#define INCRINIT_TASK 1
#define INCRINIT_ROOT 2
-/* Forward reference.
-** The vdbeIncrMergeInit() and vdbePmaReaderIncrMergeInit() routines call each
-** other (when building a merge tree).
+/*
+** Forward reference required as the vdbeIncrMergeInit() and
+** vdbePmaReaderIncrInit() routines are called mutually recursively when
+** building a merge tree.
*/
-static int vdbePmaReaderIncrMergeInit(PmaReader *pReadr, int eMode);
+static int vdbePmaReaderIncrInit(PmaReader *pReadr, int eMode);
/*
** Initialize the MergeEngine object passed as the second argument. Once this
** better advantage of multi-processor hardware. */
rc = vdbePmaReaderNext(&pMerger->aReadr[nTree-i-1]);
}else{
- rc = vdbePmaReaderIncrMergeInit(&pMerger->aReadr[i], INCRINIT_NORMAL);
+ rc = vdbePmaReaderIncrInit(&pMerger->aReadr[i], INCRINIT_NORMAL);
}
if( rc!=SQLITE_OK ) return rc;
}
}
/*
-** Initialize the IncrMerge field of a PmaReader.
-**
-** If the PmaReader passed as the first argument is not an incremental-reader
-** (if pReadr->pIncr==0), then this function is a no-op. Otherwise, it serves
-** to open and/or initialize the temp file related fields of the IncrMerge
+** The PmaReader passed as the first argument is guaranteed to be an
+** incremental-reader (pReadr->pIncr!=0). This function serves to open
+** and/or initialize the temp file related fields of the IncrMerge
** object at (pReadr->pIncr).
**
** If argument eMode is set to INCRINIT_NORMAL, then all PmaReaders
-** in the sub-tree headed by pReadr are also initialized. Data is then loaded
-** into the buffers belonging to pReadr and it is set to
-** point to the first key in its range.
+** in the sub-tree headed by pReadr are also initialized. Data is then
+** loaded into the buffers belonging to pReadr and it is set to point to
+** the first key in its range.
**
** If argument eMode is set to INCRINIT_TASK, then pReadr is guaranteed
** to be a multi-threaded PmaReader and this function is being called in a
static int vdbePmaReaderIncrMergeInit(PmaReader *pReadr, int eMode){
int rc = SQLITE_OK;
IncrMerger *pIncr = pReadr->pIncr;
+ SortSubtask *pTask = pIncr->pTask;
+ sqlite3 *db = pTask->pSorter->db;
/* eMode is always INCRINIT_NORMAL in single-threaded mode */
assert( SQLITE_MAX_WORKER_THREADS>0 || eMode==INCRINIT_NORMAL );
- if( pIncr ){
- SortSubtask *pTask = pIncr->pTask;
- sqlite3 *db = pTask->pSorter->db;
+ rc = vdbeMergeEngineInit(pTask, pIncr->pMerger, eMode);
- rc = vdbeMergeEngineInit(pTask, pIncr->pMerger, eMode);
-
- /* Set up the required files for pIncr. A multi-theaded IncrMerge object
- ** requires two temp files to itself, whereas a single-threaded object
- ** only requires a region of pTask->file2. */
- if( rc==SQLITE_OK ){
- int mxSz = pIncr->mxSz;
+ /* Set up the required files for pIncr. A multi-theaded IncrMerge object
+ ** requires two temp files to itself, whereas a single-threaded object
+ ** only requires a region of pTask->file2. */
+ if( rc==SQLITE_OK ){
+ int mxSz = pIncr->mxSz;
#if SQLITE_MAX_WORKER_THREADS>0
- if( pIncr->bUseThread ){
- rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[0].pFd);
- if( rc==SQLITE_OK ){
- rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[1].pFd);
- }
- }else
+ if( pIncr->bUseThread ){
+ rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[0].pFd);
+ if( rc==SQLITE_OK ){
+ rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[1].pFd);
+ }
+ }else
#endif
- /*if( !pIncr->bUseThread )*/{
- if( pTask->file2.pFd==0 ){
- assert( pTask->file2.iEof>0 );
- rc = vdbeSorterOpenTempFile(db, pTask->file2.iEof, &pTask->file2.pFd);
- pTask->file2.iEof = 0;
- }
- if( rc==SQLITE_OK ){
- pIncr->aFile[1].pFd = pTask->file2.pFd;
- pIncr->iStartOff = pTask->file2.iEof;
- pTask->file2.iEof += mxSz;
- }
+ /*if( !pIncr->bUseThread )*/{
+ if( pTask->file2.pFd==0 ){
+ assert( pTask->file2.iEof>0 );
+ rc = vdbeSorterOpenTempFile(db, pTask->file2.iEof, &pTask->file2.pFd);
+ pTask->file2.iEof = 0;
+ }
+ if( rc==SQLITE_OK ){
+ pIncr->aFile[1].pFd = pTask->file2.pFd;
+ pIncr->iStartOff = pTask->file2.iEof;
+ pTask->file2.iEof += mxSz;
}
}
+ }
#if SQLITE_MAX_WORKER_THREADS>0
- if( rc==SQLITE_OK && pIncr->bUseThread ){
- /* Use the current thread to populate aFile[1], even though this
- ** PmaReader is multi-threaded. The reason being that this function
- ** is already running in background thread pIncr->pTask->thread. */
- assert( eMode==INCRINIT_ROOT || eMode==INCRINIT_TASK );
- rc = vdbeIncrPopulate(pIncr);
- }
+ if( rc==SQLITE_OK && pIncr->bUseThread ){
+ /* Use the current thread to populate aFile[1], even though this
+ ** PmaReader is multi-threaded. If this is an INCRINIT_TASK object,
+ ** then this function is already running in background thread
+ ** pIncr->pTask->thread.
+ **
+ ** If this is the INCRINIT_ROOT object, then it is running in the
+ ** main VDBE thread. But that is Ok, as that thread cannot return
+ ** control to the VDBE or proceed with anything useful until the
+ ** first results are ready from this merger object anyway.
+ */
+ assert( eMode==INCRINIT_ROOT || eMode==INCRINIT_TASK );
+ rc = vdbeIncrPopulate(pIncr);
+ }
#endif
- if( rc==SQLITE_OK
- && (SQLITE_MAX_WORKER_THREADS==0 || eMode!=INCRINIT_TASK)
- ){
- rc = vdbePmaReaderNext(pReadr);
- }
+ if( rc==SQLITE_OK && (SQLITE_MAX_WORKER_THREADS==0 || eMode!=INCRINIT_TASK) ){
+ rc = vdbePmaReaderNext(pReadr);
}
+
return rc;
}
** The main routine for vdbePmaReaderIncrMergeInit() operations run in
** background threads.
*/
-static void *vdbePmaReaderBgInit(void *pCtx){
+static void *vdbePmaReaderBgIncrInit(void *pCtx){
PmaReader *pReader = (PmaReader*)pCtx;
void *pRet = SQLITE_INT_TO_PTR(
vdbePmaReaderIncrMergeInit(pReader,INCRINIT_TASK)
pReader->pIncr->pTask->bDone = 1;
return pRet;
}
+#endif
/*
-** Use a background thread to invoke vdbePmaReaderIncrMergeInit(INCRINIT_TASK)
-** on the PmaReader object passed as the first argument.
-**
-** This call will initialize the various fields of the pReadr->pIncr
-** structure and, if it is a multi-threaded IncrMerger, launch a
-** background thread to populate aFile[1].
-*/
-static int vdbePmaReaderBgIncrInit(PmaReader *pReadr){
- void *pCtx = (void*)pReadr;
- return vdbeSorterCreateThread(pReadr->pIncr->pTask, vdbePmaReaderBgInit, pCtx);
-}
+** If the PmaReader passed as the first argument is not an incremental-reader
+** (if pReadr->pIncr==0), then this function is a no-op. Otherwise, it invokes
+** the vdbePmaReaderIncrMergeInit() function with the parameters passed to
+** this routine to initialize the incremental merge.
+**
+** If the IncrMerger object is multi-threaded (IncrMerger.bUseThread==1),
+** then a background thread is launched to call vdbePmaReaderIncrMergeInit().
+** Or, if the IncrMerger is single threaded, the same function is called
+** using the current thread.
+*/
+static int vdbePmaReaderIncrInit(PmaReader *pReadr, int eMode){
+ IncrMerger *pIncr = pReadr->pIncr; /* Incremental merger */
+ int rc = SQLITE_OK; /* Return code */
+ if( pIncr ){
+#if SQLITE_MAX_WORKER_THREADS>0
+ assert( pIncr->bUseThread==0 || eMode==INCRINIT_TASK );
+ if( pIncr->bUseThread ){
+ void *pCtx = (void*)pReadr;
+ rc = vdbeSorterCreateThread(pIncr->pTask, vdbePmaReaderBgIncrInit, pCtx);
+ }else
#endif
+ {
+ rc = vdbePmaReaderIncrMergeInit(pReadr, eMode);
+ }
+ }
+ return rc;
+}
/*
** Allocate a new MergeEngine object to merge the contents of nPMA level-0
}
}
for(iTask=0; rc==SQLITE_OK && iTask<pSorter->nTask; iTask++){
+ /* Check that:
+ **
+ ** a) The incremental merge object is configured to use the
+ ** right task, and
+ ** b) If it is using task (nTask-1), it is configured to run
+ ** in single-threaded mode. This is important, as the
+ ** root merge (INCRINIT_ROOT) will be using the same task
+ ** object.
+ */
PmaReader *p = &pMain->aReadr[iTask];
- assert( p->pIncr==0 || p->pIncr->pTask==&pSorter->aTask[iTask] );
- if( p->pIncr ){
- if( iTask==pSorter->nTask-1 ){
- rc = vdbePmaReaderIncrMergeInit(p, INCRINIT_TASK);
- }else{
- rc = vdbePmaReaderBgIncrInit(p);
- }
- }
+ assert( p->pIncr==0 || (
+ (p->pIncr->pTask==&pSorter->aTask[iTask]) /* a */
+ && (iTask!=pSorter->nTask-1 || p->pIncr->bUseThread==0) /* b */
+ ));
+ rc = vdbePmaReaderIncrInit(p, INCRINIT_TASK);
}
}
pMain = 0;
projects / thirdparty / sqlite.git / commitdiff
