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Overview
Comment: | Reinstate the asynchronous I/O demonstration code and tests with minor changes. (CVS 2896) |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
eeebc640aaeeb0ab7f730d854069f159 |
User & Date: | drh 2006-01-09 17:29:53.000 |
Context
2006-01-09
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23:40 | Added database server example code (untested). Fixed serveral bugs including the autovacuum compile problem described by ticket #1593. (CVS 2897) (check-in: ec332d8822 user: drh tags: trunk) | |
17:29 | Reinstate the asynchronous I/O demonstration code and tests with minor changes. (CVS 2896) (check-in: eeebc640aa user: drh tags: trunk) | |
16:12 | Fix some errors to do with attached databases and text encodings in shared-cache mode. (CVS 2895) (check-in: 3e75d3d5ef user: danielk1977 tags: trunk) | |
Changes
Changes to main.mk.
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129 130 131 132 133 134 135 136 137 138 139 140 141 142 | $(TOP)/src/printf.c \ $(TOP)/src/test1.c \ $(TOP)/src/test2.c \ $(TOP)/src/test3.c \ $(TOP)/src/test4.c \ $(TOP)/src/test5.c \ $(TOP)/src/test6.c \ $(TOP)/src/utf.c \ $(TOP)/src/util.c \ $(TOP)/src/vdbe.c \ $(TOP)/src/md5.c \ $(TOP)/src/where.c # Header files used by all library source files. | > | 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 | $(TOP)/src/printf.c \ $(TOP)/src/test1.c \ $(TOP)/src/test2.c \ $(TOP)/src/test3.c \ $(TOP)/src/test4.c \ $(TOP)/src/test5.c \ $(TOP)/src/test6.c \ $(TOP)/src/test_async.c \ $(TOP)/src/utf.c \ $(TOP)/src/util.c \ $(TOP)/src/vdbe.c \ $(TOP)/src/md5.c \ $(TOP)/src/where.c # Header files used by all library source files. |
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Changes to src/tclsqlite.c.
1 2 3 4 5 6 7 8 9 10 11 12 13 | /* ** 2001 September 15 ** ** 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. ** ************************************************************************* ** A TCL Interface to SQLite ** | | | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | /* ** 2001 September 15 ** ** 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. ** ************************************************************************* ** A TCL Interface to SQLite ** ** $Id: tclsqlite.c,v 1.148 2006/01/09 17:29:53 drh Exp $ */ #ifndef NO_TCL /* Omit this whole file if TCL is unavailable */ #include "sqliteInt.h" #include "hash.h" #include "tcl.h" #include <stdlib.h> |
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2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 | extern int Sqlitetest2_Init(Tcl_Interp*); extern int Sqlitetest3_Init(Tcl_Interp*); extern int Sqlitetest4_Init(Tcl_Interp*); extern int Sqlitetest5_Init(Tcl_Interp*); extern int Sqlitetest6_Init(Tcl_Interp*); extern int Md5_Init(Tcl_Interp*); extern int Sqlitetestsse_Init(Tcl_Interp*); Sqlitetest1_Init(interp); Sqlitetest2_Init(interp); Sqlitetest3_Init(interp); Sqlitetest4_Init(interp); Sqlitetest5_Init(interp); Sqlitetest6_Init(interp); Md5_Init(interp); #ifdef SQLITE_SSE Sqlitetestsse_Init(interp); #endif } #endif if( argc>=2 || TCLSH==2 ){ | > > | 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 | extern int Sqlitetest2_Init(Tcl_Interp*); extern int Sqlitetest3_Init(Tcl_Interp*); extern int Sqlitetest4_Init(Tcl_Interp*); extern int Sqlitetest5_Init(Tcl_Interp*); extern int Sqlitetest6_Init(Tcl_Interp*); extern int Md5_Init(Tcl_Interp*); extern int Sqlitetestsse_Init(Tcl_Interp*); extern int Sqlitetestasync_Init(Tcl_Interp*); Sqlitetest1_Init(interp); Sqlitetest2_Init(interp); Sqlitetest3_Init(interp); Sqlitetest4_Init(interp); Sqlitetest5_Init(interp); Sqlitetest6_Init(interp); Sqlitetestasync_Init(interp); Md5_Init(interp); #ifdef SQLITE_SSE Sqlitetestsse_Init(interp); #endif } #endif if( argc>=2 || TCLSH==2 ){ |
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Added src/test_async.c.
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1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 | /* ** 2005 December 14 ** ** 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 contains an example implementation of an asynchronous IO ** backend for SQLite. It is used to test that the concept of asynchronous ** IO in SQLite is valid. */ #include "sqliteInt.h" #include "os.h" #include <tcl.h> #ifndef THREADSAFE # define THREADSAFE 0 #endif /* ** This test uses pthreads and hence only works on unix and with ** a threadsafe build of SQLite. */ #if OS_UNIX && THREADSAFE && defined(SQLITE_ENABLE_REDEF_IO) #include <pthread.h> #include <sched.h> #define MIN(x,y) ((x)<(y)?(x):(y)) #define MAX(x,y) ((x)>(y)?(x):(y)) typedef struct AsyncWrite AsyncWrite; typedef struct AsyncFile AsyncFile; #if 0 # define TRACE(X,Y) \ fprintf(stderr,"THRD=%d: ", (int)pthread_self()); \ fprintf(stderr,X,Y); #else # define TRACE(X,Y) /* noop */ #endif /* ** TODO: ** * File locks... */ /* ** THREAD SAFETY NOTES ** ** Basic rules: ** ** * Both read and write access to the global write-op queue must be ** protected by the async.queueMutex. ** ** * The file handles from the underlying system are assumed not to ** be thread safe. ** ** * See the last paragraph under "sqlite3_async_flush() Threads" for ** an assumption to do with file-handle synchronization by the Os. ** ** File system operations (invoked by SQLite thread): ** ** xOpenXXX (three versions) ** xDelete ** xFileExists ** xSyncDirectory ** ** File handle operations (invoked by SQLite thread): ** ** The following operations add an entry to the global write-op list. They ** prepare the entry, acquire the mutex momentarily while list pointers are ** manipulated to insert the new entry, and release the mutex. ** ** asyncWrite, asyncClose, asyncTruncate, asyncSync, ** asyncSetFullSync, asyncOpenDirectory. ** ** Read operations. Both of these read from both the underlying file and ** the write-op list. So we grab the mutex for the whole call (even ** while performing a blocking read on the file). ** ** asyncRead, asyncFileSize. ** ** These locking primitives become no-ops. Files are always opened for ** exclusive access when using this IO backend: ** ** asyncLock, asyncUnlock, asyncLockState, asyncCheckReservedLock ** ** The sqlite3OsFileHandle() function is currently only used when ** debugging the pager module. Unless sqlite3OsClose() is called on the ** file (shouldn't be possible for other reasons), the underlying ** implementations are safe to call without grabbing any mutex. So we just ** go ahead and call it no matter what any other thread is doing. ** ** asyncFileHandle. ** ** Calling this method just manipulates the AsyncFile.iOffset variable. ** Since this variable is never accessed by writer thread, this ** function does not require the mutex. Actual calls to OsSeek() take ** place just before OsWrite() or OsRead(), which are always protected by ** the mutex. ** ** asyncSeek. ** ** The writer thread: ** ** The async.writerMutex is used to make sure only there is only ** a single writer thread running at a time. ** ** Inside the writer thread is a loop that works like this: ** ** WHILE (write-op list is not empty) ** Do IO operation at head of write-op list ** Remove entry from head of write-op list ** END WHILE ** ** The async.queueMutex is always held during the <write-op list is ** not empty> test, and when the entry is removed from the head ** of the write-op list. Sometimes it is held for the interim ** period (while the IO is performed), and sometimes it is ** relinquished. It is relinquished if (a) the IO op is an ** ASYNC_CLOSE or (b) when the file handle was opened, two of ** the underlying systems handles were opened on the same ** file-system entry. ** ** If condition (b) above is true, then one file-handle ** (AsyncFile.pBaseRead) is used exclusively by sqlite threads to read the ** file, the other (AsyncFile.pBaseWrite) by sqlite3_async_flush() ** threads to perform write() operations. This means that read ** operations are not blocked by asynchronous writes (although ** asynchronous writes may still be blocked by reads). ** ** This assumes that the OS keeps two handles open on the same file ** properly in sync. That is, any read operation that starts after a ** write operation on the same file system entry has completed returns ** data consistent with the write. We also assume that if one thread ** reads a file while another is writing it all bytes other than the ** ones actually being written contain valid data. ** ** If the above assumptions are not true, set the preprocessor symbol ** SQLITE_ASYNC_TWO_FILEHANDLES to 0. */ #ifndef SQLITE_ASYNC_TWO_FILEHANDLES /* #define SQLITE_ASYNC_TWO_FILEHANDLES 0 */ #define SQLITE_ASYNC_TWO_FILEHANDLES 1 #endif /* ** State information is held in the static variable "async" defined ** as follows: */ static struct TestAsyncStaticData { pthread_mutex_t queueMutex; /* Mutex for access to write operation queue */ pthread_mutex_t writerMutex; /* Prevents multiple writer threads */ pthread_cond_t queueSignal; /* For waking up sleeping writer thread */ pthread_cond_t emptySignal; /* Notify when the write queue is empty */ AsyncWrite *pQueueFirst; /* Next write operation to be processed */ AsyncWrite *pQueueLast; /* Last write operation on the list */ volatile int ioDelay; /* Extra delay between write operations */ volatile int writerHaltWhenIdle; /* Writer thread halts when queue empty */ volatile int writerHaltNow; /* Writer thread halts after next op */ } async = { PTHREAD_MUTEX_INITIALIZER, PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, PTHREAD_COND_INITIALIZER, }; /* Possible values of AsyncWrite.op */ #define ASYNC_WRITE 1 #define ASYNC_SYNC 2 #define ASYNC_TRUNCATE 3 #define ASYNC_CLOSE 4 #define ASYNC_OPENDIRECTORY 5 #define ASYNC_SETFULLSYNC 6 #define ASYNC_DELETE 7 #define ASYNC_OPENEXCLUSIVE 8 #define ASYNC_SYNCDIRECTORY 9 /* ** The interpretation of the iOffset and nByte variables varies depending ** on the value of AsyncWrite.op: ** ** ASYNC_WRITE: ** iOffset -> Offset in file to write to. ** nByte -> Number of bytes of data to write (pointed to by zBuf). ** ** ASYNC_SYNC: ** iOffset -> Unused. ** nByte -> Value of "fullsync" flag to pass to sqlite3OsSync(). ** ** ASYNC_TRUNCATE: ** iOffset -> Size to truncate file to. ** nByte -> Unused. ** ** ASYNC_CLOSE: ** iOffset -> Unused. ** nByte -> Unused. ** ** ASYNC_OPENDIRECTORY: ** iOffset -> Unused. ** nByte -> Number of bytes of zBuf points to (directory name). ** ** ASYNC_SETFULLSYNC: ** iOffset -> Unused. ** nByte -> New value for the full-sync flag. ** ** ** ASYNC_DELETE: ** iOffset -> Unused. ** nByte -> Number of bytes of zBuf points to (file name). ** ** ASYNC_OPENEXCLUSIVE: ** iOffset -> Value of "delflag". ** nByte -> Number of bytes of zBuf points to (file name). ** ** For an ASYNC_WRITE operation, zBuf points to the data to write to the file. ** This space is sqliteMalloc()d along with the AsyncWrite structure in a ** single blob, so is deleted when sqliteFree() is called on the parent ** structure. */ struct AsyncWrite { AsyncFile *pFile; /* File to write data to or sync */ int op; /* One of ASYNC_xxx etc. */ i64 iOffset; /* See above */ int nByte; /* See above */ char *zBuf; /* Data to write to file (or NULL if op!=ASYNC_WRITE) */ AsyncWrite *pNext; /* Next write operation (to any file) */ }; /* ** The AsyncFile structure is a subclass of OsFile used for asynchronous IO. */ struct AsyncFile { IoMethod *pMethod; /* Must be first */ i64 iOffset; /* Current seek() offset in file */ OsFile *pBaseRead; /* Read handle to the underlying Os file */ OsFile *pBaseWrite; /* Write handle to the underlying Os file */ }; /* ** Add an entry to the end of the global write-op list. pWrite should point ** to an AsyncWrite structure allocated using sqliteMalloc(). A future call ** to sqlite3_async_flush() is responsible for calling sqliteFree(). ** ** Once an AsyncWrite structure has been added to the list, it must not be ** read or modified by the caller (in case another thread calls ** sqlite3_async_flush() ). */ static void addAsyncWrite(AsyncWrite *pWrite){ pthread_mutex_lock(&async.queueMutex); assert( !pWrite->pNext ); if( async.pQueueLast ){ assert( async.pQueueFirst ); async.pQueueLast->pNext = pWrite; }else{ async.pQueueFirst = pWrite; } async.pQueueLast = pWrite; TRACE("PUSH %p\n", pWrite); pthread_mutex_unlock(&async.queueMutex); pthread_cond_signal(&async.queueSignal); } /* ** This is a utility function to allocate and populate a new AsyncWrite ** structure and insert it (via addAsyncWrite() ) into the global list. */ static int addNewAsyncWrite( AsyncFile *pFile, int op, i64 iOffset, int nByte, const char *zByte ){ AsyncWrite *p = sqlite3OsMalloc(sizeof(AsyncWrite) + (zByte?nByte:0)); if( !p ){ return SQLITE_NOMEM; } p->op = op; p->iOffset = iOffset; p->nByte = nByte; p->pFile = pFile; p->pNext = 0; if( zByte ){ p->zBuf = (char *)&p[1]; memcpy(p->zBuf, zByte, nByte); }else{ p->zBuf = 0; } addAsyncWrite(p); return SQLITE_OK; } /* ** Close the file. This just adds an entry to the write-op list, the file is ** not actually closed. */ static int asyncClose(OsFile **pId){ return addNewAsyncWrite((AsyncFile *)*pId, ASYNC_CLOSE, 0, 0, 0); } /* ** Implementation of sqlite3OsWrite() for asynchronous files. Instead of ** writing to the underlying file, this function adds an entry to the end of ** the global AsyncWrite list. Either SQLITE_OK or SQLITE_NOMEM may be ** returned. */ static int asyncWrite(OsFile *id, const void *pBuf, int amt){ AsyncFile *pFile = (AsyncFile *)id; int rc = addNewAsyncWrite(pFile, ASYNC_WRITE, pFile->iOffset, amt, pBuf); pFile->iOffset += (i64)amt; return rc; } /* ** Truncate the file to nByte bytes in length. This just adds an entry to ** the write-op list, no IO actually takes place. */ static int asyncTruncate(OsFile *id, i64 nByte){ return addNewAsyncWrite((AsyncFile *)id, ASYNC_TRUNCATE, nByte, 0, 0); } /* ** Open the directory identified by zName and associate it with the ** specified file. This just adds an entry to the write-op list, the ** directory is opened later by sqlite3_async_flush(). */ static int asyncOpenDirectory(OsFile *id, const char *zName){ AsyncFile *pFile = (AsyncFile *)id; return addNewAsyncWrite(pFile, ASYNC_OPENDIRECTORY, 0, strlen(zName)+1,zName); } /* ** Sync the file. This just adds an entry to the write-op list, the ** sync() is done later by sqlite3_async_flush(). */ static int asyncSync(OsFile *id, int fullsync){ return addNewAsyncWrite((AsyncFile *)id, ASYNC_SYNC, 0, fullsync, 0); } /* ** Set (or clear) the full-sync flag on the underlying file. This operation ** is queued and performed later by sqlite3_async_flush(). */ static void asyncSetFullSync(OsFile *id, int value){ addNewAsyncWrite((AsyncFile *)id, ASYNC_SETFULLSYNC, 0, value, 0); } /* ** Read data from the file. First we read from the filesystem, then adjust ** the contents of the buffer based on ASYNC_WRITE operations in the ** write-op queue. Todo: Do we need to think about ASYNC_TRUNCATE in ** this method as well? ** ** This method holds the mutex from start to finish. */ static int asyncRead(OsFile *id, void *obuf, int amt){ int rc = SQLITE_OK; i64 filesize; int nRead; AsyncFile *pFile = (AsyncFile *)id; /* Grab the write queue mutex for the duration of the call */ pthread_mutex_lock(&async.queueMutex); if( pFile->pBaseRead ){ rc = sqlite3OsFileSize(pFile->pBaseRead, &filesize); if( rc!=SQLITE_OK ){ goto asyncread_out; } rc = sqlite3OsSeek(pFile->pBaseRead, pFile->iOffset); if( rc!=SQLITE_OK ){ goto asyncread_out; } nRead = MIN(filesize - pFile->iOffset, amt); if( nRead>0 ){ rc = sqlite3OsRead(((AsyncFile *)id)->pBaseRead, obuf, nRead); } } if( rc==SQLITE_OK ){ AsyncWrite *p; i64 iOffset = pFile->iOffset; /* Current seek offset */ for(p=async.pQueueFirst; p; p = p->pNext){ if( p->pFile==pFile && p->op==ASYNC_WRITE ){ int iBeginIn = (p->iOffset - iOffset); int iBeginOut = (iOffset - p->iOffset); int nCopy; if( iBeginIn<0 ) iBeginIn = 0; if( iBeginOut<0 ) iBeginOut = 0; nCopy = MIN(p->nByte-iBeginIn, amt-iBeginOut); if( nCopy>0 ){ memcpy(&((char *)obuf)[iBeginOut], &p->zBuf[iBeginIn], nCopy); } } } pFile->iOffset += (i64)amt; } asyncread_out: pthread_mutex_unlock(&async.queueMutex); return rc; } /* ** Seek to the specified offset. This just adjusts the AsyncFile.iOffset ** variable - calling seek() on the underlying file is defered until the ** next read() or write() operation. */ static int asyncSeek(OsFile *id, i64 offset){ AsyncFile *pFile = (AsyncFile *)id; pFile->iOffset = offset; return SQLITE_OK; } /* ** Read the size of the file. First we read the size of the file system ** entry, then adjust for any ASYNC_WRITE or ASYNC_TRUNCATE operations ** currently in the write-op list. ** ** This method holds the mutex from start to finish. */ int asyncFileSize(OsFile *id, i64 *pSize){ int rc = SQLITE_OK; i64 s = 0; OsFile *pBase; pthread_mutex_lock(&async.queueMutex); /* Read the filesystem size from the base file. If pBaseRead is NULL, this ** means the file hasn't been opened yet. In this case all relevant data ** must be in the write-op queue anyway, so we can omit reading from the ** file-system. */ pBase = ((AsyncFile *)id)->pBaseRead; if( pBase ){ rc = sqlite3OsFileSize(pBase, &s); } if( rc==SQLITE_OK ){ AsyncWrite *p; for(p=async.pQueueFirst; p; p = p->pNext){ if( p->pFile==(AsyncFile *)id ){ switch( p->op ){ case ASYNC_WRITE: s = MAX(p->iOffset + (i64)(p->nByte), s); break; case ASYNC_TRUNCATE: s = MIN(s, p->nByte); break; } } } *pSize = s; } pthread_mutex_unlock(&async.queueMutex); return rc; } /* ** Return the operating system file handle. This is only used for debugging ** at the moment anyway. */ static int asyncFileHandle(OsFile *id){ return sqlite3OsFileHandle(((AsyncFile *)id)->pBaseRead); } static int asyncLock(OsFile *id, int lockType){ return SQLITE_OK; } static int asyncUnlock(OsFile *id, int lockType){ return SQLITE_OK; } /* ** This function is called when the pager layer first opens a database file ** and is checking for a hot-journal. */ static int asyncCheckReservedLock(OsFile *id){ return SQLITE_OK; } /* ** This is broken. But sqlite3OsLockState() is only used for testing anyway. */ static int asyncLockState(OsFile *id){ return SQLITE_OK; } /* ** The following variables hold pointers to the original versions of ** certain OS-layer interface routines - routines that this module ** overrides. */ static int (*xOrigOpenReadWrite)(const char*, OsFile**, int*) = 0; static int (*xOrigOpenExclusive)(const char*, OsFile**, int) = 0; static int (*xOrigOpenReadOnly)(const char*, OsFile**) = 0; static int (*xOrigDelete)(const char*) = 0; static int (*xOrigFileExists)(const char*) = 0; static int (*xOrigSyncDirectory)(const char*) = 0; static int asyncOpenFile( const char *zName, OsFile **pFile, OsFile *pBaseRead, int openSecondFile ){ int rc; AsyncFile *p; OsFile *pBaseWrite = 0; static IoMethod iomethod = { asyncClose, asyncOpenDirectory, asyncRead, asyncWrite, asyncSeek, asyncTruncate, asyncSync, asyncSetFullSync, asyncFileHandle, asyncFileSize, asyncLock, asyncUnlock, asyncLockState, asyncCheckReservedLock }; if( openSecondFile && SQLITE_ASYNC_TWO_FILEHANDLES ){ int dummy; rc = xOrigOpenReadWrite(zName, &pBaseWrite, &dummy); if( rc!=SQLITE_OK ){ goto error_out; } } p = (AsyncFile *)sqlite3OsMalloc(sizeof(AsyncFile)); if( !p ){ rc = SQLITE_NOMEM; goto error_out; } memset(p, 0, sizeof(AsyncFile)); p->pMethod = &iomethod; p->pBaseRead = pBaseRead; p->pBaseWrite = pBaseWrite; *pFile = (OsFile *)p; return SQLITE_OK; error_out: assert(!p); sqlite3OsClose(&pBaseRead); sqlite3OsClose(&pBaseWrite); *pFile = 0; return rc; } /* ** The async-IO backends implementation of the three functions used to open ** a file (xOpenExclusive, xOpenReadWrite and xOpenReadOnly). Most of the ** work is done in function asyncOpenFile() - see above. */ static int asyncOpenExclusive(const char *z, OsFile **ppFile, int delFlag){ int rc = asyncOpenFile(z, ppFile, 0, 0); if( rc==SQLITE_OK ){ AsyncFile *pFile = (AsyncFile *)(*ppFile); int nByte = strlen(z)+1; i64 i = (i64)(delFlag); rc = addNewAsyncWrite(pFile, ASYNC_OPENEXCLUSIVE, i, nByte, z); if( rc!=SQLITE_OK ){ sqlite3OsFree(pFile); *ppFile = 0; } } return rc; } static int asyncOpenReadOnly(const char *z, OsFile **ppFile){ OsFile *pBase = 0; int rc = xOrigOpenReadOnly(z, &pBase); if( rc==SQLITE_OK ){ rc = asyncOpenFile(z, ppFile, pBase, 0); } return rc; } static int asyncOpenReadWrite(const char *z, OsFile **ppFile, int *pReadOnly){ OsFile *pBase = 0; int rc = xOrigOpenReadWrite(z, &pBase, pReadOnly); if( rc==SQLITE_OK ){ rc = asyncOpenFile(z, ppFile, pBase, (*pReadOnly ? 0 : 1)); } return rc; } /* ** Implementation of sqlite3OsDelete. Add an entry to the end of the ** write-op queue to perform the delete. */ static int asyncDelete(const char *z){ return addNewAsyncWrite(0, ASYNC_DELETE, 0, strlen(z)+1, z); } /* ** Implementation of sqlite3OsSyncDirectory. Add an entry to the end of the ** write-op queue to perform the directory sync. */ static int asyncSyncDirectory(const char *z){ return addNewAsyncWrite(0, ASYNC_SYNCDIRECTORY, 0, strlen(z)+1, z); } /* ** Implementation of sqlite3OsFileExists. Return true if file 'z' exists ** in the file system. ** ** This method holds the mutex from start to finish. */ static int asyncFileExists(const char *z){ int ret; AsyncWrite *p; pthread_mutex_lock(&async.queueMutex); /* See if the real file system contains the specified file. */ ret = xOrigFileExists(z); for(p=async.pQueueFirst; p; p = p->pNext){ if( p->op==ASYNC_DELETE && 0==strcmp(p->zBuf, z) ){ ret = 0; }else if( p->op==ASYNC_OPENEXCLUSIVE && 0==strcmp(p->zBuf, z) ){ ret = 1; } } pthread_mutex_unlock(&async.queueMutex); return ret; } /* ** Call this routine to enable or disable the ** asynchronous IO features implemented in this file. ** ** This routine is not even remotely threadsafe. Do not call ** this routine while any SQLite database connections are open. */ static void asyncEnable(int enable){ if( enable && xOrigOpenReadWrite==0 ){ xOrigOpenReadWrite = sqlite3Os.xOpenReadWrite; xOrigOpenReadOnly = sqlite3Os.xOpenReadOnly; xOrigOpenExclusive = sqlite3Os.xOpenExclusive; xOrigDelete = sqlite3Os.xDelete; xOrigFileExists = sqlite3Os.xFileExists; xOrigSyncDirectory = sqlite3Os.xSyncDirectory; sqlite3Os.xOpenReadWrite = asyncOpenReadWrite; sqlite3Os.xOpenReadOnly = asyncOpenReadOnly; sqlite3Os.xOpenExclusive = asyncOpenExclusive; sqlite3Os.xDelete = asyncDelete; sqlite3Os.xFileExists = asyncFileExists; sqlite3Os.xSyncDirectory = asyncSyncDirectory; } if( !enable && xOrigOpenReadWrite!=0 ){ sqlite3Os.xOpenReadWrite = xOrigOpenReadWrite; sqlite3Os.xOpenReadOnly = xOrigOpenReadOnly; sqlite3Os.xOpenExclusive = xOrigOpenExclusive; sqlite3Os.xDelete = xOrigDelete; sqlite3Os.xFileExists = xOrigFileExists; sqlite3Os.xSyncDirectory = xOrigSyncDirectory; xOrigOpenReadWrite = 0; xOrigOpenReadOnly = 0; xOrigOpenExclusive = 0; xOrigDelete = 0; xOrigFileExists = 0; xOrigSyncDirectory = 0; } } /* ** This procedure runs in a separate thread, reading messages off of the ** write queue and processing them one by one. ** ** If async.writerHaltNow is true, then this procedure exits ** after processing a single message. ** ** If async.writerHaltWhenIdle is true, then this procedure exits when ** the write queue is empty. ** ** If both of the above variables are false, this procedure runs ** indefinately, waiting for operations to be added to the write queue ** and processing them in the order in which they arrive. ** ** An artifical delay of async.ioDelay milliseconds is inserted before ** each write operation in order to simulate the effect of a slow disk. ** ** Only one instance of this procedure may be running at a time. */ static void *asyncWriterThread(void *NotUsed){ AsyncWrite *p = 0; int rc = SQLITE_OK; if( pthread_mutex_trylock(&async.writerMutex) ){ return 0; } while( async.writerHaltNow==0 ){ int holdingMutex; OsFile *pBase = 0; pthread_mutex_lock(&async.queueMutex); holdingMutex = 1; while( (p = async.pQueueFirst)==0 ){ pthread_cond_broadcast(&async.emptySignal); if( async.writerHaltWhenIdle ){ pthread_mutex_unlock(&async.queueMutex); break; }else{ TRACE("IDLE\n", 0); pthread_cond_wait(&async.queueSignal, &async.queueMutex); TRACE("WAKEUP\n", 0); } } if( p==0 ) break; TRACE("PROCESSING %p\n", p); /* Right now this thread is holding the mutex on the write-op queue. ** Variable 'p' points to the first entry in the write-op queue. In ** the general case, we hold on to the mutex for the entire body of ** the loop. ** ** However in the cases enumerated below, we relinquish the mutex, ** perform the IO, and then re-request the mutex before removing 'p' from ** the head of the write-op queue. The idea is to increase concurrency with ** sqlite threads. ** ** * An ASYNC_CLOSE operation. ** * An ASYNC_OPENEXCLUSIVE operation. For this one, we relinquish ** the mutex, call the underlying xOpenExclusive() function, then ** re-aquire the mutex before seting the AsyncFile.pBaseRead ** variable. ** * ASYNC_SYNC and ASYNC_WRITE operations, if ** SQLITE_ASYNC_TWO_FILEHANDLES was set at compile time and two ** file-handles are open for the particular file being "synced". */ if( p->pFile ){ pBase = p->pFile->pBaseWrite; if( p->op==ASYNC_CLOSE || p->op==ASYNC_OPENEXCLUSIVE || (pBase && (p->op==ASYNC_SYNC || p->op==ASYNC_WRITE) ) ){ pthread_mutex_unlock(&async.queueMutex); holdingMutex = 0; } if( !pBase ){ pBase = p->pFile->pBaseRead; } } switch( p->op ){ case ASYNC_WRITE: assert( pBase ); rc = sqlite3OsSeek(pBase, p->iOffset); if( rc==SQLITE_OK ){ rc = sqlite3OsWrite(pBase, (const void *)(p->zBuf), p->nByte); } break; case ASYNC_SYNC: assert( pBase ); rc = sqlite3OsSync(pBase, p->nByte); break; case ASYNC_TRUNCATE: assert( pBase ); rc = sqlite3OsTruncate(pBase, p->nByte); break; case ASYNC_CLOSE: sqlite3OsClose(&p->pFile->pBaseRead); sqlite3OsClose(&p->pFile->pBaseWrite); sqlite3OsFree(p->pFile); break; case ASYNC_OPENDIRECTORY: assert( pBase ); sqlite3OsOpenDirectory(pBase, p->zBuf); break; case ASYNC_SETFULLSYNC: assert( pBase ); sqlite3OsSetFullSync(pBase, p->nByte); break; case ASYNC_DELETE: rc = xOrigDelete(p->zBuf); break; case ASYNC_SYNCDIRECTORY: rc = xOrigSyncDirectory(p->zBuf); break; case ASYNC_OPENEXCLUSIVE: { AsyncFile *pFile = p->pFile; int delFlag = ((p->iOffset)?1:0); OsFile *pBase = 0; rc = xOrigOpenExclusive(p->zBuf, &pBase, delFlag); assert( holdingMutex==0 ); pthread_mutex_lock(&async.queueMutex); holdingMutex = 1; if( rc==SQLITE_OK ){ pFile->pBaseRead = pBase; } break; } default: assert(!"Illegal value for AsyncWrite.op"); } /* If we didn't hang on to the mutex during the IO op, obtain it now ** so that the AsyncWrite structure can be safely removed from the ** global write-op queue. */ if( !holdingMutex ){ pthread_mutex_lock(&async.queueMutex); holdingMutex = 1; } TRACE("UNLINK %p\n", p); if( rc==SQLITE_OK ){ if( p==async.pQueueLast ){ async.pQueueLast = 0; } async.pQueueFirst = p->pNext; } assert( holdingMutex ); /* Drop the queue mutex before continuing to the next write operation ** in order to give other threads a chance to work with the write queue. */ pthread_mutex_unlock(&async.queueMutex); if( async.ioDelay>0 ){ sqlite3OsSleep(async.ioDelay); }else{ sched_yield(); } } pthread_mutex_unlock(&async.writerMutex); return 0; } /************************************************************************** ** The remaining code defines a Tcl interface for testing the asynchronous ** IO implementation in this file. ** ** To adapt the code to a non-TCL environment, delete or comment out ** the code that follows. */ /* ** sqlite3async_enable ?YES/NO? ** ** Enable or disable the asynchronous I/O backend. This command is ** not thread-safe. Do not call it while any database connections ** are open. */ static int testAsyncEnable( void * clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[] ){ if( objc!=1 && objc!=2 ){ Tcl_WrongNumArgs(interp, 1, objv, "?YES/NO?"); return TCL_ERROR; } if( objc==1 ){ Tcl_SetObjResult(interp, Tcl_NewBooleanObj(xOrigOpenReadWrite!=0)); }else{ int en; if( Tcl_GetBooleanFromObj(interp, objv[1], &en) ) return TCL_ERROR; asyncEnable(en); } return TCL_OK; } /* ** sqlite3async_halt "now"|"idle"|"never" ** ** Set the conditions at which the writer thread will halt. */ static int testAsyncHalt( void * clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[] ){ const char *zCond; if( objc!=2 ){ Tcl_WrongNumArgs(interp, 1, objv, "\"now\"|\"idle\"|\"never\""); return TCL_ERROR; } zCond = Tcl_GetString(objv[1]); if( strcmp(zCond, "now")==0 ){ async.writerHaltNow = 1; pthread_cond_broadcast(&async.queueSignal); }else if( strcmp(zCond, "idle")==0 ){ async.writerHaltWhenIdle = 1; async.writerHaltNow = 0; pthread_cond_broadcast(&async.queueSignal); }else if( strcmp(zCond, "never")==0 ){ async.writerHaltWhenIdle = 0; async.writerHaltNow = 0; }else{ Tcl_AppendResult(interp, "should be one of: \"now\", \"idle\", or \"never\"", (char*)0); return TCL_ERROR; } return TCL_OK; } /* ** sqlite3async_delay ?MS? ** ** Query or set the number of milliseconds of delay in the writer ** thread after each write operation. The default is 0. By increasing ** the memory delay we can simulate the effect of slow disk I/O. */ static int testAsyncDelay( void * clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[] ){ if( objc!=1 && objc!=2 ){ Tcl_WrongNumArgs(interp, 1, objv, "?MS?"); return TCL_ERROR; } if( objc==1 ){ Tcl_SetObjResult(interp, Tcl_NewIntObj(async.ioDelay)); }else{ int ioDelay; if( Tcl_GetIntFromObj(interp, objv[1], &ioDelay) ) return TCL_ERROR; async.ioDelay = ioDelay; } return TCL_OK; } /* ** sqlite3async_start ** ** Start a new writer thread. */ static int testAsyncStart( void * clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[] ){ pthread_t x; int rc; rc = pthread_create(&x, 0, asyncWriterThread, 0); if( rc ){ Tcl_AppendResult(interp, "failed to create the thread", 0); return TCL_ERROR; } pthread_detach(x); return TCL_OK; } /* ** sqlite3async_wait ** ** Wait for the current writer thread to terminate. ** ** If the current writer thread is set to run forever then this ** command would block forever. To prevent that, an error is returned. */ static int testAsyncWait( void * clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[] ){ if( async.writerHaltNow==0 && async.writerHaltWhenIdle==0 ){ Tcl_AppendResult(interp, "would block forever", (char*)0); return TCL_ERROR; } TRACE("WAIT\n",0); pthread_cond_broadcast(&async.queueSignal); pthread_mutex_lock(&async.writerMutex); pthread_mutex_unlock(&async.writerMutex); return TCL_OK; } #endif /* OS_UNIX and THREADSAFE and defined(SQLITE_ENABLE_REDEF_IO) */ /* ** This routine registers the custom TCL commands defined in this ** module. This should be the only procedure visible from outside ** of this module. */ int Sqlitetestasync_Init(Tcl_Interp *interp){ #if OS_UNIX && THREADSAFE && defined(SQLITE_ENABLE_REDEF_IO) Tcl_CreateObjCommand(interp,"sqlite3async_enable",testAsyncEnable,0,0); Tcl_CreateObjCommand(interp,"sqlite3async_halt",testAsyncHalt,0,0); Tcl_CreateObjCommand(interp,"sqlite3async_delay",testAsyncDelay,0,0); Tcl_CreateObjCommand(interp,"sqlite3async_start",testAsyncStart,0,0); Tcl_CreateObjCommand(interp,"sqlite3async_wait",testAsyncWait,0,0); #endif /* OS_UNIX and THREADSAFE and defined(SQLITE_ENABLE_REDEF_IO) */ return TCL_OK; } |
Added test/async.test.
> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | # # 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 runs all tests. # # $Id: async.test,v 1.3 2006/01/09 17:29:53 drh Exp $ if {[catch {sqlite3async_enable}]} { # The async logic is not built into this system return } set testdir [file dirname $argv0] source $testdir/tester.tcl rename finish_test really_finish_test proc finish_test {} {} set ISQUICK 1 set INCLUDE { select1.test select2.test select3.test select4.test insert.test insert2.test insert3.test } #set INCLUDE [lrange $INCLUDE 0 0] # Enable asynchronous IO. sqlite3async_enable 1 sqlite3async_halt never sqlite3async_start rename do_test really_do_test proc do_test {name args} { uplevel really_do_test async_io-$name $args sqlite3async_halt idle sqlite3async_wait sqlite3async_halt never sqlite3async_start } foreach testfile [lsort -dictionary [glob $testdir/*.test]] { set tail [file tail $testfile] if {[lsearch -exact $INCLUDE $tail]<0} continue source $testfile catch {db close} } set sqlite_open_file_count 0 really_finish_test sqlite3async_halt now sqlite3async_wait sqlite3async_enable 0 rename really_do_test do_test rename really_finish_test finish_test |