From bc1da7f1fd2e366d290db4b33f07b9806d2a6932 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Wed, 20 Mar 2019 17:09:46 +0100
Subject: Kernel: Snooze the NetworkTask until there are incoming packets to
 process.

This is accomplished using a new Alarm class and a BlockedSnoozing state.
Basically, you call Process::snooze_until(some_alarm) and then the scheduler
won't wake up the process until some_alarm.is_ringing() returns true.
---
 Kernel/NetworkAdapter.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

(limited to 'Kernel/NetworkAdapter.h')

diff --git a/Kernel/NetworkAdapter.h b/Kernel/NetworkAdapter.h
index 512c80dfa4..a040aaced2 100644
--- a/Kernel/NetworkAdapter.h
+++ b/Kernel/NetworkAdapter.h
@@ -7,6 +7,18 @@
 #include <Kernel/IPv4.h>
 #include <Kernel/ARP.h>
 #include <Kernel/ICMP.h>
+#include <Kernel/Alarm.h>
+
+class NetworkAdapter;
+
+class PacketQueueAlarm final : public Alarm {
+public:
+    PacketQueueAlarm(NetworkAdapter& adapter) : m_adapter(adapter) { }
+    virtual ~PacketQueueAlarm() override { }
+    virtual bool is_ringing() const override;
+private:
+    NetworkAdapter& m_adapter;
+};
 
 class NetworkAdapter {
 public:
@@ -24,6 +36,10 @@ public:
 
     ByteBuffer dequeue_packet();
 
+    Alarm& packet_queue_alarm() { return m_packet_queue_alarm; }
+
+    bool has_queued_packets() const { return !m_packet_queue.is_empty(); }
+
 protected:
     NetworkAdapter();
     void set_mac_address(const MACAddress& mac_address) { m_mac_address = mac_address; }
@@ -33,5 +49,6 @@ protected:
 private:
     MACAddress m_mac_address;
     IPv4Address m_ipv4_address;
+    PacketQueueAlarm m_packet_queue_alarm;
     SinglyLinkedList<ByteBuffer> m_packet_queue;
 };
-- 
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