base-fiasco/sel4: unified cancelable_lock.h

On seL4 and L4/Fiasco, we employ a simple yielding spinlock as lock
implementation. Consequently these base platforms used to have a
simplified header. However, since the regular cancelable_lock has all
the member variables needed to implement a spinlock, we can simply use
the generic header on those two platforms too, just leaving some other
parts of the generic header unused. So at API level, the difference is
not visible.

Issue genodelabs#1832

repos/base-fiasco/src/base/lock/lock.cc

@@ -26,7 +26,7 @@ using namespace Genode;
 
 
 Cancelable_lock::Cancelable_lock(Cancelable_lock::State initial)
-: _lock(UNLOCKED)
+: _state(UNLOCKED), _owner(nullptr)
 {
 	if (initial == LOCKED)
 		lock();
@@ -39,7 +39,7 @@ void Cancelable_lock::lock()
 	 * XXX: How to notice cancel-blocking signals issued when  being outside the
 	 *      'l4_ipc_sleep' system call?
 	 */
-	while (!Genode::cmpxchg(&_lock, UNLOCKED, LOCKED))
+	while (!Genode::cmpxchg(&_state, UNLOCKED, LOCKED))
 		if (Fiasco::l4_ipc_sleep(Fiasco::l4_ipc_timeout(0, 0, 500, 0)) != L4_IPC_RETIMEOUT)
 			throw Genode::Blocking_canceled();
 }
@@ -48,5 +48,5 @@ void Cancelable_lock::lock()
 void Cancelable_lock::unlock()
 {
 	Genode::memory_barrier();
-	_lock = UNLOCKED;
+	_state = UNLOCKED;
 }

repos/base-sel4/src/base/lock/lock.cc

@@ -23,7 +23,7 @@ using namespace Genode;
 
 
 Cancelable_lock::Cancelable_lock(Cancelable_lock::State initial)
-: _lock(UNLOCKED)
+: _state(UNLOCKED), _owner(nullptr)
 {
 	if (initial == LOCKED)
 		lock();
@@ -32,13 +32,13 @@ Cancelable_lock::Cancelable_lock(Cancelable_lock::State initial)
 
 void Cancelable_lock::lock()
 {
-	while (!Genode::cmpxchg(&_lock, UNLOCKED, LOCKED))
+	while (!Genode::cmpxchg(&_state, UNLOCKED, LOCKED))
 		seL4_Yield();
 }
 
 
 void Cancelable_lock::unlock()
 {
 	Genode::memory_barrier();
-	_lock = UNLOCKED;
+	_state = UNLOCKED;
 }