Fix SQLITE_DBSTATUS_SCHEMA_USED so that it works with SQLITE_OPEN_SHARED_SCHEMA connections.

FossilOrigin-Name: d43b3c056cb13930865c504c9498b2c83e4bebce9bff01ee21293e7dc7a6711e

doc/shared_schema.md

@@ -33,9 +33,9 @@ database is treated as empty. This usually means that corruption results in
 a "no such table: xxx" error instead of a more specific error message.
 
 For SQLITE_OPEN_SHARED_SCHEMA connections, the
-SQLITE_DBSTATUS_SCHEMA_USED sqlite3_db_used() distributes
-the memory used for a shared schema object evenly between all database
-connections that share it.
+SQLITE_DBSTATUS_SCHEMA_USED sqlite3_db_status() verb
+distributes the memory used for a shared schema object evenly between all
+database connections that share it.
 
 ## Implementation Notes
 

manifest

@@ -1,5 +1,5 @@
-C Change\sthe\sname\sof\sthe\sSQLITE_OPEN_REUSE_SCHEMA\sflag\sto\sSQLITE_OPEN_SHARED_SCHEMA.
-D 2019-02-14T18:38:44.649
+C Fix\sSQLITE_DBSTATUS_SCHEMA_USED\sso\sthat\sit\sworks\swith\sSQLITE_OPEN_SHARED_SCHEMA\sconnections.
+D 2019-02-14T21:04:27.065
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 56456706c4da271309914c756c9c8ea537685f1c79f8785afa72f968d6810482
@@ -39,7 +39,7 @@ F contrib/sqlitecon.tcl 210a913ad63f9f991070821e599d600bd913e0ad
 F doc/F2FS.txt c1d4a0ae9711cfe0e1d8b019d154f1c29e0d3abfe820787ba1e9ed7691160fcd
 F doc/lemon.html 24956ab2995e55fe171e55bdd04f22b553957dc8bb43501dbb9311e30187e0d3
 F doc/pager-invariants.txt 27fed9a70ddad2088750c4a2b493b63853da2710
-F doc/shared_schema.md 8659d89eaeab5547c435284e0356237df31beb30a7575f30d76d9bc0eb825f9d
+F doc/shared_schema.md 4c1ea0da3c9a83afe646c696f4402827b38134dbc73c1e0637adce6546cb2a79
 F doc/vfs-shm.txt e101f27ea02a8387ce46a05be2b1a902a021d37a
 F ext/README.md fd5f78013b0a2bc6f0067afb19e6ad040e89a10179b4f6f03eee58fac5f169bd
 F ext/async/README.txt e12275968f6fde133a80e04387d0e839b0c51f91
@@ -459,8 +459,8 @@ F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
 F src/btree.c 161b6a57b91d160065e512a4d0be180e402a16a059034a380cbdc2411924f8ac
 F src/btree.h 63b94fb38ce571c15eb6a3661815561b501d23d5948b2d1e951fbd7a2d04e8d3
 F src/btreeInt.h 6111c15868b90669f79081039d19e7ea8674013f907710baa3c814dc3f8bfd3f
-F src/build.c 66830361a2d820e52c483bd5ac3af0fd111795fc7836d99cfdc8818dbfa23d5d
-F src/callback.c 8d0402ae92ba24b99b4af9abf6881821e78826a9cfe984b38dfbf7664804fea2
+F src/build.c 364c8fa52cca6002be42c987e7421bd38c40e0f3afdf3198bc174fb92da4f4e8
+F src/callback.c e60a0c3928adb5b5c8dffa3df2d1b34c67177b7c149c9d109012c22a631fc20a
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 109e58d00f62e8e71ee1eb5944ac18b90171c928ab2e082e058056e1137cc20b
 F src/date.c ebe1dc7c8a347117bb02570f1a931c62dd78f4a2b1b516f4837d45b7d6426957
@@ -520,9 +520,9 @@ F src/shell.c.in d7d63fd1ecef44d19088adc188652252327eab782d59cf1958657943132b508
 F src/sqlite.h.in cd9b7c397b942a4903c46ebbabee47f920a9916e96e70e0b4f793076d4b45e31
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 960f1b86c3610fa23cb6a267572a97dcf286e77aa0dd3b9b23292ffaa1ea8683
-F src/sqliteInt.h 176ae22317dda2b49d9c3c28bf9215e7ae8f012f88c37dd505f6be8b3637db28
+F src/sqliteInt.h 0238a621a7d054370b6700c2d1368870cd2282f38a74f3ddafb238a8ea3c181c
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
-F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
+F src/status.c 0361d78dabfd2a92c740911f42723d2f6775d619feb8f8910827f9c9fe8bc30f
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
 F src/tclsqlite.c f11d822fb2bd6e155d41535a629d1c34daf3d98a37b1f0ea6b4cb11d150d3c57
 F src/test1.c 353b066e7ec761c4c715c1c20b888e0e7a0b0c0eda7f68c110e032d63713cade
@@ -1229,7 +1229,7 @@ F test/resetdb.test 8062cf10a09d8c048f8de7711e94571c38b38168db0e5877ba7561789e5e
 F test/resolver01.test f4022acafda7f4d40eca94dbf16bc5fc4ac30ceb
 F test/reuse1.test 31c312375ccfcc5c2abc1fca5e4a89d6309c57ea6b1fa3179a5eee68016f9c74
 F test/reuse2.test 51a4ba225c602bf19847c27c5f0156c3f273f2c8de2456c22b97c2a9a3824d87
-F test/reuse3.test 3e865c031fe71242ebcdd90baf34cba8be4dddacad2fe025e697ecf035335f4a
+F test/reuse3.test b04e9b7115ece25b28ca57b42464e058cc0de35742b150840a5937c3ddb7ca8a
 F test/rollback.test 06680159bc6746d0f26276e339e3ae2f951c64812468308838e0a3362d911eaa
 F test/rollback2.test bc868d57899dc6972e2b4483faae0e03365a0556941474eec487ae21d8d38bb6
 F test/rollbackfault.test 0e646aeab8840c399cfbfa43daab46fd609cf04a
@@ -1370,7 +1370,7 @@ F test/tabfunc01.test 20e98ffe55f35d8d33fd834ca8bf9d4b637e560af8fcd00464b4154d90
 F test/table.test eb3463b7add9f16a5bb836badf118cf391b809d09fdccd1f79684600d07ec132
 F test/tableapi.test ecbcc29c4ab62c1912c3717c48ea5c5e59f7d64e4a91034e6148bd2b82f177f4
 F test/tableopts.test dba698ba97251017b7c80d738c198d39ab747930
-F test/tclsqlite.test 049da602775bebfadfa2fae0710e1099a38ef2fc9f76c7546be3ba8fdbb02263
+F test/tclsqlite.test 74cc8404f69e2c3aafbc9bc73a0e686aa91612b88284f9cfd868cb916b67f6b0
 F test/tempdb.test 4cdaa23ddd8acb4d79cbb1b68ccdfd09b0537aaba909ca69a876157c2a2cbd08
 F test/tempdb2.test 2479226e4cb96f4c663eccd2d12c077cf6bda29ca5cc69a8a58a06127105dd62
 F test/tempfault.test 0c0d349c9a99bf5f374655742577f8712c647900
@@ -1809,7 +1809,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P e47a5aea76560e86e5417fea9e2219ec6c30e47ef383e499cfe927f64d584dac
-R 8625b684c268ad69e5f2e6997ec316b6
+P 7257fcc8c990b46a4f6a9e506f4a4a40195e6b2c626efd380cfa01f0ce8eb0fb
+R 335d544fb33c769d2c93a5ba7269ae2c
 U dan
-Z 501ceb9c380b311fe8ede824c64ca859
+Z 4a0370c09441d299e3638aa59f7363a2

manifest.uuid

@@ -1 +1 @@
-7257fcc8c990b46a4f6a9e506f4a4a40195e6b2c626efd380cfa01f0ce8eb0fb
+d43b3c056cb13930865c504c9498b2c83e4bebce9bff01ee21293e7dc7a6711e

src/build.c

@@ -294,7 +294,7 @@ int sqlite3UserAuthTable(const char *zTable){
 ** Non-zero is returned if a schema is loaded, or zero if it was already 
 ** loaded when this function was called..
 */
-static int loadSharableSchema(sqlite3 *db, int iDb){
+int sqlite3SchemaLoad(sqlite3 *db, int iDb){
   if( IsReuseSchema(db) 
    && DbHasProperty(db, iDb, DB_SchemaLoaded)==0 
    && (db->init.busy==0 || (iDb!=1 && db->init.iDb==1))
@@ -341,7 +341,7 @@ Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){
       if( zDatabase==0 || sqlite3StrICmp(zDatabase, db->aDb[j].zDbSName)==0 ){
         int bUnload;
         assert( sqlite3SchemaMutexHeld(db, j, 0) );
-        bUnload = loadSharableSchema(db, j);
+        bUnload = sqlite3SchemaLoad(db, j);
         p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName);
         if( p ) return p;
         if( bUnload ){
@@ -398,7 +398,7 @@ Table *sqlite3LocateTable(
         pMod = sqlite3PragmaVtabRegister(db, zName);
       }
       if( pMod ){
-        loadSharableSchema(db, 0);
+        sqlite3SchemaLoad(db, 0);
         if( sqlite3VtabEponymousTableInit(pParse, pMod) ){
           return pMod->pEpoTab;
         }

src/callback.c

@@ -549,6 +549,28 @@ static SchemaPool *SQLITE_WSD schemaPoolList = 0;
 SchemaPool *sqlite3SchemaPoolList(void){ return schemaPoolList; }
 #endif
 
+/*
+** Database handle db was opened with the SHARED_SCHEMA flag, and database
+** iDb is currently connected to a schema-pool. When this function is called,
+** (*pnByte) is set to nInit plus the amount of memory used to store a 
+** single instance of the Schema objects managed by the schema-pool.
+** This function adjusts (*pnByte) sot hat it is set to nInit plus
+** (nSchema/nRef) of the amount of memory used by a single Schema object,
+** where nSchema is the number of Schema objects allocated by this pool,
+** and nRef is the number of connections to the schema-pool.
+*/
+void sqlite3SchemaAdjustUsed(sqlite3 *db, int iDb, int nInit, int *pnByte){
+  SchemaPool *pSPool = db->aDb[iDb].pSPool;
+  int nSchema = 0;
+  Schema *p;
+  sqlite3_mutex_enter( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+  for(p=pSPool->pSchema; p; p=p->pNext){
+    nSchema++;
+  }
+  *pnByte = nInit + ((*pnByte - nInit) * nSchema) / pSPool->nRef;
+  sqlite3_mutex_leave( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+}
+
 /*
 ** Check that the schema of db iDb is writable (either because it is the 
 ** temp db schema or because the db handle was opened without

src/sqliteInt.h

@@ -4325,8 +4325,10 @@ int sqlite3SchemaConnect(sqlite3*, int, u64);
 int sqlite3SchemaDisconnect(sqlite3 *, int, int);
 void sqlite3SchemaClearOrDisconnect(sqlite3*, int);
 Schema *sqlite3SchemaExtract(SchemaPool*);
+int sqlite3SchemaLoad(sqlite3*, int);
 void sqlite3SchemaReleaseAll(sqlite3*);
 void sqlite3SchemaRelease(sqlite3*, int);
+void sqlite3SchemaAdjustUsed(sqlite3*, int, int, int*);
 void sqlite3SchemaWritable(Parse*, int);
 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);

src/status.c

@@ -275,11 +275,19 @@ int sqlite3_db_status(
     case SQLITE_DBSTATUS_SCHEMA_USED: {
       int i;                      /* Used to iterate through schemas */
       int nByte = 0;              /* Used to accumulate return value */
+      int bReleaseSchema;
 
       sqlite3BtreeEnterAll(db);
+      bReleaseSchema = sqlite3LockReusableSchema(db);
       db->pnBytesFreed = &nByte;
       for(i=0; i<db->nDb; i++){
-        Schema *pSchema = db->aDb[i].pSchema;
+        int bUnload = 0;
+        int nUsed = nByte;
+        Schema *pSchema;
+        if( db->aDb[i].pSPool ){
+          bUnload = sqlite3SchemaLoad(db, i);
+        }
+        pSchema = db->aDb[i].pSchema;
         if( ALWAYS(pSchema!=0) ){
           HashElem *p;
 
@@ -301,7 +309,12 @@ int sqlite3_db_status(
             sqlite3DeleteTable(db, (Table *)sqliteHashData(p));
           }
         }
+        if( db->aDb[i].pSPool ){
+          if( bUnload ) sqlite3SchemaRelease(db, i);
+          sqlite3SchemaAdjustUsed(db, i, nUsed, &nByte);
         }
+      }
+      sqlite3UnlockReusableSchema(db, bReleaseSchema);
       db->pnBytesFreed = 0;
       sqlite3BtreeLeaveAll(db);
 

test/reuse3.test

@@ -88,5 +88,41 @@ do_catchsql_test 2.2 {
   SELECT * FROM x1;
 } {1 {no such table: x1}}
 
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 3.0 {
+  CREATE TABLE x1(a, b, c);
+  CREATE INDEX i1 ON x1(a, b, c);
+  CREATE TRIGGER tr1 AFTER INSERT ON x1 BEGIN
+    SELECT 1, 2, 3, 4, 5;
+  END;
+  INSERT INTO x1 VALUES(1, 2, 3);
+}
+sqlite3 db1 test.db -shared-schema 1
+
+do_test 3.1 {
+  execsql { SELECT * FROM x1 } db1
+  set N [lindex [sqlite3_db_status db1 SCHEMA_USED 0] 1]
+  expr $N==$N
+} 1
+
+sqlite3 db2 test.db -shared-schema 1
+do_test 3.2 {
+  execsql { SELECT * FROM x1 } db2
+  breakpoint
+  set N2 [lindex [sqlite3_db_status db2 SCHEMA_USED 0] 1]
+  expr $N2>($N/2) && $N2<($N/2)+400
+} 1
+
+sqlite3 db3 test.db -shared-schema 1
+sqlite3 db4 test.db -shared-schema 1
+do_test 3.3 {
+  execsql { SELECT * FROM x1 } db3
+  execsql { SELECT * FROM x1 } db4
+  set N4 [lindex [sqlite3_db_status db2 SCHEMA_USED 0] 1]
+  set M [expr 2*($N-$N2)]
+  expr {$N4 == (($M / 4) + $N-$M)}
+} 1
+
 finish_test
 

test/tclsqlite.test

@@ -24,7 +24,7 @@ source $testdir/tester.tcl
 
 # Check the error messages generated by tclsqlite
 #
-set r "sqlite_orig HANDLE ?FILENAME? ?-vfs VFSNAME? ?-readonly BOOLEAN? ?-create BOOLEAN? ?-nomutex BOOLEAN? ?-fullmutex BOOLEAN? ?-uri BOOLEAN? ?-reuse-schema BOOLEAN?"
+set r "sqlite_orig HANDLE ?FILENAME? ?-vfs VFSNAME? ?-readonly BOOLEAN? ?-create BOOLEAN? ?-nomutex BOOLEAN? ?-fullmutex BOOLEAN? ?-uri BOOLEAN? ?-shared-schema BOOLEAN?"
 if {[sqlite3 -has-codec]} {
   append r " ?-key CODECKEY?"
 }