lock_region.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997, 1998
* Sleepycat Software. All rights reserved.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)lock_region.c 10.21 (Sleepycat) 10/19/98";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#endif
#include "db_int.h"
#include "shqueue.h"
#include "db_shash.h"
#include "lock.h"
#include "common_ext.h"
static u_int32_t __lock_count_locks __P((DB_LOCKREGION *));
static u_int32_t __lock_count_objs __P((DB_LOCKREGION *));
static void __lock_dump_locker __P((DB_LOCKTAB *, DB_LOCKOBJ *, FILE *));
static void __lock_dump_object __P((DB_LOCKTAB *, DB_LOCKOBJ *, FILE *));
static const char *
__lock_dump_status __P((db_status_t));
static void __lock_reset_region __P((DB_LOCKTAB *));
static int __lock_tabinit __P((DB_ENV *, DB_LOCKREGION *));
int
lock_open(path, flags, mode, dbenv, ltp)
const char *path;
u_int32_t flags;
int mode;
DB_ENV *dbenv;
DB_LOCKTAB **ltp;
{
DB_LOCKTAB *lt;
u_int32_t lock_modes, maxlocks, regflags;
int ret;
/* Validate arguments. */
#ifdef HAVE_SPINLOCKS
#define OKFLAGS (DB_CREATE | DB_THREAD)
#else
#define OKFLAGS (DB_CREATE)
#endif
if ((ret = __db_fchk(dbenv, "lock_open", flags, OKFLAGS)) != 0)
return (ret);
/* Create the lock table structure. */
if ((ret = __os_calloc(1, sizeof(DB_LOCKTAB), &lt)) != 0)
return (ret);
lt->dbenv = dbenv;
/* Grab the values that we need to compute the region size. */
lock_modes = DB_LOCK_RW_N;
maxlocks = DB_LOCK_DEFAULT_N;
regflags = REGION_SIZEDEF;
if (dbenv != NULL) {
if (dbenv->lk_modes != 0) {
lock_modes = dbenv->lk_modes;
regflags = 0;
}
if (dbenv->lk_max != 0) {
maxlocks = dbenv->lk_max;
regflags = 0;
}
}
/* Join/create the lock region. */
lt->reginfo.dbenv = dbenv;
lt->reginfo.appname = DB_APP_NONE;
if (path == NULL)
lt->reginfo.path = NULL;
else
if ((ret = __os_strdup(path, &lt->reginfo.path)) != 0)
goto err;
lt->reginfo.file = DB_DEFAULT_LOCK_FILE;
lt->reginfo.mode = mode;
lt->reginfo.size =
LOCK_REGION_SIZE(lock_modes, maxlocks, __db_tablesize(maxlocks));
lt->reginfo.dbflags = flags;
lt->reginfo.addr = NULL;
lt->reginfo.fd = -1;
lt->reginfo.flags = regflags;
if ((ret = __db_rattach(&lt->reginfo)) != 0)
goto err;
/* Now set up the pointer to the region. */
lt->region = lt->reginfo.addr;
/* Initialize the region if we created it. */
if (F_ISSET(&lt->reginfo, REGION_CREATED)) {
lt->region->maxlocks = maxlocks;
lt->region->nmodes = lock_modes;
if ((ret = __lock_tabinit(dbenv, lt->region)) != 0)
goto err;
} else {
/* Check for an unexpected region. */
if (lt->region->magic != DB_LOCKMAGIC) {
__db_err(dbenv,
"lock_open: %s: bad magic number", path);
ret = EINVAL;
goto err;
}
}
/* Check for automatic deadlock detection. */
if (dbenv != NULL && dbenv->lk_detect != DB_LOCK_NORUN) {
if (lt->region->detect != DB_LOCK_NORUN &&
dbenv->lk_detect != DB_LOCK_DEFAULT &&
lt->region->detect != dbenv->lk_detect) {
__db_err(dbenv,
"lock_open: incompatible deadlock detector mode");
ret = EINVAL;
goto err;
}
if (lt->region->detect == DB_LOCK_NORUN)
lt->region->detect = dbenv->lk_detect;
}
/* Set up remaining pointers into region. */
lt->conflicts = (u_int8_t *)lt->region + sizeof(DB_LOCKREGION);
lt->hashtab =
(DB_HASHTAB *)((u_int8_t *)lt->region + lt->region->hash_off);
lt->mem = (void *)((u_int8_t *)lt->region + lt->region->mem_off);
UNLOCK_LOCKREGION(lt);
*ltp = lt;
return (0);
err: if (lt->reginfo.addr != NULL) {
UNLOCK_LOCKREGION(lt);
(void)__db_rdetach(&lt->reginfo);
if (F_ISSET(&lt->reginfo, REGION_CREATED))
(void)lock_unlink(path, 1, dbenv);
}
if (lt->reginfo.path != NULL)
__os_freestr(lt->reginfo.path);
__os_free(lt, sizeof(*lt));
return (ret);
}
/*
* __lock_panic --
* Panic a lock region.
*
* PUBLIC: void __lock_panic __P((DB_ENV *));
*/
void
__lock_panic(dbenv)
DB_ENV *dbenv;
{
if (dbenv->lk_info != NULL)
dbenv->lk_info->region->hdr.panic = 1;
}
/*
* __lock_tabinit --
* Initialize the lock region.
*/
static int
__lock_tabinit(dbenv, lrp)
DB_ENV *dbenv;
DB_LOCKREGION *lrp;
{
struct __db_lock *lp;
struct lock_header *tq_head;
struct obj_header *obj_head;
DB_LOCKOBJ *op;
u_int32_t i, nelements;
const u_int8_t *conflicts;
u_int8_t *curaddr;
conflicts = dbenv == NULL || dbenv->lk_conflicts == NULL ?
db_rw_conflicts : dbenv->lk_conflicts;
lrp->table_size = __db_tablesize(lrp->maxlocks);
lrp->magic = DB_LOCKMAGIC;
lrp->version = DB_LOCKVERSION;
lrp->id = 0;
/*
* These fields (lrp->maxlocks, lrp->nmodes) are initialized
* in the caller, since we had to grab those values to size
* the region.
*/
lrp->need_dd = 0;
lrp->detect = DB_LOCK_NORUN;
lrp->numobjs = lrp->maxlocks;
lrp->nlockers = 0;
lrp->mem_bytes = ALIGN(STRING_SIZE(lrp->maxlocks), sizeof(size_t));
lrp->increment = lrp->hdr.size / 2;
lrp->nconflicts = 0;
lrp->nrequests = 0;
lrp->nreleases = 0;
lrp->ndeadlocks = 0;
/*
* As we write the region, we've got to maintain the alignment
* for the structures that follow each chunk. This information
* ends up being encapsulated both in here as well as in the
* lock.h file for the XXX_SIZE macros.
*/
/* Initialize conflict matrix. */
curaddr = (u_int8_t *)lrp + sizeof(DB_LOCKREGION);
memcpy(curaddr, conflicts, lrp->nmodes * lrp->nmodes);
curaddr += lrp->nmodes * lrp->nmodes;
/*
* Initialize hash table.
*/
curaddr = (u_int8_t *)ALIGNP(curaddr, LOCK_HASH_ALIGN);
lrp->hash_off = curaddr - (u_int8_t *)lrp;
nelements = lrp->table_size;
__db_hashinit(curaddr, nelements);
curaddr += nelements * sizeof(DB_HASHTAB);
/*
* Initialize locks onto a free list. Since locks contains mutexes,
* we need to make sure that each lock is aligned on a MUTEX_ALIGNMENT
* boundary.
*/
curaddr = (u_int8_t *)ALIGNP(curaddr, MUTEX_ALIGNMENT);
tq_head = &lrp->free_locks;
SH_TAILQ_INIT(tq_head);
for (i = 0; i++ < lrp->maxlocks;
curaddr += ALIGN(sizeof(struct __db_lock), MUTEX_ALIGNMENT)) {
lp = (struct __db_lock *)curaddr;
lp->status = DB_LSTAT_FREE;
SH_TAILQ_INSERT_HEAD(tq_head, lp, links, __db_lock);
}
/* Initialize objects onto a free list. */
obj_head = &lrp->free_objs;
SH_TAILQ_INIT(obj_head);
for (i = 0; i++ < lrp->maxlocks; curaddr += sizeof(DB_LOCKOBJ)) {
op = (DB_LOCKOBJ *)curaddr;
SH_TAILQ_INSERT_HEAD(obj_head, op, links, __db_lockobj);
}
/*
* Initialize the string space; as for all shared memory allocation
* regions, this requires size_t alignment, since we store the
* lengths of malloc'd areas in the area.
*/
curaddr = (u_int8_t *)ALIGNP(curaddr, sizeof(size_t));
lrp->mem_off = curaddr - (u_int8_t *)lrp;
__db_shalloc_init(curaddr, lrp->mem_bytes);
return (0);
}
int
lock_close(lt)
DB_LOCKTAB *lt;
{
int ret;
LOCK_PANIC_CHECK(lt);
if ((ret = __db_rdetach(&lt->reginfo)) != 0)
return (ret);
if (lt->reginfo.path != NULL)
__os_freestr(lt->reginfo.path);
__os_free(lt, sizeof(*lt));
return (0);
}
int
lock_unlink(path, force, dbenv)
const char *path;
int force;
DB_ENV *dbenv;
{
REGINFO reginfo;
int ret;
memset(&reginfo, 0, sizeof(reginfo));
reginfo.dbenv = dbenv;
reginfo.appname = DB_APP_NONE;
if (path != NULL && (ret = __os_strdup(path, &reginfo.path)) != 0)
return (ret);
reginfo.file = DB_DEFAULT_LOCK_FILE;
ret = __db_runlink(&reginfo, force);
if (reginfo.path != NULL)
__os_freestr(reginfo.path);
return (ret);
}
/*
* __lock_validate_region --
* Called at every interface to verify if the region has changed size,
* and if so, to remap the region in and reset the process' pointers.
*
* PUBLIC: int __lock_validate_region __P((DB_LOCKTAB *));
*/
int
__lock_validate_region(lt)
DB_LOCKTAB *lt;
{
int ret;
if (lt->reginfo.size == lt->region->hdr.size)
return (0);
/* Detach/reattach the region. */
if ((ret = __db_rreattach(&lt->reginfo, lt->region->hdr.size)) != 0)
return (ret);
/* Reset region information. */
lt->region = lt->reginfo.addr;
__lock_reset_region(lt);
return (0);
}
/*
* __lock_grow_region --
* We have run out of space; time to grow the region.
*
* PUBLIC: int __lock_grow_region __P((DB_LOCKTAB *, int, size_t));
*/
int
__lock_grow_region(lt, which, howmuch)
DB_LOCKTAB *lt;
int which;
size_t howmuch;
{
struct __db_lock *newl;
struct lock_header *lock_head;
struct obj_header *obj_head;
DB_LOCKOBJ *op;
DB_LOCKREGION *lrp;
float lock_ratio, obj_ratio;
size_t incr, oldsize, used, usedmem;
u_int32_t i, newlocks, newmem, newobjs, usedlocks, usedobjs;
u_int8_t *curaddr;
int ret;
lrp = lt->region;
oldsize = lrp->hdr.size;
incr = lrp->increment;
/* Figure out how much of each sort of space we have. */
usedmem = lrp->mem_bytes - __db_shalloc_count(lt->mem);
usedobjs = lrp->numobjs - __lock_count_objs(lrp);
usedlocks = lrp->maxlocks - __lock_count_locks(lrp);
/*
* Figure out what fraction of the used space belongs to each
* different type of "thing" in the region. Then partition the
* new space up according to this ratio.
*/
used = usedmem +
usedlocks * ALIGN(sizeof(struct __db_lock), MUTEX_ALIGNMENT) +
usedobjs * sizeof(DB_LOCKOBJ);
lock_ratio = usedlocks *
ALIGN(sizeof(struct __db_lock), MUTEX_ALIGNMENT) / (float)used;
obj_ratio = usedobjs * sizeof(DB_LOCKOBJ) / (float)used;
newlocks = (u_int32_t)(lock_ratio *
incr / ALIGN(sizeof(struct __db_lock), MUTEX_ALIGNMENT));
newobjs = (u_int32_t)(obj_ratio * incr / sizeof(DB_LOCKOBJ));
newmem = incr -
(newobjs * sizeof(DB_LOCKOBJ) +
newlocks * ALIGN(sizeof(struct __db_lock), MUTEX_ALIGNMENT));
/*
* Make sure we allocate enough memory for the object being
* requested.
*/
switch (which) {
case DB_LOCK_LOCK:
if (newlocks == 0) {
newlocks = 10;
incr += newlocks * sizeof(struct __db_lock);
}
break;
case DB_LOCK_OBJ:
if (newobjs == 0) {
newobjs = 10;
incr += newobjs * sizeof(DB_LOCKOBJ);
}
break;
case DB_LOCK_MEM:
if (newmem < howmuch * 2) {
incr += howmuch * 2 - newmem;
newmem = howmuch * 2;
}
break;
}
newmem += ALIGN(incr, sizeof(size_t)) - incr;
incr = ALIGN(incr, sizeof(size_t));
/*
* Since we are going to be allocating locks at the beginning of the
* new chunk, we need to make sure that the chunk is MUTEX_ALIGNMENT
* aligned. We did not guarantee this when we created the region, so
* we may need to pad the old region by extra bytes to ensure this
* alignment.
*/
incr += ALIGN(oldsize, MUTEX_ALIGNMENT) - oldsize;
__db_err(lt->dbenv,
"Growing lock region: %lu locks %lu objs %lu bytes",
(u_long)newlocks, (u_long)newobjs, (u_long)newmem);
if ((ret = __db_rgrow(&lt->reginfo, oldsize + incr)) != 0)
return (ret);
lt->region = lt->reginfo.addr;
__lock_reset_region(lt);
/* Update region parameters. */
lrp = lt->region;
lrp->increment = incr << 1;
lrp->maxlocks += newlocks;
lrp->numobjs += newobjs;
lrp->mem_bytes += newmem;
curaddr = (u_int8_t *)lrp + oldsize;
curaddr = (u_int8_t *)ALIGNP(curaddr, MUTEX_ALIGNMENT);
/* Put new locks onto the free list. */
lock_head = &lrp->free_locks;
for (i = 0; i++ < newlocks;
curaddr += ALIGN(sizeof(struct __db_lock), MUTEX_ALIGNMENT)) {
newl = (struct __db_lock *)curaddr;
SH_TAILQ_INSERT_HEAD(lock_head, newl, links, __db_lock);
}
/* Put new objects onto the free list. */
obj_head = &lrp->free_objs;
for (i = 0; i++ < newobjs; curaddr += sizeof(DB_LOCKOBJ)) {
op = (DB_LOCKOBJ *)curaddr;
SH_TAILQ_INSERT_HEAD(obj_head, op, links, __db_lockobj);
}
*((size_t *)curaddr) = newmem - sizeof(size_t);
curaddr += sizeof(size_t);
__db_shalloc_free(lt->mem, curaddr);
return (0);
}
static void
__lock_reset_region(lt)
DB_LOCKTAB *lt;
{
lt->conflicts = (u_int8_t *)lt->region + sizeof(DB_LOCKREGION);
lt->hashtab =
(DB_HASHTAB *)((u_int8_t *)lt->region + lt->region->hash_off);
lt->mem = (void *)((u_int8_t *)lt->region + lt->region->mem_off);
}
/*
* lock_stat --
* Return LOCK statistics.
*/
int
lock_stat(lt, gspp, db_malloc)
DB_LOCKTAB *lt;
DB_LOCK_STAT **gspp;
void *(*db_malloc) __P((size_t));
{
DB_LOCKREGION *rp;
int ret;
*gspp = NULL;
LOCK_PANIC_CHECK(lt);
if ((ret = __os_malloc(sizeof(**gspp), db_malloc, gspp)) != 0)
return (ret);
/* Copy out the global statistics. */
LOCK_LOCKREGION(lt);
rp = lt->region;
(*gspp)->st_magic = rp->magic;
(*gspp)->st_version = rp->version;
(*gspp)->st_maxlocks = rp->maxlocks;
(*gspp)->st_nmodes = rp->nmodes;
(*gspp)->st_numobjs = rp->numobjs;
(*gspp)->st_nlockers = rp->nlockers;
(*gspp)->st_nconflicts = rp->nconflicts;
(*gspp)->st_nrequests = rp->nrequests;
(*gspp)->st_nreleases = rp->nreleases;
(*gspp)->st_ndeadlocks = rp->ndeadlocks;
(*gspp)->st_region_nowait = rp->hdr.lock.mutex_set_nowait;
(*gspp)->st_region_wait = rp->hdr.lock.mutex_set_wait;
(*gspp)->st_refcnt = rp->hdr.refcnt;
(*gspp)->st_regsize = rp->hdr.size;
UNLOCK_LOCKREGION(lt);
return (0);
}
static u_int32_t
__lock_count_locks(lrp)
DB_LOCKREGION *lrp;
{
struct __db_lock *newl;
u_int32_t count;
count = 0;
for (newl = SH_TAILQ_FIRST(&lrp->free_locks, __db_lock);
newl != NULL;
newl = SH_TAILQ_NEXT(newl, links, __db_lock))
count++;
return (count);
}
static u_int32_t
__lock_count_objs(lrp)
DB_LOCKREGION *lrp;
{
DB_LOCKOBJ *obj;
u_int32_t count;
count = 0;
for (obj = SH_TAILQ_FIRST(&lrp->free_objs, __db_lockobj);
obj != NULL;
obj = SH_TAILQ_NEXT(obj, links, __db_lockobj))
count++;
return (count);
}
#define LOCK_DUMP_CONF 0x001 /* Conflict matrix. */
#define LOCK_DUMP_FREE 0x002 /* Display lock free list. */
#define LOCK_DUMP_LOCKERS 0x004 /* Display lockers. */
#define LOCK_DUMP_MEM 0x008 /* Display region memory. */
#define LOCK_DUMP_OBJECTS 0x010 /* Display objects. */
#define LOCK_DUMP_ALL 0x01f /* Display all. */
/*
* __lock_dump_region --
*
* PUBLIC: void __lock_dump_region __P((DB_LOCKTAB *, char *, FILE *));
*/
void
__lock_dump_region(lt, area, fp)
DB_LOCKTAB *lt;
char *area;
FILE *fp;
{
struct __db_lock *lp;
DB_LOCKOBJ *op;
DB_LOCKREGION *lrp;
u_int32_t flags, i, j;
int label;
/* Make it easy to call from the debugger. */
if (fp == NULL)
fp = stderr;
for (flags = 0; *area != '\0'; ++area)
switch (*area) {
case 'A':
LF_SET(LOCK_DUMP_ALL);
break;
case 'c':
LF_SET(LOCK_DUMP_CONF);
break;
case 'f':
LF_SET(LOCK_DUMP_FREE);
break;
case 'l':
LF_SET(LOCK_DUMP_LOCKERS);
break;
case 'm':
LF_SET(LOCK_DUMP_MEM);
break;
case 'o':
LF_SET(LOCK_DUMP_OBJECTS);
break;
}
lrp = lt->region;
fprintf(fp, "%s\nLock region parameters\n", DB_LINE);
fprintf(fp, "%s: %lu, %s: %lu, %s: %lu, %s: %lu\n%s: %lu, %s: %lu\n",
"table size", (u_long)lrp->table_size,
"hash_off", (u_long)lrp->hash_off,
"increment", (u_long)lrp->increment,
"mem_off", (u_long)lrp->mem_off,
"mem_bytes", (u_long)lrp->mem_bytes,
"need_dd", (u_long)lrp->need_dd);
if (LF_ISSET(LOCK_DUMP_CONF)) {
fprintf(fp, "\n%s\nConflict matrix\n", DB_LINE);
for (i = 0; i < lrp->nmodes; i++) {
for (j = 0; j < lrp->nmodes; j++)
fprintf(fp, "%lu\t",
(u_long)lt->conflicts[i * lrp->nmodes + j]);
fprintf(fp, "\n");
}
}
if (LF_ISSET(LOCK_DUMP_LOCKERS | LOCK_DUMP_OBJECTS)) {
fprintf(fp, "%s\nLock hash buckets\n", DB_LINE);
for (i = 0; i < lrp->table_size; i++) {
label = 1;
for (op = SH_TAILQ_FIRST(&lt->hashtab[i], __db_lockobj);
op != NULL;
op = SH_TAILQ_NEXT(op, links, __db_lockobj)) {
if (LF_ISSET(LOCK_DUMP_LOCKERS) &&
op->type == DB_LOCK_LOCKER) {
if (label) {
fprintf(fp,
"Bucket %lu:\n", (u_long)i);
label = 0;
}
__lock_dump_locker(lt, op, fp);
}
if (LF_ISSET(LOCK_DUMP_OBJECTS) &&
op->type == DB_LOCK_OBJTYPE) {
if (label) {
fprintf(fp,
"Bucket %lu:\n", (u_long)i);
label = 0;
}
__lock_dump_object(lt, op, fp);
}
}
}
}
if (LF_ISSET(LOCK_DUMP_FREE)) {
fprintf(fp, "%s\nLock free list\n", DB_LINE);
for (lp = SH_TAILQ_FIRST(&lrp->free_locks, __db_lock);
lp != NULL;
lp = SH_TAILQ_NEXT(lp, links, __db_lock))
fprintf(fp, "0x%lx: %lu\t%lu\t%s\t0x%lx\n", (u_long)lp,
(u_long)lp->holder, (u_long)lp->mode,
__lock_dump_status(lp->status), (u_long)lp->obj);
fprintf(fp, "%s\nObject free list\n", DB_LINE);
for (op = SH_TAILQ_FIRST(&lrp->free_objs, __db_lockobj);
op != NULL;
op = SH_TAILQ_NEXT(op, links, __db_lockobj))
fprintf(fp, "0x%lx\n", (u_long)op);
}
if (LF_ISSET(LOCK_DUMP_MEM))
__db_shalloc_dump(lt->mem, fp);
}
static void
__lock_dump_locker(lt, op, fp)
DB_LOCKTAB *lt;
DB_LOCKOBJ *op;
FILE *fp;
{
struct __db_lock *lp;
u_int32_t locker;
void *ptr;
ptr = SH_DBT_PTR(&op->lockobj);
memcpy(&locker, ptr, sizeof(u_int32_t));
fprintf(fp, "L %lx", (u_long)locker);
lp = SH_LIST_FIRST(&op->heldby, __db_lock);
if (lp == NULL) {
fprintf(fp, "\n");
return;
}
for (; lp != NULL; lp = SH_LIST_NEXT(lp, locker_links, __db_lock))
__lock_printlock(lt, lp, 0);
}
static void
__lock_dump_object(lt, op, fp)
DB_LOCKTAB *lt;
DB_LOCKOBJ *op;
FILE *fp;
{
struct __db_lock *lp;
u_int32_t j;
u_int8_t *ptr;
u_int ch;
ptr = SH_DBT_PTR(&op->lockobj);
for (j = 0; j < op->lockobj.size; ptr++, j++) {
ch = *ptr;
fprintf(fp, isprint(ch) ? "%c" : "\\%o", ch);
}
fprintf(fp, "\n");
fprintf(fp, "H:");
for (lp =
SH_TAILQ_FIRST(&op->holders, __db_lock);
lp != NULL;
lp = SH_TAILQ_NEXT(lp, links, __db_lock))
__lock_printlock(lt, lp, 0);
lp = SH_TAILQ_FIRST(&op->waiters, __db_lock);
if (lp != NULL) {
fprintf(fp, "\nW:");
for (; lp != NULL; lp = SH_TAILQ_NEXT(lp, links, __db_lock))
__lock_printlock(lt, lp, 0);
}
}
static const char *
__lock_dump_status(status)
db_status_t status;
{
switch (status) {
case DB_LSTAT_ABORTED:
return ("aborted");
case DB_LSTAT_ERR:
return ("err");
case DB_LSTAT_FREE:
return ("free");
case DB_LSTAT_HELD:
return ("held");
case DB_LSTAT_NOGRANT:
return ("nogrant");
case DB_LSTAT_PENDING:
return ("pending");
case DB_LSTAT_WAITING:
return ("waiting");
}
return ("unknown status");
}