The iInUseDB and iInUseMM variables do not need to be volatile.

FossilOrigin-Name: bb18f5785283e1067338b6b85098e8f2ff3b093a

manifest

@@ -1,5 +1,8 @@
-C Version\s3.5.9\s(CVS\s5131)
-D 2008-05-14T16:18:11
+-----BEGIN PGP SIGNED MESSAGE-----
+Hash: SHA1
+
+C The\siInUseDB\sand\siInUseMM\svariables\sdo\snot\sneed\sto\sbe\svolatile.
+D 2010-01-30T23:08:24
 F Makefile.arm-wince-mingw32ce-gcc ac5f7b2cef0cd850d6f755ba6ee4ab961b1fadf7
 F Makefile.in 79aeba12300a54903f1b1257c1e7c190234045dd
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -121,7 +124,7 @@ F src/os_common.h e8b748b2f2ecc8a498e50bfe5d8721f189c19d2a
 F src/os_os2.c 0c3a5802bc4fdb7cb5f66771552b081c4e48a216
 F src/os_unix.c a810e2aefdaddacf479407f76f8f4ca381d231b2
 F src/os_win.c 3a60bddd07ea6f8adb2314dd5996ac97b988f403
-F src/pager.c 2607309c4848bfb8a5766d94d74157b54a44c6c0
+F src/pager.c 8e6b147f46c80fe31ee4d202d2478f461aa7ce18
 F src/pager.h 4f051fd856de6fd3c19aef5f82eace54122b9173
 F src/parse.y fc4bd35c6088901f7c8daead26c6fb11c87d22e7
 F src/pragma.c 2e4bb2e76e48a32750529fdc4bfe86ac5f54e01b
@@ -634,7 +637,14 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P e4aab150042bd22868ab02645151cb69a1c02ba0
-R c25ac8c50b83839e3cddbf23a801f9cb
+P 622c17177af6851fec11bdec8fb6246c13135b2f
+R e9eaccaf9f16fa14643ac18463a7e091
 U drh
-Z 5d9759a5b998826f7607e53c2a3b8fed
+Z ba00ac2997800f42b378226025ca0d50
+-----BEGIN PGP SIGNATURE-----
+Version: GnuPG v1.4.6 (GNU/Linux)
+
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+1AHQmR5SOB5iTAk/+APTz0g=
+=9KoF
+-----END PGP SIGNATURE-----

manifest.uuid

@@ -1 +1 @@
-b6129f4cc28f6ba55d19039545555b33857ffd72
+bb18f5785283e1067338b6b85098e8f2ff3b093a

src/pager.c

@@ -401,8 +401,9 @@ struct Pager {
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
   Pager *pNext;               /* Doubly linked list of pagers on which */
   Pager *pPrev;               /* sqlite3_release_memory() will work */
-  int iInUseMM;               /* Non-zero if unavailable to MM */
   int iInUseDB;               /* Non-zero if in sqlite3_release_memory() */
+  u8 iInUseMM;                /* Non-zero if unavailable to MM */
+  u8 onPagerList;             /* True if part of the sqlite3PagerList */
 #endif
   char *pTmpSpace;            /* Pager.pageSize bytes of space for tmp use */
   char dbFileVers[16];        /* Changes whenever database file changes */
@@ -511,29 +512,35 @@ static const unsigned char aJournalMagic[] = {
 ** function.  It does not prevent, for example, two Btrees from accessing
 ** the same pager at the same time.  Other general-purpose mutexes in
 ** the btree layer handle that chore.
+**
+** The pagerMutexHeld(X) macro is for sanity checking.  This macro verifies
+** that the database-connection mutex is held for pager X and asserts if it
+** is not.
 */
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
   static void pagerEnter(Pager *p){
-    p->iInUseDB++;
-    if( p->iInUseMM && p->iInUseDB==1 ){
+    if( p->iInUseDB>0 ){
+      p->iInUseDB++;
+    }else{
 #ifndef SQLITE_MUTEX_NOOP
       sqlite3_mutex *mutex;
       mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM2);
 #endif
-      p->iInUseDB = 0;
       sqlite3_mutex_enter(mutex);
+      assert( p->iInUseMM==0 );
       p->iInUseDB = 1;
       sqlite3_mutex_leave(mutex);
     }
-    assert( p->iInUseMM==0 );
   }
   static void pagerLeave(Pager *p){
     p->iInUseDB--;
     assert( p->iInUseDB>=0 );
   }
+# define pagerMutexHeld(X)  assert( (X)->iInUseDB>0 || !(X)->onPagerList )
 #else
 # define pagerEnter(X)
 # define pagerLeave(X)
+# define pagerMutexHeld(X)
 #endif
 
 /*
@@ -699,6 +706,7 @@ static void pager_resize_hash_table(Pager *pPager, int N){
   sqlite3_free(pPager->aHash);
   pPager->nHash = N;
   pPager->aHash = aHash;
+  pagerMutexHeld(pPager);
   for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
     int h;
     if( pPg->pgno==0 ){
@@ -1273,6 +1281,7 @@ static PgHdr *pager_lookup(Pager *pPager, Pgno pgno){
 static void pager_reset(Pager *pPager){
   PgHdr *pPg, *pNext;
   if( pPager->errCode ) return;
+  pagerMutexHeld(pPager);
   for(pPg=pPager->pAll; pPg; pPg=pNext){
     IOTRACE(("PGFREE %p %d\n", pPager, pPg->pgno));
     PAGER_INCR(sqlite3_pager_pgfree_count);
@@ -1416,6 +1425,7 @@ static int pager_end_transaction(Pager *pPager, int hasMaster){
     }
     sqlite3BitvecDestroy(pPager->pInJournal);
     pPager->pInJournal = 0;
+    pagerMutexHeld(pPager);
     for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
       pPg->inJournal = 0;
       pPg->dirty = 0;
@@ -2373,6 +2383,7 @@ int sqlite3PagerOpen(
     }
     pPager->pPrev = 0;
     sqlite3PagerList = pPager;
+    pPager->onPagerList = 1;
     sqlite3_mutex_leave(mutex);
   }
 #endif
@@ -2637,6 +2648,7 @@ static void pager_truncate_cache(Pager *pPager){
   PgHdr **ppPg;
   int dbSize = pPager->dbSize;
 
+  pagerMutexHeld(pPager);
   ppPg = &pPager->pAll;
   while( (pPg = *ppPg)!=0 ){
     if( pPg->pgno<=dbSize ){
@@ -2707,7 +2719,9 @@ int sqlite3PagerTruncate(Pager *pPager, Pgno nPage){
   }
   if( MEMDB ){
     pPager->dbSize = nPage;
+    pagerEnter(pPager);
     pager_truncate_cache(pPager);
+    pagerLeave(pPager);
     return SQLITE_OK;
   }
   pagerEnter(pPager);
@@ -2720,12 +2734,10 @@ int sqlite3PagerTruncate(Pager *pPager, Pgno nPage){
   /* Get an exclusive lock on the database before truncating. */
   pagerEnter(pPager);
   rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);
-  pagerLeave(pPager);
-  if( rc!=SQLITE_OK ){
-    return rc;
+  if( rc==SQLITE_OK ){
+    rc = pager_truncate(pPager, nPage);
   }
-
-  rc = pager_truncate(pPager, nPage);
+  pagerLeave(pPager);
   return rc;
 }
 
@@ -2744,6 +2756,10 @@ int sqlite3PagerTruncate(Pager *pPager, Pgno nPage){
 ** to the caller.
 */
 int sqlite3PagerClose(Pager *pPager){
+  pagerEnter(pPager);
+  pPager->errCode = 0;
+  pager_reset(pPager);
+  pagerLeave(pPager);
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
   if( !MEMDB ){
 #ifndef SQLITE_MUTEX_NOOP
@@ -2759,14 +2775,12 @@ int sqlite3PagerClose(Pager *pPager){
       pPager->pNext->pPrev = pPager->pPrev;
     }
     sqlite3_mutex_leave(mutex);
+    pPager->onPagerList = 0;
   }
 #endif
-
   disable_simulated_io_errors();
   sqlite3FaultBeginBenign(-1);
-  pPager->errCode = 0;
   pPager->exclusiveMode = 0;
-  pager_reset(pPager);
   pagerUnlockAndRollback(pPager);
   enable_simulated_io_errors();
   sqlite3FaultEndBenign(-1);
@@ -2930,6 +2944,7 @@ static int syncJournal(Pager *pPager){
   ** invariant is true.
   */
   else{
+    pagerMutexHeld(pPager);
     for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
       assert( pPg->needSync==0 );
     }
@@ -3168,7 +3183,7 @@ static int pager_recycle(Pager *pPager, PgHdr **ppPg){
 
   /* It is illegal to call this function unless the pager object
   ** pointed to by pPager has at least one free page (page with nRef==0).
-  */ 
+  */
   assert(!MEMDB);
   assert(pPager->lru.pFirst);
 
@@ -3279,7 +3294,6 @@ int sqlite3PagerReleaseMemory(int nReq){
 
   while( rc==SQLITE_OK && (nReq<0 || nReleased<nReq) ){
     PgHdr *pPg;
-    PgHdr *pRecycled;
  
     /* Try to find a page to recycle that does not require a sync(). If
     ** this is not possible, find one that does require a sync().
@@ -3304,14 +3318,12 @@ int sqlite3PagerReleaseMemory(int nReq){
     if( !pPg ) break;
 
     pPager = pPg->pPager;
-    assert(!pPg->needSync || pPg==pPager->lru.pFirst);
-    assert(pPg->needSync || pPg==pPager->lru.pFirstSynced);
-  
+    assert( pPager->iInUseDB==0 );
     savedBusy = pPager->pBusyHandler;
     pPager->pBusyHandler = 0;
-    rc = pager_recycle(pPager, &pRecycled);
+    rc = pager_recycle(pPager, &pPg);
+    assert( pPager->iInUseDB==0 );
     pPager->pBusyHandler = savedBusy;
-    assert(pRecycled==pPg || rc!=SQLITE_OK);
     if( rc==SQLITE_OK ){
       /* We've found a page to free. At this point the page has been 
       ** removed from the page hash-table, free-list and synced-list 
@@ -3618,8 +3630,11 @@ static int pagerAllocatePage(Pager *pPager, PgHdr **ppPg){
   PgHdr *pPg;
   int nByteHdr;
 
+
   /* Create a new PgHdr if any of the four conditions defined 
-  ** above are met: */
+  ** above are met: 
+  */
+  pagerMutexHeld(pPager);
   if( pPager->nPage<pPager->mxPage
    || pPager->lru.pFirst==0 
    || MEMDB
@@ -3653,11 +3668,13 @@ static int pagerAllocatePage(Pager *pPager, PgHdr **ppPg){
     memset(pPg, 0, nByteHdr);
     pPg->pData = pData;
     pPg->pPager = pPager;
+    pagerMutexHeld(pPager);
     pPg->pNextAll = pPager->pAll;
     pPager->pAll = pPg;
     pPager->nPage++;
   }else{
     /* Recycle an existing page with a zero ref-count. */
+    pagerMutexHeld(pPager);
     rc = pager_recycle(pPager, &pPg);
     if( rc==SQLITE_BUSY ){
       rc = SQLITE_IOERR_BLOCKED;
@@ -4704,6 +4721,7 @@ int sqlite3PagerCommitPhaseOne(
 #endif
       rc = writeMasterJournal(pPager, zMaster);
       if( rc!=SQLITE_OK ) goto sync_exit;
+      pagerMutexHeld(pPager);
       rc = syncJournal(pPager);
     }
     if( rc!=SQLITE_OK ) goto sync_exit;
@@ -4831,6 +4849,7 @@ int sqlite3PagerRollback(Pager *pPager){
   PAGERTRACE2("ROLLBACK %d\n", PAGERID(pPager));
   if( MEMDB ){
     PgHdr *p;
+    pagerMutexHeld(pPager);
     for(p=pPager->pAll; p; p=p->pNextAll){
       PgHistory *pHist;
       assert( !p->alwaysRollback );