1 files changed, 52 insertions, 0 deletions
diff --git a/nest/locks.h b/nest/locks.h
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+/*
+ *	BIRD Object Locks
+ *
+ *	(c) 1999 Martin Mares <mj@ucw.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_LOCKS_H_
+#define _BIRD_LOCKS_H_
+
+#include "lib/resource.h"
+#include "lib/event.h"
+
+/*
+ *  The object locks are used for controlling exclusive access
+ *  to various physical resources like UDP ports on specific devices.
+ *  When you want to access such resource, you ask for a object lock
+ *  structure, fill in specification of the object and your function
+ *  you want to have called when the object is available and invoke
+ *  olock_acquire() afterwards. When the object becomes free, the lock
+ *  manager calls your function. To free the object lock, just call rfree
+ *  on its resource.
+ */
+
+struct object_lock {
+  resource r;
+  ip_addr addr;		/* Identification of a object: IP address */
+  unsigned int type;	/* ... object type (OBJLOCK_xxx) */
+  struct iface *iface;	/* ... interface */
+  unsigned int port;	/* ... port number */
+  void (*hook)(struct object_lock *);	/* Called when the lock succeeds */
+  void *data;		/* User data */
+  /* ... internal to lock manager, don't touch ... */
+  node n;		/* Node in list of olocks */
+  int state;		/* OLOCK_STATE_xxx */
+  list waiters;		/* Locks waiting for the same resource */
+};
+
+struct object_lock *olock_new(pool *);
+void olock_acquire(struct object_lock *);
+void olock_init(void);
+
+#define OBJLOCK_UDP 1			/* UDP port */
+#define OBJLOCK_TCP 2			/* TCP port */
+
+#define OLOCK_STATE_FREE 0
+#define OLOCK_STATE_LOCKED 1
+#define OLOCK_STATE_WAITING 2
+#define OLOCK_STATE_EVENT 3		/* waiting for unlock processing */
+
+#endif