First pass at message syscalls

src/kernel/process.h

@@ -25,7 +25,9 @@ enum class process_wait : uint8_t
 	none,
 	signal,
 	child,
-	time
+	time,
+	send,
+	receive
 };
 
 /// A process
@@ -52,15 +54,30 @@ struct process
 
 	/// Unready this process until it gets a signal
 	/// \arg sigmask  A bitfield of signals to wake on
-	void wait_on_signal(uint64_t sigmask);
+	/// \returns  Whether the process should be rescheduled
+	bool wait_on_signal(uint64_t sigmask);
 
 	/// Unready this process until a child exits
 	/// \arg pid  PID of the child to wait for, or 0 for any
-	void wait_on_child(uint32_t pid);
+	/// \returns  Whether the process should be rescheduled
+	bool wait_on_child(uint32_t pid);
 
 	/// Unready this process until after the given time
 	/// \arg time  The time after which to wake
-	void wait_on_time(uint64_t time);
+	/// \returns  Whether the process should be rescheduled
+	bool wait_on_time(uint64_t time);
+
+	/// Try to send to the target process, becoming unready if it
+	/// is not waiting on receive.
+	/// \arg target_id  The process to send to
+	/// \returns  Whether the process should be rescheduled
+	bool wait_on_send(uint32_t target_id);
+
+	/// Try to receive from one or more processes, becoming unready
+	/// if none of them are waiting on a send to this process.
+	/// \arg source_id  The process to receive from
+	/// \returns  Whether the process should be rescheduled
+	bool wait_on_receive(uint32_t source_id);
 
 	/// If this process is waiting on the given signal, wake it
 	/// \argument signal  The signal sent to the process
@@ -76,6 +93,17 @@ struct process
 	/// \argument now  The current time
 	/// \returns  True if this wake was handled
 	bool wake_on_time(uint64_t now);
+
+	/// If this process is waiting to send to this target, wake it
+	/// \argument target  The target process
+	/// \returns  True if this wake was handled
+	bool wake_on_send(process *target);
+
+	/// If this process is waiting to receieve from this source, wake it
+	/// \argument source  The process that is sending
+	/// \returns  True if this wake was handled
+	bool wake_on_receive(process *source);
+
 };
 
 using process_list = kutil::linked_list<process>;