erl_node_tables.h

/*
 * %CopyrightBegin%
 *
 * Copyright Ericsson AB 2001-2010. All Rights Reserved.
 *
 * The contents of this file are subject to the Erlang Public License,
 * Version 1.1, (the "License"); you may not use this file except in
 * compliance with the License. You should have received a copy of the
 * Erlang Public License along with this software. If not, it can be
 * retrieved online at http://www.erlang.org/.
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * %CopyrightEnd%
 */

#ifndef ERL_NODE_TABLES_H__
#define ERL_NODE_TABLES_H__

/*
 * The "node_tables module" contain two (hash) tables: the node_table
 * and the dist_table.
 *
 * The elements of the node_table represents a specific incarnation of
 * an Erlang node and has {Nodename, Creation} pairs as keys. Elements
 * in the node_table are referred to from node containers (see
 * node_container_utils.h).
 *
 * The elements of the dist_table represents a (potential) connection
 * to an Erlang node and has Nodename as key. Elements in the
 * dist_table are either referred to from elements in the node_table
 * or from the process or port structure of the entity controlling
 * the connection.
 *
 * Both tables are garbage collected by reference counting.
 */

#include "sys.h"
#include "hash.h"
#include "erl_process.h"
#include "erl_monitors.h"
#include "erl_smp.h"
#define ERTS_PORT_TASK_ONLY_BASIC_TYPES__
#include "erl_port_task.h"
#undef ERTS_PORT_TASK_ONLY_BASIC_TYPES__
 
#define ERST_INTERNAL_CHANNEL_NO 0

#define ERTS_DE_SFLG_CONNECTED			(((Uint32) 1) <<  0)
#define ERTS_DE_SFLG_EXITING			(((Uint32) 1) <<  1)

#define ERTS_DE_SFLGS_ALL			(ERTS_DE_SFLG_CONNECTED \
						 | ERTS_DE_SFLG_EXITING)

#define ERTS_DE_QFLG_BUSY			(((Uint32) 1) <<  0)
#define ERTS_DE_QFLG_EXIT			(((Uint32) 1) <<  1)

#define ERTS_DE_QFLGS_ALL			(ERTS_DE_QFLG_BUSY \
						 | ERTS_DE_QFLG_EXIT)

#if defined(ARCH_64) && !HALFWORD_HEAP
#define ERTS_DIST_OUTPUT_BUF_DBG_PATTERN ((Uint) 0xf713f713f713f713UL)
#else
#define ERTS_DIST_OUTPUT_BUF_DBG_PATTERN ((Uint) 0xf713f713)
#endif

typedef struct ErtsDistOutputBuf_ ErtsDistOutputBuf;
struct ErtsDistOutputBuf_ {
#ifdef DEBUG
    Uint dbg_pattern;
#endif
    ErtsDistOutputBuf *next;
    byte *extp;
    byte *ext_endp;
    byte data[1];
};

typedef struct {
    ErtsDistOutputBuf *first;
    ErtsDistOutputBuf *last;
} ErtsDistOutputQueue;

struct ErtsProcList_;
typedef struct {
    struct ErtsProcList_ *first;
    struct ErtsProcList_ *last;
} ErtsDistSuspended;

/*
 * Lock order:
 *   1. dist_entry->rwmtx
 *   2. erts_node_table_rwmtx
 *   3. erts_dist_table_rwmtx
 *
 *   Lock mutexes with lower numbers before mutexes with higher numbers and
 *   unlock mutexes with higher numbers before mutexes with higher numbers.
 */

struct erl_link;
struct port;

typedef struct dist_entry_ {
    HashBucket hash_bucket;     /* Hash bucket */
    struct dist_entry_ *next;	/* Next entry in dist_table (not sorted) */
    struct dist_entry_ *prev;	/* Previous entry in dist_table (not sorted) */
    erts_refc_t refc;		/* Reference count */

    erts_smp_rwmtx_t rwmtx;     /* Protects all fields below until lck_mtx. */
    Eterm sysname;		/* name@host atom for efficiency */
    Uint32 creation;		/* creation of connected node */
    Eterm cid;			/* connection handler (pid or port), NIL == free */
    Uint32 connection_id;	/* Connection id incremented on connect */
    Uint32 status;		/* Slot status, like exiting reserved etc */
    Uint32 flags;		/* Distribution flags, like hidden, 
				   atom cache etc. */
    unsigned long version;	/* Protocol version */


    erts_smp_mtx_t lnk_mtx;     /* Protects node_links, nlinks, and
				   monitors. */
    ErtsLink *node_links;       /* In a dist entry, node links are kept 
				   in a separate tree, while they are 
				   colocted with the ordinary link tree
				   for processes. It's not due to confusion,
				   it's because the link tree for the dist 
				   entry is in two levels, see erl_monitors.h 
				*/
    ErtsLink *nlinks;           /* Link tree with subtrees */
    ErtsMonitor *monitors;      /* Monitor tree */

    erts_smp_mtx_t qlock;       /* Protects qflgs and out_queue */
    Uint32 qflgs;
    Sint qsize;
    ErtsDistOutputQueue out_queue;
    ErtsDistSuspended suspended;

    ErtsDistOutputQueue finalized_out_queue;
    erts_smp_atomic_t dist_cmd_scheduled;
    ErtsPortTaskHandle dist_cmd;

    Uint (*send)(struct port *prt, ErtsDistOutputBuf *obuf);

    struct cache* cache;	/* The atom cache */
} DistEntry;

typedef struct erl_node_ {
  HashBucket hash_bucket;	/* Hash bucket */
  erts_refc_t refc;		/* Reference count */
  Eterm	sysname;		/* name@host atom for efficiency */
  Uint32 creation;		/* Creation */
  DistEntry *dist_entry;	/* Corresponding dist entry */
} ErlNode;


extern Hash erts_dist_table;
extern Hash erts_node_table;
extern erts_smp_rwmtx_t erts_dist_table_rwmtx;
extern erts_smp_rwmtx_t erts_node_table_rwmtx;

extern DistEntry *erts_hidden_dist_entries;
extern DistEntry *erts_visible_dist_entries;
extern DistEntry *erts_not_connected_dist_entries;
extern Sint erts_no_of_hidden_dist_entries;
extern Sint erts_no_of_visible_dist_entries;
extern Sint erts_no_of_not_connected_dist_entries;

extern DistEntry *erts_this_dist_entry;
extern ErlNode *erts_this_node;
extern char erts_this_node_sysname[];

DistEntry *erts_channel_no_to_dist_entry(Uint);
DistEntry *erts_sysname_to_connected_dist_entry(Eterm);
DistEntry *erts_find_or_insert_dist_entry(Eterm);
DistEntry *erts_find_dist_entry(Eterm);
void erts_delete_dist_entry(DistEntry *);
Uint erts_dist_table_size(void);
void erts_dist_table_info(int, void *);
void erts_set_dist_entry_not_connected(DistEntry *);
void erts_set_dist_entry_connected(DistEntry *, Eterm, Uint);
ErlNode *erts_find_or_insert_node(Eterm, Uint);
void erts_delete_node(ErlNode *);
void erts_set_this_node(Eterm, Uint);
Uint erts_node_table_size(void);
void erts_init_node_tables(void);
void erts_node_table_info(int, void *);
void erts_print_node_info(int, void *, Eterm, int*, int*);
Eterm erts_get_node_and_dist_references(struct process *);
#if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
int erts_lc_is_de_rwlocked(DistEntry *);
int erts_lc_is_de_rlocked(DistEntry *);
#endif

ERTS_GLB_INLINE void erts_deref_dist_entry(DistEntry *dep);
ERTS_GLB_INLINE void erts_deref_node_entry(ErlNode *np);
ERTS_GLB_INLINE void erts_smp_de_rlock(DistEntry *dep);
ERTS_GLB_INLINE void erts_smp_de_runlock(DistEntry *dep);
ERTS_GLB_INLINE void erts_smp_de_rwlock(DistEntry *dep);
ERTS_GLB_INLINE void erts_smp_de_rwunlock(DistEntry *dep);
ERTS_GLB_INLINE void erts_smp_de_links_lock(DistEntry *dep);
ERTS_GLB_INLINE void erts_smp_de_links_unlock(DistEntry *dep);

#if ERTS_GLB_INLINE_INCL_FUNC_DEF

ERTS_GLB_INLINE void
erts_deref_dist_entry(DistEntry *dep)
{
    ASSERT(dep);
    if (erts_refc_dectest(&dep->refc, 0) == 0)
	erts_delete_dist_entry(dep);
}

ERTS_GLB_INLINE void
erts_deref_node_entry(ErlNode *np)
{
    ASSERT(np);
    if (erts_refc_dectest(&np->refc, 0) == 0)
	erts_delete_node(np);
}

ERTS_GLB_INLINE void
erts_smp_de_rlock(DistEntry *dep)
{
    erts_smp_rwmtx_rlock(&dep->rwmtx);
}

ERTS_GLB_INLINE void
erts_smp_de_runlock(DistEntry *dep)
{
    erts_smp_rwmtx_runlock(&dep->rwmtx);
}

ERTS_GLB_INLINE void
erts_smp_de_rwlock(DistEntry *dep)
{
    erts_smp_rwmtx_rwlock(&dep->rwmtx);
}

ERTS_GLB_INLINE void
erts_smp_de_rwunlock(DistEntry *dep)
{
    erts_smp_rwmtx_rwunlock(&dep->rwmtx);
}

ERTS_GLB_INLINE void
erts_smp_de_links_lock(DistEntry *dep)
{
    erts_smp_mtx_lock(&dep->lnk_mtx);
}

ERTS_GLB_INLINE void
erts_smp_de_links_unlock(DistEntry *dep)
{
    erts_smp_mtx_unlock(&dep->lnk_mtx);
}

#endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */


#endif