From 776c2a6046f076b6e9fc85dcde6523499507e900 Mon Sep 17 00:00:00 2001
From: Stefan Kalkowski <stefan.kalkowski@genode-labs.com>
Date: Mon, 5 Feb 2024 10:23:39 +0100
Subject: [PATCH] hw: avoid state & code duplication in scheduler

The `_head_was_removed` variable got introduced in solving #4710, but it
reflects only whether `_head` is a valid pointer or not, thereby it
duplicates state.

Ref genodelabs/genode#5115
---
 .../base-hw/src/core/kernel/cpu_scheduler.cc  | 20 +++++--------------
 repos/base-hw/src/core/kernel/cpu_scheduler.h |  1 -
 2 files changed, 5 insertions(+), 16 deletions(-)

diff --git a/repos/base-hw/src/core/kernel/cpu_scheduler.cc b/repos/base-hw/src/core/kernel/cpu_scheduler.cc
index 91ca63e258..1d5b7f7331 100644
--- a/repos/base-hw/src/core/kernel/cpu_scheduler.cc
+++ b/repos/base-hw/src/core/kernel/cpu_scheduler.cc
@@ -178,27 +178,19 @@ void Cpu_scheduler::update(time_t time)
 	unsigned duration = (unsigned) (time - _last_time);
 	_last_time        = time;
 	_need_to_schedule = false;
+	unsigned const r  = _trim_consumption(duration);
 
 	/* do not detract the quota if the head context was removed even now */
 	if (_head) {
-		unsigned const r = _trim_consumption(duration);
-
 		if (_head_claims)
 			_head_claimed(r);
 		else
 			_head_filled(r);
-
-		_head_yields = false;
-		_consumed(duration);
-
-	} else if (_head_was_removed) {
-
-		_trim_consumption(duration);
-		_head_was_removed = false;
-		_head_yields = false;
-		_consumed(duration);
 	}
 
+	_head_yields = false;
+	_consumed(duration);
+
 	if (_claim_for_head())
 		return;
 
@@ -276,10 +268,8 @@ void Cpu_scheduler::remove(Share &s)
 
 	if (s._ready) unready(s);
 
-	if (&s == _head) {
+	if (&s == _head)
 		_head = nullptr;
-		_head_was_removed = true;
-	}
 
 	if (!s._quota)
 		return;
diff --git a/repos/base-hw/src/core/kernel/cpu_scheduler.h b/repos/base-hw/src/core/kernel/cpu_scheduler.h
index 4699292f40..45247f6ae1 100644
--- a/repos/base-hw/src/core/kernel/cpu_scheduler.h
+++ b/repos/base-hw/src/core/kernel/cpu_scheduler.h
@@ -134,7 +134,6 @@ class Kernel::Cpu_scheduler
 		unsigned                _head_quota  = 0;
 		bool                    _head_claims = false;
 		bool                    _head_yields = false;
-		bool                    _head_was_removed = false;
 		unsigned const          _quota;
 		unsigned                _residual;
 		unsigned const          _fill;