Clean up base-library structure

This patch moves the base library from src/base to src/lib/base,
flattens the library-internal directory structure, and moves the common
parts of the library-description files to base/lib/mk/base.inc and
base/lib/mk/base-common.inc.

Furthermore, the patch fixes a few cosmetic issues (whitespace and
comments only) that I encountered while browsing the result.

Fixes #1952

repos/base-hw/src/lib/base/signal.cc

@@ -0,0 +1,142 @@
+/*
+ * \brief  Implementations of the signaling framework specific for HW-core
+ * \author Martin Stein
+ * \date   2012-05-05
+ */
+
+/*
+ * Copyright (C) 2012-2013 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 <util/retry.h>
+#include <base/thread.h>
+#include <base/signal.h>
+#include <base/env.h>
+#include <base/trace/events.h>
+
+/* base-internal includes */
+#include <base/internal/native_utcb.h>
+
+/* base-hw includes */
+#include <kernel/interface.h>
+
+using namespace Genode;
+
+
+namespace Genode {
+
+	/*
+	 * On base-hw, no signal thread is needed.
+	 */
+	void init_signal_thread() __attribute__((weak));
+	void init_signal_thread() { }
+	void destroy_signal_thread() { }
+}
+
+
+/********************
+ ** Signal context **
+ ********************/
+
+void Signal_context::submit(unsigned) { PERR("not implemented"); }
+
+
+/************************
+ ** Signal transmitter **
+ ************************/
+
+void Signal_transmitter::submit(unsigned cnt)
+{
+	{
+		Trace::Signal_submit trace_event(cnt);
+	}
+	Kernel::submit_signal(_context.dst(), cnt);
+}
+
+
+/*********************
+ ** Signal_receiver **
+ *********************/
+
+Signal_receiver::Signal_receiver()
+{
+	retry<Pd_session::Out_of_metadata>(
+		[&] () {
+			_cap = env()->pd_session()->alloc_signal_source();
+		},
+		[&] () {
+			PINF("upgrading quota donation for PD session");
+			env()->parent()->upgrade(env()->pd_session_cap(), "ram_quota=8K");
+		}
+	);
+}
+
+
+void Signal_receiver::_platform_destructor()
+{
+	/* release server resources of receiver */
+	env()->pd_session()->free_signal_source(_cap);
+}
+
+
+void Signal_receiver::_platform_begin_dissolve(Signal_context * const c)
+{
+	Kernel::kill_signal_context(c->_cap.dst());
+}
+
+void Signal_receiver::_platform_finish_dissolve(Signal_context *) { }
+
+
+Signal_context_capability Signal_receiver::manage(Signal_context * const c)
+{
+	/* ensure that the context isn't managed already */
+	Lock::Guard contexts_guard(_contexts_lock);
+	Lock::Guard context_guard(c->_lock);
+	if (c->_receiver) { throw Context_already_in_use(); }
+
+	retry<Pd_session::Out_of_metadata>(
+		[&] () {
+			/* use signal context as imprint */
+			c->_cap = env()->pd_session()->alloc_context(_cap, (unsigned long)c);
+			c->_receiver = this;
+			_contexts.insert(&c->_receiver_le);
+			return c->_cap;
+		},
+		[&] () {
+			PINF("upgrading quota donation for PD session");
+			env()->parent()->upgrade(env()->pd_session_cap(), "ram_quota=8K");
+		}
+	);
+
+	return c->_cap;
+}
+
+
+void Signal_receiver::block_for_signal()
+{
+	/* wait for a signal */
+	if (Kernel::await_signal(_cap.dst())) {
+		PERR("failed to receive signal");
+		return;
+	}
+	/* read signal data */
+	const void * const     utcb    = Thread_base::myself()->utcb()->data();
+	Signal::Data * const   data    = (Signal::Data *)utcb;
+	Signal_context * const context = data->context;
+	{
+		/* update signal context */
+		Lock::Guard lock_guard(context->_lock);
+		unsigned const num    = context->_curr_signal.num + data->num;
+		context->_pending     = true;
+		context->_curr_signal = Signal::Data(context, num);
+	}
+	/* end kernel-aided life-time management */
+	Kernel::ack_signal(data->context->_cap.dst());
+}
+
+
+void Signal_receiver::local_submit(Signal::Data) { PERR("not implemented"); }