Index: libcfa/src/concurrency/kernel/startup.cfa
===================================================================
--- libcfa/src/concurrency/kernel/startup.cfa	(revision 878cfcc025be2d89d167ef9fdf1b60ca2d6941b5)
+++ libcfa/src/concurrency/kernel/startup.cfa	(revision a167c70c7fa1e05fd7fb5472f69e13eba33b22b7)
@@ -16,4 +16,6 @@
 #define __cforall_thread__
 #define _GNU_SOURCE
+
+// #define __CFA_DEBUG_PRINT_RUNTIME_CORE__
 
 // C Includes
@@ -336,5 +338,5 @@
 
 		/* paranoid */ verify( this.do_terminate == true );
-		__cfaabi_dbg_print_safe("Kernel : destroyed main processor context %p\n", &runner);
+		__cfadbg_print_safe(runtime_core, "Kernel : destroyed main processor context %p\n", &runner);
 	}
 
@@ -397,5 +399,5 @@
 	(proc->runner){ proc, &info };
 
-	__cfaabi_dbg_print_safe("Coroutine : created stack %p\n", get_coroutine(proc->runner)->stack.storage);
+	__cfadbg_print_safe(runtime_core, "Coroutine : created stack %p\n", get_coroutine(proc->runner)->stack.storage);
 
 	//Set global state
@@ -662,4 +664,7 @@
 	io.params = io_params;
 
+	managed.procs = 0p;
+	managed.cnt = 0;
+
 	doregister(this);
 
@@ -677,4 +682,6 @@
 
 void ^?{}(cluster & this) libcfa_public {
+	set_concurrency( this, 0 );
+
 	destroy(this.io.arbiter);
 
@@ -848,4 +855,29 @@
 }
 
+unsigned set_concurrency( cluster & this, unsigned new ) libcfa_public {
+	unsigned old = this.managed.cnt;
+
+	__cfadbg_print_safe(runtime_core, "Kernel : resizing cluster from %u to %u\n", old, (unsigned)new);
+
+	// Delete all the old unneeded procs
+	if(old > new) for(i; (unsigned)new ~ old) {
+		__cfadbg_print_safe(runtime_core, "Kernel : destroying %u\n", i);
+		delete( this.managed.procs[i] );
+	}
+
+	// Allocate new array (uses realloc and memcpies the data)
+	this.managed.procs = alloc( new, this.managed.procs`realloc );
+	this.managed.cnt = new;
+
+	// Create the desired new procs
+	if(old < new) for(i; old ~ new) {
+		__cfadbg_print_safe(runtime_core, "Kernel : constructing %u\n", i);
+		(*(this.managed.procs[i] = alloc())){ this };
+	}
+
+	// return the old count
+	return old;
+}
+
 #if defined(__CFA_WITH_VERIFY__)
 static bool verify_fwd_bck_rng(void) {