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Overview
Comment:Fix a race condition in the sorter code.
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SHA1: 2d2edfe58db101d42a96772b856e6e55b401aab6
User & Date: dan 2014-05-05 15:58:40.542
Context
2014-05-05
20:03
Add test file sort4.test, containing brute force tests for the multi-theaded sorter. (check-in: 9cc364c42c user: dan tags: threads)
15:58
Fix a race condition in the sorter code. (check-in: 2d2edfe58d user: dan tags: threads)
09:08
Add tests so that the "coverage-sorter" test permutation covers all branches in vdbesort.c. Fix a few minor problems in the same file. (check-in: bde28b702d user: dan tags: threads)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/vdbesort.c.
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/*
** Join all outstanding threads launched by SorterWrite() to create 
** level-0 PMAs.
*/
static int vdbeSorterJoinAll(VdbeSorter *pSorter, int rcin){
  int rc = rcin;
  int i;








  for(i=0; i<pSorter->nTask; i++){
    SortSubtask *pTask = &pSorter->aTask[i];
    int rc2 = vdbeSorterJoinThread(pTask);
    if( rc==SQLITE_OK ) rc = rc2;
  }
  return rc;
}
#else








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/*
** Join all outstanding threads launched by SorterWrite() to create 
** level-0 PMAs.
*/
static int vdbeSorterJoinAll(VdbeSorter *pSorter, int rcin){
  int rc = rcin;
  int i;

  /* This function is always called by the main user thread.
  **
  ** If this function is being called after SorterRewind() has been called, 
  ** it is possible that thread pSorter->aTask[pSorter->nTask-1].pThread
  ** is currently attempt to join one of the other threads. To avoid a race
  ** condition where this thread also attempts to join the same object, join 
  ** thread pSorter->aTask[pSorter->nTask-1].pThread first. */
  for(i=pSorter->nTask-1; i>=0; i--){
    SortSubtask *pTask = &pSorter->aTask[i];
    int rc2 = vdbeSorterJoinThread(pTask);
    if( rc==SQLITE_OK ) rc = rc2;
  }
  return rc;
}
#else
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