SQLite

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.129 2004/06/16 07:45:24 danielk1977 Exp $
*/
#include "os.h"         /* Must be first to enable large file support */
#include "sqliteInt.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

**
** TODO: Consider keeping the journal file open for temporary databases.
** This might give a performance improvement on windows where opening
** a file is an expensive operation.
*/
static int pager_unwritelock(Pager *pPager){
  PgHdr *pPg;
  assert( !pPager->memDb );
  if( pPager->state<PAGER_RESERVED ){
    return SQLITE_OK;
  }
  sqlite3pager_stmt_commit(pPager);
  if( pPager->stmtOpen ){
    sqlite3OsClose(&pPager->stfd);
    pPager->stmtOpen = 0;

    }
    default: {
      /* Do nothing */
      break;
    }
  }
  for(pPg=pPager->pAll; pPg; pPg=pNext){
#ifndef NDEBUG
    if( pPager->memDb ){
      PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
      assert( !pPg->alwaysRollback );
      assert( !pHist->pOrig );
      assert( !pHist->pStmt );
    }
#endif
    pNext = pPg->pNextAll;
    sqliteFree(pPg);
  }
  if( !pPager->memDb ){
    sqlite3OsClose(&pPager->fd);
  }
  assert( pPager->journalOpen==0 );

** or EXCLUSIVE lock on the database file when this routine is called.
**
** Return SQLITE_OK if everything.  Return an error code and release the
** write lock if anything goes wrong.
*/
static int pager_open_journal(Pager *pPager){
  int rc;
  assert( !pPager->memDb );
  assert( pPager->state>=PAGER_RESERVED );
  assert( pPager->journalOpen==0 );
  assert( pPager->useJournal );
  sqlite3pager_pagecount(pPager);
  pPager->aInJournal = sqliteMalloc( pPager->dbSize/8 + 1 );
  if( pPager->aInJournal==0 ){
    sqlite3OsUnlock(&pPager->fd, SHARED_LOCK);

** is first added to the freelist, this routine is called.  When reused,
** the dont_rollback() routine is called.  But because the page contains
** critical data, we still need to be sure it gets rolled back in spite
** of the dont_rollback() call.
*/
void sqlite3pager_dont_write(Pager *pPager, Pgno pgno){
  PgHdr *pPg;

  if( pPager->memDb ) return;

  pPg = pager_lookup(pPager, pgno);
  pPg->alwaysRollback = 1;
  if( pPg && pPg->dirty ){
    if( pPager->dbSize==(int)pPg->pgno && pPager->origDbSize<pPager->dbSize ){
      /* If this pages is the last page in the file and the file has grown
      ** during the current transaction, then do NOT mark the page as clean.

      clearHistory(PGHDR_TO_HIST(pPg, pPager));
      pPg->dirty = 0;
      pPg->inJournal = 0;
      pPg->inStmt = 0;
      pPg->pPrevStmt = pPg->pNextStmt = 0;
      pPg = pPg->pDirty;
    }
#ifndef NDEBUG
    for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
      PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
      assert( !pPg->alwaysRollback );
      assert( !pHist->pOrig );
      assert( !pHist->pStmt );
    }
#endif
    pPager->pStmt = 0;
    pPager->state = PAGER_SHARED;
    return SQLITE_OK;
  }
  if( pPager->dirtyCache==0 ){
    /* Exit early (without doing the time-consuming sqlite3OsSync() calls)
    ** if there have been no changes to the database file. */

int sqlite3pager_rollback(Pager *pPager){
  int rc;
  TRACE2("ROLLBACK %d\n", pPager->fd.h);
  if( pPager->memDb ){
    PgHdr *p;
    for(p=pPager->pAll; p; p=p->pNextAll){
      PgHistory *pHist;
      assert( !p->alwaysRollback );
      if( !p->dirty ){
        assert( !((PgHistory *)PGHDR_TO_HIST(p, pPager))->pOrig );
        assert( !((PgHistory *)PGHDR_TO_HIST(p, pPager))->pStmt );
        continue;
      }

      pHist = PGHDR_TO_HIST(p, pPager);
      if( pHist->pOrig ){
        memcpy(PGHDR_TO_DATA(p), pHist->pOrig, pPager->pageSize);
        TRACE2("ROLLBACK-PAGE %d\n", p->pgno);
      }else{
        TRACE2("PAGE %d is clean\n", p->pgno);
      }

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.102 2004/06/16 07:45:29 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

#if SQLITE_DEBUG>2 && defined(__GLIBC__)
#include <execinfo.h>
void print_stack_trace(){
  void *bt[30];
  int i;
  int n = backtrace(bt, 30);

  fprintf(stderr, "STACK: ");
  for(i=0; i<n;i++){
    fprintf(stderr, "%p ", bt[i]);
  }
  fprintf(stderr, "\n");
}
#else
#define print_stack_trace()
#endif

/*
** If malloc() ever fails, this global variable gets set to 1.
** This causes the library to abort and never again function.
*/
int sqlite3_malloc_failed = 0;

  sqlite3_nMalloc++;
  for(i=0; i<N_GUARD; i++) pi[i] = 0xdead1122;
  pi[N_GUARD] = n;
  for(i=0; i<N_GUARD; i++) pi[k+1+N_GUARD+i] = 0xdead3344;
  p = &pi[N_GUARD+1];
  memset(p, bZero==0, n);
#if SQLITE_DEBUG>1
  print_stack_trace();
  fprintf(stderr,"%06d malloc %d bytes at 0x%x from %s:%d\n",
      ++memcnt, n, (int)p, zFile,line);
#endif
  return p;
}

/*

  memcpy(p, oldP, n>oldN ? oldN : n);
  if( n>oldN ){
    memset(&((char*)p)[oldN], 0, n-oldN);
  }
  memset(oldPi, 0xab, (oldK+N_GUARD+2)*sizeof(int));
  free(oldPi);
#if SQLITE_DEBUG>1
  print_stack_trace();
  fprintf(stderr,"%06d realloc %d to %d bytes at 0x%x to 0x%x at %s:%d\n",
    ++memcnt, oldN, n, (int)oldP, (int)p, zFile, line);
#endif
  return p;
}

/*

          ctx.s.flags = MEM_Null;
          ctx.pAgg = pMem->z;
          ctx.cnt = pMem->i;
          ctx.isStep = 0;
          ctx.isError = 0;
          (*pAgg->apFunc[i]->xFinalize)(&ctx);
          pMem->z = ctx.pAgg;
          if( pMem->z!=0 && pMem->z!=pMem->zShort ){
            sqliteFree(pMem->z);
          }
          sqlite3VdbeMemRelease(&ctx.s);
        }else{
          sqlite3VdbeMemRelease(pMem);
        }
      }
      sqliteFree(pElem);
      rc=sqlite3BtreeNext(pCsr, &res);
    }

#/bin/sh
# \
exec `which tclsh` $0 "$@"
#
# 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 doco "
This script is a tool to help track down memory leaks in the sqlite
library. The library must be compiled with the preprocessor symbol
SQLITE_DEBUG set to at least 2. It must be set to 3 to enable stack traces.

To use, run the leaky application and save the standard error output.
Then, execute this program with the first argument the name of the
application binary (or interpreter) and the second argument the name of the
text file that contains the collected stderr output.

If all goes well a summary of unfreed allocations is printed out. If the
GNU C library is in use and SQLITE_DEBUG is 3 or greater a stack trace is
printed out for each unmatched allocation.

Example:

$ ./testfixture ../sqlite/test/select1.test 2> memtrace.out
$ tclsh $argv0 ./testfixture memtrace.out
"

# If stack traces are enabled, the 'addr2line' program is called to
# translate a binary stack address into a human-readable form.
set addr2line addr2line

if { [llength $argv]!=2 } {
  puts "Usage: $argv0 <binary file> <mem trace file>"
  puts ""
  puts [string trim $doco]
  exit -1
}


proc process_input {input_file array_name} {
  upvar $array_name mem 
  set input [open $input_file]

  set MALLOC {([[:digit:]]+) malloc ([[:digit:]]+) bytes at 0x([[:xdigit:]]+)}
  set STACK {^STACK: (.*)$}
  set FREE {[[:digit:]]+ free ([[:digit:]]+) bytes at 0x([[:xdigit:]]+)}
  set REALLOC {([[:digit:]]+) realloc ([[:digit:]]+) to ([[:digit:]]+)}
  append REALLOC { bytes at 0x([[:xdigit:]]+) to 0x([[:xdigit:]]+)}

  set stack ""
  while { ![eof $input] } {
    set line [gets $input]
    if {[regexp $STACK $line dummy stack]} {
      # Do nothing. The variable $stack now stores the hexadecimal stack dump
      # for the next malloc() or realloc().

    } elseif { [regexp $MALLOC $line dummy mallocid bytes addr]  } {
      # If this is a 'malloc' line, set an entry in the mem array. Each entry
      # is a list of length three, the number of bytes allocated , the malloc
      # number and the stack dump when it was allocated.
      set mem($addr) [list $bytes "malloc $mallocid" $stack]
      set stack ""

    } elseif { [regexp $FREE $line dummy bytes addr] } {
      # If this is a 'free' line, remove the entry from the mem array. If the 
      # entry does not exist, or is the wrong number of bytes, announce a
      # problem. This is more likely a bug in the regular expressions for
      # this script than an SQLite defect.
      if { [lindex $mem($addr) 0] != $bytes } {
        error "byte count mismatch"
      }
      unset mem($addr) 

    } elseif { [regexp $REALLOC $line dummy mallocid ob b oa a] } {
      # If it is a realloc line, remove the old mem entry and add a new one.
      unset mem($oa);
      set mem($a) [list $b "realloc $mallocid" $stack]
      set stack ""
    } else {
      # puts "REJECT: $line"
    }
  }

  close $input
}

process_input [lindex $argv 1] mem
set exe [lindex $argv 0]

foreach key [array names mem] {
  set bytes [lindex $mem($key) 0]
  set mallocid [lindex $mem($key) 1]
  set stack [lindex $mem($key) 2]
  puts "Leaked $bytes bytes at 0x$key: $mallocid"
  foreach frame [lrange $stack 1 10] {
    foreach {f l} [split [exec $addr2line -f --exe=$exe $frame] \n] {}
    puts [format "%-30s %s" $f $l]
  }
  if {[llength $stack]>0 } {puts ""}
}