Locking subsystem: Just a global BIRD lock to begin with.

1 files changed, 46 insertions, 0 deletions

diff --git a/lib/locking.h b/lib/locking.h
new file mode 100644
index 00000000..eb1bc8fa
--- /dev/null
+++ b/lib/locking.h
@@ -0,0 +1,46 @@
+/*
+ *	BIRD Library -- Locking
+ *
+ *	(c) 2020--2021 Maria Matejka <mq@jmq.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_LOCKING_H_
+#define _BIRD_LOCKING_H_
+
+struct domain_generic;
+
+/* Here define the global lock order; first to last. */
+struct lock_order {
+  struct domain_generic *the_bird;
+};
+
+#define LOCK_ORDER_DEPTH  (sizeof(struct lock_order) / sizeof(struct domain_generic *))
+
+extern _Thread_local struct lock_order locking_stack;
+extern _Thread_local struct domain_generic **last_locked;
+
+#define DOMAIN(type) struct domain__##type
+#define DEFINE_DOMAIN(type) DOMAIN(type) { struct domain_generic *type; }
+
+#define DOMAIN_NEW(type, name)  (DOMAIN(type)) { .type = domain_new(name) }
+struct domain_generic *domain_new(const char *name);
+
+#define DOMAIN_NULL(type)   (DOMAIN(type)) {}
+
+#define LOCK_DOMAIN(type, d)	do_lock(((d).type), &(locking_stack.type))
+#define UNLOCK_DOMAIN(type, d)  do_unlock(((d).type), &(locking_stack.type))
+
+/* Internal for locking */
+void do_lock(struct domain_generic *dg, struct domain_generic **lsp);
+void do_unlock(struct domain_generic *dg, struct domain_generic **lsp);
+
+/* Use with care. To be removed in near future. */
+DEFINE_DOMAIN(the_bird);
+extern DOMAIN(the_bird) the_bird_domain;
+
+#define the_bird_lock()		LOCK_DOMAIN(the_bird, the_bird_domain)
+#define the_bird_unlock()	UNLOCK_DOMAIN(the_bird, the_bird_domain)
+
+#endif