Thread API cleanup

This patch cleans up the thread API and comes with the following
noteworthy changes:

- Introduced Cpu_session::Weight type that replaces a formerly used
  plain integer value to prevent the accidental mix-up of
  arguments.
- The enum definition of Cpu_session::DEFAULT_WEIGHT moved to
  Cpu_session::Weight::DEFAULT_WEIGHT
- New Thread constructor that takes a 'Env &' as first argument.
  The original constructors are now marked as deprecated. For the
  common use case where the default 'Weight' and 'Affinity' are
  used, a shortcut is provided. In the long term, those two
  constructors should be the only ones to remain.
- The former 'Thread<>' class template has been renamed to
  'Thread_deprecated'.
- The former 'Thread_base' class is now called 'Thread'.
- The new 'name()' accessor returns the thread's name as 'Name'
  object as centrally defined via 'Cpu_session::Name'. It is meant to
  replace the old-fashioned 'name' method that takes a buffer and size
  as arguments.
- Adaptation of the thread test to the new API

Issue #1954

repos/base-nova/src/lib/base/ipc.cc

@@ -43,7 +43,7 @@ Rpc_exception_code Genode::ipc_call(Native_capability dst,
 		rcv_window.rcv_wnd(log2_max);
 	}
 
-	Nova::Utcb &utcb = *(Nova::Utcb *)Thread_base::myself()->utcb();
+	Nova::Utcb &utcb = *(Nova::Utcb *)Thread::myself()->utcb();
 
 	/* the protocol value is unused as the badge is delivered by the kernel */
 	if (!copy_msgbuf_to_utcb(utcb, snd_msg, 0)) {

repos/base-nova/src/lib/base/rpc_entrypoint.cc

@@ -83,7 +83,7 @@ void Rpc_entrypoint::_dissolve(Rpc_object_base *obj)
 	 */
 	using namespace Nova;
 
-	Utcb *utcb = reinterpret_cast<Utcb *>(Thread_base::myself()->utcb());
+	Utcb *utcb = reinterpret_cast<Utcb *>(Thread::myself()->utcb());
 	/* don't call ourself */
 	if (utcb == reinterpret_cast<Utcb *>(this->utcb()))
 		return;
@@ -111,7 +111,7 @@ static void reply(Nova::Utcb &utcb, Rpc_exception_code exc, Msgbuf_base &snd_msg
 {
 	copy_msgbuf_to_utcb(utcb, snd_msg, exc.value);
 
-	Nova::reply(Thread_base::myself()->stack_top());
+	Nova::reply(Thread::myself()->stack_top());
 }
 
 
@@ -124,8 +124,8 @@ void Rpc_entrypoint::_activation_entry()
 	addr_t id_pt; asm volatile ("" : "=a" (id_pt));
 #endif
 
-	Rpc_entrypoint &ep   = *static_cast<Rpc_entrypoint *>(Thread_base::myself());
-	Nova::Utcb     &utcb = *(Nova::Utcb *)Thread_base::myself()->utcb();
+	Rpc_entrypoint &ep   = *static_cast<Rpc_entrypoint *>(Thread::myself());
+	Nova::Utcb     &utcb = *(Nova::Utcb *)Thread::myself()->utcb();
 
 	Receive_window &rcv_window = ep.native_thread().rcv_window;
 	rcv_window.post_ipc(utcb);
@@ -219,7 +219,7 @@ Rpc_entrypoint::Rpc_entrypoint(Pd_session *pd_session, size_t stack_size,
                                const char  *name, bool start_on_construction,
                                Affinity::Location location)
 :
-	Thread_base(Cpu_session::DEFAULT_WEIGHT, name, stack_size, location),
+	Thread(Cpu_session::Weight::DEFAULT_WEIGHT, name, stack_size, location),
 	_delay_start(Lock::LOCKED),
 	_pd_session(*pd_session)
 {
@@ -228,7 +228,7 @@ Rpc_entrypoint::Rpc_entrypoint(Pd_session *pd_session, size_t stack_size,
 		native_thread().ec_sel = Native_thread::INVALID_INDEX - 1;
 
 	/* required to create a 'local' EC */
-	Thread_base::start();
+	Thread::start();
 
 	/* create cleanup portal */
 	_cap = _alloc_rpc_cap(_pd_session, Native_capability(native_thread().ec_sel),
@@ -236,7 +236,7 @@ Rpc_entrypoint::Rpc_entrypoint(Pd_session *pd_session, size_t stack_size,
 	if (!_cap.valid())
 		throw Cpu_session::Thread_creation_failed();
 
-	Receive_window &rcv_window = Thread_base::native_thread().rcv_window;
+	Receive_window &rcv_window = Thread::native_thread().rcv_window;
 
 	/* prepare portal receive window of new thread */
 	if (!rcv_window.prepare_rcv_window(*(Nova::Utcb *)&_stack->utcb()))

repos/base-nova/src/lib/base/sleep.cc

@@ -27,7 +27,7 @@ void Genode::sleep_forever()
 {
 	using namespace Nova;
 
-	Thread_base *myself = Thread_base::myself();
+	Thread *myself = Thread::myself();
 	addr_t sem = myself ? myself->native_thread().exc_pt_sel + SM_SEL_EC : SM_SEL_EC;
 
 	while (1) {

repos/base-nova/src/lib/base/stack.cc

@@ -109,11 +109,11 @@ void prepare_reinit_main_thread()
 }
 
 
-/*****************
- ** Thread_base **
- *****************/
+/************
+ ** Thread **
+ ************/
 
-Native_utcb *Thread_base::utcb()
+Native_utcb *Thread::utcb()
 {
 	/*
 	 * If 'utcb' is called on the object returned by 'myself',

repos/base-nova/src/lib/base/thread_start.cc

@@ -36,19 +36,17 @@ using namespace Genode;
 /**
  * Entry point entered by new threads
  */
-void Thread_base::_thread_start()
+void Thread::_thread_start()
 {
 	using namespace Genode;
 
 	/* catch any exception at this point and try to print an error message */
 	try {
-		Thread_base::myself()->entry();
+		Thread::myself()->entry();
 	} catch (...) {
-		char thread_name[48];
-		Thread_base::myself()->name(thread_name, sizeof(thread_name));
-
 		try {
-			PERR("Thread '%s' died because of an uncaught exception", thread_name);
+			PERR("Thread '%s' died because of an uncaught exception",
+			     Thread::myself()->name().string());
 		} catch (...) {
 			/* die in a noisy way */
 			nova_die();
@@ -57,7 +55,7 @@ void Thread_base::_thread_start()
 		throw;
 	}
 
-	Thread_base::myself()->_join_lock.unlock();
+	Thread::myself()->_join_lock.unlock();
 
 	/* sleep silently */
 	Genode::sleep_forever();
@@ -68,7 +66,7 @@ void Thread_base::_thread_start()
  ** Thread base **
  *****************/
 
-void Thread_base::_init_platform_thread(size_t weight, Type type)
+void Thread::_init_platform_thread(size_t weight, Type type)
 {
 	using namespace Nova;
 
@@ -113,16 +111,14 @@ void Thread_base::_init_platform_thread(size_t weight, Type type)
 		_cpu_session = env()->cpu_session();
 
 	/* create thread at core */
-	char buf[48];
-	name(buf, sizeof(buf));
-
-	_thread_cap = _cpu_session->create_thread(env()->pd_session_cap(), weight, buf, _affinity);
+	_thread_cap = _cpu_session->create_thread(env()->pd_session_cap(), name(),
+	                                          _affinity, Weight(weight));
 	if (!_thread_cap.valid())
 		throw Cpu_session::Thread_creation_failed();
 }
 
 
-void Thread_base::_deinit_platform_thread()
+void Thread::_deinit_platform_thread()
 {
 	using namespace Nova;
 
@@ -139,7 +135,7 @@ void Thread_base::_deinit_platform_thread()
 }
 
 
-void Thread_base::start()
+void Thread::start()
 {
 	if (native_thread().ec_sel < Native_thread::INVALID_INDEX - 1)
 		throw Cpu_session::Thread_creation_failed();
@@ -201,7 +197,7 @@ void Thread_base::start()
 }
 
 
-void Thread_base::cancel_blocking()
+void Thread::cancel_blocking()
 {
 	using namespace Nova;