db47/db47-4.7.25-dd_segfaults.patch

*** lock/lock_deadlock.c	2008-03-11 00:31:33.000000000 +1100
--- lock/lock_deadlock.c	2008-12-16 21:54:18.000000000 +1100
***************
*** 121,127 ****
  	DB_LOCKTAB *lt;
  	db_timespec now;
  	locker_info *idmap;
! 	u_int32_t *bitmap, *copymap, **deadp, **free_me, *tmpmap;
  	u_int32_t i, cid, keeper, killid, limit, nalloc, nlockers;
  	u_int32_t lock_max, txn_max;
  	int ret, status;
--- 121,127 ----
  	DB_LOCKTAB *lt;
  	db_timespec now;
  	locker_info *idmap;
! 	u_int32_t *bitmap, *copymap, **deadp, **deadlist, *tmpmap;
  	u_int32_t i, cid, keeper, killid, limit, nalloc, nlockers;
  	u_int32_t lock_max, txn_max;
  	int ret, status;
***************
*** 133,139 ****
  	if (IS_REP_CLIENT(env))
  		atype = DB_LOCK_MINWRITE;
  
! 	free_me = NULL;
  
  	lt = env->lk_handle;
  	if (rejectp != NULL)
--- 133,140 ----
  	if (IS_REP_CLIENT(env))
  		atype = DB_LOCK_MINWRITE;
  
! 	copymap = tmpmap = NULL;
! 	deadlist = NULL;
  
  	lt = env->lk_handle;
  	if (rejectp != NULL)
***************
*** 179,189 ****
  	memcpy(copymap, bitmap, nlockers * sizeof(u_int32_t) * nalloc);
  
  	if ((ret = __os_calloc(env, sizeof(u_int32_t), nalloc, &tmpmap)) != 0)
! 		goto err1;
  
  	/* Find a deadlock. */
  	if ((ret =
! 	    __dd_find(env, bitmap, idmap, nlockers, nalloc, &deadp)) != 0)
  		return (ret);
  
  	/*
--- 180,190 ----
  	memcpy(copymap, bitmap, nlockers * sizeof(u_int32_t) * nalloc);
  
  	if ((ret = __os_calloc(env, sizeof(u_int32_t), nalloc, &tmpmap)) != 0)
! 		goto err;
  
  	/* Find a deadlock. */
  	if ((ret =
! 	    __dd_find(env, bitmap, idmap, nlockers, nalloc, &deadlist)) != 0)
  		return (ret);
  
  	/*
***************
*** 204,211 ****
  		txn_max = TXN_MAXIMUM;
  
  	killid = BAD_KILLID;
! 	free_me = deadp;
! 	for (; *deadp != NULL; deadp++) {
  		if (rejectp != NULL)
  			++*rejectp;
  		killid = (u_int32_t)(*deadp - bitmap) / nalloc;
--- 205,211 ----
  		txn_max = TXN_MAXIMUM;
  
  	killid = BAD_KILLID;
! 	for (deadp = deadlist; *deadp != NULL; deadp++) {
  		if (rejectp != NULL)
  			++*rejectp;
  		killid = (u_int32_t)(*deadp - bitmap) / nalloc;
***************
*** 342,352 ****
  			__db_msg(env,
  			    "Aborting locker %lx", (u_long)idmap[killid].id);
  	}
! 	__os_free(env, tmpmap);
! err1:	__os_free(env, copymap);
! 
! err:	if (free_me != NULL)
! 		__os_free(env, free_me);
  	__os_free(env, bitmap);
  	__os_free(env, idmap);
  
--- 342,353 ----
  			__db_msg(env,
  			    "Aborting locker %lx", (u_long)idmap[killid].id);
  	}
! err:	if(copymap != NULL)
! 		__os_free(env, copymap);
! 	if (deadlist != NULL)
! 		__os_free(env, deadlist);
! 	if(tmpmap != NULL)
! 		__os_free(env, tmpmap);
  	__os_free(env, bitmap);
  	__os_free(env, idmap);
  
***************
*** 360,365 ****
--- 361,377 ----
  
  #define	DD_INVALID_ID	((u_int32_t) -1)
  
+ /*
+  * __dd_build --
+  *	Build the lock dependency bit maps.
+  * Notes on syncronization:  
+  *	LOCK_SYSTEM_LOCK is used to hold objects locked when we have
+  *		a single partition.
+  *	LOCK_LOCKERS is held while we are walking the lockers list and
+  *		to single thread the use of lockerp->dd_id.
+  *	LOCK_DD protects the DD list of objects.
+  */
+ 
  static int
  __dd_build(env, atype, bmp, nlockers, allocp, idmap, rejectp)
  	ENV *env;
***************
*** 393,398 ****
--- 405,411 ----
  	 * In particular we do not build the conflict array and our caller
  	 * needs to expect this.
  	 */
+ 	LOCK_SYSTEM_LOCK(lt, region);
  	if (atype == DB_LOCK_EXPIRE) {
  skip:		LOCK_DD(env, region);
  		op = SH_TAILQ_FIRST(&region->dd_objs, __db_lockobj);
***************
*** 430,446 ****
  			OBJECT_UNLOCK(lt, region, indx);
  		}
  		UNLOCK_DD(env, region);
  		goto done;
  	}
  
  	/*
! 	 * We'll check how many lockers there are, add a few more in for
! 	 * good measure and then allocate all the structures.  Then we'll
! 	 * verify that we have enough room when we go back in and get the
! 	 * mutex the second time.
  	 */
! retry:	count = region->stat.st_nlockers;
  	if (count == 0) {
  		*nlockers = 0;
  		return (0);
  	}
--- 443,460 ----
  			OBJECT_UNLOCK(lt, region, indx);
  		}
  		UNLOCK_DD(env, region);
+ 		LOCK_SYSTEM_UNLOCK(lt, region);
  		goto done;
  	}
  
  	/*
! 	 * Allocate after locking the region
! 	 * to make sure the structures are large enough.
  	 */
! 	LOCK_LOCKERS(env, region);
! 	count = region->stat.st_nlockers;
  	if (count == 0) {
+ 		UNLOCK_LOCKERS(env, region);
  		*nlockers = 0;
  		return (0);
  	}
***************
*** 448,497 ****
  	if (FLD_ISSET(env->dbenv->verbose, DB_VERB_DEADLOCK))
  		__db_msg(env, "%lu lockers", (u_long)count);
  
- 	count += 20;
  	nentries = (u_int32_t)DB_ALIGN(count, 32) / 32;
  
! 	/*
! 	 * Allocate enough space for a count by count bitmap matrix.
! 	 *
! 	 * XXX
! 	 * We can probably save the malloc's between iterations just
! 	 * reallocing if necessary because count grew by too much.
! 	 */
  	if ((ret = __os_calloc(env, (size_t)count,
! 	    sizeof(u_int32_t) * nentries, &bitmap)) != 0)
  		return (ret);
  
  	if ((ret = __os_calloc(env,
  	    sizeof(u_int32_t), nentries, &tmpmap)) != 0) {
  		__os_free(env, bitmap);
  		return (ret);
  	}
  
  	if ((ret = __os_calloc(env,
  	    (size_t)count, sizeof(locker_info), &id_array)) != 0) {
  		__os_free(env, bitmap);
  		__os_free(env, tmpmap);
  		return (ret);
  	}
  
  	/*
- 	 * Now go back in and actually fill in the matrix.
- 	 */
- 	if (region->stat.st_nlockers > count) {
- 		__os_free(env, bitmap);
- 		__os_free(env, tmpmap);
- 		__os_free(env, id_array);
- 		goto retry;
- 	}
- 
- 	/*
  	 * First we go through and assign each locker a deadlock detector id.
  	 */
  	id = 0;
- 	LOCK_LOCKERS(env, region);
  	SH_TAILQ_FOREACH(lip, &region->lockers, ulinks, __db_locker) {
  		if (lip->master_locker == INVALID_ROFF) {
  			lip->dd_id = id++;
  			id_array[lip->dd_id].id = lip->id;
  			switch (atype) {
--- 462,498 ----
  	if (FLD_ISSET(env->dbenv->verbose, DB_VERB_DEADLOCK))
  		__db_msg(env, "%lu lockers", (u_long)count);
  
  	nentries = (u_int32_t)DB_ALIGN(count, 32) / 32;
  
! 	/* Allocate enough space for a count by count bitmap matrix. */
  	if ((ret = __os_calloc(env, (size_t)count,
! 	    sizeof(u_int32_t) * nentries, &bitmap)) != 0) {
! 		UNLOCK_LOCKERS(env, region);
  		return (ret);
+ 	}
  
  	if ((ret = __os_calloc(env,
  	    sizeof(u_int32_t), nentries, &tmpmap)) != 0) {
+ 		UNLOCK_LOCKERS(env, region);
  		__os_free(env, bitmap);
  		return (ret);
  	}
  
  	if ((ret = __os_calloc(env,
  	    (size_t)count, sizeof(locker_info), &id_array)) != 0) {
+ 		UNLOCK_LOCKERS(env, region);
  		__os_free(env, bitmap);
  		__os_free(env, tmpmap);
  		return (ret);
  	}
  
  	/*
  	 * First we go through and assign each locker a deadlock detector id.
  	 */
  	id = 0;
  	SH_TAILQ_FOREACH(lip, &region->lockers, ulinks, __db_locker) {
  		if (lip->master_locker == INVALID_ROFF) {
+ 			DB_ASSERT(env, id < count);
  			lip->dd_id = id++;
  			id_array[lip->dd_id].id = lip->id;
  			switch (atype) {
***************
*** 510,516 ****
  			lip->dd_id = DD_INVALID_ID;
  
  	}
- 	UNLOCK_LOCKERS(env, region);
  
  	/*
  	 * We only need consider objects that have waiters, so we use
--- 511,516 ----
***************
*** 669,675 ****
  	 * status after building the bit maps so that we will not detect
  	 * a blocked transaction without noting that it is already aborting.
  	 */
- 	LOCK_LOCKERS(env, region);
  	for (id = 0; id < count; id++) {
  		if (!id_array[id].valid)
  			continue;
--- 669,674 ----
***************
*** 738,743 ****
--- 737,743 ----
  			id_array[id].in_abort = 1;
  	}
  	UNLOCK_LOCKERS(env, region);
+ 	LOCK_SYSTEM_UNLOCK(lt, region);
  
  	/*
  	 * Now we can release everything except the bitmap matrix that we
***************
*** 839,844 ****
--- 839,845 ----
  	ret = 0;
  
  	/* We must lock so this locker cannot go away while we abort it. */
+ 	LOCK_SYSTEM_LOCK(lt, region);
  	LOCK_LOCKERS(env, region);
  
  	/*
***************
*** 895,900 ****
--- 896,902 ----
  done:	OBJECT_UNLOCK(lt, region, info->last_ndx);
  err:
  out:	UNLOCK_LOCKERS(env, region);
+ 	LOCK_SYSTEM_UNLOCK(lt, region);
  	return (ret);
  }