From b5f5a40fbcf0a0b40c6d024c25dac2dad9363486 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Lov=C3=A9n?= <thomasloven@gmail.com>
Date: Mon, 19 Feb 2018 10:24:47 +0100
Subject: [PATCH] Further queue improvements

---
 src/kernel/include/queue.h     |  8 ++++++++
 src/kernel/include/queue.tt    | 15 +++++++++++++++
 src/kernel/include/scheduler.h |  4 ++--
 src/kernel/include/thread.h    |  2 +-
 src/kernel/proc/scheduler.c    |  8 +++-----
 5 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/src/kernel/include/queue.h b/src/kernel/include/queue.h
index b7359f9..096fdfa 100644
--- a/src/kernel/include/queue.h
+++ b/src/kernel/include/queue.h
@@ -50,3 +50,11 @@
 #define _QUEUE_PEEK(queue, entry, type) \
     (queue.first)
 #define queue_peek(...) _QUEUE_PEEK(__VA_ARGS__)
+
+#define _QUEUE_POP(queue, entry, type) \
+  __extension__({ \
+      type *_ret = _QUEUE_PEEK(queue, entry, type); \
+   _QUEUE_DROP(queue, entry, type); \
+   _ret; \
+   })
+#define queue_pop(...) _QUEUE_POP(__VA_ARGS__)
diff --git a/src/kernel/include/queue.tt b/src/kernel/include/queue.tt
index f7b7bfa..3105154 100644
--- a/src/kernel/include/queue.tt
+++ b/src/kernel/include/queue.tt
@@ -58,3 +58,18 @@ TEST(empty_reports_nonempty_queue_not_empty)
   queue_add(TestQ, &item1);
   ASSERT_EQ_INT(!!queue_empty(TestQ), 0);
 }
+
+TEST(pop_returns_queued_item)
+{
+  queue_add(TestQ, &item1);
+  struct item *i = queue_pop(TestQ);
+  ASSERT_EQ_INT(i->id, 1);
+}
+TEST(pop_removes_item_from_queue)
+{
+  queue_add(TestQ, &item1);
+  queue_add(TestQ, &item2);
+  queue_pop(TestQ);
+  struct item *i = queue_peek(TestQ);
+  ASSERT_EQ_INT(i->id, 2);
+}
diff --git a/src/kernel/include/scheduler.h b/src/kernel/include/scheduler.h
index d4abad6..a98c689 100644
--- a/src/kernel/include/scheduler.h
+++ b/src/kernel/include/scheduler.h
@@ -1,8 +1,8 @@
 #pragma once
 #include <queue.h>
 
-#define READYQ readyQ, readyQ_next, struct thread
-QUEUE_DECLARE(READYQ);
+#define runQ readyQ, readyQ_next, struct thread
+QUEUE_DECLARE(runQ);
 
 void ready(struct thread *th);
 struct thread *scheduler_next();
diff --git a/src/kernel/include/thread.h b/src/kernel/include/thread.h
index d03a9e5..0bf316c 100644
--- a/src/kernel/include/thread.h
+++ b/src/kernel/include/thread.h
@@ -8,7 +8,7 @@ struct thread
   uintptr_t stack_ptr;
   uint64_t tid;
   uint64_t state;
-  QUEUE_SPOT(READYQ);
+  QUEUE_SPOT(runQ);
 };
 
 
diff --git a/src/kernel/proc/scheduler.c b/src/kernel/proc/scheduler.c
index f671502..b1f7ef2 100644
--- a/src/kernel/proc/scheduler.c
+++ b/src/kernel/proc/scheduler.c
@@ -2,16 +2,14 @@
 #include <queue.h>
 #include <thread.h>
 
-QUEUE_DEFINE(READYQ);
+QUEUE_DEFINE(runQ);
 
 void ready(struct thread *th)
 {
-  queue_add(READYQ, th);
+  queue_add(runQ, th);
 }
 
 struct thread *scheduler_next()
 {
-  struct thread *th = queue_peek(READYQ);
-  queue_drop(READYQ);
-  return th;
+  return queue_pop(runQ);
 }