base: test for the pseudo-parallel use of an FPU

fix #1126

repos/base/src/test/fpu/main.cc

@@ -0,0 +1,114 @@
+/*
+ * \brief  Test pseudo-parallel use of FPU if available
+ * \author Martin Stein
+ * \date   2014-04-29
+ */
+
+/*
+ * Copyright (C) 2012-2014 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+/* Genode includes */
+#include <base/thread.h>
+#include <base/sleep.h>
+#include <base/printf.h>
+
+using namespace Genode;
+
+class Sync_signal_transmitter : public Signal_transmitter
+{
+	private:
+
+		Lock _lock;
+
+	public:
+
+		Sync_signal_transmitter(Signal_context_capability context = Signal_context_capability())
+		:
+			Signal_transmitter(context),
+			_lock(Lock::UNLOCKED)
+		{ }
+
+		void submit(unsigned cnt)
+		{
+			Lock::Guard guard(_lock);
+			Signal_transmitter::submit(cnt);
+		}
+};
+
+class Fpu_user : public Thread<4 * 1024>
+{
+	private:
+
+		float _x;
+		Sync_signal_transmitter * _st;
+
+		void _calc(float volatile & x, float volatile & y)
+		{
+			for (unsigned j = 0; j < 100; j++) {
+				x *= (y * 1.357);
+				x /= (y * 1.246);
+			}
+		}
+
+	public:
+
+		Fpu_user() : Thread("fpu_user"), _x(0), _st(0) { }
+
+		void start(float const x, Sync_signal_transmitter * const st)
+		{
+			_x = x;
+			_st = st;
+			Thread::start();
+		}
+
+		void entry()
+		{
+			Genode::printf("FPU user started\n");
+			bool submitted = false;
+			while (1) {
+				enum { TRIALS = 1000 };
+				for (unsigned i = 0; i < TRIALS; i++) {
+					float volatile a = _x + (float)i * ((float)1 / TRIALS);
+					float volatile b = _x + (float)i * ((float)1 / TRIALS);
+					float volatile c = _x;
+					_calc(a, c);
+					_calc(b, c);
+					if (a != b) {
+						PERR("calculation error");
+						_st->submit(1);
+						sleep_forever();
+					}
+				}
+				if (!submitted) {
+					_st->submit(1);
+					submitted = true;
+				}
+			}
+		}
+};
+
+int main()
+{
+	/* create ack signal */
+	Signal_context sc;
+	Signal_receiver sr;
+	Signal_context_capability const scc = sr.manage(&sc);
+	Sync_signal_transmitter st(scc);
+
+	/* start pseudo-parallel FPU users */
+	enum { FPU_USERS = 10 };
+	Fpu_user fpu_users[FPU_USERS];
+	for (unsigned i = 0; i < FPU_USERS; i++) {
+		float const x = (i + 1) * 1.234;
+		fpu_users[i].start(x, &st);
+	}
+	/* wait for an ack of every FPU user */
+	for (unsigned i = 0; i < FPU_USERS;) { i += sr.wait_for_signal().num(); }
+	printf("test done\n");
+	sleep_forever();
+	return 0;
+}

repos/base/src/test/fpu/target.mk

@@ -0,0 +1,14 @@
+#
+# \brief   Test pseudo-parallel use of FPU if available
+# \author  Martin Stein
+# \date    2012-04-25
+#
+
+# Set program name
+TARGET = test-fpu
+
+# Add C++ sources
+SRC_CC += main.cc
+
+# Add libraries
+LIBS += base