e8a2f89..79959cd 100644
--- a/src/syscall.zig
+++ b/src/syscall.zig
@@ -165,19 +165,20 @@ fn leave(proc: *const process.Info, trap_frame: *const TrapFrame) void {
     channel.leave(proc.id, id);
 }
 
-// pass(channel: usize, receiver: u16, bytes: [*]const u8, len: usize) !void
+// pass(channel: usize, receiver: u16, identify: bool, bytes: [*]const u8, len: usize) !void
 fn pass(proc: *const process.Info, trap_frame: *const TrapFrame) !void {
     const id = trap_frame.general_purpose_registers[10];
     const receiver_wide = trap_frame.general_purpose_registers[11];
-    const bytes_ptr: [*]const u8 = @ptrFromInt(trap_frame.general_purpose_registers[12]);
-    const len = trap_frame.general_purpose_registers[13];
+    const identify: bool = trap_frame.general_purpose_registers[12] != 0;
+    const bytes_ptr: [*]const u8 = @ptrFromInt(trap_frame.general_purpose_registers[13]);
+    const len = trap_frame.general_purpose_registers[14];
 
     const receiver = std.math.cast(u16, receiver_wide) orelse return ArgumentError.OutOfRange;
     const bytes = bytes_ptr[0..len];
 
     const copy = try channel.allocator().alloc(u8, bytes.len);
     @memcpy(copy, bytes);
-    try channel.pass(proc.id, id, receiver, copy);
+    try channel.pass(proc.id, id, receiver, identify, copy);
 }
 
 // receive(channel: usize, sender: ?*u16, buffer: [*]u8, len: usize) !usize