kernel: msg: implement asynchronous event messages

include/kernel/msg.h

@@ -13,6 +13,7 @@ enum kmsg_status {
 	KMSG_WAIT_RECEIVE,
 	KMSG_WAIT_REPLY,
 	KMSG_REPLY_SENT,
+	KMSG_ASYNC,
 };
 
 struct msg {
@@ -20,10 +21,26 @@ struct msg {
 	enum kmsg_status msg_status;
 	struct btree_node msg_node;
 	msgid_t msg_id;
-	kern_status_t msg_result;
 	struct port *msg_sender_port;
 	struct thread *msg_sender_thread;
+	kern_status_t msg_result;
+	kern_msg_type_t msg_type;
+
+	union {
+		/* msg_type = KERN_MSG_TYPE_DATA */
+		struct {
 			kern_msg_t msg_req, msg_resp;
 		};
 
+		/* msg_type = KERN_MSG_TYPE_EVENT */
+		struct {
+			kern_msg_event_type_t msg_event;
+		};
+	};
+};
+
+extern void msg_init(void);
+extern struct msg *msg_alloc(void);
+extern void msg_free(struct msg *msg);
+
 #endif

init/main.c

@@ -78,6 +78,7 @@ void kernel_init(uintptr_t arg)
 
 	port_type_init();
 	channel_type_init();
+	msg_init();
 
 	struct boot_module bsp_image = {0};
 	bsp_get_location(&bsp_image);

kernel/channel.c

@@ -98,11 +98,18 @@ static struct msg *get_next_msg(
 	while (cur) {
 		struct msg *msg = BTREE_CONTAINER(struct msg, msg_node, cur);
 		spin_lock_irqsave(&msg->msg_lock, lock_flags);
-		if (msg->msg_status == KMSG_WAIT_RECEIVE) {
+		switch (msg->msg_status) {
+		case KMSG_WAIT_RECEIVE:
 			msg->msg_status = KMSG_WAIT_REPLY;
 			msg->msg_sender_port->p_status = PORT_REPLY_BLOCKED;
 			channel->c_msg_waiting--;
 			return msg;
+		case KMSG_ASYNC:
+			btree_delete(&channel->c_msg, &msg->msg_node);
+			channel->c_msg_waiting--;
+			return msg;
+		default:
+			break;
 		}
 
 		spin_unlock_irqrestore(&msg->msg_lock, *lock_flags);
@@ -146,24 +153,22 @@ extern kern_status_t channel_recv_msg(
 			&channel->c_base,
 			CHANNEL_SIGNAL_MSG_RECEIVED);
 	}
-#if 0
-	wait_item_init(&waiter, self);
-	for (;;) {
-		thread_wait_begin(&waiter, &channel->c_wq);
-		msg = get_next_msg(channel, &msg_lock_flags);
-		if (msg) {
-			break;
-		}
-
-		object_unlock_irqrestore(&channel->c_base, *irq_flags);
-		schedule(SCHED_NORMAL);
-		object_lock_irqsave(&channel->c_base, irq_flags);
-	}
-	thread_wait_end(&waiter, &channel->c_wq);
-#endif
 
 	/* msg is now set to the next message to process */
 
+	if (msg->msg_type != KERN_MSG_TYPE_DATA) {
+		/* event messages as asynchronous */
+		out_msg->msg_id = msg->msg_id;
+		out_msg->msg_type = msg->msg_type;
+		out_msg->msg_event = msg->msg_event;
+		out_msg->msg_sender = msg->msg_sender_thread->tr_parent->t_id;
+		out_msg->msg_endpoint = msg->msg_sender_port->p_base.ob_id;
+		spin_unlock_irqrestore(&msg->msg_lock, msg_lock_flags);
+		msg_free(msg);
+
+		return KERN_OK;
+	}
+
 	struct task *sender = msg->msg_sender_thread->tr_parent;
 	struct task *receiver = self->tr_parent;
 
@@ -218,6 +223,7 @@ extern kern_status_t channel_recv_msg(
 	}
 
 	out_msg->msg_id = msg->msg_id;
+	out_msg->msg_type = msg->msg_type;
 	out_msg->msg_sender = msg->msg_sender_thread->tr_parent->t_id;
 	out_msg->msg_endpoint = msg->msg_sender_port->p_base.ob_id;
 

kernel/msg.c

@@ -0,0 +1,22 @@
+#include <kernel/msg.h>
+#include <kernel/vm.h>
+
+static struct vm_cache msg_cache = {
+	.c_name = "msg",
+	.c_obj_size = sizeof(struct msg),
+};
+
+void msg_init(void)
+{
+	vm_cache_init(&msg_cache);
+}
+
+struct msg *msg_alloc(void)
+{
+	return vm_cache_alloc(&msg_cache, VM_NORMAL);
+}
+
+void msg_free(struct msg *msg)
+{
+	vm_cache_free(&msg_cache, msg);
+}

kernel/port.c

@@ -1,16 +1,29 @@
 #include <kernel/channel.h>
 #include <kernel/port.h>
+#include <kernel/printk.h>
 #include <kernel/thread.h>
 #include <kernel/util.h>
 
 #define PORT_CAST(p) OBJECT_C_CAST(struct port, p_base, &port_type, p)
 
+static kern_status_t port_cleanup(struct object *obj);
+
 static struct object_type port_type = {
 	.ob_name = "port",
 	.ob_size = sizeof(struct port),
 	.ob_header_offset = offsetof(struct port, p_base),
+	.ob_ops = {
+		.destroy = port_cleanup,
+	},
 };
 
+static kern_status_t port_cleanup(struct object *obj, struct queue *q)
+{
+	struct port *port = PORT_CAST(obj);
+	port_disconnect(port);
+	return KERN_OK;
+}
+
 kern_status_t port_type_init(void)
 {
 	return object_type_register(&port_type);
@@ -58,9 +71,26 @@ struct port *port_create(void)
 kern_status_t port_connect(struct port *port, struct channel *remote)
 {
 	if (port->p_status != PORT_OFFLINE) {
+		tracek("port_connect: port in bad state (%d)", port->p_status);
 		return KERN_BAD_STATE;
 	}
 
+	struct msg *msg = msg_alloc();
+	if (!msg) {
+		return KERN_NO_MEMORY;
+	}
+
+	msg->msg_status = KMSG_ASYNC;
+	msg->msg_type = KERN_MSG_TYPE_EVENT;
+	msg->msg_event = KERN_MSG_EVENT_CONNECTION;
+	msg->msg_sender_thread = current_thread();
+	msg->msg_sender_port = port;
+
+	unsigned long flags;
+	channel_lock_irqsave(remote, &flags);
+	channel_enqueue_msg(remote, msg);
+	channel_unlock_irqrestore(remote, flags);
+
 	port->p_remote = remote;
 	port->p_status = PORT_READY;
 	return KERN_OK;
@@ -69,9 +99,27 @@ kern_status_t port_connect(struct port *port, struct channel *remote)
 kern_status_t port_disconnect(struct port *port)
 {
 	if (port->p_status != PORT_READY) {
+		tracek("port_disconnect: port in bad state (%d)",
+		       port->p_status);
 		return KERN_BAD_STATE;
 	}
 
+	struct msg *msg = msg_alloc();
+	if (!msg) {
+		return KERN_NO_MEMORY;
+	}
+
+	msg->msg_status = KMSG_ASYNC;
+	msg->msg_type = KERN_MSG_TYPE_EVENT;
+	msg->msg_event = KERN_MSG_EVENT_DISCONNECTION;
+	msg->msg_sender_thread = current_thread();
+	msg->msg_sender_port = port;
+
+	unsigned long flags;
+	channel_lock_irqsave(port->p_remote, &flags);
+	channel_enqueue_msg(port->p_remote, msg);
+	channel_unlock_irqrestore(port->p_remote, flags);
+
 	port->p_remote = NULL;
 	port->p_status = PORT_OFFLINE;
 	return KERN_OK;
@@ -84,12 +132,14 @@ kern_status_t port_send_msg(
 	unsigned long *lock_flags)
 {
 	if (port->p_status != PORT_READY) {
+		tracek("port_send_msg: port in bad state (%d)", port->p_status);
 		return KERN_BAD_STATE;
 	}
 
 	struct thread *self = current_thread();
 	struct msg msg;
 	memset(&msg, 0x0, sizeof msg);
+	msg.msg_type = KERN_MSG_TYPE_DATA;
 	msg.msg_status = KMSG_WAIT_RECEIVE;
 	msg.msg_sender_thread = self;
 	msg.msg_sender_port = port;

libmango/include/mango/types.h

@@ -44,6 +44,16 @@
  * kern_object_wait */
 #define KERN_WAIT_MAX_ITEMS          64
 
+/* message types */
+#define KERN_MSG_TYPE_NONE           0
+#define KERN_MSG_TYPE_DATA           1
+#define KERN_MSG_TYPE_EVENT          2
+
+/* event message types */
+#define KERN_MSG_EVENT_NONE          0
+#define KERN_MSG_EVENT_CONNECTION    1
+#define KERN_MSG_EVENT_DISCONNECTION 2
+
 /* equeue packet types */
 #define EQUEUE_PKT_PAGE_REQUEST      0x01u
 #define EQUEUE_PKT_ASYNC_SIGNAL      0x02u
@@ -92,6 +102,8 @@ typedef uint32_t kern_config_key_t;
 typedef uint32_t vm_prot_t;
 typedef int64_t ssize_t;
 typedef uint32_t kern_futex_t;
+typedef uint32_t kern_msg_type_t;
+typedef uint32_t kern_msg_event_type_t;
 
 typedef unsigned short equeue_packet_type_t;
 
@@ -122,14 +134,27 @@ typedef struct {
 	tid_t msg_sender;
 	/* the id of the port or channel used to send a particular message. */
 	koid_t msg_endpoint;
-	/* a list of iovecs that point to the buffers that make up the main
+	/* the message type */
-	 * message data. */
+	kern_msg_type_t msg_type;
+
+	union {
+		/* msg_type = KERN_MSG_TYPE_DATA */
+		struct {
+			/* a list of iovecs that point to the buffers that make
+			 * up the main message data. */
 			kern_iovec_t *msg_data;
 			size_t msg_data_count;
-	/* a list of handle entries that contain the kernel handles included
+			/* a list of handle entries that contain the kernel
-	 * in a message. */
+			 * handles included in a message. */
 			kern_msg_handle_t *msg_handles;
 			size_t msg_handles_count;
+		};
+
+		/* msg_type = KERN_MSG_TYPE_EVENT */
+		struct {
+			kern_msg_event_type_t msg_event;
+		};
+	};
 } kern_msg_t;
 
 typedef struct {

syscall/msg.c

@@ -60,9 +60,9 @@ kern_status_t sys_port_create(kern_handle_t *out)
 	kern_status_t status
 		= task_open_handle(self, &port->p_base, 0, &handle);
 	task_unlock_irqrestore(self, irq_flags);
+	object_unref(&port->p_base);
 
 	if (status != KERN_OK) {
-		object_unref(&port->p_base);
 		return status;
 	}
 
@@ -114,6 +114,7 @@ kern_status_t sys_port_connect(
 	status = port_connect(port, remote);
 	port_unlock_irqrestore(port, flags);
 	object_unref(&remote->c_base);
+	object_unref(port_obj);
 
 	return KERN_OK;
 }