/* * 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