minimal plan9port to cross-build Jehanne

lib/lib9/qlock.c

@@ -0,0 +1,166 @@
+#include <u.h>
+#include <libc.h>
+
+/*
+ * The function pointers are supplied by the thread
+ * library during its initialization.  If there is no thread
+ * library, there is no multithreading.
+ */
+
+int	(*_lock)(Lock*, int, ulong);
+void	(*_unlock)(Lock*, ulong);
+int	(*_qlock)(QLock*, int, ulong);	/* do not use */
+void	(*_qunlock)(QLock*, ulong);
+void	(*_rsleep)(Rendez*, ulong);	/* do not use */
+int	(*_rwakeup)(Rendez*, int, ulong);
+int	(*_rlock)(RWLock*, int, ulong);	/* do not use */
+int	(*_wlock)(RWLock*, int, ulong);
+void	(*_runlock)(RWLock*, ulong);
+void	(*_wunlock)(RWLock*, ulong);
+
+void
+lock(Lock *l)
+{
+	if(_lock)
+		(*_lock)(l, 1, getcallerpc(&l));
+	else
+		l->held = 1;
+}
+
+int
+canlock(Lock *l)
+{
+	if(_lock)
+		return (*_lock)(l, 0, getcallerpc(&l));
+	else{
+		if(l->held)
+			return 0;
+		l->held = 1;
+		return 1;
+	}
+}
+
+void
+unlock(Lock *l)
+{
+	if(_unlock)
+		(*_unlock)(l, getcallerpc(&l));
+	else
+		l->held = 0;
+}
+
+void
+qlock(QLock *l)
+{
+	if(_qlock)
+		(*_qlock)(l, 1, getcallerpc(&l));
+	else
+		l->l.held = 1;
+}
+
+int
+canqlock(QLock *l)
+{
+	if(_qlock)
+		return (*_qlock)(l, 0, getcallerpc(&l));
+	else{
+		if(l->l.held)
+			return 0;
+		l->l.held = 1;
+		return 1;
+	}
+}
+
+void
+qunlock(QLock *l)
+{
+	if(_qunlock)
+		(*_qunlock)(l, getcallerpc(&l));
+	else
+		l->l.held = 0;
+}
+
+void
+rlock(RWLock *l)
+{
+	if(_rlock)
+		(*_rlock)(l, 1, getcallerpc(&l));
+	else
+		l->readers++;
+}
+
+int
+canrlock(RWLock *l)
+{
+	if(_rlock)
+		return (*_rlock)(l, 0, getcallerpc(&l));
+	else{
+		if(l->writer)
+			return 0;
+		l->readers++;
+		return 1;
+	}
+}
+
+void
+runlock(RWLock *l)
+{
+	if(_runlock)
+		(*_runlock)(l, getcallerpc(&l));
+	else
+		l->readers--;
+}
+
+void
+wlock(RWLock *l)
+{
+	if(_wlock)
+		(*_wlock)(l, 1, getcallerpc(&l));
+	else
+		l->writer = (void*)1;
+}
+
+int
+canwlock(RWLock *l)
+{
+	if(_wlock)
+		return (*_wlock)(l, 0, getcallerpc(&l));
+	else{
+		if(l->writer || l->readers)
+			return 0;
+		l->writer = (void*)1;
+		return 1;
+	}
+}
+
+void
+wunlock(RWLock *l)
+{
+	if(_wunlock)
+		(*_wunlock)(l, getcallerpc(&l));
+	else
+		l->writer = nil;
+}
+
+void
+rsleep(Rendez *r)
+{
+	if(_rsleep)
+		(*_rsleep)(r, getcallerpc(&r));
+}
+
+int
+rwakeup(Rendez *r)
+{
+	if(_rwakeup)
+		return (*_rwakeup)(r, 0, getcallerpc(&r));
+	return 0;
+}
+
+int
+rwakeupall(Rendez *r)
+{
+	if(_rwakeup)
+		return (*_rwakeup)(r, 1, getcallerpc(&r));
+	return 0;
+}