Index: src/vdbesort.c ================================================================== --- src/vdbesort.c +++ src/vdbesort.c @@ -2061,15 +2061,16 @@ */ #define INCRINIT_NORMAL 0 #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 ** function returns, the first key of merged data may be read from the ** MergeEngine object in the usual fashion. @@ -2112,11 +2113,11 @@ ** the main thread to fill its buffer. So calling PmaReaderNext() ** on this PmaReader before any of the multi-threaded PmaReaders takes ** 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; } for(i=pMerger->nTree-1; i>0; i--){ @@ -2124,21 +2125,19 @@ } return pTask->pUnpacked->errCode; } /* -** 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 ** background thread. In this case all PmaReaders in the sub-tree are ** initialized as for INCRINIT_NORMAL and the aFile[1] buffer belonging to @@ -2161,93 +2160,112 @@ ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. */ 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; } #if SQLITE_MAX_WORKER_THREADS>0 /* ** 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]. +** 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 vdbePmaReaderBgIncrInit(PmaReader *pReadr){ - void *pCtx = (void*)pReadr; - return vdbeSorterCreateThread(pReadr->pIncr->pTask, vdbePmaReaderBgInit, pCtx); -} +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 ** PMAs from pTask->file. If no error occurs, set *ppOut to point to ** the new object and return SQLITE_OK. Or, if an error does occur, set *ppOut @@ -2488,19 +2506,25 @@ vdbeIncrMergerSetThreads(pIncr); assert( pIncr->pTask!=pLast ); } } for(iTask=0; rc==SQLITE_OK && iTasknTask; 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; } if( rc==SQLITE_OK ){