From 68b7783f32500396e53c28baa63f12c79f087e86 Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Sun, 15 Mar 2026 09:43:22 +0000
Subject: [PATCH] lib: xpc: implement non-blocking msg receive function

---
 lib/libxpc/include/xpc/msg.h |  1 +
 lib/libxpc/msg.c             | 43 ++++++++++++++++++++++++++++++++++--
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/lib/libxpc/include/xpc/msg.h b/lib/libxpc/include/xpc/msg.h
index 6bcae28..3ae443e 100644
--- a/lib/libxpc/include/xpc/msg.h
+++ b/lib/libxpc/include/xpc/msg.h
@@ -29,6 +29,7 @@ extern void xpc_msg_header_init(
 	unsigned short func);
 extern bool xpc_msg_header_validate(const xpc_msg_header_t *msg);
 extern kern_status_t xpc_msg_recv(kern_handle_t channel, xpc_msg_t *out);
+extern kern_status_t xpc_msg_recv_nowait(kern_handle_t channel, xpc_msg_t *out);
 extern kern_status_t xpc_msg_read(
 	const xpc_msg_t *msg,
 	size_t offset,
diff --git a/lib/libxpc/msg.c b/lib/libxpc/msg.c
index 6d92428..ec4b7d2 100644
--- a/lib/libxpc/msg.c
+++ b/lib/libxpc/msg.c
@@ -1,4 +1,6 @@
 #include <mango/msg.h>
+#include <mango/object.h>
+#include <mango/signal.h>
 #include <string.h>
 #include <xpc/msg.h>
 
@@ -20,8 +22,25 @@ bool xpc_msg_header_validate(const xpc_msg_header_t *msg)
 	return msg->hdr_magic == XPC_MSG_MAGIC;
 }
 
-kern_status_t xpc_msg_recv(kern_handle_t channel, xpc_msg_t *out)
+static kern_status_t __msg_recv(
+	kern_handle_t channel,
+	xpc_msg_t *out,
+	bool nowait)
 {
+	kern_status_t status = KERN_OK;
+
+	if (!nowait) {
+		kern_wait_item_t wait = {
+			.w_handle = channel,
+			.w_waitfor = CHANNEL_SIGNAL_MSG_RECEIVED,
+		};
+
+		status = kern_object_wait(&wait, 1);
+		if (status != KERN_OK) {
+			return status;
+		}
+	}
+
 	kern_iovec_t iov = IOVEC(&out->msg_header, sizeof out->msg_header);
 	kern_msg_t msg = {
 		.msg_data = &iov,
@@ -29,7 +48,8 @@ kern_status_t xpc_msg_recv(kern_handle_t channel, xpc_msg_t *out)
 		.msg_handles = out->msg_handles,
 		.msg_handles_count = KERN_MSG_MAX_HANDLES,
 	};
-	kern_status_t status = msg_recv(channel, &msg);
+
+	status = msg_recv(channel, &msg);
 	if (status != KERN_OK) {
 		return status;
 	}
@@ -46,6 +66,25 @@ kern_status_t xpc_msg_recv(kern_handle_t channel, xpc_msg_t *out)
 	return KERN_OK;
 }
 
+kern_status_t xpc_msg_recv(kern_handle_t channel, xpc_msg_t *out)
+{
+	kern_status_t status = KERN_OK;
+	while (1) {
+		status = __msg_recv(channel, out, false);
+
+		if (status != KERN_NO_ENTRY) {
+			break;
+		}
+	}
+
+	return status;
+}
+
+kern_status_t xpc_msg_recv_nowait(kern_handle_t channel, xpc_msg_t *out)
+{
+	return __msg_recv(channel, out, true);
+}
+
 kern_status_t xpc_msg_read(
 	const xpc_msg_t *msg,
 	size_t offset,