From 195be5ff6ea33c8912352c1083ff166237c4f66a Mon Sep 17 00:00:00 2001
From: Michael Mueller <michael.mueller@uos.de>
Date: Tue, 29 Nov 2022 12:21:02 +0100
Subject: [PATCH] core: Export interface for explicit thread migration and
 pinning.

---
 repos/base/include/base/thread.h                    |  2 ++
 repos/base/include/cpu_session/client.h             |  3 +++
 repos/base/include/cpu_session/cpu_session.h        | 12 +++++++++++-
 repos/base/src/core/cpu_session_component.cc        |  6 ++++++
 repos/base/src/core/include/cpu_session_component.h |  1 +
 5 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/repos/base/include/base/thread.h b/repos/base/include/base/thread.h
index 23c85e88c3..8604d2c2e4 100644
--- a/repos/base/include/base/thread.h
+++ b/repos/base/include/base/thread.h
@@ -429,6 +429,8 @@ class Genode::Thread
 		 * Thread affinity
 		 */
 		Affinity::Location affinity() const { return _affinity; }
+
+		void pin(Affinity::Location &loc);
 };
 
 #endif /* _INCLUDE__BASE__THREAD_H_ */
diff --git a/repos/base/include/cpu_session/client.h b/repos/base/include/cpu_session/client.h
index e677d64ef5..60e65f801b 100644
--- a/repos/base/include/cpu_session/client.h
+++ b/repos/base/include/cpu_session/client.h
@@ -33,6 +33,9 @@ struct Genode::Cpu_session_client : Rpc_client<Cpu_session>
 	void kill_thread(Thread_capability thread) override {
 		call<Rpc_kill_thread>(thread); }
 
+	void migrate_thread(Thread_capability thread, Affinity::Location loc) override {
+		call<Rpc_migrate_thread>(thread, loc); }
+
 	void exception_sigh(Signal_context_capability sigh) override {
 		call<Rpc_exception_sigh>(sigh); }
 
diff --git a/repos/base/include/cpu_session/cpu_session.h b/repos/base/include/cpu_session/cpu_session.h
index 67389f49e1..6297d5eadf 100644
--- a/repos/base/include/cpu_session/cpu_session.h
+++ b/repos/base/include/cpu_session/cpu_session.h
@@ -21,6 +21,7 @@
 #include <session/session.h>
 #include <dataspace/capability.h>
 #include <pd_session/pd_session.h>
+#include <base/affinity.h>
 
 namespace Genode {
 
@@ -109,6 +110,14 @@ struct Genode::Cpu_session : Session
 	 */
 	virtual void kill_thread(Thread_capability thread) = 0;
 
+	/**
+	 * Migrate a thread to a new location
+	 * 
+	 * \param thread 	capability of the thread to migrate
+	 * \param loc 		component-local location to migrate the thread to 
+	 */
+	virtual void migrate_thread(Thread_capability thread, Genode::Affinity::Location loc) = 0;
+
 	/**
 	 * Register default signal handler for exceptions
 	 *
@@ -237,6 +246,7 @@ struct Genode::Cpu_session : Session
 	                 Capability<Pd_session>, Name const &, Affinity::Location,
 	                 Weight, addr_t);
 	GENODE_RPC(Rpc_kill_thread, void, kill_thread, Thread_capability);
+	GENODE_RPC(Rpc_migrate_thread, void, migrate_thread, Thread_capability, Affinity::Location);
 	GENODE_RPC(Rpc_exception_sigh, void, exception_sigh, Signal_context_capability);
 	GENODE_RPC(Rpc_affinity_space, Affinity::Space, affinity_space);
 	GENODE_RPC(Rpc_trace_control, Dataspace_capability, trace_control);
@@ -247,7 +257,7 @@ struct Genode::Cpu_session : Session
 
 	GENODE_RPC_INTERFACE(Rpc_create_thread, Rpc_kill_thread, Rpc_exception_sigh,
 	                     Rpc_affinity_space, Rpc_trace_control, Rpc_ref_account,
-	                     Rpc_transfer_quota, Rpc_quota, Rpc_native_cpu);
+	                     Rpc_transfer_quota, Rpc_quota, Rpc_native_cpu, Rpc_migrate_thread);
 };
 
 
diff --git a/repos/base/src/core/cpu_session_component.cc b/repos/base/src/core/cpu_session_component.cc
index 959e1ab113..760cacbb87 100644
--- a/repos/base/src/core/cpu_session_component.cc
+++ b/repos/base/src/core/cpu_session_component.cc
@@ -16,6 +16,7 @@
 /* Genode includes */
 #include <base/log.h>
 #include <util/arg_string.h>
+#include <cpu_thread/client.h>
 
 /* core includes */
 #include <cpu_session_component.h>
@@ -23,6 +24,7 @@
 #include <pd_session_component.h>
 #include <platform_generic.h>
 
+
 using namespace Genode;
 
 
@@ -144,6 +146,10 @@ void Cpu_session_component::kill_thread(Thread_capability thread_cap)
 	}
 }
 
+void Cpu_session_component::migrate_thread(Thread_capability thread_cap, Affinity::Location loc) 
+{
+	_thread_ep.apply(thread_cap, [&] (Cpu_thread_component *t) { t->affinity(_thread_affinity(loc)); });
+}
 
 void Cpu_session_component::exception_sigh(Signal_context_capability sigh)
 {
diff --git a/repos/base/src/core/include/cpu_session_component.h b/repos/base/src/core/include/cpu_session_component.h
index 328a498911..1b904ab3bf 100644
--- a/repos/base/src/core/include/cpu_session_component.h
+++ b/repos/base/src/core/include/cpu_session_component.h
@@ -169,6 +169,7 @@ class Genode::Cpu_session_component : public  Session_object<Cpu_session>,
 		Thread_capability create_thread(Capability<Pd_session>, Name const &,
 		                                Affinity::Location, Weight, addr_t) override;
 		void kill_thread(Thread_capability) override;
+		void migrate_thread(Thread_capability, Affinity::Location) override;
 		void exception_sigh(Signal_context_capability) override;
 		Affinity::Space affinity_space() const override;
 		Dataspace_capability trace_control() override;