Move server API concept to base framework

This commit introduces the new `Component` interface in the form of the
headers base/component.h and base/entrypoint.h. The os/server.h API
has become merely a compatibilty wrapper and will eventually be removed.
The same holds true for os/signal_rpc_dispatcher.h. The mechanism has
moved to base/signal.h and is now called 'Signal_handler'.

Since the patch shuffles headers around, please do a 'make clean' in the
build directory.

Issue #1832

repos/base-linux/src/test/lx_hybrid_ctors/main.cc

@@ -11,11 +11,16 @@
  * under the terms of the GNU General Public License version 2.
  */
 
-
+/* Genode includes */
+#include <base/component.h>
 #include <base/printf.h>
 
+/* local includes */
 #include "testlib.h"
 
+/* Linux includes */
+#include <stdlib.h>
+
 using namespace Genode;
 
 
@@ -35,7 +40,18 @@ extern Testlib_testclass testlib_testobject;
 Testapp_testclass testapp_testobject;
 
 
-int main(int argc, char *argv[])
+static int exit_status;
+static void exit_on_suspended() { exit(exit_status); }
+
+
+Genode::size_t Component::stack_size() { return 16*1024*sizeof(long); }
+char const * Component::name()         { return "lx_hybrid_ctors"; }
+
+
+/*
+ * Component implements classical main function in construct.
+ */
+void Component::construct(Genode::Environment &env)
 {
 	printf("--- lx_hybrid global static constructor test ---\n");
 
@@ -47,6 +63,6 @@ int main(int argc, char *argv[])
 	testapp_testobject.dummy();
 
 	printf("--- returning from main ---\n");
-
-	return 0;
+	exit_status = 0;
+	env.ep().schedule_suspend(exit_on_suspended, nullptr);
 }

repos/base-linux/src/test/lx_hybrid_errno/main.cc

@@ -5,6 +5,7 @@
  */
 
 /* Genode includes */
+#include <base/component.h>
 #include <base/thread.h>
 #include <base/printf.h>
 
@@ -12,6 +13,7 @@
 #include <sys/stat.h>
 #include <unistd.h>
 #include <errno.h>
+#include <stdlib.h>
 
 enum { STACK_SIZE = 4096 };
 
@@ -40,7 +42,20 @@ struct Thread : Genode::Thread<STACK_SIZE>
 };
 
 
-int main(int, char **)
+static int exit_status;
+static void exit_on_suspended() { exit(exit_status); }
+
+
+Genode::size_t Component::stack_size() { return 16*1024*sizeof(long); }
+char const * Component::name()         { return "lx_hybrid_errno"; }
+
+
+struct Unexpected_errno_change { };
+
+/*
+ * Component implements classical main function in construct.
+ */
+void Component::construct(Genode::Environment &env)
 {
 	Genode::printf("--- thread-local errno test ---\n");
 
@@ -60,9 +75,10 @@ int main(int, char **)
 
 	if (orig_errno != errno) {
 		PERR("unexpected change of main thread's errno value");
-		return -1;
+		throw Unexpected_errno_change();
 	}
 
 	Genode::printf("--- finished thread-local errno test ---\n");
-	return 0;
+	exit_status = 0;
+	env.ep().schedule_suspend(exit_on_suspended, nullptr);
 }

repos/base-linux/src/test/lx_hybrid_exception/main.cc

@@ -11,27 +11,41 @@
  * under the terms of the GNU General Public License version 2.
  */
 
+/* Genode includes */
+#include <base/component.h>
 #include <base/printf.h>
 
+/* Linux includes */
+#include <stdlib.h>
+
 using namespace Genode;
 
+
 class Test_exception { };
 
-/**
- * Main program
+static int exit_status;
+static void exit_on_suspended() { exit(exit_status); }
+
+
+Genode::size_t Component::stack_size() { return 16*1024*sizeof(long); }
+char const * Component::name()         { return "lx_hybrid_exception"; }
+
+
+/*
+ * Component implements classical main function in construct.
  */
-int main(int, char **)
+void Component::construct(Genode::Environment &env)
 {
 	printf("--- lx_hybrid exception test ---\n");
 
 	try {
 		printf("Throwing Test_exception\n");
 		throw Test_exception();
-	} catch(Test_exception) {
+	} catch (Test_exception) {
 		printf("Caught Test_exception\n");
 	}
 
 	printf("--- returning from main ---\n");
-
-	return 0;
+	exit_status = 0;
+	env.ep().schedule_suspend(exit_on_suspended, nullptr);
 }

repos/base-linux/src/test/lx_hybrid_pthread_ipc/main.cc

@@ -12,11 +12,14 @@
  */
 
 /* Genode includes */
+#include <base/component.h>
 #include <base/thread.h>
 #include <base/printf.h>
 
 /* libc includes */
 #include <pthread.h>
+#include <stdlib.h>
+
 
 
 static Genode::Lock *main_wait_lock()
@@ -46,7 +49,18 @@ static void *pthread_entry(void *)
 }
 
 
-int main(int, char **)
+static int exit_status;
+static void exit_on_suspended() { exit(exit_status); }
+
+
+Genode::size_t Component::stack_size() { return 16*1024*sizeof(long); }
+char const * Component::name()         { return "lx_hybrid_pthread_ipc"; }
+
+
+/*
+ * Component implements classical main function in construct.
+ */
+void Component::construct(Genode::Environment &env)
 {
 	Genode::printf("--- pthread IPC test ---\n");
 
@@ -58,5 +72,6 @@ int main(int, char **)
 	main_wait_lock()->lock();
 
 	Genode::printf("--- finished pthread IPC test ---\n");
-	return 0;
+	exit_status = 0;
+	env.ep().schedule_suspend(exit_on_suspended, nullptr);
 }