icu.o insert.o json1.o legacy.o loadext.o \
         main.o malloc.o mem0.o mem1.o mem2.o mem3.o mem5.o \
         memjournal.o \
         mutex.o mutex_noop.o mutex_unix.o mutex_w32.o \
         notify.o opcodes.o os.o os_unix.o os_win.o \
         pager.o pcache.o pcache1.o pragma.o prepare.o printf.o \
         random.o resolve.o rowset.o rtree.o select.o sqlite3rbu.o status.o \
	 server.o \
         table.o threads.o tokenize.o treeview.o trigger.o \
         update.o userauth.o util.o vacuum.o \
         vdbeapi.o vdbeaux.o vdbeblob.o vdbemem.o vdbesort.o \
	 vdbetrace.o wal.o walker.o where.o wherecode.o whereexpr.o \
         utf.o vtab.o

LIBOBJ += sqlite3session.o

  $(TOP)/src/pragma.h \
  $(TOP)/src/prepare.c \
  $(TOP)/src/printf.c \
  $(TOP)/src/random.c \
  $(TOP)/src/resolve.c \
  $(TOP)/src/rowset.c \
  $(TOP)/src/select.c \
  $(TOP)/src/server.c \
  $(TOP)/src/server.h \
  $(TOP)/src/status.c \
  $(TOP)/src/shell.c \
  $(TOP)/src/sqlite.h.in \
  $(TOP)/src/sqlite3ext.h \
  $(TOP)/src/sqliteInt.h \
  $(TOP)/src/sqliteLimit.h \
  $(TOP)/src/table.c \

  ){
    return btreePrevious(pCur, pRes);
  }
  pCur->ix--;
  return SQLITE_OK;
}

#ifdef SQLITE_SERVER_EDITION

#define SERVER_DEFAULT_FREELISTS      16
#define SERVER_DEFAULT_FREELIST_SIZE 128

/*
** Allocate the free-node and the first SERVER_DEFAULT_FREELISTS 
** trunk pages.
*/
static int allocateServerFreenode(BtShared *pBt){
  int rc;
  MemPage *pPage1 = pBt->pPage1;

  rc = sqlite3PagerWrite(pPage1->pDbPage);
  if( rc==SQLITE_OK ){
    Pgno pgnoNode = (++pBt->nPage);
    MemPage *pNode = 0;
    int i;

    put4byte(&pPage1->aData[32], pgnoNode);
    rc = btreeGetUnusedPage(pBt, pgnoNode, &pNode, PAGER_GET_NOCONTENT);
    if( rc==SQLITE_OK ){
      rc = sqlite3PagerWrite(pNode->pDbPage);
    }
    if( rc==SQLITE_OK ){
      put4byte(&pNode->aData[0], 0);
      put4byte(&pNode->aData[4], SERVER_DEFAULT_FREELISTS);
    }
    for(i=0; rc==SQLITE_OK && i<SERVER_DEFAULT_FREELISTS; i++){
      MemPage *pTrunk = 0;
      Pgno pgnoTrunk;
      if( ++pBt->nPage==PENDING_BYTE_PAGE(pBt) ) pBt->nPage++;
      pgnoTrunk = pBt->nPage;

      rc = btreeGetUnusedPage(pBt, pgnoTrunk, &pTrunk, PAGER_GET_NOCONTENT);
      if( rc==SQLITE_OK ){
        rc = sqlite3PagerWrite(pTrunk->pDbPage);
      }
      if( rc==SQLITE_OK ){
        memset(pTrunk->aData, 0, 8);
        put4byte(&pNode->aData[8+i*4], pgnoTrunk);
      }
      releasePage(pTrunk);
    }
    releasePage(pNode);
  }

  return rc;
}

/*
** Return a reference to the first trunk page in one of the database free-lists.
** Allocate the database free-lists if required.
*/
static int findServerTrunk(BtShared *pBt, int bAlloc, MemPage **ppTrunk){
  MemPage *pPage1 = pBt->pPage1;
  MemPage *pNode = 0;             /* The node page */
  MemPage *pTrunk = 0;            /* The returned page */
  Pgno iNode;                     /* Page number of node page */
  int rc = SQLITE_OK;

  /* If the node page and free-list trunks have not yet been allocated, allocate
  ** them now.  */
  pPage1 = pBt->pPage1;
  iNode = get4byte(&pPage1->aData[32]);
  if( iNode==0 ){
    rc = allocateServerFreenode(pBt);
    iNode = get4byte(&pPage1->aData[32]);
  }

  /* Grab the node page */
  if( rc==SQLITE_OK ){
    rc = btreeGetUnusedPage(pBt, iNode, &pNode, 0);
  }
  if( rc==SQLITE_OK ){
    int nList;                    /* Number of free-lists in this db */
    int i;

    /* Try to lock a free-list trunk. If bAlloc is true, it has to be a
    ** free-list trunk with at least one entry in the free-list. */
    nList = (int)get4byte(&pNode->aData[4]);
    for(i=0; i<nList; i++){
      Pgno iTrunk = get4byte(&pNode->aData[8+i*4]);
      if( SQLITE_OK==sqlite3PagerPagelock(pBt->pPager, iTrunk, 1) ){
        rc = btreeGetUnusedPage(pBt, iTrunk, &pTrunk, 0);
        if( rc==SQLITE_OK && bAlloc ){
          if( !get4byte(&pTrunk->aData[0]) && !get4byte(&pTrunk->aData[4]) ){
            releasePage(pTrunk);
            pTrunk = 0;
          }
        }
        if( rc!=SQLITE_OK || pTrunk ) break;
      }
    }

    /* No free pages in any free-list. Or perhaps we were locked out. In 
    ** either case, try to allocate more from the end of the file now.  */
    if( i==nList ){
      assert( rc==SQLITE_OK && pTrunk==0 );
      rc = sqlite3PagerWrite(pPage1->pDbPage);
      for(i=0; rc==SQLITE_OK && i<nList; i++){
        /* Add some free pages to each free-list. No server-locks are required
        ** to do this as we have a write-lock on page 1 - guaranteeing
        ** exclusive access to the db file.  */
        MemPage *pT = 0;
        Pgno iTrunk = get4byte(&pNode->aData[8+i*4]);
        rc = btreeGetUnusedPage(pBt, iTrunk, &pT, 0);
        if( rc==SQLITE_OK ){
          rc = sqlite3PagerWrite(pT->pDbPage);
        }
        if( rc==SQLITE_OK ){
          int iPg = get4byte(&pT->aData[4]);
          for(/*no-op*/; iPg<SERVER_DEFAULT_FREELIST_SIZE; iPg++){
            if( ++pBt->nPage==PENDING_BYTE_PAGE(pBt) ) pBt->nPage++;
            put4byte(&pT->aData[8+iPg*4], pBt->nPage);
          }
          put4byte(&pT->aData[4], iPg);
          if( pTrunk==0 ){
            pTrunk = pT;
            pT = 0;
          }
        }
        releasePage(pT);
      }
      if( rc==SQLITE_OK ){
        MemPage *pLast = 0;
        rc = btreeGetUnusedPage(pBt, pBt->nPage, &pLast, 0);
        if( rc==SQLITE_OK ){
          rc = sqlite3PagerWrite(pLast->pDbPage);
          releasePage(pLast);
          put4byte(28 + (u8*)pPage1->aData, pBt->nPage);
        }
      }
    }
  }

  releasePage(pNode);
  if( rc==SQLITE_OK ){
    assert( pTrunk );
    rc = sqlite3PagerWrite(pTrunk->pDbPage);
  }
  if( rc!=SQLITE_OK ){
    releasePage(pTrunk);
    pTrunk = 0;
  }
  *ppTrunk = pTrunk;
  return rc;
}

static int allocateServerPage(
  BtShared *pBt,         /* The btree */
  MemPage **ppPage,      /* Store pointer to the allocated page here */
  Pgno *pPgno,           /* Store the page number here */
  Pgno nearby,           /* Search for a page near this one */
  u8 eMode               /* BTALLOC_EXACT, BTALLOC_LT, or BTALLOC_ANY */
){
  int rc;                         /* Return code */
  MemPage *pTrunk = 0;            /* The node page */
  Pgno pgnoNew = 0;

#ifdef SQLITE_DEBUG
  int nRef = sqlite3PagerRefcount(pBt->pPager);
#endif

  assert( eMode==BTALLOC_ANY );
  assert( sqlite3_mutex_held(pBt->mutex) );

  *ppPage = 0;
  rc = findServerTrunk(pBt, 1, &pTrunk);
  if( rc==SQLITE_OK ){
    int nFree;              /* Number of free pages on this trunk page */
    nFree = (int)get4byte(&pTrunk->aData[4]);
    if( nFree==0 ){
      pgnoNew = get4byte(&pTrunk->aData[0]);
      assert( pgnoNew );
    }else{
      nFree--;
      pgnoNew = get4byte(&pTrunk->aData[8+4*nFree]);
      put4byte(&pTrunk->aData[4], (u32)nFree);
      releasePage(pTrunk);
      pTrunk = 0;
    }
  }

  if( rc==SQLITE_OK ){
    MemPage *pNew = 0;
    int flags = pTrunk ? 0 : PAGER_GET_NOCONTENT;
    rc = btreeGetUnusedPage(pBt, pgnoNew, &pNew, flags);
    if( rc==SQLITE_OK ){
      rc = sqlite3PagerWrite(pNew->pDbPage);
      if( rc!=SQLITE_OK ){
        releasePage(pNew);
        pNew = 0;
      }
    }
    if( rc==SQLITE_OK && pTrunk ){
      memcpy(pTrunk->aData, pNew->aData, pBt->usableSize);
    }
    *ppPage = pNew;
    *pPgno = pgnoNew;
  }

  releasePage(pTrunk);
  assert( (rc==SQLITE_OK)==(*ppPage!=0) );
  assert( sqlite3PagerRefcount(pBt->pPager)==(nRef+(*ppPage!=0)) );
  return rc;
}

static int freeServerPage2(BtShared *pBt, MemPage *pPage, Pgno iPage){
  int rc;                         /* Return code */
  MemPage *pTrunk = 0;            /* The node page */
#ifdef SQLITE_DEBUG
  int nRef = sqlite3PagerRefcount(pBt->pPager);
#endif

  assert( sqlite3_mutex_held(pBt->mutex) );
  rc = findServerTrunk(pBt, 0, &pTrunk);
  if( rc==SQLITE_OK ){
    int nFree;              /* Number of free pages on this trunk page */
    nFree = (int)get4byte(&pTrunk->aData[4]);
    if( nFree>=((pBt->usableSize / 4) - 2) ){
      if( pPage==0 ){
        rc = btreeGetUnusedPage(pBt, iPage, &pPage, 0);
      }else{
        sqlite3PagerRef(pPage->pDbPage);
      }
      rc = sqlite3PagerWrite(pPage->pDbPage);
      if( rc==SQLITE_OK ){
        memcpy(pPage->aData, pTrunk->aData, pBt->usableSize);
        put4byte(&pTrunk->aData[0], iPage);
        put4byte(&pTrunk->aData[4], 0);
      }
      releasePage(pPage);
    }else{
      put4byte(&pTrunk->aData[8+nFree*4], iPage);
      put4byte(&pTrunk->aData[4], (u32)nFree+1);
    }
    releasePage(pTrunk);
  }

  assert( nRef==sqlite3PagerRefcount(pBt->pPager) );
  return rc;
}

#else
# define allocateServerPage(v, w, x, y, z) SQLITE_OK
# define freeServerPage2(x, y, z) SQLITE_OK
#endif /* SQLITE_SERVER_EDITION */

/*
** Allocate a new page from the database file.
**
** The new page is marked as dirty.  (In other words, sqlite3PagerWrite()
** has already been called on the new page.)  The new page has also
** been referenced and the calling routine is responsible for calling
** sqlite3PagerUnref() on the new page when it is done.

  MemPage *pPage1;
  int rc;
  u32 n;     /* Number of pages on the freelist */
  u32 k;     /* Number of leaves on the trunk of the freelist */
  MemPage *pTrunk = 0;
  MemPage *pPrevTrunk = 0;
  Pgno mxPage;     /* Total size of the database file */

  if( sqlite3PagerIsServer(pBt->pPager) ){
    return allocateServerPage(pBt, ppPage, pPgno, nearby, eMode); 
  }

  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( eMode==BTALLOC_ANY || (nearby>0 && IfNotOmitAV(pBt->autoVacuum)) );
  pPage1 = pBt->pPage1;
  mxPage = btreePagecount(pBt);
  /* EVIDENCE-OF: R-05119-02637 The 4-byte big-endian integer at offset 36
  ** stores stores the total number of pages on the freelist. */

  if( pMemPage ){
    pPage = pMemPage;
    sqlite3PagerRef(pPage->pDbPage);
  }else{
    pPage = btreePageLookup(pBt, iPage);
  }







  if( pBt->btsFlags & BTS_SECURE_DELETE ){
    /* If the secure_delete option is enabled, then
    ** always fully overwrite deleted information with zeros.
    */
    if( (!pPage && ((rc = btreeGetPage(pBt, iPage, &pPage, 0))!=0) )
     ||            ((rc = sqlite3PagerWrite(pPage->pDbPage))!=0)
    ){
      goto freepage_out;
    }
    memset(pPage->aData, 0, pPage->pBt->pageSize);
  }
  
  if( sqlite3PagerIsServer(pBt->pPager) ){
    rc = freeServerPage2(pBt, pPage, iPage);
    goto freepage_out;
  }

  /* Increment the free page count on pPage1 */
  rc = sqlite3PagerWrite(pPage1->pDbPage);
  if( rc ) goto freepage_out;
  nFree = get4byte(&pPage1->aData[36]);
  put4byte(&pPage1->aData[36], nFree+1);

  /* If the database supports auto-vacuum, write an entry in the pointer-map
  ** to indicate that the page is free.
  */
  if( ISAUTOVACUUM ){
    ptrmapPut(pBt, iPage, PTRMAP_FREEPAGE, 0, &rc);
    if( rc ) goto freepage_out;

  pCheck->v1 = saved_v1;
  pCheck->v2 = saved_v2;
  return depth+1;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_INTEGRITY_CHECK

#if !defined(SQLITE_OMIT_INTEGRITY_CHECK) && defined(SQLITE_SERVER_EDITION)
static void checkServerList(IntegrityCk *pCheck){
  u32 pgnoNode = get4byte(&pCheck->pBt->pPage1->aData[32]);
  if( pgnoNode ){
    DbPage *pNode = 0;
    u8 *aNodeData;
    u32 nList;                    /* Number of free-lists */
    int i;

    checkRef(pCheck, pgnoNode);
    if( sqlite3PagerGet(pCheck->pPager, (Pgno)pgnoNode, &pNode, 0) ){
      checkAppendMsg(pCheck, "failed to get node page %d", pgnoNode);
      return;
    }
    aNodeData = sqlite3PagerGetData(pNode);
    nList = get4byte(&aNodeData[4]);
    for(i=0; i<nList; i++){
      u32 pgnoTrunk = get4byte(&aNodeData[8+4*i]);
      while( pgnoTrunk ){
        DbPage *pTrunk = 0;
        checkRef(pCheck, pgnoTrunk);
        if( sqlite3PagerGet(pCheck->pPager, (Pgno)pgnoTrunk, &pTrunk, 0) ){
          checkAppendMsg(pCheck, "failed to get page %d", pgnoTrunk);
          pgnoTrunk = 0;
        }else{
          u8 *aTrunkData = sqlite3PagerGetData(pTrunk);
          int nLeaf = (int)get4byte(&aTrunkData[4]);
          int iLeaf;
          for(iLeaf=0; iLeaf<nLeaf; iLeaf++){
            u32 pgnoLeaf = get4byte(&aTrunkData[8+iLeaf*4]);
            checkRef(pCheck, pgnoLeaf);
          }
          pgnoTrunk = get4byte(&aTrunkData[0]);
          sqlite3PagerUnref(pTrunk);
        }
      }
    }

    sqlite3PagerUnref(pNode);
  }
}
#endif
/*
** This routine does a complete check of the given BTree file.  aRoot[] is
** an array of pages numbers were each page number is the root page of
** a table.  nRoot is the number of entries in aRoot.
**
** A read-only or read-write transaction must be opened before calling
** this function.

  i = PENDING_BYTE_PAGE(pBt);
  if( i<=sCheck.nPage ) setPageReferenced(&sCheck, i);

  /* Check the integrity of the freelist
  */
  sCheck.zPfx = "Main freelist: ";
#ifdef SQLITE_SERVER_EDITION
  if( sqlite3PagerIsServer(pBt->pPager) ){
    checkServerList(&sCheck);
  }else
#endif
  {
    checkList(&sCheck, 1, get4byte(&pBt->pPage1->aData[32]),
        get4byte(&pBt->pPage1->aData[36]));
  }
  sCheck.zPfx = 0;

  /* Check all the tables.
  */
  testcase( pBt->db->flags & SQLITE_CellSizeCk );
  pBt->db->flags &= ~SQLITE_CellSizeCk;
  for(i=0; (int)i<nRoot && sCheck.mxErr; i++){

#endif
  char *pTmpSpace;            /* Pager.pageSize bytes of space for tmp use */
  PCache *pPCache;            /* Pointer to page cache object */
#ifndef SQLITE_OMIT_WAL
  Wal *pWal;                  /* Write-ahead log used by "journal_mode=wal" */
  char *zWal;                 /* File name for write-ahead log */
#endif
#ifdef SQLITE_SERVER_EDITION
  Server *pServer;
#endif
};

/*
** Indexes for use with Pager.aStat[]. The Pager.aStat[] array contains
** the values accessed by passing SQLITE_DBSTATUS_CACHE_HIT, CACHE_MISS 
** or CACHE_WRITE to sqlite3_db_status().
*/

#else
# define pagerUseWal(x) 0
# define pagerRollbackWal(x) 0
# define pagerWalFrames(v,w,x,y) 0
# define pagerOpenWalIfPresent(z) SQLITE_OK
# define pagerBeginReadTransaction(z) SQLITE_OK
#endif

#ifdef SQLITE_SERVER_EDITION
# define pagerIsServer(x) ((x)->pServer!=0)
#else
# define pagerIsServer(x) 0
#endif

#ifndef NDEBUG 
/*
** Usage:
**
**   assert( assert_pager_state(pPager) );
**

*/
static int pagerUnlockDb(Pager *pPager, int eLock){
  int rc = SQLITE_OK;

  assert( !pPager->exclusiveMode || pPager->eLock==eLock );
  assert( eLock==NO_LOCK || eLock==SHARED_LOCK );
  assert( eLock!=NO_LOCK || pagerUseWal(pPager)==0 );
  assert( eLock!=NO_LOCK || pagerIsServer(pPager)==0 );
  if( isOpen(pPager->fd) ){
    assert( pPager->eLock>=eLock );
    rc = pPager->noLock ? SQLITE_OK : sqlite3OsUnlock(pPager->fd, eLock);
    if( pPager->eLock!=UNKNOWN_LOCK ){
      pPager->eLock = (u8)eLock;
    }
    IOTRACE(("UNLOCK %p %d\n", pPager, eLock))

       || pPager->eState==PAGER_ERROR 
  );

  sqlite3BitvecDestroy(pPager->pInJournal);
  pPager->pInJournal = 0;
  releaseAllSavepoints(pPager);

#ifdef SQLITE_SERVER_EDITION
  if( pagerIsServer(pPager) ){
    sqlite3ServerEnd(pPager->pServer);
    pPager->eState = PAGER_OPEN;
  }else 
#endif
  if( pagerUseWal(pPager) ){
    assert( !isOpen(pPager->jfd) );
    sqlite3WalEndReadTransaction(pPager->pWal);
    pPager->eState = PAGER_OPEN;
  }else if( !pPager->exclusiveMode ){
    int rc;                       /* Error code returned by pagerUnlockDb() */
    int iDc = isOpen(pPager->fd)?sqlite3OsDeviceCharacteristics(pPager->fd):0;

  }

  if( rc==SQLITE_OK && bCommit && isOpen(pPager->fd) ){
    rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_COMMIT_PHASETWO, 0);
    if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
  }

#ifdef SQLITE_SERVER_EDITION
  if( pagerIsServer(pPager) ){
    rc2 = sqlite3ServerReleaseWriteLocks(pPager->pServer);
  }else
#endif
  if( !pPager->exclusiveMode 
   && (!pagerUseWal(pPager) || sqlite3WalExclusiveMode(pPager->pWal, 0))
  ){
    rc2 = pagerUnlockDb(pPager, SHARED_LOCK);
    pPager->changeCountDone = 0;
  }
  pPager->eState = PAGER_READER;

    ** If an error occurs while trying to sync the journal, shift the pager
    ** into the ERROR state. This causes UnlockAndRollback to unlock the
    ** database and close the journal file without attempting to roll it
    ** back or finalize it. The next database user will have to do hot-journal
    ** rollback before accessing the database file.
    */
    if( isOpen(pPager->jfd) ){
      if( pagerIsServer(pPager) ){
        assert( pPager->journalMode==PAGER_JOURNALMODE_PERSIST );
        pPager->journalMode = PAGER_JOURNALMODE_DELETE;
        /* If necessary, change the pager state so that the journal file 
        ** is deleted by the call to pagerUnlockAndRollback() below.  */
        if( pPager->eState==PAGER_OPEN ) pPager->eState = PAGER_READER;
      }
      pager_error(pPager, pagerSyncHotJournal(pPager));
    }
    pagerUnlockAndRollback(pPager);
  }
#ifdef SQLITE_SERVER_EDITION
  if( pagerIsServer(pPager) ){
    sqlite3ServerDisconnect(pPager->pServer, pPager->fd);
    pPager->pServer = 0;
    sqlite3_free(pPager->zJournal);
  }
#endif
  sqlite3EndBenignMalloc();
  enable_simulated_io_errors();
  PAGERTRACE(("CLOSE %d\n", PAGERID(pPager)));
  IOTRACE(("CLOSE %p\n", pPager))
  sqlite3OsClose(pPager->jfd);
  sqlite3OsClose(pPager->fd);
  sqlite3PageFree(pTmp);

        }
      }
    }
  }

  return rc;
}

#ifdef SQLITE_SERVER_EDITION
static int pagerServerConnect(Pager *pPager){
  int rc = SQLITE_OK;
  if( pPager->tempFile==0 ){
    int iClient = 0;
    pPager->noLock = 1;
    pPager->journalMode = PAGER_JOURNALMODE_PERSIST;
    rc = sqlite3ServerConnect(pPager, &pPager->pServer, &iClient);
    if( rc==SQLITE_OK ){
      pPager->zJournal = sqlite3_mprintf(
          "%s-journal%d", pPager->zFilename, iClient
      );
      if( pPager->zJournal==0 ){
        rc = SQLITE_NOMEM_BKPT;
      }
    }
  }
  return rc;
}

int sqlite3PagerRollbackJournal(Pager *pPager, int iClient){
  int rc;
  char *zJrnl = sqlite3_mprintf("%s-journal%d", pPager->zFilename, iClient);

  if( zJrnl ){
    int bExists = 0;
    sqlite3_file *jfd = 0;
    sqlite3_vfs * const pVfs = pPager->pVfs;

    rc = sqlite3OsAccess(pVfs, zJrnl, SQLITE_ACCESS_EXISTS, &bExists);
    if( rc==SQLITE_OK && bExists ){
      int flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;
      rc = sqlite3OsOpenMalloc(pVfs, zJrnl, &jfd, flags, &flags);
    }
    assert( rc==SQLITE_OK || jfd==0 );
    if( jfd ){
      sqlite3_file *saved_jfd = pPager->jfd;
      u8 saved_eState = pPager->eState;
      u8 saved_eLock = pPager->eLock;
      i64 saved_journalOff = pPager->journalOff;
      i64 saved_journalHdr = pPager->journalHdr;
      char *saved_zJournal = pPager->zJournal;

      pPager->eLock = EXCLUSIVE_LOCK;
      pPager->eState = PAGER_WRITER_DBMOD;
      pPager->jfd = jfd;
      rc = pagerSyncHotJournal(pPager);
      if( rc==SQLITE_OK ) rc = pager_playback(pPager, 1);

      pPager->jfd = saved_jfd;
      pPager->eState = saved_eState;
      pPager->eLock = saved_eLock;
      pPager->journalOff = saved_journalOff;
      pPager->journalHdr = saved_journalHdr;
      pPager->zJournal = saved_zJournal;

      sqlite3OsCloseFree(jfd);
      if( rc==SQLITE_OK ){
        rc = sqlite3OsDelete(pVfs, zJrnl, 0);
      }
    }
    sqlite3_free(zJrnl);
  }else{
    rc = SQLITE_NOMEM_BKPT;
  }

  return rc;
}

#else
# define pagerServerConnect(pPager) SQLITE_OK
#endif


/*
** This function is called to obtain a shared lock on the database file.
** It is illegal to call sqlite3PagerGet() until after this function
** has been successfully called. If a shared-lock is already held when
** this function is called, it is a no-op.
**

  ** be OPEN or READER. READER is only possible if the pager is or was in 
  ** exclusive access mode.  */
  assert( sqlite3PcacheRefCount(pPager->pPCache)==0 );
  assert( assert_pager_state(pPager) );
  assert( pPager->eState==PAGER_OPEN || pPager->eState==PAGER_READER );
  assert( pPager->errCode==SQLITE_OK );

  if( !pagerUseWal(pPager) 
   && !pagerIsServer(pPager) 
   && pPager->eState==PAGER_OPEN ){
    int bHotJournal = 1;          /* True if there exists a hot journal-file */

    assert( !MEMDB );
    assert( pPager->tempFile==0 || pPager->eLock==EXCLUSIVE_LOCK );

    rc = pager_wait_on_lock(pPager, SHARED_LOCK);
    if( rc!=SQLITE_OK ){

        ** to be the right size but is not actually valid. Avoid this
        ** possibility by unmapping the db here. */
        if( USEFETCH(pPager) ){
          sqlite3OsUnfetch(pPager->fd, 0, 0);
        }
      }
    }

    rc = pagerServerConnect(pPager);

    /* If there is a WAL file in the file-system, open this database in WAL
    ** mode. Otherwise, the following function call is a no-op.
    */
    if( rc==SQLITE_OK ){
      rc = pagerOpenWalIfPresent(pPager);
    }
#ifndef SQLITE_OMIT_WAL
    assert( pPager->pWal==0 || rc==SQLITE_OK );
#endif
  }

#ifdef SQLITE_SERVER_EDITION
  if( pagerIsServer(pPager) ){
    assert( rc==SQLITE_OK );
    pager_reset(pPager);
    rc = sqlite3ServerBegin(pPager->pServer);
  }
#endif
  if( rc==SQLITE_OK && pagerUseWal(pPager) ){
    assert( rc==SQLITE_OK );
    rc = pagerBeginReadTransaction(pPager);
  }

  if( pPager->tempFile==0 && pPager->eState==PAGER_OPEN && rc==SQLITE_OK ){
    rc = pagerPagecount(pPager, &pPager->dbSize);
  }

*/
int sqlite3PagerGet(
  Pager *pPager,      /* The pager open on the database file */
  Pgno pgno,          /* Page number to fetch */
  DbPage **ppPage,    /* Write a pointer to the page here */
  int flags           /* PAGER_GET_XXX flags */
){
#ifdef SQLITE_SERVER_EDITION
  if( pagerIsServer(pPager) ){
    int rc = sqlite3ServerLock(pPager->pServer, pgno, 0, 0);
    if( rc!=SQLITE_OK ) return rc;
  }
#endif
  return pPager->xGet(pPager, pgno, ppPage, flags);
}

/*
** Acquire a page if it is already in the in-memory cache.  Do
** not read the page from disk.  Return a pointer to the page,
** or 0 if the page is not in cache. 

       || pPager->eState==PAGER_WRITER_CACHEMOD
       || pPager->eState==PAGER_WRITER_DBMOD
  );
  assert( assert_pager_state(pPager) );
  assert( pPager->errCode==0 );
  assert( pPager->readOnly==0 );
  CHECK_PAGE(pPg);

#ifdef SQLITE_SERVER_EDITION
  if( pagerIsServer(pPager) ){
    rc = sqlite3ServerLock(pPager->pServer, pPg->pgno, 1, 0);
    if( rc!=SQLITE_OK ) return rc;
  }
#endif

  /* The journal file needs to be opened. Higher level routines have already
  ** obtained the necessary locks to begin the write-transaction, but the
  ** rollback journal might not yet be open. Open it now if this is the case.
  **
  ** This is done before calling sqlite3PcacheMakeDirty() on the page. 
  ** Otherwise, if it were done after calling sqlite3PcacheMakeDirty(), then

# define DIRECT_MODE 0
  assert( isDirectMode==0 );
  UNUSED_PARAMETER(isDirectMode);
#else
# define DIRECT_MODE isDirectMode
#endif

  if( 0==pagerIsServer(pPager) 
   && !pPager->changeCountDone 
   && ALWAYS(pPager->dbSize>0) 
  ){
    PgHdr *pPgHdr;                /* Reference to page 1 */

    assert( !pPager->tempFile && isOpen(pPager->fd) );

    /* Open page 1 of the file for writing. */
    rc = sqlite3PagerGet(pPager, 1, &pPgHdr, 0);
    assert( pPgHdr==0 || rc==SQLITE_OK );

  assert( isOpen(pPager->fd) || pPager->tempFile );
  if( 0==pagerFlushOnCommit(pPager, 1) ){
    /* If this is an in-memory db, or no pages have been written to, or this
    ** function has already been called, it is mostly a no-op.  However, any
    ** backup in progress needs to be restarted.  */
    sqlite3BackupRestart(pPager->pBackup);
  }else{
    /* If this connection is in server mode, ignore any master journal. */
    if( pagerIsServer(pPager) ){
      zMaster = 0;
    }
    if( pagerUseWal(pPager) ){
      PgHdr *pList = sqlite3PcacheDirtyList(pPager->pPCache);
      PgHdr *pPageOne = 0;
      if( pList==0 ){
        /* Must have at least one page for the WAL commit flag.
        ** Ticket [2d1a5c67dfc2363e44f29d9bbd57f] 2011-05-18 */
        rc = sqlite3PagerGet(pPager, 1, &pPageOne, 0);

/*
** Return true if the underlying VFS for the given pager supports the
** primitives necessary for write-ahead logging.
*/
int sqlite3PagerWalSupported(Pager *pPager){
  const sqlite3_io_methods *pMethods = pPager->fd->pMethods;
  if( pPager->noLock && !pagerIsServer(pPager) ) return 0;
  return pPager->exclusiveMode || (pMethods->iVersion>=2 && pMethods->xShmMap);
}

/*
** Attempt to take an exclusive lock on the database file. If a PENDING lock
** is obtained instead, immediately release it.
*/

    /* Close any rollback journal previously open */
    sqlite3OsClose(pPager->jfd);

    rc = pagerOpenWal(pPager);
    if( rc==SQLITE_OK ){
      pPager->journalMode = PAGER_JOURNALMODE_WAL;
      pPager->eState = PAGER_OPEN;
#ifdef SQLITE_SERVER_EDITION
      sqlite3WalServer(pPager->pWal, pPager->pServer);
#endif
    }
  }else{
    *pbOpen = 1;
  }

  return rc;
}

** is empty, return 0.
*/
int sqlite3PagerWalFramesize(Pager *pPager){
  assert( pPager->eState>=PAGER_READER );
  return sqlite3WalFramesize(pPager->pWal);
}
#endif

#ifdef SQLITE_SERVER_EDITION
int sqlite3PagerIsServer(Pager *pPager){
  return pagerIsServer(pPager);
}
int sqlite3PagerPagelock(Pager *pPager, Pgno pgno, int bWrite){
  return sqlite3ServerLock(pPager->pServer, pgno, bWrite, 0);
}
#endif

#endif /* SQLITE_OMIT_DISKIO */

  void sqlite3PagerRefdump(Pager*);
  void disable_simulated_io_errors(void);
  void enable_simulated_io_errors(void);
#else
# define disable_simulated_io_errors()
# define enable_simulated_io_errors()
#endif

#ifdef SQLITE_SERVER_EDITION
  int sqlite3PagerRollbackJournal(Pager*, int);
  int sqlite3PagerIsServer(Pager *pPager);
  int sqlite3PagerPagelock(Pager *pPager, Pgno, int);
#endif

#endif /* SQLITE_PAGER_H */

/*
** 2017 April 24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

#include "sqliteInt.h"

/*
** HMA file layout:
**
**      4 bytes - DMS slot. All connections read-lock this slot.
**
**   16*4 bytes - locking slots. Connections hold a read-lock on a locking slot
**                when they are connected, a write lock when they have an open
**                transaction.
**
**    N*4 bytes - Page locking slots. N is HMA_PAGELOCK_SLOTS.
**
** Page-locking slot format:
**
**   Each page-locking slot provides SHARED/RESERVED/EXCLUSIVE locks on a
**   single page. A RESERVED lock is similar to a RESERVED in SQLite's
**   rollback mode - existing SHARED locks may continue but new SHARED locks
**   may not be established. As in rollback mode, EXCLUSIVE and RESERVED 
**   locks are mutually exclusive.
**
**   Each 32-bit locking slot is divided into two sections - a bitmask for
**   read-locks and a single integer field for the write lock. The bitmask
**   occupies the least-significant 27 bits of the slot. The integer field
**   occupies the remaining 5 bits (so that it can store values from 0-31).
**
**   Each client has a unique integer client id. Currently these range from
**   0-15 (maximum of 16 concurrent connections). The page-locking slot format
**   allows this to be increased to 0-26 (maximum of 26 connections). To
**   take a SHARED lock, the corresponding bit is set in the locking slot
**   bitmask:
**
**     slot = slot | (1 << iClient);
**
**   To take an EXCLUSIVE or RESERVED lock, the integer part of the locking
**   slot is set to the client-id of the locker plus one (a value of zero 
**   indicates that no connection holds a RESERVED or EXCLUSIVE lock):
**
**     slot = slot | ((iClient+1) << 27)
*/

#ifdef SQLITE_SERVER_EDITION

#define HMA_CLIENT_SLOTS   16
#define HMA_PAGELOCK_SLOTS (256*1024)

#define HMA_FILE_SIZE (4 + 4*HMA_CLIENT_SLOTS + 4*HMA_PAGELOCK_SLOTS)

#include "unistd.h"
#include "fcntl.h"
#include "sys/mman.h"
#include "sys/types.h"
#include "sys/stat.h"
#include "errno.h"

typedef struct ServerHMA ServerHMA;

struct ServerGlobal {
  ServerHMA *pHma;                /* Linked list of all ServerHMA objects */
};
static struct ServerGlobal g_server;

/*
** There is one instance of the following structure for each distinct 
** HMA file opened by clients within this process. 
*/
struct ServerHMA {
  char *zName;                         /* hma file path */
  int fd;                              /* Fd open on hma file */
  int nClient;                         /* Current number of clients */
  Server *aClient[HMA_CLIENT_SLOTS];   /* Local (this process) clients */
  u32 *aMap;                           /* MMapped hma file */
  ServerHMA *pNext;                    /* Next HMA in this process */

  dev_t st_dev;
  ino_t st_ino;
};

struct Server {
  ServerHMA *pHma;                /* Hma file object */
  int iClient;                    /* Client id */
  Pager *pPager;                  /* Associated pager object */
  i64 nUsWrite;                   /* Cumulative us holding WRITER lock */
  i64 iUsWrite;                   /* Time WRITER lock was taken */
  int nAlloc;                     /* Allocated size of aLock[] array */
  int nLock;                      /* Number of entries in aLock[] */
  u32 *aLock;                     /* Mapped lock file */
};

#define SERVER_WRITE_LOCK 3
#define SERVER_READ_LOCK  2
#define SERVER_NO_LOCK    1

/*
** Global mutex functions used by code in this file.
*/
static void serverEnterMutex(void){
  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_APP1));
}
static void serverLeaveMutex(void){
  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_APP1));
}
static void serverAssertMutexHeld(void){
  assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_APP1)) );
}

static int posixLock(int fd, int iSlot, int eLock, int bBlock){
  int res;
  struct flock l;
  short aType[4] = {0, F_UNLCK, F_RDLCK, F_WRLCK};
  assert( eLock==SERVER_WRITE_LOCK 
       || eLock==SERVER_READ_LOCK 
       || eLock==SERVER_NO_LOCK 
  );
  memset(&l, 0, sizeof(l));
  l.l_type = aType[eLock];
  l.l_whence = SEEK_SET;
  l.l_start = iSlot*sizeof(u32);
  l.l_len = 1;

  res = fcntl(fd, (bBlock ? F_SETLKW : F_SETLK), &l);
  if( res && bBlock && errno==EDEADLK ){
    return SQLITE_BUSY_DEADLOCK;
  }
  return (res==0 ? SQLITE_OK : SQLITE_BUSY);
}

static int serverMapFile(ServerHMA *p){
  assert( p->aMap==0 );
  p->aMap = mmap(0, HMA_FILE_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, p->fd, 0);
  if( p->aMap==0 ){
    return SQLITE_ERROR;
  }
  return SQLITE_OK;
}


static void serverDecrHmaRefcount(ServerHMA *pHma){
  if( pHma ){
    pHma->nClient--;
    if( pHma->nClient<=0 ){
      ServerHMA **pp;
      if( pHma->aMap ) munmap(pHma->aMap, HMA_FILE_SIZE);
      if( pHma->fd>=0 ) close(pHma->fd);
      for(pp=&g_server.pHma; *pp!=pHma; pp=&(*pp)->pNext);
      *pp = pHma->pNext;
      sqlite3_free(pHma);
    }
  }
}


static int serverOpenHma(Pager *pPager, const char *zPath, ServerHMA **ppHma){
  struct stat sStat;              /* Structure populated by stat() */
  int res;                        /* result of stat() */
  int rc = SQLITE_OK;             /* Return code */
  ServerHMA *pHma = 0;

  serverAssertMutexHeld();

  res = stat(zPath, &sStat);
  if( res!=0 ){
    sqlite3_log(SQLITE_CANTOPEN, "Failed to stat(%s)", zPath);
    rc = SQLITE_ERROR;
  }else{
    for(pHma=g_server.pHma; pHma; pHma=pHma->pNext){
      if( sStat.st_dev==pHma->st_dev && sStat.st_ino==pHma->st_ino ) break;
    }
    if( pHma==0 ){
      int nPath = strlen(zPath);
      int nByte = sizeof(ServerHMA) + nPath+1 + 4;

      pHma = (ServerHMA*)sqlite3_malloc(nByte);
      if( pHma==0 ){
        rc = SQLITE_NOMEM;
      }else{
        int i;
        memset(pHma, 0, nByte);
        pHma->zName = (char*)&pHma[1];
        pHma->nClient = 1;
        pHma->st_dev = sStat.st_dev;
        pHma->st_ino = sStat.st_ino;
        pHma->pNext = g_server.pHma;
        g_server.pHma = pHma;

        memcpy(pHma->zName, zPath, nPath);
        memcpy(&pHma->zName[nPath], "-hma", 5);

        pHma->fd = open(pHma->zName, O_RDWR|O_CREAT, 0644);
        if( pHma->fd<0 ){
          sqlite3_log(SQLITE_CANTOPEN, "Failed to open(%s)", pHma->zName);
          rc = SQLITE_ERROR;
        }

        if( rc==SQLITE_OK ){
          /* Write-lock the DMS slot. If successful, initialize the hma file. */
          rc = posixLock(pHma->fd, 0, SERVER_WRITE_LOCK, 0);
          if( rc==SQLITE_OK ){
            res = ftruncate(pHma->fd, HMA_FILE_SIZE);
            if( res!=0 ){
              sqlite3_log(SQLITE_CANTOPEN, 
                  "Failed to ftruncate(%s)", pHma->zName
              );
              rc = SQLITE_ERROR;
            }
            if( rc==SQLITE_OK ){
              rc = serverMapFile(pHma);
            }
            if( rc==SQLITE_OK ){
              memset(pHma->aMap, 0, HMA_FILE_SIZE);
            }else{
              rc = SQLITE_ERROR;
            }
            for(i=0; rc==SQLITE_OK && i<HMA_CLIENT_SLOTS; i++){
              rc = sqlite3PagerRollbackJournal(pPager, i);
            }
          }else{
            rc = serverMapFile(pHma);
          }
          if( rc==SQLITE_OK ){
            rc = posixLock(pHma->fd, 0, SERVER_READ_LOCK, 1);
          }
        }

        if( rc!=SQLITE_OK ){
          serverDecrHmaRefcount(pHma);
          pHma = 0;
        }
      }
    }else{
      pHma->nClient++;
    }
  }

  *ppHma = pHma;
  return rc;
}

static u32 *serverPageLockSlot(Server *p, Pgno pgno){
  int iSlot = pgno % HMA_PAGELOCK_SLOTS;
  return &p->pHma->aMap[1 + HMA_CLIENT_SLOTS + iSlot];
}
static u32 *serverClientSlot(Server *p, int iClient){
  return &p->pHma->aMap[1 + iClient];
}

/*
** Close the "connection" and *-hma file. This deletes the object passed
** as the first argument.
*/
void sqlite3ServerDisconnect(Server *p, sqlite3_file *dbfd){
  if( p->pHma ){
    ServerHMA *pHma = p->pHma;
    serverEnterMutex();
    if( p->iClient>=0 ){
      u32 *pSlot = serverClientSlot(p, p->iClient);
      *pSlot = 0;
      assert( pHma->aClient[p->iClient]==p );
      pHma->aClient[p->iClient] = 0;
      posixLock(pHma->fd, p->iClient+1, SERVER_NO_LOCK, 0);
    }
    if( dbfd 
     && pHma->nClient==1 
     && SQLITE_OK==sqlite3OsLock(dbfd, SQLITE_LOCK_EXCLUSIVE)
    ){
      unlink(pHma->zName);
    }
    serverDecrHmaRefcount(pHma);
    serverLeaveMutex();
  }
  sqlite3_free(p->aLock);
  sqlite3_free(p);
}

static int serverRollbackClient(Server *p, int iBlock){
  int rc;

  sqlite3_log(SQLITE_NOTICE, "Rolling back failed client %d", iBlock);

  /* Roll back any journal file for client iBlock. */
  rc = sqlite3PagerRollbackJournal(p->pPager, iBlock);

  /* Clear any locks held by client iBlock from the HMA file.  */
  if( rc==SQLITE_OK ){
    int i;
    for(i=0; i<HMA_PAGELOCK_SLOTS; i++){
      u32 *pSlot = serverPageLockSlot(p, (Pgno)i);
      u32 v = *pSlot;
      while( 1 ){
        u32 n = v & ~(1 << iBlock);
        if( (v>>HMA_CLIENT_SLOTS)==iBlock+1 ){
          n = n & ((1<<HMA_CLIENT_SLOTS)-1);
        }
        if( __sync_val_compare_and_swap(pSlot, v, n)==v ) break;
        v = *pSlot;
      }
    }
  }

  return rc;
}


/*
** Open the *-hma file and "connect" to the system.
*/
int sqlite3ServerConnect(
  Pager *pPager, 
  Server **ppOut, 
  int *piClient
){
  const char *zPath = sqlite3PagerFilename(pPager, 0);
  int rc = SQLITE_OK;
  Server *p;

  p = (Server*)sqlite3_malloc(sizeof(Server));
  if( p==0 ){
    rc = SQLITE_NOMEM;
  }else{
    memset(p, 0, sizeof(Server));
    p->iClient = -1;
    p->pPager = pPager;

    serverEnterMutex();
    rc = serverOpenHma(pPager, zPath, &p->pHma);

    /* File is now mapped. Find a free client slot. */
    if( rc==SQLITE_OK ){
      int i;
      Server **aClient = p->pHma->aClient;
      int fd = p->pHma->fd;
      for(i=0; i<HMA_CLIENT_SLOTS; i++){
        if( aClient[i]==0 ){
          int res = posixLock(fd, i+1, SERVER_WRITE_LOCK, 0);
          if( res==SQLITE_OK ){
            u32 *pSlot = serverClientSlot(p, i);
            if( *pSlot ){
              rc = serverRollbackClient(p, i);
            }
            posixLock(fd, i+1, (!rc ? SERVER_READ_LOCK : SERVER_NO_LOCK), 0);
            break;
          }
        }
      }

      if( rc==SQLITE_OK ){
        if( i>HMA_CLIENT_SLOTS ){
          rc = SQLITE_BUSY;
        }else{
          u32 *pSlot = serverClientSlot(p, i);
          *piClient = p->iClient = i;
          aClient[i] = p;
          *pSlot = 1;
        }
      }
    }

    serverLeaveMutex();
  }

  if( rc!=SQLITE_OK ){
    sqlite3ServerDisconnect(p, 0);
    p = 0;
  }
  *ppOut = p;
  return rc;
}

static int serverOvercomeLock(
  Server *p,                      /* Server connection */
  int bWrite,                     /* True for a write-lock */
  int bBlock,                     /* If true, block for this lock */
  u32 v,                          /* Value of blocking page locking slot */
  int *pbRetry                    /* OUT: True if caller should retry lock */
){
  int rc = SQLITE_OK;
  int iBlock = ((int)(v>>HMA_CLIENT_SLOTS))-1;

  if( iBlock<0 || iBlock==p->iClient ){
    for(iBlock=0; iBlock<HMA_CLIENT_SLOTS; iBlock++){
      if( iBlock!=p->iClient && (v & (1<<iBlock)) ) break;
    }
  }
  assert( iBlock<HMA_CLIENT_SLOTS );

  serverEnterMutex();

  if( 0==p->pHma->aClient[iBlock] ){
    rc = posixLock(p->pHma->fd, iBlock+1, SERVER_WRITE_LOCK, 0);
    if( rc==SQLITE_OK ){
      rc = serverRollbackClient(p, iBlock);

      /* Release the lock on slot iBlock */
      posixLock(p->pHma->fd, iBlock+1, SERVER_NO_LOCK, 0);
      if( rc==SQLITE_OK ){
        *pbRetry = 1;
      }
    }else if( rc==SQLITE_BUSY ){
      if( bBlock ){
        rc = posixLock(p->pHma->fd, iBlock+1, SERVER_READ_LOCK, 1);
        if( rc==SQLITE_OK ){
          posixLock(p->pHma->fd, iBlock+1, SERVER_NO_LOCK, 0);
          *pbRetry = 1;
        }
      }

      if( rc==SQLITE_BUSY ){
        rc = SQLITE_OK;
      }
    }
  }

  serverLeaveMutex();

  return rc;
}

/*
** Begin a transaction.
*/
int sqlite3ServerBegin(Server *p){
#if 1
  int rc = posixLock(p->pHma->fd, p->iClient+1, SERVER_WRITE_LOCK, 1);
  if( rc ) return rc;
#endif
  return sqlite3ServerLock(p, 1, 0, 1);
}

/*
** End a transaction (and release all locks).
*/
int sqlite3ServerEnd(Server *p){
  int i;
  for(i=0; i<p->nLock; i++){
    u32 *pSlot = serverPageLockSlot(p, p->aLock[i]);
    while( 1 ){
      u32 v = *pSlot;
      u32 n = v;
      if( (v>>HMA_CLIENT_SLOTS)==p->iClient+1 ){
        n = n & ((1 << HMA_CLIENT_SLOTS)-1);
      }
      n = n & ~(1 << p->iClient);
      if( __sync_val_compare_and_swap(pSlot, v, n)==v ) break;
    }
    if( p->aLock[i]==0 ){
      struct timeval t2;
      i64 nUs;
      gettimeofday(&t2, 0);
      nUs = (i64)t2.tv_sec * 1000000 + t2.tv_usec - p->iUsWrite; 
      p->nUsWrite += nUs;
      if( (p->nUsWrite / 1000000)!=((p->nUsWrite + nUs)/1000000) ){
        sqlite3_log(SQLITE_WARNING, 
            "Cumulative WRITER time: %lldms\n", p->nUsWrite/1000
        );
      }
    }
  }
  p->nLock = 0;
#if 1
  return posixLock(p->pHma->fd, p->iClient+1, SERVER_READ_LOCK, 0);
#endif
  return SQLITE_OK;
}

/*
** Release all write-locks.
*/
int sqlite3ServerReleaseWriteLocks(Server *p){
  int rc = SQLITE_OK;
  return rc;
}

/*
** Return the client id of the client that currently holds the EXCLUSIVE
** or RESERVED lock according to page-locking slot value v. Or -1 if no
** client holds such a lock.
*/
int serverWriteLocker(u32 v){
  return ((int)(v >> HMA_CLIENT_SLOTS)) - 1;
}

/*
** Lock page pgno for reading (bWrite==0) or writing (bWrite==1).
**
** If parameter bBlock is non-zero, then make this a blocking lock if
** possible.
*/
int sqlite3ServerLock(Server *p, Pgno pgno, int bWrite, int bBlock){
  int rc = SQLITE_OK;
  int bReserved = 0;
  u32 *pSlot = serverPageLockSlot(p, pgno);

  /* Grow the aLock[] array, if required */
  if( p->nLock==p->nAlloc ){
    int nNew = p->nAlloc ? p->nAlloc*2 : 128;
    u32 *aNew;
    aNew = (u32*)sqlite3_realloc(p->aLock, sizeof(u32)*nNew);
    if( aNew==0 ){
      rc = SQLITE_NOMEM_BKPT;
    }else{
      p->aLock = aNew;
      p->nAlloc = nNew;
    }
  }
  if( rc==SQLITE_OK ){
    u32 v = *pSlot;

    /* Check if the required lock is already held. If so, exit this function
    ** early. Otherwise, add an entry to the aLock[] array to record the fact
    ** that the lock may need to be released.  */
    if( bWrite ){
      int iLock = ((int)(v>>HMA_CLIENT_SLOTS)) - 1;
      if( iLock==p->iClient ) goto server_lock_out;
    }else{
      if( v & (1<<p->iClient) ) goto server_lock_out;
    }
    p->aLock[p->nLock++] = pgno;

    while( 1 ){
      u32 n;
      int w;
      u32 mask = (bWrite ? (((1<<HMA_CLIENT_SLOTS)-1) & ~(1<<p->iClient)) : 0);

      while( ((w = serverWriteLocker(v))>=0 && w!=p->iClient) || (v & mask) ){
        int bRetry = 0;

        if( w<0 && bWrite && bBlock ){
          /* Attempt a RESERVED lock before anything else */
          n = v | ((p->iClient+1) << HMA_CLIENT_SLOTS);
          assert( serverWriteLocker(n)==p->iClient );
          if( __sync_val_compare_and_swap(pSlot, v, n)!=v ){
            v = *pSlot;
            continue;
          }
          v = n;
          bReserved = 1;
        }

        rc = serverOvercomeLock(p, bWrite, bBlock, v, &bRetry);
        if( rc!=SQLITE_OK ) goto server_lock_out;
        if( bRetry==0 ){
          /* There is a conflicting lock. Cannot obtain this lock. */
          sqlite3_log(SQLITE_BUSY_DEADLOCK, "Conflict at page %d", (int)pgno);
          rc = SQLITE_BUSY_DEADLOCK;
          goto server_lock_out;
        }

        v = *pSlot;
      }

      n = v | (1 << p->iClient);
      if( bWrite ){
        n = n | ((p->iClient+1) << HMA_CLIENT_SLOTS);
      }
      if( __sync_val_compare_and_swap(pSlot, v, n)==v ) break;
      v = *pSlot;
    }
  }

server_lock_out:
  if( rc!=SQLITE_OK && bReserved ){
    u32 n;
    u32 v;
    do{
      v = *pSlot;
      assert( serverWriteLocker(v)==p->iClient );
      n = v & ((1<<HMA_CLIENT_SLOTS)-1);
    }while( __sync_val_compare_and_swap(pSlot, v, n)!=v );
  }

  if( pgno==0 ){
    struct timeval t1;
    gettimeofday(&t1, 0);
    p->iUsWrite = ((i64)t1.tv_sec * 1000000) + (i64)t1.tv_usec;
  }
  assert( rc!=SQLITE_OK || sqlite3ServerHasLock(p, pgno, bWrite) );
  return rc;
}

int sqlite3ServerHasLock(Server *p, Pgno pgno, int bWrite){
  u32 v = *serverPageLockSlot(p, pgno);
  if( bWrite ){
    return (v>>HMA_CLIENT_SLOTS)==(p->iClient+1);
  }
  return (v & (1 << p->iClient))!=0;
}

#endif /* ifdef SQLITE_SERVER_EDITION */

/*
** 2017 April 24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

#ifdef SQLITE_SERVER_EDITION

#ifndef SQLITE_SERVER_H
#define SQLITE_SERVER_H


typedef struct Server Server;

int sqlite3ServerConnect(Pager *pPager, Server **ppOut, int *piClient);

void sqlite3ServerDisconnect(Server *p, sqlite3_file *dbfd);

int sqlite3ServerBegin(Server *p);
int sqlite3ServerEnd(Server *p);
int sqlite3ServerReleaseWriteLocks(Server *p);

int sqlite3ServerLock(Server *p, Pgno pgno, int bWrite, int bBlock);

int sqlite3ServerHasLock(Server *p, Pgno pgno, int bWrite);

#endif /* SQLITE_SERVER_H */

#endif /* SQLITE_SERVER_EDITION */

#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
#define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
#define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
#define SQLITE_BUSY_DEADLOCK           (SQLITE_BUSY   |  (3<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
#define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))

*/
#include "btree.h"
#include "vdbe.h"
#include "pager.h"
#include "pcache.h"
#include "os.h"
#include "mutex.h"
#include "server.h"

/* The SQLITE_EXTRA_DURABLE compile-time option used to set the default
** synchronous setting to EXTRA.  It is no longer supported.
*/
#ifdef SQLITE_EXTRA_DURABLE
# warning Use SQLITE_DEFAULT_SYNCHRONOUS=3 instead of SQLITE_EXTRA_DURABLE
# define SQLITE_DEFAULT_SYNCHRONOUS 3

    /* Lock all btrees used by the statement */
    sqlite3VdbeEnter(p);

    /* Check for one of the special errors */
    mrc = p->rc & 0xff;
    isSpecialError = mrc==SQLITE_NOMEM || mrc==SQLITE_IOERR
                     || mrc==SQLITE_INTERRUPT || mrc==SQLITE_FULL
                     || p->rc==SQLITE_BUSY_DEADLOCK;
    if( isSpecialError ){
      /* If the query was read-only and the error code is SQLITE_INTERRUPT
      ** or SQLITE_BUSY_SERVER, no rollback is necessary. Otherwise, at 
      ** least a savepoint transaction must be rolled back to restore the
      ** database to a consistent state.
      **
      ** Even if the statement is read-only, it is important to perform
      ** a statement or transaction rollback operation. If the error 
      ** occurred while writing to the journal, sub-journal or database
      ** file as part of an effort to free up cache space (see function
      ** pagerStress() in pager.c), the rollback is required to restore 
      ** the pager to a consistent state.
      */
      if( !p->readOnly || (mrc!=SQLITE_INTERRUPT && mrc!=SQLITE_BUSY) ){
        if( (mrc==SQLITE_NOMEM || mrc==SQLITE_FULL) && p->usesStmtJournal ){
          eStatementOp = SAVEPOINT_ROLLBACK;
        }else{
          /* We are forced to roll back the active transaction. Before doing
          ** so, abort any other statements this handle currently has active.
          */
          sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);

  u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
#ifdef SQLITE_DEBUG
  u8 lockError;              /* True if a locking error has occurred */
#endif
#ifdef SQLITE_ENABLE_SNAPSHOT
  WalIndexHdr *pSnapshot;    /* Start transaction here if not NULL */
#endif
#ifdef SQLITE_SERVER_EDITION
  Server *pServer;
#endif
};

#ifdef SQLITE_SERVER_EDITION
# define walIsServer(p) ((p)->pServer!=0)
#else
# define walIsServer(p) 0
#endif

/*
** Candidate values for Wal.exclusiveMode.
*/
#define WAL_NORMAL_MODE     0
#define WAL_EXCLUSIVE_MODE  1     
#define WAL_HEAPMEMORY_MODE 2

      pWal->apWiData[i] = 0;
    }
  }else{
    sqlite3OsShmUnmap(pWal->pDbFd, isDelete);
  }
}

#ifdef SQLITE_SERVER_EDITION
int sqlite3WalServer(Wal *pWal, Server *pServer){
  assert( pWal->pServer==0 );
  pWal->pServer = pServer;
  return SQLITE_OK;
}
#endif

/* 
** Open a connection to the WAL file zWalName. The database file must 
** already be opened on connection pDbFd. The buffer that zWalName points
** to must remain valid for the lifetime of the returned Wal* handle.
**
** A SHARED lock should be held on the database file when this function
** is called. The purpose of this SHARED lock is to prevent any other

          ** checkpointed and behave accordingly. This seems unsafe though,
          ** as it would leave the system in a state where the contents of
          ** the wal-index header do not match the contents of the 
          ** file-system. To avoid this, update the wal-index header to
          ** indicate that the log file contains zero valid frames.  */
          walRestartHdr(pWal, salt1);
          rc = sqlite3OsTruncate(pWal->pWalFd, 0);
        }else if( walIsServer(pWal) ){
          assert( eMode==SQLITE_CHECKPOINT_RESTART );
          walRestartHdr(pWal, salt1);
        }
        walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);
      }
    }
  }

 walcheckpoint_out:

    testcase( pWal->szPage<=32768 );
    testcase( pWal->szPage>=65536 );
  }

  /* The header was successfully read. Return zero. */
  return 0;
}

static int walIndexWriteLock(Wal *pWal){
  if( walIsServer(pWal) ){
    return sqlite3ServerLock(pWal->pServer, 0, 1, 0);
  }else{
    return walLockExclusive(pWal, WAL_WRITE_LOCK, 1);
  }
}

/*
** Read the wal-index header from the wal-index and into pWal->hdr.
** If the wal-header appears to be corrupt, try to reconstruct the
** wal-index from the WAL before returning.
**
** Set *pChanged to 1 if the wal-index header value in pWal->hdr is

  /* If the first attempt failed, it might have been due to a race
  ** with a writer.  So get a WRITE lock and try again.
  */
  assert( badHdr==0 || pWal->writeLock==0 );
  if( badHdr ){
    if( pWal->readOnly & WAL_SHM_RDONLY ){
      assert( walIsServer(pWal)==0 );
      if( SQLITE_OK==(rc = walLockShared(pWal, WAL_WRITE_LOCK)) ){
        walUnlockShared(pWal, WAL_WRITE_LOCK);
        rc = SQLITE_READONLY_RECOVERY;
      }
    }else if( SQLITE_OK==(rc = walIndexWriteLock(pWal)) ){
      pWal->writeLock = 1;
      if( SQLITE_OK==(rc = walIndexPage(pWal, 0, &page0)) ){
        badHdr = walIndexTryHdr(pWal, pChanged);
        if( badHdr ){
          /* If the wal-index header is still malformed even while holding
          ** a WRITE lock, it can only mean that the header is corrupted and
          ** needs to be reconstructed.  So run recovery to do exactly that.
          */
          rc = walIndexRecover(pWal);
          *pChanged = 1;
        }
      }
      pWal->writeLock = 0;
      if( walIsServer(pWal)==0 ){
        walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);
      }
    }
  }

  /* If the header is read successfully, check the version number to make
  ** sure the wal-index was not constructed with some future format that
  ** this version of SQLite cannot understand.
  */

      }
    }
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }

  assert( rc==SQLITE_OK );
  if( walIsServer(pWal) ) return SQLITE_OK;

  pInfo = walCkptInfo(pWal);
  if( !useWal && pInfo->nBackfill==pWal->hdr.mxFrame 
#ifdef SQLITE_ENABLE_SNAPSHOT
   && (pWal->pSnapshot==0 || pWal->hdr.mxFrame==0
     || 0==memcmp(&pWal->hdr, pWal->pSnapshot, sizeof(WalIndexHdr)))
#endif
  ){

){
  u32 iRead = 0;                  /* If !=0, WAL frame to return data from */
  u32 iLast = pWal->hdr.mxFrame;  /* Last page in WAL for this reader */
  int iHash;                      /* Used to loop through N hash tables */
  int iMinHash;

  /* This routine is only be called from within a read transaction. */
  assert( walIsServer(pWal) || pWal->readLock>=0 || pWal->lockError );

  assert( walIsServer(pWal)==0 || pWal->writeLock==0 
       || sqlite3ServerHasLock(pWal->pServer, 0, 1) 
  );
  if( walIsServer(pWal) && pWal->writeLock==0 ){
    /* A server mode connection must read from the most recent snapshot. */
    iLast = walIndexHdr(pWal)->mxFrame;
  }

  /* If the "last page" field of the wal-index header snapshot is 0, then
  ** no data will be read from the wal under any circumstances. Return early
  ** in this case as an optimization.  Likewise, if pWal->readLock==0, 
  ** then the WAL is ignored by the reader so return early, as if the 
  ** WAL were empty.
  */

  return sqlite3OsRead(pWal->pWalFd, pOut, (nOut>sz ? sz : nOut), iOffset);
}

/* 
** Return the size of the database in pages (or zero, if unknown).
*/
Pgno sqlite3WalDbsize(Wal *pWal){
  if( pWal && (walIsServer(pWal) || ALWAYS(pWal->readLock>=0)) ){
    return pWal->hdr.nPage;
  }
  return 0;
}


/* 

** There can only be a single writer active at a time.
*/
int sqlite3WalBeginWriteTransaction(Wal *pWal){
  int rc;

  /* Cannot start a write transaction without first holding a read
  ** transaction. */
  assert( walIsServer(pWal) || pWal->readLock>=0 );
  assert( pWal->writeLock==0 && pWal->iReCksum==0 );

  if( pWal->readOnly ){
    return SQLITE_READONLY;
  }

  /* For a server connection, do nothing at this point. */
  if( walIsServer(pWal) ){
    return SQLITE_OK;
  }

  /* Only one writer allowed at a time.  Get the write lock.  Return
  ** SQLITE_BUSY if unable.
  */
  rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1);
  if( rc ){
    return rc;

** returned to the caller.
**
** Otherwise, if the callback function does not return an error, this
** function returns SQLITE_OK.
*/
int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx){
  int rc = SQLITE_OK;
  if( pWal->writeLock ){
    Pgno iMax = pWal->hdr.mxFrame;
    Pgno iFrame;
  
    /* Restore the clients cache of the wal-index header to the state it
    ** was in before the client began writing to the database. 
    */
    memcpy(&pWal->hdr, (void *)walIndexHdr(pWal), sizeof(WalIndexHdr));

** unchanged.
**
** SQLITE_OK is returned if no error is encountered (regardless of whether
** or not pWal->hdr.mxFrame is modified). An SQLite error code is returned
** if an error occurs.
*/
static int walRestartLog(Wal *pWal){
  volatile WalCkptInfo *pInfo = walCkptInfo(pWal);
  int rc = SQLITE_OK;
  int cnt;

  if( pWal->readLock==0 
   || (walIsServer(pWal) && pInfo->nBackfill==pWal->hdr.mxFrame)
  ){
    assert( pInfo->nBackfill==pWal->hdr.mxFrame );
    if( pInfo->nBackfill>0 ){
      u32 salt1;
      sqlite3_randomness(4, &salt1);
      rc = walLockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);
      if( rc==SQLITE_OK ){
        /* If all readers are using WAL_READ_LOCK(0) (in other words if no

        ** to handle if this transaction is rolled back.  */
        walRestartHdr(pWal, salt1);
        walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);
      }else if( rc!=SQLITE_BUSY ){
        return rc;
      }
    }
    if( walIsServer(pWal) ) return rc;
    walUnlockShared(pWal, WAL_READ_LOCK(0));
    pWal->readLock = -1;
    cnt = 0;
    do{
      int notUsed;
      rc = walTryBeginRead(pWal, &notUsed, 1, ++cnt);
    }while( rc==WAL_RETRY );

  int szFrame;                    /* The size of a single frame */
  i64 iOffset;                    /* Next byte to write in WAL file */
  WalWriter w;                    /* The writer */
  u32 iFirst = 0;                 /* First frame that may be overwritten */
  WalIndexHdr *pLive;             /* Pointer to shared header */

  assert( pList );
  assert( pWal->writeLock || walIsServer(pWal) );
  if( pWal->writeLock==0 ){
    int bDummy = 0;
#if 0
    rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1);
#endif
    rc = sqlite3ServerLock(pWal->pServer, 0, 1, 1);
    if( rc==SQLITE_OK ){
      pWal->writeLock = 1;
      rc = walIndexTryHdr(pWal, &bDummy);
    }
    if( rc!=SQLITE_OK ){
      return rc;
    }
    assert( sqlite3ServerHasLock(pWal->pServer, 0, 1) );
  }
  assert( walIsServer(pWal)==0 || sqlite3ServerHasLock(pWal->pServer, 0, 1) );

  /* If this frame set completes a transaction, then nTruncate>0.  If
  ** nTruncate==0 then this frame set does not complete the transaction. */
  assert( (isCommit!=0)==(nTruncate!=0) );

#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
  { int cnt; for(cnt=0, p=pList; p; p=p->pDirty, cnt++){}
    WALTRACE(("WAL%p: frame write begin. %d frames. mxFrame=%d. %s\n",
              pWal, cnt, pWal->hdr.mxFrame, isCommit ? "Commit" : "Spill"));
  }
#endif

  pLive = (WalIndexHdr*)walIndexHdr(pWal);
  if( memcmp(&pWal->hdr, (void *)pLive, sizeof(WalIndexHdr))!=0 ){
    iFirst = pLive->mxFrame+1;
  }

  /* See if it is possible to write these frames into the start of the
  ** log file, instead of appending to it at pWal->hdr.mxFrame.
  */
  if( walIsServer(pWal)==0 && SQLITE_OK!=(rc = walRestartLog(pWal)) ){
    return rc;
  }

  /* If this is the first frame written into the log, write the WAL
  ** header to the start of the WAL file. See comments at the top of
  ** this source file for a description of the WAL header format.
  */

  **
  ** EVIDENCE-OF: R-60642-04082 If the writer lock cannot be obtained
  ** immediately, and a busy-handler is configured, it is invoked and the
  ** writer lock retried until either the busy-handler returns 0 or the
  ** lock is successfully obtained.
  */
  if( eMode!=SQLITE_CHECKPOINT_PASSIVE ){
    if( walIsServer(pWal) ){
      rc = sqlite3ServerBegin(pWal->pServer);
      if( rc!=SQLITE_OK ) goto ckpt_out;
      if( eMode>=SQLITE_CHECKPOINT_RESTART ){
        /* Exclusive lock on page 1. This is exclusive access to the db. */
        rc = sqlite3ServerLock(pWal->pServer, 1, 1, 1);
      }else{
        /* Take the server write-lock ("page" 0) */
        rc = sqlite3ServerLock(pWal->pServer, 0, 1, 1);
      }
    }else{
      rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_WRITE_LOCK, 1);
    }
    if( rc==SQLITE_OK ){
      pWal->writeLock = 1;
    }else if( rc==SQLITE_BUSY ){
      eMode2 = SQLITE_CHECKPOINT_PASSIVE;
      xBusy2 = 0;
      rc = SQLITE_OK;
    }

    ** next time the pager opens a snapshot on this database it knows that
    ** the cache needs to be reset.
    */
    memset(&pWal->hdr, 0, sizeof(WalIndexHdr));
  }

  /* Release the locks. */
 ckpt_out:
  sqlite3WalEndWriteTransaction(pWal);
  walUnlockExclusive(pWal, WAL_CKPT_LOCK, 1);
  pWal->ckptLock = 0;
  WALTRACE(("WAL%p: checkpoint %s\n", pWal, rc ? "failed" : "ok"));
  if( walIsServer(pWal) ) sqlite3ServerEnd(pWal->pServer);
  return (rc==SQLITE_OK && eMode!=eMode2 ? SQLITE_BUSY : rc);
}

/* Return the value to pass to a sqlite3_wal_hook callback, the
** number of frames in the WAL at the point of the last commit since
** sqlite3WalCallback() was called.  If no commits have occurred since
** the last call, then return 0.

** stored in each frame (i.e. the db page-size when the WAL was created).
*/
int sqlite3WalFramesize(Wal *pWal);
#endif

/* Return the sqlite3_file object for the WAL file */
sqlite3_file *sqlite3WalFile(Wal *pWal);

#ifdef SQLITE_SERVER_EDITION
int sqlite3WalServer(Wal *pWal, Server *pServer);
#endif

#endif /* ifndef SQLITE_OMIT_WAL */
#endif /* SQLITE_WAL_H */

  fts3corrupt3.test
  fts3misc.test
}

test_suite "fts5" -prefix "" -description {
  All FTS5 tests.
} -files [glob -nocomplain $::testdir/../ext/fts5/test/*.test]

test_suite "server" -prefix "" -description {
  All server-edition tests.
} -files [
  test_set \
      select1.test \
      [glob -nocomplain $::testdir/server*.test] \
      -exclude *server1.test
]

test_suite "fts5-light" -prefix "" -description {
  All FTS5 tests.
} -files [
  test_set \
      [glob -nocomplain $::testdir/../ext/fts5/test/*.test] \
      -exclude *corrupt* *fault* *big* *fts5aj*

# 2017 April 25
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the server mode of SQLite.
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix server2

#-------------------------------------------------------------------------
# Check that the *-hma file is deleted correctly.
#
do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);
} {}
do_test 1.1 {
  file exists test.db-hma
} {1}
do_test 1.2 {
  db close
  file exists test.db-hma
} {0}
do_test 1.3 {
  sqlite3 db test.db
  db eval { CREATE TABLE t2(a, b) }
  sqlite3 db2 test.db
  db2 eval { CREATE TABLE t3(a, b) }
  file exists test.db-hma
} {1}
do_test 1.4 {
  db2 close
  file exists test.db-hma
} {1}
integrity_check 1.5
do_test 1.6 {
  db close
  file exists test.db-hma
} {0}


#-------------------------------------------------------------------------
#
reset_db
sqlite3 db2 test.db

do_execsql_test 2.0 {
  CREATE TABLE t1(a, b);
  CREATE TABLE t2(c, d);
}

# Two concurrent transactions committed.
#
do_test 2.1 {
  db eval {
    BEGIN;
      INSERT INTO t1 VALUES(1, 2);
  }
  db2 eval {
    BEGIN;
      INSERT INTO t2 VALUES(3, 4);
  }
} {}
do_test 2.2 {
  lsort [glob test.db*]
} {test.db test.db-hma test.db-journal0 test.db-journal1}
do_test 2.3.1 { db eval COMMIT  } {}
do_test 2.3.2 { db2 eval COMMIT } {}
do_execsql_test 2.4 {SELECT * FROM t1, t2} {1 2 3 4}
do_test 2.5 {
  lsort [glob test.db*]
} {test.db test.db-hma test.db-journal0 test.db-journal1}

do_test 2.6 {
  execsql {BEGIN}
  execsql {INSERT INTO t1 VALUES(5, 6)}

  execsql {BEGIN} db2
  catchsql {INSERT INTO t1 VALUES(7, 8)} db2
} {1 {database is locked}}
do_test 2.7 {
  # Transaction is automatically rolled back in this case.
  sqlite3_get_autocommit db2
} {1}
do_test 2.8 {
  execsql COMMIT
  execsql { SELECT * FROM t1 } db2
} {1 2 5 6}
db2 close

#-------------------------------------------------------------------------
#
reset_db
do_execsql_test 3.0 {
  CREATE TABLE t1(a, b);
}

do_test 3.1 {
  glob test.db*
} {test.db-journal0 test.db test.db-hma}

do_test 3.2 {
  db close
  glob test.db*
} {test.db}

finish_test

# 2017 April 25
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the server mode of SQLite.
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
set testprefix server3

db close

do_multiclient_test tn {
  do_test $tn.1 {
    sql1 { CREATE TABLE t1(a, b) }
    sql2 { CREATE TABLE t2(a, b) }
  } {}

  do_test $tn.2 {
    sql1 {
      INSERT INTO t2 VALUES(1, 2);
      BEGIN;
        INSERT INTO t1 VALUES(1, 2);
    }
  } {}

  do_test $tn.3 { csql2 { SELECT * FROM t1 } } {1 {database is locked}}
  do_test $tn.4 { csql2 { SELECT * FROM t1 } } {1 {database is locked}}
  do_test $tn.5 {  sql2 { SELECT * FROM t2 } } {1 2}


}

finish_test

# 2017 April 27
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix servercrash

ifcapable !crashtest {
  finish_test
  return
}
do_not_use_codec

do_execsql_test 1.0 {
  PRAGMA page_siBlockze = 4096;
  PRAGMA auto_vacuum = OFF;
  CREATE TABLE t1(a, b);
  CREATE TABLE t2(c, d);

  INSERT INTO t1 VALUES(1, 2), (3, 4);
  INSERT INTO t2 VALUES(1, 2), (3, 4);
}

for {set i 0} {$i < 10} {incr i} {
  do_test 1.$i.1 {
    crashsql -delay 1 -file test.db { INSERT INTO t1 VALUES(5, 6) }
  } {1 {child process exited abnormally}}

  do_execsql_test 1.$i.2 {
    SELECT * FROM t1
  } {1 2 3 4}
}

for {set i 0} {$i < 10} {incr i} {
  do_test 2.$i.1 {
    crashsql -delay 1 -file test.db { INSERT INTO t1 VALUES(5, 6) }
  } {1 {child process exited abnormally}}

  do_test 2.$i.2 {
    sqlite3 dbX test.db
    execsql { SELECT * FROM t1 } dbX
  } {1 2 3 4}
  dbX close
}

db close
for {set i 0} {$i < 10} {incr i} {
  do_test 3.$i.1 {
    crashsql -delay 1 -file test.db { INSERT INTO t1 VALUES(5, 6) }
  } {1 {child process exited abnormally}}

  sqlite3 db test.db
  do_execsql_test 3.$i.2 { SELECT * FROM t1 } {1 2 3 4}
  db close
}

finish_test

# 2017 April 25
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the server mode of SQLite.
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix serverwal

# Check files are created and deleted as expected.
#
do_execsql_test 1.0 {
  PRAGMA journal_mode = wal;
} {wal}
do_execsql_test 1.1 {
  CREATE TABLE t1(a, b);
}
do_execsql_test 1.2 {
  SELECT * FROM t1;
} {}
do_test 1.3 {
  lsort [glob test.db*]
} {test.db test.db-hma test.db-shm test.db-wal}
do_test 1.4 {
  db close
  glob test.db*
} {test.db}

#-------------------------------------------------------------------------
# Two concurrent transactions.
#
do_test 2.0 {
  sqlite3 db  test.db
  sqlite3 db2 test.db
  db eval {
    CREATE TABLE t2(a, b);
  }
} {}
do_test 2.1 {
  execsql {
    BEGIN;
      INSERT INTO t1 VALUES(1, 2);
  } db
  execsql {
    BEGIN;
      INSERT INTO t2 VALUES(1, 2);
  } db2
} {}
do_test 2.2 {
  execsql COMMIT db
  execsql COMMIT db2
} {}
db close
db2 close

#-------------------------------------------------------------------------
# That the wal file can be wrapped around.
#
reset_db
do_execsql_test 3.0 {
  PRAGMA journal_mode = wal;
  CREATE TABLE ttt(a, b);
  INSERT INTO ttt VALUES(1, 2);
  INSERT INTO ttt VALUES(3, 4);
  INSERT INTO ttt VALUES(5, 6);
  INSERT INTO ttt VALUES(7, 8);
  INSERT INTO ttt VALUES(9, 10);
} {wal}

do_test 3.1 {
  set N [file size test.db-wal]
  execsql {
    PRAGMA wal_checkpoint = restart;
    INSERT INTO ttt VALUES(11, 12);
    INSERT INTO ttt VALUES(13, 14);
  }
  expr {$N == [file size test.db-wal]}
} {1}

#-------------------------------------------------------------------------
# That ROLLBACK appears to work.
#
reset_db
do_execsql_test 4.0 {
  PRAGMA cache_size = 10;
  CREATE TABLE ttt(a, b);
  CREATE INDEX yyy ON ttt(b, a);
  PRAGMA journal_mode = wal;
  WITH s(i) AS (
    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<100
  )
  INSERT INTO ttt SELECT randomblob(100), randomblob(100) FROM s;
} {wal}

do_execsql_test 4.1 {
  PRAGMA integrity_check;
  BEGIN;
    UPDATE ttt SET b=a;
  ROLLBACK;
  PRAGMA integrity_check;
} {ok ok}

reset_db
do_execsql_test 5.1 {
  CREATE TABLE xyz(a);
  PRAGMA journal_mode = wal;
  INSERT INTO xyz VALUES(1);
  INSERT INTO xyz VALUES(2);
  INSERT INTO xyz VALUES(3);
} {wal}

breakpoint

do_test 5.2 {
  sqlite3 db2 test.db
  execsql { SELECT * FROM xyz } db2
} {1 2 3}

do_execsql_test 5.3 {
  PRAGMA wal_checkpoint = restart 
} {0 0 0}

do_test 5.4 {
  execsql { SELECT * FROM xyz } db2
} {1 2 3}

finish_test

# Create a test database
#
proc reset_db {} {
  catch {db close}
  forcedelete test.db
  forcedelete test.db-journal
  forcedelete test.db-wal
  for {set i 0} {$i < 16} {incr i} {
    forcedelete test.db-journal$i
  }

  sqlite3 db ./test.db
  set ::DB [sqlite3_connection_pointer db]
  if {[info exists ::SETUP_SQL]} {
    db eval $::SETUP_SQL
  }
}
reset_db

   os_win.h
   os.h
   pager.h
   parse.h
   pcache.h
   pragma.h
   rtree.h
   server.h
   sqlite3session.h
   sqlite3.h
   sqlite3ext.h
   sqlite3rbu.h
   sqliteicu.h
   sqliteInt.h
   sqliteLimit.h

   bitvec.c
   pcache.c
   pcache1.c
   rowset.c
   pager.c
   wal.c
   server.c

   btmutex.c
   btree.c
   backup.c

   vdbemem.c
   vdbeaux.c

/*
** 2017 June 7
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** Simple multi-threaded server used for informal testing of concurrency
** between connections in different threads. Listens for tcp/ip connections
** on port 9999 of the 127.0.0.1 interface only. To build:
**
**   gcc -g $(TOP)/tool/tserver.c sqlite3.o -lpthread -o tserver
**
** To run using "x.db" as the db file:
**
**   ./tserver x.db
**
** To connect, open a client socket on port 9999 and start sending commands.
** Commands are either SQL - which must be terminated by a semi-colon, or
** dot-commands, which must be terminated by a newline. If an SQL statement
** is seen, it is prepared and added to an internal list.
**
** Dot-commands are:
**
**   .list                    Display all SQL statements in the list.
**   .quit                    Disconnect.
**   .run                     Run all SQL statements in the list.
**   .repeats N               Configure the number of repeats per ".run".
**   .seconds N               Configure the number of seconds to ".run" for.
**
** Example input:
**
**   BEGIN;
**     INSERT INTO t1 VALUES(randomblob(10), randomblob(100));
**     INSERT INTO t1 VALUES(randomblob(10), randomblob(100));
**     INSERT INTO t1 VALUES(randomblob(10), randomblob(100));
**   COMMIT;
**   .repeats 100000
**   .run
**
*/
#define TSERVER_PORTNUMBER 9999

#include <arpa/inet.h>
#include <assert.h>
#include <pthread.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <unistd.h>

#include "sqlite3.h"

/* Database used by this server */
static char *zDatabaseName = 0;

typedef struct ClientCtx ClientCtx;
struct ClientCtx {
  sqlite3 *db;                    /* Database handle for this client */
  int fd;                         /* Client fd */
  int nRepeat;                    /* Number of times to repeat SQL */
  int nSecond;                    /* Number of seconds to run for */
  sqlite3_stmt **apPrepare;       /* Array of prepared statements */
  int nPrepare;                   /* Valid size of apPrepare[] */
  int nAlloc;                     /* Allocated size of apPrepare[] */
};

static int is_eol(int i){
  return (i=='\n' || i=='\r');
}
static int is_whitespace(int i){
  return (i==' ' || i=='\t' || is_eol(i));
}

static void trim_string(const char **pzStr, int *pnStr){
  const char *zStr = *pzStr;
  int nStr = *pnStr;

  while( nStr>0 && is_whitespace(zStr[0]) ){
    zStr++;
    nStr--;
  }
  while( nStr>0 && is_whitespace(zStr[nStr-1]) ){
    nStr--;
  }

  *pzStr = zStr;
  *pnStr = nStr;
}

static int send_message(ClientCtx *p, const char *zFmt, ...){
  char *zMsg;
  va_list ap;                             /* Vararg list */
  va_start(ap, zFmt);
  int res = -1;

  zMsg = sqlite3_vmprintf(zFmt, ap);
  if( zMsg ){
    res = write(p->fd, zMsg, strlen(zMsg));
  }
  sqlite3_free(zMsg);
  va_end(ap);

  return (res<0);
}

static int handle_some_sql(ClientCtx *p, const char *zSql, int nSql){
  const char *zTail = zSql;
  int nTail = nSql;
  int rc = SQLITE_OK;

  while( rc==SQLITE_OK ){
    if( p->nPrepare>=p->nAlloc ){
      int nByte = (p->nPrepare+32) * sizeof(sqlite3_stmt*);
      sqlite3_stmt **apNew = sqlite3_realloc(p->apPrepare, nByte);
      if( apNew ){
        p->apPrepare = apNew;
        p->nAlloc = p->nPrepare+32;
      }else{
        rc = SQLITE_NOMEM;
        break;
      }
    }
    rc = sqlite3_prepare_v2(
        p->db, zTail, nTail, &p->apPrepare[p->nPrepare], &zTail
    );
    if( rc!=SQLITE_OK ){
      send_message(p, "error - %s\n", sqlite3_errmsg(p->db));
      rc = 1;
      break;
    }
    if( p->apPrepare[p->nPrepare]==0 ){
      break;
    }
    p->nPrepare++;
    nTail = nSql - (zTail-zSql);
    rc = send_message(p, "ok (%d SQL statements)\n", p->nPrepare);
  }

  return rc;
}

static sqlite3_int64 get_timer(void){
  struct timeval t;
  gettimeofday(&t, 0);
  return ((sqlite3_int64)t.tv_usec / 1000) + ((sqlite3_int64)t.tv_sec * 1000);
}

static void clear_sql(ClientCtx *p){
  int j;
  for(j=0; j<p->nPrepare; j++){
    sqlite3_finalize(p->apPrepare[j]);
  }
  p->nPrepare = 0;
}

static int handle_dot_command(ClientCtx *p, const char *zCmd, int nCmd){
  assert( zCmd[0]=='.' );
  int n;
  int rc = 0;
  const char *z = &zCmd[1];
  const char *zArg;
  int nArg;

  for(n=0; n<(nCmd-1); n++){
    if( is_whitespace(z[n]) ) break;
  }

  zArg = &z[n];
  nArg = nCmd-n;
  trim_string(&zArg, &nArg);

  if( n>=1 && n<=4 && 0==strncmp(z, "list", n) ){
    int i;
    for(i=0; rc==0 && i<p->nPrepare; i++){
      const char *zSql = sqlite3_sql(p->apPrepare[i]);
      int nSql = strlen(zSql);
      trim_string(&zSql, &nSql);
      rc = send_message(p, "%d: %.*s\n", i, nSql, zSql);
    }
  }

  else if( n>=1 && n<=4 && 0==strncmp(z, "quit", n) ){
    rc = 1;
  }

  else if( n>=2 && n<=7 && 0==strncmp(z, "repeats", n) ){
    if( nArg ){
      p->nRepeat = strtol(zArg, 0, 0);
      if( p->nRepeat>0 ) p->nSecond = 0;
    }
    rc = send_message(p, "ok (repeat=%d)\n", p->nRepeat);
  }

  else if( n>=2 && n<=3 && 0==strncmp(z, "run", n) ){
    int i, j;
    int nBusy = 0;
    sqlite3_int64 t0 = get_timer();
    sqlite3_int64 t1 = t0;
    int nT1 = 0;
    int nTBusy1 = 0;

    for(j=0; (p->nRepeat<=0 || j<p->nRepeat) && rc==SQLITE_OK; j++){
      sqlite3_int64 t2;

      for(i=0; i<p->nPrepare && rc==SQLITE_OK; i++){
        sqlite3_stmt *pStmt = p->apPrepare[i];

        /* Execute the statement */
        while( sqlite3_step(pStmt)==SQLITE_ROW );
        rc = sqlite3_reset(pStmt);

        if( (rc & 0xFF)==SQLITE_BUSY ){
          if( sqlite3_get_autocommit(p->db)==0 ){
            sqlite3_exec(p->db, "ROLLBACK", 0, 0, 0);
          }
          nBusy++;
          rc = SQLITE_OK;
          break;
        }
        else if( rc!=SQLITE_OK ){
          send_message(p, "error - %s\n", sqlite3_errmsg(p->db));
        }
      }

      t2 = get_timer();
      if( t2>=(t1+1000) ){
        int nMs = (t2 - t1);
        int nDone = (j+1 - nBusy - nT1);

        rc = send_message(
            p, "(%d done @ %d per second, %d busy)\n", 
            nDone, (1000*nDone + nMs/2) / nMs, nBusy - nTBusy1
        );
        t1 = t2;
        nT1 = j+1 - nBusy;
        nTBusy1 = nBusy;
        if( p->nSecond>0 && (p->nSecond*1000)<=t1-t0 ) break;
      }
    }

    if( rc==SQLITE_OK ){
      send_message(p, "ok (%d/%d SQLITE_BUSY)\n", nBusy, j);
    }
    clear_sql(p);
  }

  else if( n>=1 && n<=7 && 0==strncmp(z, "seconds", n) ){
    if( nArg ){
      p->nSecond = strtol(zArg, 0, 0);
      if( p->nSecond>0 ) p->nRepeat = 0;
    }
    rc = send_message(p, "ok (repeat=%d)\n", p->nRepeat);
  }

  else{
    send_message(p, 
        "unrecognized dot command: %.*s\n"
        "should be \"list\", \"run\", \"repeats\", or \"seconds\"\n", n, z
    );
    rc = 1;
  }

  return rc;
}

static void *handle_client(void *pArg){
  char zCmd[32*1024];             /* Read buffer */
  int nCmd = 0;                   /* Valid bytes in zCmd[] */
  int res;                        /* Result of read() call */
  int rc = SQLITE_OK;
  int j;

  ClientCtx ctx;
  memset(&ctx, 0, sizeof(ClientCtx));

  ctx.fd = (int)(intptr_t)pArg;
  ctx.nRepeat = 1;
  rc = sqlite3_open(zDatabaseName, &ctx.db);
  if( rc!=SQLITE_OK ){
    fprintf(stderr, "sqlite3_open(): %s\n", sqlite3_errmsg(ctx.db));
    return 0;
  }

  while( rc==SQLITE_OK ){
    int i;
    int iStart;
    int nConsume;
    res = read(ctx.fd, &zCmd[nCmd], sizeof(zCmd)-nCmd-1);
    if( res<=0 ) break;
    nCmd += res;
    if( nCmd>=sizeof(zCmd)-1 ){
      fprintf(stderr, "oversized (>32KiB) message\n");
      res = 0;
      break;
    }
    zCmd[nCmd] = '\0';

    do {
      nConsume = 0;

      /* Gobble up any whitespace */
      iStart = 0;
      while( is_whitespace(zCmd[iStart]) ) iStart++;

      if( zCmd[iStart]=='.' ){
        /* This is a dot-command. Search for end-of-line. */
        for(i=iStart; i<nCmd; i++){
          if( is_eol(zCmd[i]) ){
            rc = handle_dot_command(&ctx, &zCmd[iStart], i-iStart);
            nConsume = i+1;
            break;
          }
        }
      }else{

        int iSemi;
        char c = 0;
        for(iSemi=iStart; iSemi<nCmd; iSemi++){
          if( zCmd[iSemi]==';' ){
            c = zCmd[iSemi+1];
            zCmd[iSemi+1] = '\0';
            break;
          }
        }

        if( iSemi<nCmd ){
          if( sqlite3_complete(zCmd) ){
            rc = handle_some_sql(&ctx, zCmd, iSemi+1);
            nConsume = iSemi+1;
          }

          if( c ){
            zCmd[iSemi+1] = c;
          }
        }
      }

      if( nConsume>0 ){
        nCmd = nCmd-nConsume;
        if( nCmd>0 ){
          memmove(zCmd, &zCmd[nConsume], nCmd);
        }
      }
    }while( rc==SQLITE_OK && nConsume>0 );
  }

  fprintf(stdout, "Client %d disconnects\n", ctx.fd);
  close(ctx.fd);
  clear_sql(&ctx);
  sqlite3_free(ctx.apPrepare);
  sqlite3_close(ctx.db);
  return 0;
} 

int main(int argc, char *argv[]) {
  sqlite3 *db;
  int sfd;
  int rc;
  int yes = 1;
  struct sockaddr_in server;

  /* Ignore SIGPIPE. Otherwise the server exits if a client disconnects
  ** abruptly.  */
  signal(SIGPIPE, SIG_IGN);

  if( argc!=2 ){
    fprintf(stderr, "Usage: %s DATABASE\n", argv[0]);
    return 1;
  }
  zDatabaseName = argv[1];

  rc = sqlite3_open(zDatabaseName, &db);
  if( rc!=SQLITE_OK ){
    fprintf(stderr, "sqlite3_open(): %s\n", sqlite3_errmsg(db));
    return 1;
  }

  rc = sqlite3_exec(db, "SELECT * FROM sqlite_master", 0, 0, 0);
  if( rc!=SQLITE_OK ){
    fprintf(stderr, "sqlite3_exec(): %s\n", sqlite3_errmsg(db));
    return 1;
  }

  sfd = socket(AF_INET, SOCK_STREAM, 0);
  if( sfd<0 ){
    fprintf(stderr, "socket() failed\n");
    return 1;
  }

  rc = setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
  if( rc<0 ){
    perror("setsockopt");
    return 1;
  }

  memset(&server, 0, sizeof(server));
  server.sin_family = AF_INET;
  server.sin_addr.s_addr = inet_addr("127.0.0.1");
  server.sin_port = htons(TSERVER_PORTNUMBER);

  rc = bind(sfd, (struct sockaddr *)&server, sizeof(struct sockaddr));
  if( rc<0 ){
    fprintf(stderr, "bind() failed\n");
    return 1;
  }

  rc = listen(sfd, 8);
  if( rc<0 ){
    fprintf(stderr, "listen() failed\n");
    return 1;
  }

  while( 1 ){
    pthread_t tid;
    int cfd = accept(sfd, NULL, NULL);
    if( cfd<0 ){
      perror("accept()");
      return 1;
    }

    fprintf(stdout, "Client %d connects\n", cfd);
    rc = pthread_create(&tid, NULL, handle_client, (void*)(intptr_t)cfd);
    if( rc!=0 ){
      perror("pthread_create()");
      return 1;
    }

    pthread_detach(tid);
  }

  return 0;
}