Index: src/btree.c
==================================================================
--- src/btree.c
+++ src/btree.c
@@ -2335,13 +2335,13 @@
assert( (pBt->pageSize & 7)==0 ); /* 8-byte alignment of pageSize */
#if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)
/* Add the new BtShared object to the linked list sharable BtShareds.
*/
+ pBt->nRef = 1;
if( p->sharable ){
MUTEX_LOGIC( sqlite3_mutex *mutexShared; )
- pBt->nRef = 1;
MUTEX_LOGIC( mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);)
if( SQLITE_THREADSAFE && sqlite3GlobalConfig.bCoreMutex ){
pBt->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_FAST);
if( pBt->mutex==0 ){
rc = SQLITE_NOMEM_BKPT;
@@ -2408,10 +2408,11 @@
}
if( mutexOpen ){
assert( sqlite3_mutex_held(mutexOpen) );
sqlite3_mutex_leave(mutexOpen);
}
+ assert( rc!=SQLITE_OK || sqlite3BtreeConnectionCount(*ppBtree)>0 );
return rc;
}
/*
** Decrement the BtShared.nRef counter. When it reaches zero,
@@ -9696,6 +9697,16 @@
** Return true if the Btree passed as the only argument is sharable.
*/
int sqlite3BtreeSharable(Btree *p){
return p->sharable;
}
+
+/*
+** Return the number of connections to the BtShared object accessed by
+** the Btree handle passed as the only argument. For private caches
+** this is always 1. For shared caches it may be 1 or greater.
+*/
+int sqlite3BtreeConnectionCount(Btree *p){
+ testcase( p->sharable );
+ return p->pBt->nRef;
+}
#endif
Index: src/btree.h
==================================================================
--- src/btree.h
+++ src/btree.h
@@ -326,15 +326,17 @@
#ifndef SQLITE_OMIT_SHARED_CACHE
void sqlite3BtreeEnter(Btree*);
void sqlite3BtreeEnterAll(sqlite3*);
int sqlite3BtreeSharable(Btree*);
void sqlite3BtreeEnterCursor(BtCursor*);
+ int sqlite3BtreeConnectionCount(Btree*);
#else
# define sqlite3BtreeEnter(X)
# define sqlite3BtreeEnterAll(X)
# define sqlite3BtreeSharable(X) 0
# define sqlite3BtreeEnterCursor(X)
+# define sqlite3BtreeConnectionCount(X) 1
#endif
#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
void sqlite3BtreeLeave(Btree*);
void sqlite3BtreeLeaveCursor(BtCursor*);
Index: src/sqlite.h.in
==================================================================
--- src/sqlite.h.in
+++ src/sqlite.h.in
@@ -6763,10 +6763,22 @@
** [[SQLITE_DBSTATUS_CACHE_USED]] ^(SQLITE_DBSTATUS_CACHE_USED
** This parameter returns the approximate number of bytes of heap
** memory used by all pager caches associated with the database connection.)^
** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
**
+** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
+** ^(SQLITE_DBSTATUS_CACHE_USED_SHARED
+** This parameter is similar to DBSTATUS_CACHE_USED, except that if a
+** pager cache is shared between two or more connections the bytes of heap
+** memory used by that pager cache is divided evenly between the attached
+** connections.)^ In other words, if none of the pager caches associated
+** with the database connection are shared, this request returns the same
+** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
+** shared, the value returned by this call will be smaller than that returned
+** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
+** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
+**
** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(SQLITE_DBSTATUS_SCHEMA_USED
** This parameter returns the approximate number of bytes of heap
** memory used to store the schema for all databases associated
** with the connection - main, temp, and any [ATTACH]-ed databases.)^
** ^The full amount of memory used by the schemas is reported, even if the
@@ -6820,11 +6832,12 @@
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
#define SQLITE_DBSTATUS_CACHE_HIT 7
#define SQLITE_DBSTATUS_CACHE_MISS 8
#define SQLITE_DBSTATUS_CACHE_WRITE 9
#define SQLITE_DBSTATUS_DEFERRED_FKS 10
-#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */
+#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
+#define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */
/*
** CAPI3REF: Prepared Statement Status
** METHOD: sqlite3_stmt
Index: src/status.c
==================================================================
--- src/status.c
+++ src/status.c
@@ -217,19 +217,24 @@
/*
** Return an approximation for the amount of memory currently used
** by all pagers associated with the given database connection. The
** highwater mark is meaningless and is returned as zero.
*/
+ case SQLITE_DBSTATUS_CACHE_USED_SHARED:
case SQLITE_DBSTATUS_CACHE_USED: {
int totalUsed = 0;
int i;
sqlite3BtreeEnterAll(db);
for(i=0; inDb; i++){
Btree *pBt = db->aDb[i].pBt;
if( pBt ){
Pager *pPager = sqlite3BtreePager(pBt);
- totalUsed += sqlite3PagerMemUsed(pPager);
+ int nByte = sqlite3PagerMemUsed(pPager);
+ if( op==SQLITE_DBSTATUS_CACHE_USED_SHARED ){
+ nByte = nByte / sqlite3BtreeConnectionCount(pBt);
+ }
+ totalUsed += nByte;
}
}
sqlite3BtreeLeaveAll(db);
*pCurrent = totalUsed;
*pHighwater = 0;
Index: src/test_malloc.c
==================================================================
--- src/test_malloc.c
+++ src/test_malloc.c
@@ -1415,11 +1415,12 @@
{ "LOOKASIDE_MISS_SIZE", SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE },
{ "LOOKASIDE_MISS_FULL", SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL },
{ "CACHE_HIT", SQLITE_DBSTATUS_CACHE_HIT },
{ "CACHE_MISS", SQLITE_DBSTATUS_CACHE_MISS },
{ "CACHE_WRITE", SQLITE_DBSTATUS_CACHE_WRITE },
- { "DEFERRED_FKS", SQLITE_DBSTATUS_DEFERRED_FKS }
+ { "DEFERRED_FKS", SQLITE_DBSTATUS_DEFERRED_FKS },
+ { "CACHE_USED_SHARED", SQLITE_DBSTATUS_CACHE_USED_SHARED },
};
Tcl_Obj *pResult;
if( objc!=4 ){
Tcl_WrongNumArgs(interp, 1, objv, "DB PARAMETER RESETFLAG");
return TCL_ERROR;
Index: test/dbstatus.test
==================================================================
--- test/dbstatus.test
+++ test/dbstatus.test
@@ -12,10 +12,11 @@
# Tests for the sqlite3_db_status() function
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl
+set testprefix dbstatus
ifcapable !compound {
finish_test
return
}
@@ -22,10 +23,11 @@
# Memory statistics must be enabled for this test.
db close
sqlite3_shutdown
sqlite3_config_memstatus 1
+sqlite3_config_uri 1
sqlite3_initialize
sqlite3 db test.db
# Make sure sqlite3_db_config() and sqlite3_db_status are working.
@@ -374,7 +376,42 @@
do_test dbstatus-3.$tn.c { list $nAlloc1 $nStmt1 } [list $nAlloc3 $nStmt3]
do_test dbstatus-3.$tn.d { list $nAlloc2 $nStmt2 } [list $nAlloc4 $nStmt4]
}
}
+
+#-------------------------------------------------------------------------
+# The following tests focus on DBSTATUS_CACHE_USED_SHARED
+#
+ifcapable shared_cache {
+ proc do_cacheused_test {tn db res} {
+ set cu [sqlite3_db_status $db SQLITE_DBSTATUS_CACHE_USED 0]
+ set pcu [sqlite3_db_status $db SQLITE_DBSTATUS_CACHE_USED_SHARED 0]
+ set cu [lindex $cu 1]
+ set pcu [lindex $pcu 1]
+ uplevel [list do_test $tn [list list $cu $pcu] [list {*}$res]]
+ }
+ reset_db
+ sqlite3 db file:test.db?cache=shared
+
+ do_execsql_test 4.0 {
+ CREATE TABLE t1(a, b, c);
+ INSERT INTO t1 VALUES(1, 2, 3);
+ }
+ do_cacheused_test 4.0.1 db { 4568 4568 }
+ do_execsql_test 4.1 {
+ CREATE TEMP TABLE tt(a, b, c);
+ INSERT INTO tt VALUES(1, 2, 3);
+ }
+ do_cacheused_test 4.1.1 db { 9000 9000 }
+
+ sqlite3 db2 file:test.db?cache=shared
+ do_cacheused_test 4.2.1 db2 { 4568 2284 }
+ do_cacheused_test 4.2.2 db { 9000 6716 }
+ db close
+ do_cacheused_test 4.2.3 db2 { 4568 4568 }
+ sqlite3 db file:test.db?cache=shared
+ do_cacheused_test 4.2.4 db2 { 4568 2284 }
+ db2 close
+}
finish_test