From e90c74304bde38211b74624a559fcfd51f581431 Mon Sep 17 00:00:00 2001
From: Emery Hemingway <ehmry@posteo.net>
Date: Sat, 16 May 2020 02:23:50 +0530
Subject: [PATCH] solo5: do not yield for expired deadlines

---
 packages/solo5/default.nix |  2 +-
 packages/solo5/time.patch  | 60 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 packages/solo5/time.patch

diff --git a/packages/solo5/default.nix b/packages/solo5/default.nix
index 39b780d..2d8c681 100644
--- a/packages/solo5/default.nix
+++ b/packages/solo5/default.nix
@@ -20,7 +20,7 @@ in stdenv.mkDerivation {
 
   enableParallelBuilding = true;
 
-  patches = [ ./genode.patch ./elftool.patch ];
+  patches = [ ./genode.patch ./elftool.patch ./time.patch ];
 
   configurePhase = ''
     runHook preConfigure
diff --git a/packages/solo5/time.patch b/packages/solo5/time.patch
new file mode 100644
index 0000000..ab0da2e
--- /dev/null
+++ b/packages/solo5/time.patch
@@ -0,0 +1,60 @@
+commit a7902e24ba8fd2c6cfd56f68952f8d5417b9a303
+Author: Emery Hemingway <ehmry@posteo.net>
+Date:   Sat May 16 02:07:54 2020 +0530
+
+    Genode: do not yield for expired deadlines
+
+diff --git a/bindings/genode/bindings.cc b/bindings/genode/bindings.cc
+index 5785ae5..a4a4a34 100644
+--- a/bindings/genode/bindings.cc
++++ b/bindings/genode/bindings.cc
+@@ -104,6 +104,12 @@ namespace Solo5
+ 
+ 		return epoch;
+ 	}
++
++	static Microseconds from_ns(solo5_time_t ns) {
++		return Microseconds { ns / 1000ULL }; }
++
++	static solo5_time_t to_ns(Microseconds us) {
++		return us.value * 1000ULL; }
+ }
+ 
+ 
+@@ -431,20 +437,19 @@ struct Solo5::Platform
+ 			_initial_epoch = rtc_epoch(env);
+ 
+ 		return _initial_epoch * 1000000000ULL
+-		     + timer.curr_time().trunc_to_plain_us().value * 1000ULL;
++		     + to_ns(timer.curr_time().trunc_to_plain_us());
+ 	}
+ 
+ 	void
+ 	yield(solo5_time_t deadline_ns, solo5_handle_set_t *ready_set)
+ 	{
+ 		if (!nic_ready) {
+-			solo5_time_t deadline_us = deadline_ns / 1000;
+-			solo5_time_t now_us = timer.curr_time()
+-				.trunc_to_plain_us().value;
++			Microseconds deadline = from_ns(deadline_ns);
++			Microseconds now = timer.curr_time().trunc_to_plain_us();
++			if (deadline.value <= now.value) return;
+ 
+ 			// schedule a timeout signal
+-			yield_timeout.schedule(
+-				Genode::Microseconds{deadline_us - now_us});
++			yield_timeout.schedule(Microseconds {deadline.value - now.value});
+ 
+ 			/*
+ 			 * Block for Nic and Timer signals until a packet is
+@@ -531,8 +536,8 @@ void solo5_abort(void)
+ 
+ solo5_time_t solo5_clock_monotonic(void)
+ {
+-	return Platform::instance->timer.curr_time()
+-		.trunc_to_plain_us().value*1000;
++	return Solo5::to_ns(Platform::instance->
++		timer.curr_time().trunc_to_plain_us());
+ }
+ 
+