Index: src/tests/.expect/concurrent/preempt.txt
===================================================================
--- src/tests/.expect/concurrent/preempt.txt	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
+++ src/tests/.expect/concurrent/preempt.txt	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -0,0 +1,10 @@
+100
+200
+300
+400
+500
+600
+700
+800
+900
+1000
Index: src/tests/preempt.c
===================================================================
--- src/tests/preempt.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
+++ src/tests/preempt.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -0,0 +1,42 @@
+#include <kernel>
+#include <thread>
+
+#ifndef PREEMPTION_RATE
+#define PREEMPTION_RATE 10_000ul
+#endif
+
+unsigned int default_preemption() {
+	return PREEMPTION_RATE;
+}
+
+static volatile int counter = 0;
+
+thread Worker {
+	int value;
+};
+
+void ?{}( Worker * this, int value ) {
+	this->value = value;
+}
+
+void main(Worker * this) {
+	while(counter < 1000) {
+		if( (counter % 7) == this->value ) {
+			int next = __atomic_add_fetch_4(&counter, 1, __ATOMIC_SEQ_CST);
+			if( (next % 100) == 0 ) printf("%d\n", next);
+		}
+	}
+}
+
+int main(int argc, char* argv[]) {
+	processor p;
+	{
+		Worker w0 = 0;
+		Worker w1 = 1;
+		Worker w2 = 2;
+		Worker w3 = 3;
+		Worker w4 = 4;
+		Worker w5 = 5;
+		Worker w6 = 6;
+	}
+}
Index: src/tests/preempt_longrun/Makefile.am
===================================================================
--- src/tests/preempt_longrun/Makefile.am	(revision 7c03d6db65469e4f71a28659478ead50ca5cbe52)
+++ src/tests/preempt_longrun/Makefile.am	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -10,6 +10,6 @@
 ## Author           : Thierry Delisle
 ## Created On       : Fri Jun 16 10:57:34 2017
-## Last Modified By : 
-## Last Modified On : 
+## Last Modified By :
+## Last Modified On :
 ## Update Count     : 0
 ###############################################################################
@@ -17,5 +17,5 @@
 repeats=10
 max_time=30
-preempt=10_000ul
+preempt=1_000ul
 
 REPEAT = ${abs_top_srcdir}/tools/repeat -s
@@ -25,5 +25,5 @@
 CC = @CFA_BINDIR@/@CFA_NAME@
 
-TESTS = barge block create disjoint processor stack wait yield
+TESTS = barge block create disjoint enter enter3 processor stack wait yield
 
 .INTERMEDIATE: ${TESTS}
Index: src/tests/preempt_longrun/Makefile.in
===================================================================
--- src/tests/preempt_longrun/Makefile.in	(revision 7c03d6db65469e4f71a28659478ead50ca5cbe52)
+++ src/tests/preempt_longrun/Makefile.in	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -450,8 +450,8 @@
 repeats = 10
 max_time = 30
-preempt = 10_000ul
+preempt = 1_000ul
 REPEAT = ${abs_top_srcdir}/tools/repeat -s
 BUILD_FLAGS = -g -Wall -Wno-unused-function -quiet @CFA_FLAGS@ -debug -O2 -DPREEMPTION_RATE=${preempt}
-TESTS = barge block create disjoint processor stack wait yield
+TESTS = barge block create disjoint enter enter3 processor stack wait yield
 all: all-am
 
@@ -663,4 +663,18 @@
 	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
 	"$$tst" $(AM_TESTS_FD_REDIRECT)
+enter.log: enter
+	@p='enter'; \
+	b='enter'; \
+	$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+	--log-file $$b.log --trs-file $$b.trs \
+	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
+	"$$tst" $(AM_TESTS_FD_REDIRECT)
+enter3.log: enter3
+	@p='enter3'; \
+	b='enter3'; \
+	$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+	--log-file $$b.log --trs-file $$b.trs \
+	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
+	"$$tst" $(AM_TESTS_FD_REDIRECT)
 processor.log: processor
 	@p='processor'; \
Index: src/tests/preempt_longrun/create.c
===================================================================
--- src/tests/preempt_longrun/create.c	(revision 7c03d6db65469e4f71a28659478ead50ca5cbe52)
+++ src/tests/preempt_longrun/create.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -15,5 +15,5 @@
 
 int main(int argc, char* argv[]) {
-	for(int i = 0; i < 100_000ul; i++) {
+	for(int i = 0; i < 250_000ul; i++) {
 		Worker w;
 	}
Index: src/tests/preempt_longrun/enter.c
===================================================================
--- src/tests/preempt_longrun/enter.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
+++ src/tests/preempt_longrun/enter.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -0,0 +1,35 @@
+#include <kernel>
+#include <monitor>
+#include <thread>
+
+#undef N
+static const unsigned long N  = 70_000ul;
+
+#ifndef PREEMPTION_RATE
+#define PREEMPTION_RATE 10_000ul
+#endif
+
+unsigned int default_preemption() {
+	return PREEMPTION_RATE;
+}
+
+monitor mon_t {};
+
+mon_t mon;
+
+void foo( mon_t * mutex this ) {}
+
+thread worker_t {};
+
+void main( worker_t * this ) {
+	for( unsigned long i = 0; i < N; i++ ) {
+		foo( &mon );
+	}
+}
+
+int main(int argc, char * argv[] ) {
+	processor p;
+	{
+		worker_t w[7];
+	}
+}
Index: src/tests/preempt_longrun/enter3.c
===================================================================
--- src/tests/preempt_longrun/enter3.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
+++ src/tests/preempt_longrun/enter3.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -0,0 +1,35 @@
+#include <kernel>
+#include <monitor>
+#include <thread>
+
+#undef N
+static const unsigned long N  = 50_000ul;
+
+#ifndef PREEMPTION_RATE
+#define PREEMPTION_RATE 10_000ul
+#endif
+
+unsigned int default_preemption() {
+	return PREEMPTION_RATE;
+}
+
+monitor mon_t {};
+
+mon_t mon1, mon2, mon3;
+
+void foo( mon_t * mutex a, mon_t * mutex b, mon_t * mutex c ) {}
+
+thread worker_t {};
+
+void main( worker_t * this ) {
+	for( unsigned long i = 0; i < N; i++ ) {
+		foo( &mon1, &mon2, &mon3 );
+	}
+}
+
+int main(int argc, char * argv[] ) {
+	processor p;
+	{
+		worker_t w[7];
+	}
+}
Index: src/tests/preempt_longrun/processor.c
===================================================================
--- src/tests/preempt_longrun/processor.c	(revision 7c03d6db65469e4f71a28659478ead50ca5cbe52)
+++ src/tests/preempt_longrun/processor.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -15,5 +15,5 @@
 
 int main(int argc, char* argv[]) {
-	for(int i = 0; i < 100_000ul; i++) {
+	for(int i = 0; i < 10_000ul; i++) {
 		processor p;
 	}
Index: src/tests/preempt_longrun/yield.c
===================================================================
--- src/tests/preempt_longrun/yield.c	(revision 7c03d6db65469e4f71a28659478ead50ca5cbe52)
+++ src/tests/preempt_longrun/yield.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -13,5 +13,5 @@
 
 void main(Worker * this) {
-	for(int i = 0; i < 100_000ul; i++) {
+	for(int i = 0; i < 325_000ul; i++) {
 		yield();
 	}
Index: src/tests/sched-int-block.c
===================================================================
--- src/tests/sched-int-block.c	(revision 7c03d6db65469e4f71a28659478ead50ca5cbe52)
+++ src/tests/sched-int-block.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -6,5 +6,5 @@
 
 #ifndef N
-#define N 100_000
+#define N 10_000
 #endif
 
@@ -31,5 +31,5 @@
 //------------------------------------------------------------------------------
 void wait_op( global_data_t * mutex a, global_data_t * mutex b, unsigned i ) {
-	wait( &cond, (uintptr_t)this_thread() );
+	wait( &cond, (uintptr_t)this_thread );
 
 	yield( ((unsigned)rand48()) % 10 );
@@ -40,5 +40,5 @@
 	}
 
-	a->last_thread = b->last_thread = this_thread();
+	a->last_thread = b->last_thread = this_thread;
 
 	yield( ((unsigned)rand48()) % 10 );
@@ -56,5 +56,5 @@
 	yield( ((unsigned)rand48()) % 10 );
 
-	a->last_thread = b->last_thread = a->last_signaller = b->last_signaller = this_thread();
+	a->last_thread = b->last_thread = a->last_signaller = b->last_signaller = this_thread;
 
 	if( !is_empty( &cond ) ) {
@@ -86,5 +86,5 @@
 //------------------------------------------------------------------------------
 void barge_op( global_data_t * mutex a ) {
-	a->last_thread = this_thread();
+	a->last_thread = this_thread;
 }
 
Index: src/tests/sched-int-wait.c
===================================================================
--- src/tests/sched-int-wait.c	(revision 7c03d6db65469e4f71a28659478ead50ca5cbe52)
+++ src/tests/sched-int-wait.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -50,14 +50,14 @@
 		unsigned action = (unsigned)rand48() % 4;
 		switch( action ) {
-			case 0: 
+			case 0:
 				signal( &condABC, &globalA, &globalB, &globalC );
 				break;
-			case 1: 
+			case 1:
 				signal( &condAB , &globalA, &globalB );
 				break;
-			case 2: 
+			case 2:
 				signal( &condBC , &globalB, &globalC );
 				break;
-			case 3: 
+			case 3:
 				signal( &condAC , &globalA, &globalC );
 				break;
@@ -67,5 +67,5 @@
 		}
 		yield();
-	}	
+	}
 }
 
Index: src/tests/thread.c
===================================================================
--- src/tests/thread.c	(revision 7c03d6db65469e4f71a28659478ead50ca5cbe52)
+++ src/tests/thread.c	(revision eaace252967f5f7d75220819f0a1b84b5517f298)
@@ -4,15 +4,9 @@
 #include <thread>
 
-// thread First;
-// void main(First* this);
+thread First  { semaphore* lock; };
+thread Second { semaphore* lock; };
 
-// thread Second;
-// void main(Second* this);
-
-thread First  { signal_once* lock; };
-thread Second { signal_once* lock; };
-
-void ?{}( First * this, signal_once* lock ) { this->lock = lock; }
-void ?{}( Second * this, signal_once* lock ) { this->lock = lock; }
+void ?{}( First * this, semaphore* lock ) { this->lock = lock; }
+void ?{}( Second * this, semaphore* lock ) { this->lock = lock; }
 
 void main(First* this) {
@@ -21,9 +15,9 @@
 		yield();
 	}
-	signal(this->lock);
+	V(this->lock);
 }
 
 void main(Second* this) {
-	wait(this->lock);
+	P(this->lock);
 	for(int i = 0; i < 10; i++) {
 		sout | "Second : Suspend No." | i + 1 | endl;
@@ -34,5 +28,5 @@
 
 int main(int argc, char* argv[]) {
-	signal_once lock;
+	semaphore lock = { 0 };
 	sout | "User main begin" | endl;
 	{