genode/repos/base/src/core/signal_source_component.cc
Norman Feske 17c79a9e23 base: avoid use of deprecated base/printf.h
Besides adapting the components to the use of base/log.h, the patch
cleans up a few base headers, i.e., it removes unused includes from
root/component.h, specifically base/heap.h and
ram_session/ram_session.h. Hence, components that relied on the implicit
inclusion of those headers have to manually include those headers now.

While adjusting the log messages, I repeatedly stumbled over the problem
that printing char * arguments is ambiguous. It is unclear whether to
print the argument as pointer or null-terminated string. To overcome
this problem, the patch introduces a new type 'Cstring' that allows the
caller to express that the argument should be handled as null-terminated
string. As a nice side effect, with this type in place, the optional len
argument of the 'String' class could be removed. Instead of supplying a
pair of (char const *, size_t), the constructor accepts a 'Cstring'.
This, in turn, clears the way let the 'String' constructor use the new
output mechanism to assemble a string from multiple arguments (and
thereby getting rid of snprintf within Genode in the near future).

To enforce the explicit resolution of the char * ambiguity, the 'char *'
overload of the 'print' function is marked as deleted.

Issue #1987
2016-08-29 17:27:10 +02:00

111 lines
2.5 KiB
C++

/*
* \brief Implementation of the SIGNAL interface
* \author Norman Feske
* \date 2009-08-11
*/
/*
* Copyright (C) 2009-2013 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 <base/ipc.h>
/* core includes */
#include <signal_source_component.h>
using namespace Genode;
/*****************************
** Signal-source component **
*****************************/
void Signal_source_component::release(Signal_context_component *context)
{
if (context && context->enqueued())
_signal_queue.remove(context);
}
void Signal_source_component::submit(Signal_context_component *context,
unsigned long cnt)
{
/*
* If the client does not block in 'wait_for_signal', the
* signal will be delivered as result of the next
* 'wait_for_signal' call.
*/
context->increment_signal_cnt(cnt);
/*
* If the client is blocking at the signal source (indicated by
* the valid reply capability), we wake him up.
*/
if (_reply_cap.valid()) {
_entrypoint->reply_signal_info(_reply_cap, context->imprint(), context->cnt());
/*
* We unblocked the client and, therefore, can invalidate
* the reply capability.
*/
_reply_cap = Untyped_capability();
context->reset_signal_cnt();
} else {
if (!context->enqueued())
_signal_queue.enqueue(context);
}
}
Signal_source::Signal Signal_source_component::wait_for_signal()
{
/* keep client blocked */
if (_signal_queue.empty()) {
/*
* Keep reply capability for outstanding request to be used
* for the later call of 'explicit_reply()'.
*/
_reply_cap = _entrypoint->reply_dst();
_entrypoint->omit_reply();
return Signal(0, 0); /* just a dummy */
}
/* dequeue and return pending signal */
Signal_context_component *context = _signal_queue.dequeue();
Signal result(context->imprint(), context->cnt());
context->reset_signal_cnt();
return result;
}
Signal_source_component::Signal_source_component(Rpc_entrypoint *ep)
:
_entrypoint(ep), _finalizer(*this),
_finalizer_cap(_entrypoint->manage(&_finalizer))
{ }
Signal_source_component::~Signal_source_component()
{
_finalizer_cap.call<Finalizer::Rpc_exit>();
_entrypoint->dissolve(&_finalizer);
}
void Signal_source_component::Finalizer_component::exit()
{
if (!source._reply_cap.valid())
return;
source._entrypoint->reply_signal_info(source._reply_cap, 0, 0);
source._reply_cap = Untyped_capability();
}