SQLite

** continue accessing the database using the xRead() and xWrite()
** methods.
*/
static void unixRemapfile(
  unixFile *pFd,                  /* File descriptor object */
  i64 nNew                        /* Required mapping size */
){
  const char *zErr = "mmap";
  int h = pFd->h;                      /* File descriptor open on db file */
  u8 *pOrig = (u8 *)pFd->pMapRegion;   /* Pointer to current file mapping */
  i64 nOrig = pFd->mmapOrigsize;       /* Size of pOrig region in bytes */
  u8 *pNew = 0;                        /* Location of new mapping */
  int flags = PROT_READ;               /* Flags to pass to mmap() */

  assert( pFd->nFetchOut==0 );
  assert( nNew>pFd->mmapSize );
  assert( nNew<=pFd->mmapLimit );
  assert( nNew>0 );
  assert( pFd->mmapOrigsize>=pFd->mmapSize );
  assert( MAP_FAILED!=0 );

  if( (pFd->ctrlFlags & UNIXFILE_RDONLY)==0 ) flags |= PROT_WRITE;

  if( pOrig ){
    const int szSyspage = unixGetPagesize();
    i64 nReuse = (pFd->mmapSize & ~(szSyspage-1));
    u8 *pReq = &pOrig[nReuse];

    /* Unmap any pages of the existing mapping that cannot be reused. */
    if( nReuse!=nOrig ){
      osMunmap(pReq, nOrig-nReuse);
    }

#if HAVE_MREMAP
    pNew = osMremap(pOrig, nReuse, nNew, MREMAP_MAYMOVE);
    zErr = "mremap";
#else
    pNew = osMmap(pReq, nNew-nReuse, flags, MAP_SHARED, h, nReuse);
    if( pNew!=MAP_FAILED ){
      if( pNew!=pReq ){
        osMunmap(pNew, nNew - nReuse);
        pNew = 0;
      }else{
        pNew = pOrig;
      }
    }
#endif

    /* The attempt to extend the existing mapping failed. Free the existing
    ** mapping and set pNew to NULL so that the code below will create a
    ** new mapping from scratch.  */
    if( pNew==MAP_FAILED ){

      osMunmap(pOrig, nReuse);
    }
  }

  /* If pNew is still NULL, try to create an entirely new mapping. */
  if( pNew==0 ){
    pNew = osMmap(0, nNew, flags, MAP_SHARED, h, 0);
  }

  if( pNew==MAP_FAILED ){
    pNew = 0;
    nNew = 0;
    unixLogError(SQLITE_OK, zErr, pFd->zPath);

    /* If the mmap() above failed, assume that all subsequent mmap() calls
    ** will probably fail too. Fall back to using xRead/xWrite exclusively
    ** in this case.  */
    pFd->mmapLimit = 0;
  }


  pFd->pMapRegion = (void *)pNew;
  pFd->mmapSize = pFd->mmapOrigsize = nNew;
}

/*
** Memory map or remap the file opened by file-descriptor pFd (if the file
** is already mapped, the existing mapping is replaced by the new). Or, if 

static int ts_pread64(int fd, void *aBuf, size_t nBuf, off_t off);
static int ts_write(int fd, const void *aBuf, size_t nBuf);
static int ts_pwrite(int fd, const void *aBuf, size_t nBuf, off_t off);
static int ts_pwrite64(int fd, const void *aBuf, size_t nBuf, off_t off);
static int ts_fchmod(int fd, mode_t mode);
static int ts_fallocate(int fd, off_t off, off_t len);
static void *ts_mmap(void *, size_t, int, int, int, off_t);
static void *ts_mremap(void*, size_t, size_t, int, ...);

struct TestSyscallArray {
  const char *zName;
  sqlite3_syscall_ptr xTest;
  sqlite3_syscall_ptr xOrig;
  int default_errno;              /* Default value for errno following errors */
  int custom_errno;               /* Current value for errno if error */

  /* 10 */ { "pread64",   (sqlite3_syscall_ptr)ts_pread64,   0, 0, 0 },
  /* 11 */ { "write",     (sqlite3_syscall_ptr)ts_write,     0, 0, 0 },
  /* 12 */ { "pwrite",    (sqlite3_syscall_ptr)ts_pwrite,    0, 0, 0 },
  /* 13 */ { "pwrite64",  (sqlite3_syscall_ptr)ts_pwrite64,  0, 0, 0 },
  /* 14 */ { "fchmod",    (sqlite3_syscall_ptr)ts_fchmod,    0, 0, 0 },
  /* 15 */ { "fallocate", (sqlite3_syscall_ptr)ts_fallocate, 0, 0, 0 },
  /* 16 */ { "mmap",      (sqlite3_syscall_ptr)ts_mmap,      0, 0, 0 },
  /* 17 */ { "mremap",    (sqlite3_syscall_ptr)ts_mremap,    0, 0, 0 },
           { 0, 0, 0, 0, 0 }
};

#define orig_open      ((int(*)(const char *, int, int))aSyscall[0].xOrig)
#define orig_close     ((int(*)(int))aSyscall[1].xOrig)
#define orig_access    ((int(*)(const char*,int))aSyscall[2].xOrig)
#define orig_getcwd    ((char*(*)(char*,size_t))aSyscall[3].xOrig)

#define orig_pwrite    ((ssize_t(*)(int,const void*,size_t,off_t))\
                       aSyscall[12].xOrig)
#define orig_pwrite64  ((ssize_t(*)(int,const void*,size_t,off_t))\
                       aSyscall[13].xOrig)
#define orig_fchmod    ((int(*)(int,mode_t))aSyscall[14].xOrig)
#define orig_fallocate ((int(*)(int,off_t,off_t))aSyscall[15].xOrig)
#define orig_mmap      ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[16].xOrig)
#define orig_mremap    ((void*(*)(void*,size_t,size_t,int,...))aSyscall[17].xOrig)

/*
** This function is called exactly once from within each invocation of a
** system call wrapper in this file. It returns 1 if the function should
** fail, or 0 if it should succeed.
*/
static int tsIsFail(void){

  off_t iOff
){
  if( tsIsFailErrno("mmap") ){
    return MAP_FAILED;
  }
  return orig_mmap(pAddr, nByte, prot, flags, fd, iOff);
}

static void *ts_mremap(void *a, size_t b, size_t c, int d, ...){
  va_list ap;
  void *pArg;
  if( tsIsFailErrno("mremap") ){
    return MAP_FAILED;
  }
  va_start(ap, d);
  pArg = va_arg(ap, void *);
  return orig_mremap(a, b, c, d, pArg);
}

static int test_syscall_install(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){

# 2013 March 20
#
# 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 tests the effect of the mmap() or mremap() system calls 
# returning an error on the library. 
#
# If either mmap() or mremap() fails, SQLite should log an error 
# message, then continue accessing the database using read() and 
# write() exclusively.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix mmap2

if {[test_syscall defaultvfs] != "unix"} {
  finish_test
  return
}

db close
sqlite3_shutdown
test_sqlite3_log xLog
proc xLog {error_code msg} {
  if {[string match os_unix.c* $msg]} {
    lappend ::log $msg 
  }
}

foreach syscall {mmap mremap} {
  test_syscall uninstall 
  if {[catch {test_syscall install $syscall}]} continue

  for {set i 1} {$i < 20} {incr i} {
    reset_db

    test_syscall fault $i 1
    test_syscall errno $syscall ENOMEM
    set ::log ""

    do_execsql_test 1.$syscall.$i.1 {
      CREATE TABLE t1(a, b, UNIQUE(a, b));
      INSERT INTO t1 VALUES(randomblob(1000), randomblob(1000));
      INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
      INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
      INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
      INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
      INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
      INSERT INTO t1 SELECT randomblob(1000), randomblob(1000) FROM t1;
    }

    set nFail [test_syscall fault 0 0]

    do_execsql_test 1.$syscall.$i.2 {
      SELECT count(*) FROM t1;
      PRAGMA integrity_check;
    } {64 ok}

    do_test 1.$syscall.$i.3 {
      expr {$nFail==0 || $nFail==1}
    } {1}

    do_test 1.$syscall.$i.4.nFail=$nFail {
      regexp ".*${syscall}.*" $::log
    } [expr $nFail>0]
  }
}

test_syscall uninstall 
finish_test

#sqlite3_config_scratch 29000 1
set old_lookaside [sqlite3_config_lookaside 2048 300]
#sqlite3_config_pagecache 1024 11000
set testdir [file dirname $argv0]
source $testdir/tester.tcl
speed_trial_init speed1

sqlite3_memdebug_vfs_oom_test 0

# Set a uniform random seed
expr srand(0)

# The number_name procedure below converts its argment (an integer)
# into a string which is the English-language name for that number.
#
# Example:

    CREATE INDEX i2a ON t2(a);
    CREATE INDEX i2b ON t2(b);
  }
  execsql {
    SELECT name FROM sqlite_master ORDER BY 1;
  }
} {i2a i2b t1 t2}


# 50000 INSERTs on an unindexed table
#
set list {}
for {set i 1} {$i<=50000} {incr i} {
  set r [expr {int(rand()*500000)}]
  set x [number_name $r]