From 019528ee6a6327cd3b5dccbecd21dc26c4d25ef6 Mon Sep 17 00:00:00 2001
From: Christian Helmuth <christian.helmuth@genode-labs.com>
Date: Fri, 16 Jun 2017 16:27:56 +0200
Subject: [PATCH] Disable lock tests on platforms without priorities

The implementations of the lock and C++ guards tests depend on
thread-execution priorities, which produces false negatives of the whole
thread test on platforms without priority support.
---
 repos/base/run/thread.run          | 29 ++++++++++++++++++-----------
 repos/base/src/test/thread/main.cc | 16 ++++++++++++----
 2 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/repos/base/run/thread.run b/repos/base/run/thread.run
index 21720e2af6..54b96bcb26 100644
--- a/repos/base/run/thread.run
+++ b/repos/base/run/thread.run
@@ -7,13 +7,25 @@ create_boot_directory
 # supported.
 #
 proc pause_resume_supported { } {
-	if {[have_spec pistachio]} { return 0 }
-	if {[have_spec linux]}     { return 0 }
-	if {[have_spec fiasco]}    { return 0 }
-	return 1;
+	if {[have_spec pistachio]} { return false }
+	if {[have_spec linux]}     { return false }
+	if {[have_spec fiasco]}    { return false }
+	return true
 }
 
-set config {
+#
+# We skip the lock and C++ guard tests on kernels without priority support (as
+# it is needed for the test implementation).
+#
+proc prio_supported { } {
+	if {[have_spec hw]}        { return false }
+	if {[have_spec sel4]}      { return false }
+	if {[have_spec linux]}     { return false }
+	if {[have_spec fiasco]}    { return false }
+	return true
+}
+
+append config {
 	<config prio_levels="2">
 		<parent-provides>
 			<service name="LOG"/>
@@ -27,12 +39,7 @@ set config {
 		<start name="test-thread" caps="2000">
 			<resource name="RAM" quantum="10M"/>
 			<resource name="CPU" quantum="100"/>
-			<config>}
-
-append_if [pause_resume_supported] config {				<pause_resume/> }
-
-append config {
-			</config>
+			<config pause_resume="} [pause_resume_supported] {" prio="} [prio_supported] {"/>
 		</start>
 	</config>
 }
diff --git a/repos/base/src/test/thread/main.cc b/repos/base/src/test/thread/main.cc
index 5c819cdc11..ab02eb48ab 100644
--- a/repos/base/src/test/thread/main.cc
+++ b/repos/base/src/test/thread/main.cc
@@ -21,6 +21,7 @@
 #include <util/reconstructible.h>
 #include <cpu_session/connection.h>
 #include <cpu_thread/client.h>
+#include <cpu/memory_barrier.h>
 
 using namespace Genode;
 
@@ -407,6 +408,12 @@ static void test_locks(Genode::Env &env)
 	Lock_helper l5(env, "lock_low5", cpu_l, lock, lock_is_free, SYNC_STARTUP);
 	l5.start();
 
+	log(" spin for some time");
+	for (unsigned volatile i = 0; i < 8000000; ++i) memory_barrier();
+	log(" still spinning");
+	for (unsigned volatile i = 0; i < 8000000; ++i) memory_barrier();
+	log(" spinning done");
+
 	lock.lock();
 	log(" I'm the lock holder - still alive");
 	lock_is_free = true;
@@ -648,10 +655,11 @@ void Component::construct(Env &env)
 		test_stack_alignment(env);
 		test_main_thread();
 		test_cpu_session(env);
-		test_locks(env);
-		test_cxa_guards(env);
-
-		if (config.xml().has_sub_node("pause_resume"))
+		if (config.xml().attribute_value("prio", false)) {
+			test_locks(env);
+			test_cxa_guards(env);
+		}
+		if (config.xml().attribute_value("pause_resume", false))
 			test_pause_resume(env);
 
 		test_create_as_many_threads(env);