base: remove deprecated cancel_blocking() support

for threads.

Fixes #3806

repos/base-linux/src/core/include/platform_thread.h

@@ -80,11 +80,6 @@ namespace Genode {
 
 			~Platform_thread();
 
-			/**
-			 * Cancel currently blocking operation
-			 */
-			void cancel_blocking();
-
 			/**
 			 * Pause this thread
 			 */

repos/base-linux/src/core/platform_thread.cc

@@ -89,12 +89,6 @@ Platform_thread::~Platform_thread()
 }
 
 
-void Platform_thread::cancel_blocking()
-{
-	lx_tgkill(_pid, _tid, LX_SIGUSR1);
-}
-
-
 void Platform_thread::pause()
 {
 	warning(__func__, "not implemented");

repos/base-linux/src/core/thread_linux.cc

@@ -69,6 +69,3 @@ void Thread::start()
 	native_thread().tid = lx_create_thread(Thread::_thread_start, stack_top(), this);
 	native_thread().pid = lx_getpid();
 }
-
-
-void Thread::cancel_blocking() { }

repos/base-linux/src/lib/base/thread_linux.cc

@@ -166,9 +166,3 @@ void Thread::start()
 	/* wait until the 'thread_start' function got entered */
 	startup_lock().block();
 }
-
-
-void Thread::cancel_blocking()
-{
-	Cpu_thread_client(_thread_cap).cancel_blocking();
-}

repos/base-linux/src/lib/lx_hybrid/lx_hybrid.cc

@@ -531,14 +531,6 @@ Thread::Thread(Env &env, Name const &name, size_t stack_size)
 : Thread(env, name, stack_size, Location(), Weight(), env.cpu()) { }
 
 
-void Thread::cancel_blocking()
-{
-	/*
-	 * XXX implement interaction with CPU session
-	 */
-}
-
-
 Thread::~Thread()
 {
 	bool const needs_join = (pthread_cancel(native_thread().meta_data->pt) == 0);