base: changes for GDB monitor

- add a new function 'binary_ready_hook_for_gdb()' in ldso. GDB can set a
  breakpoint at this function to know when ldso has loaded the binary
  into memory.
- get the thread state from the NOVA kernel immediately on 'pause()'

Fixes #1968

repos/base-nova/include/cpu_thread/client.h

@@ -0,0 +1,82 @@
+/*
+ * \brief  Client-side CPU thread interface
+ * \author Norman Feske
+ * \date   2016-05-10
+ */
+
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef _INCLUDE__CPU_THREAD__CLIENT_H_
+#define _INCLUDE__CPU_THREAD__CLIENT_H_
+
+#include <cpu_thread/cpu_thread.h>
+#include <base/rpc_client.h>
+
+namespace Genode { struct Cpu_thread_client; }
+
+
+struct Genode::Cpu_thread_client : Rpc_client<Cpu_thread>
+{
+	explicit Cpu_thread_client(Thread_capability cap)
+	: Rpc_client<Cpu_thread>(cap) { }
+
+	Dataspace_capability utcb() override {
+		return call<Rpc_utcb>(); }
+
+	void start(addr_t ip, addr_t sp) override {
+		call<Rpc_start>(ip, sp); }
+
+	void pause() override {
+
+		for (;;) {
+
+			call<Rpc_pause>();
+
+			try {
+				/* check if the thread state is valid */
+				state();
+				/* the thread is paused */
+				return;
+			} catch (State_access_failed) {
+				/* the thread is (most likely) running on a different CPU */
+			}
+		}
+	}
+
+	void resume() override {
+		call<Rpc_resume>(); }
+
+	void cancel_blocking() override {
+		call<Rpc_cancel_blocking>(); }
+
+	Thread_state state() override {
+		return call<Rpc_get_state>(); }
+
+	void state(Thread_state const &state) override {
+		call<Rpc_set_state>(state); }
+
+	void exception_sigh(Signal_context_capability handler) override {
+		call<Rpc_exception_sigh>(handler); }
+
+	void single_step(bool enabled) override {
+		call<Rpc_single_step>(enabled); }
+
+	void affinity(Affinity::Location location) override {
+		call<Rpc_affinity>(location); }
+
+	unsigned trace_control_index() override {
+		return call<Rpc_trace_control_index>(); }
+
+	Dataspace_capability trace_buffer() override {
+		return call<Rpc_trace_buffer>(); }
+
+	Dataspace_capability trace_policy() override {
+		return call<Rpc_trace_policy>(); }
+};
+
+#endif /* _INCLUDE__CPU_THREAD__CLIENT_H_ */