Only pass -1 as the size parameter to xShmGet when the caller does not care what size mapping is returned. Only call xShmSize when the underlying allocation (not the mapping) should be resized.

FossilOrigin-Name: 637f51ddf9e4a57e1f171b6d2c6c93152074267e

manifest

@@ -1,5 +1,5 @@
-C Fix\sa\sbug\swhereby\san\sold\ssnapshot\scould\sbe\scheckpointed\s(and\ssubsequent\stransactions\sdiscarded)\sif\sthe\slast\sconnection\sto\sdisconnect\sfrom\sa\sWAL\sdatabase\shappended\sto\sbe\sholding\san\sout-of-date\swal-index\sheader.
-D 2010-05-06T17:28:09
+C Only\spass\s-1\sas\sthe\ssize\sparameter\sto\sxShmGet\swhen\sthe\scaller\sdoes\snot\scare\swhat\ssize\smapping\sis\sreturned.\sOnly\scall\sxShmSize\swhen\sthe\sunderlying\sallocation\s(not\sthe\smapping)\sshould\sbe\sresized.
+D 2010-05-06T18:04:51
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in a5cad1f8f3e021356bfcc6c77dc16f6f1952bbc3
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -207,7 +207,7 @@ F src/test_schema.c 8c06ef9ddb240c7a0fcd31bc221a6a2aade58bf0
 F src/test_server.c bbba05c144b5fc4b52ff650a4328027b3fa5fcc6
 F src/test_tclvar.c f4dc67d5f780707210d6bb0eb6016a431c04c7fa
 F src/test_thread.c aa9919c885a1fe53eafc73492f0898ee6c0a0726
-F src/test_vfs.c a6a8b594b4b9ce884fcf7d822887b8e16e61f797
+F src/test_vfs.c 72b8ad1a6bc6c27d9e5b4362d6320d3834c87db6
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/tokenize.c 25ceb0f0a746ea1d0f9553787f3f0a56853cfaeb
 F src/trigger.c 8927588cb9e6d47f933b53bfe74200fbb504100d
@@ -224,7 +224,7 @@ F src/vdbeblob.c 5327132a42a91e8b7acfb60b9d2c3b1c5c863e0e
 F src/vdbemem.c 2a82f455f6ca6f78b59fb312f96054c04ae0ead1
 F src/vdbetrace.c 864cef96919323482ebd9986f2132435115e9cc2
 F src/vtab.c a0f8a40274e4261696ef57aa806de2776ab72cda
-F src/wal.c d7250e0da0d389d9fc3839363570f3f74da0b60d
+F src/wal.c 1730243c6491a5b4e325c8977b15fcb9aa4486c6
 F src/wal.h b4c42014b5fa3b4e6244ac8c65de7ff67adeb27c
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
 F src/where.c 75fee9e255b62f773fcadd1d1f25b6f63ac7a356
@@ -762,7 +762,7 @@ F test/vtab_alter.test 9e374885248f69e251bdaacf480b04a197f125e5
 F test/vtab_err.test 0d4d8eb4def1d053ac7c5050df3024fd47a3fbd8
 F test/vtab_shared.test 0eff9ce4f19facbe0a3e693f6c14b80711a4222d
 F test/wal.test f0b78497bbe2e7f3c35a1c28e9772fe0dead1fc8
-F test/wal2.test 4a8e20416020f83b792464edee18107321dea99a
+F test/wal2.test 1d5b761f55070e242a983bf08634c79fb46724f2
 F test/walbak.test a0e45187c7d8928df035dfea29b99b016b21ca3c
 F test/walcrash.test f6d5fb2bb108876f04848720a488065d9deef69f
 F test/walfault.test ae37204f4375e0e5eba75094d0d0db7148de70a8
@@ -813,7 +813,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 56a17dae91600a3863903f8d654ed52a0f720caf
-R aee4f4f487984caf56f9844933d88af1
+P d0c0034b0baa83046c1d6b94c886f7039e4e06f5
+R 4a69eca7dd8c02399282e41c5a135767
 U dan
-Z 2489bba830e3043eba5db422e0f13170
+Z 6b8130cf037212b2a014832ceb2e7bfd

manifest.uuid

@@ -1 +1 @@
-d0c0034b0baa83046c1d6b94c886f7039e4e06f5
+637f51ddf9e4a57e1f171b6d2c6c93152074267e

src/test_vfs.c

@@ -648,7 +648,7 @@ static void testvfs_obj_del(ClientData cd){
 #define TESTVFS_MAX_ARGS 12
 
 /*
-** Usage:  testvfs VFSNAME SCRIPT
+** Usage:  testvfs ?-noshm? VFSNAME SCRIPT
 **
 ** This command creates two things when it is invoked: an SQLite VFS, and
 ** a Tcl command. Both are named VFSNAME. The VFS is installed. It is not
@@ -732,13 +732,15 @@ static int testvfs_cmd(
   Tcl_Obj **apScript;             /* Array of pScript elements */
   int nByte;                      /* Bytes of space to allocate at p */
   int i;                          /* Counter variable */
+  int isNoshm = 0;                /* True if -noshm is passed */
 
-  if( objc!=3 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "VFSNAME SCRIPT");
-    return TCL_ERROR;
+  if( objc<3 ) goto bad_args;
+  if( strcmp(Tcl_GetString(objv[1]), "-noshm")==0 ){
+    isNoshm = 1;
   }
-  zVfs = Tcl_GetString(objv[1]);
-  pScript = objv[2];
+  if( objc!=3+isNoshm ) goto bad_args;
+  zVfs = Tcl_GetString(objv[isNoshm+1]);
+  pScript = objv[isNoshm+2];
 
   if( TCL_OK!=Tcl_ListObjGetElements(interp, pScript, &nScript, &apScript) ){
     return TCL_ERROR;
@@ -768,11 +770,23 @@ static int testvfs_cmd(
   pVfs->mxPathname = p->pParent->mxPathname;
   pVfs->szOsFile += p->pParent->szOsFile;
   p->pVfs = pVfs;
+  if( isNoshm ){
+    pVfs->xShmOpen = 0;
+    pVfs->xShmGet = 0;
+    pVfs->xShmSize = 0;
+    pVfs->xShmRelease = 0;
+    pVfs->xShmClose = 0;
+    pVfs->xShmLock = 0;
+  }
 
   Tcl_CreateObjCommand(interp, zVfs, testvfs_obj_cmd, p, testvfs_obj_del);
   sqlite3_vfs_register(pVfs, 0);
 
   return TCL_OK;
+
+ bad_args:
+  Tcl_WrongNumArgs(interp, 1, objv, "?-noshm? VFSNAME SCRIPT");
+  return TCL_ERROR;
 }
 
 int Sqlitetestvfs_Init(Tcl_Interp *interp){

src/wal.c

@@ -577,8 +577,13 @@ static int walIndexRecover(Wal *pWal){
   }
 
 finished:
+  if( rc==SQLITE_OK && hdr.iLastPg==0 ){
+    rc = walIndexRemap(pWal, WALINDEX_MMAP_INCREMENT);
+  }
+  if( rc==SQLITE_OK ){
     walIndexWriteHdr(pWal, &hdr);
     memcpy(&pWal->hdr, &hdr, sizeof(hdr));
+  }
   return rc;
 }
 
@@ -698,7 +703,7 @@ static int walIteratorInit(Wal *pWal, WalIterator **pp){
   u8 *aTmp;                       /* Temp space used by merge-sort */
   int rc;                         /* Return code of walIndexMap() */
 
-  rc = walIndexMap(pWal, -1);
+  rc = walIndexMap(pWal, walMappingSize(pWal->hdr.iLastPg));
   if( rc!=SQLITE_OK ){
     return rc;
   }
@@ -878,10 +883,9 @@ int walIndexTryHdr(Wal *pWal, int *pisValid, int *pChanged){
   u32 aCksum[2] = {1, 1};
   u32 aHdr[WALINDEX_HDR_NFIELD+2];
 
+  assert( *pisValid==0 );
   if( pWal->szWIndex==0 ){
-    int rc;
-    rc = walIndexRemap(pWal, WALINDEX_MMAP_INCREMENT);
-    if( rc ) return rc;
+    return SQLITE_OK;
   }
 
   /* Read the header. The caller may or may not have locked the wal-index
@@ -939,7 +943,7 @@ static int walIndexReadHdr(Wal *pWal, int *pChanged){
     /* This call to walIndexTryHdr() may not return an error code, as the
     ** wal-index is already mapped. It may find that the header is invalid,
     ** but there is no chance of hitting an actual error.  */
-    assert( pWal->szWIndex );
+    assert( pWal->pWiData );
     rc = walIndexTryHdr(pWal, &isValid, pChanged);
     assert( rc==SQLITE_OK );
     if( isValid==0 ){
@@ -972,13 +976,6 @@ int sqlite3WalOpenSnapshot(Wal *pWal, int *pChanged){
     if( rc!=SQLITE_OK ){
       /* An error occured while attempting log recovery. */
       sqlite3WalCloseSnapshot(pWal);
-    }else{
-      /* Check if the mapping needs to grow. */
-      if( pWal->hdr.iLastPg 
-       && walIndexEntry(pWal->hdr.iLastPg)*sizeof(u32)>=pWal->szWIndex
-      ){
-         walIndexRemap(pWal, -1);
-      }
     }
   }
 
@@ -1012,7 +1009,7 @@ int sqlite3WalRead(
   int iFrame = (pWal->hdr.iLastPg & 0xFFFFFF00);
 
   assert( pWal->lockState==SQLITE_SHM_READ||pWal->lockState==SQLITE_SHM_WRITE );
-  rc = walIndexMap(pWal, -1);
+  rc = walIndexMap(pWal, walMappingSize(pWal->hdr.iLastPg));
   if( rc!=SQLITE_OK ){
     return rc;
   }
@@ -1100,7 +1097,7 @@ int sqlite3WalWriteLock(Wal *pWal, int op){
     ** the write locks and return SQLITE_BUSY.
     */
     if( rc==SQLITE_OK ){
-      rc = walIndexMap(pWal, -1);
+      rc = walIndexMap(pWal, sizeof(WalIndexHdr));
       if( rc==SQLITE_OK
        && memcmp(&pWal->hdr, pWal->pWiData, sizeof(WalIndexHdr))
       ){

test/wal2.test

@@ -306,4 +306,34 @@ db close
 tvfs delete
 file delete -force test.db test.db-wal test.db-journal
 
+#-------------------------------------------------------------------------
+# Test that a database connection using a VFS that does not support the
+# xShmXXX interfaces cannot open a WAL database.
+#
+do_test wal2-4.1 {
+  sqlite3 db test.db
+  execsql {
+    PRAGMA journal_mode = WAL;
+    CREATE TABLE data(x);
+    INSERT INTO data VALUES('need xShmOpen to see this');
+    PRAGMA wal_checkpoint;
+  }
+} {wal}
+do_test wal2-4.2 {
+  db close
+  proc ok {args} {return SQLITE_OK}
+  testvfs -noshm tvfs ok
+  sqlite3 db test.db -vfs tvfs
+  catchsql { SELECT * FROM data }
+} {1 {unable to open database file}}
+do_test wal2-4.3 {
+  db close
+  proc ok {args} {return SQLITE_OK}
+  testvfs tvfs ok
+  sqlite3 db test.db -vfs tvfs
+  catchsql { SELECT * FROM data }
+} {0 {{need xShmOpen to see this}}}
+db close
+tvfs delete
+
 finish_test