0
0
mirror of https://gitlab.nic.cz/labs/bird.git synced 2024-12-25 11:11:53 +00:00
bird/lib/locking.h
Maria Matejka 794a4eefa1 Keeping un-unmmappable pages until they can be reused
On Linux, munmap() may fail with ENOMEM when virtual memory is too
fragmented. Working this around by just keeping such blocks for future
use.
2021-11-22 19:05:44 +01:00

67 lines
2.2 KiB
C

/*
* 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;
struct domain_generic *proto;
struct domain_generic *rtable;
struct domain_generic *attrs;
struct domain_generic *cork;
struct domain_generic *event;
struct domain_generic *resource;
};
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_ORDER(type) OFFSETOF(struct lock_order, type)
#define DOMAIN_NEW(type, name) (DOMAIN(type)) { .type = domain_new(name, DOMAIN_ORDER(type)) }
struct domain_generic *domain_new(const char *name, uint order);
#define DOMAIN_FREE(type, d) domain_free((d).type)
void domain_free(struct domain_generic *);
#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))
#define DOMAIN_IS_LOCKED(type, d) (((d).type) == (locking_stack.type))
#define DG_IS_LOCKED(d) ((d) == *(DG_LSP(d)))
/* 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);
uint dg_order(struct domain_generic *dg);
#define DG_LSP(d) ((struct domain_generic **) (((void *) &locking_stack) + dg_order(d)))
#define DG_LOCK(d) do_lock(d, DG_LSP(d))
#define DG_UNLOCK(d) do_unlock(d, DG_LSP(d))
/* 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)
#define the_bird_locked() DOMAIN_IS_LOCKED(the_bird, the_bird_domain)
#define ASSERT_THE_BIRD_LOCKED ({ if (!the_bird_locked()) bug("The BIRD lock must be locked here: %s:%d", __FILE__, __LINE__); })
#endif