This source file includes following definitions.
- asyncTrace
- async_os_initialize
- async_os_shutdown
- async_mutex_enter
- async_mutex_leave
- async_cond_wait
- async_cond_signal
- async_sched_yield
- async_os_initialize
- async_os_shutdown
- async_mutex_enter
- async_mutex_leave
- async_cond_wait
- async_cond_signal
- async_sched_yield
- addAsyncWrite
- incrOpenFileCount
- addNewAsyncWrite
- asyncClose
- asyncWrite
- asyncRead
- asyncTruncate
- asyncSync
- asyncFileSize
- getFileLock
- findLock
- asyncLock
- asyncUnlock
- asyncCheckReservedLock
- asyncFileControl
- asyncSectorSize
- asyncDeviceCharacteristics
- unlinkAsyncFile
- doAsynchronousOpen
- asyncOpen
- asyncDelete
- asyncAccess
- asyncFullPathname
- asyncDlOpen
- asyncDlError
- asyncDlSym
- asyncDlClose
- asyncRandomness
- asyncSleep
- asyncCurrentTime
- asyncWriterThread
- sqlite3async_initialize
- sqlite3async_shutdown
- sqlite3async_run
- sqlite3async_control
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ASYNCIO)
#include "sqlite3async.h"
#include "sqlite3.h"
#include <stdarg.h>
#include <string.h>
#include <assert.h>
#define MIN(x,y) ((x)<(y)?(x):(y))
#define MAX(x,y) ((x)>(y)?(x):(y))
#ifndef SQLITE_AMALGAMATION
#define UNUSED_PARAMETER(x) (void)(x)
#endif
typedef struct AsyncWrite AsyncWrite;
typedef struct AsyncFile AsyncFile;
typedef struct AsyncFileData AsyncFileData;
typedef struct AsyncFileLock AsyncFileLock;
typedef struct AsyncLock AsyncLock;
#ifndef NDEBUG
#include <stdio.h>
static int sqlite3async_trace = 0;
# define ASYNC_TRACE(X) if( sqlite3async_trace ) asyncTrace X
static void asyncTrace(const char *zFormat, ...){
char *z;
va_list ap;
va_start(ap, zFormat);
z = sqlite3_vmprintf(zFormat, ap);
va_end(ap);
fprintf(stderr, "[%d] %s", 0 , z);
sqlite3_free(z);
}
#else
# define ASYNC_TRACE(X)
#endif
#ifndef NDEBUG
# define TESTONLY( X ) X
#else
# define TESTONLY( X )
#endif
static void async_mutex_enter(int eMutex);
static void async_mutex_leave(int eMutex);
static void async_cond_wait(int eCond, int eMutex);
static void async_cond_signal(int eCond);
static void async_sched_yield(void);
static int async_os_initialize(void);
static void async_os_shutdown(void);
#define ASYNC_MUTEX_LOCK 0
#define ASYNC_MUTEX_QUEUE 1
#define ASYNC_MUTEX_WRITER 2
#define ASYNC_COND_QUEUE 0
#if SQLITE_OS_WIN || defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || defined(__MINGW32__) || defined(__BORLANDC__)
#include <windows.h>
#define mutex_held(X) (GetCurrentThreadId()==primitives.aHolder[X])
static struct AsyncPrimitives {
int isInit;
DWORD aHolder[3];
CRITICAL_SECTION aMutex[3];
HANDLE aCond[1];
} primitives = { 0 };
static int async_os_initialize(void){
if( !primitives.isInit ){
primitives.aCond[0] = CreateEvent(NULL, TRUE, FALSE, 0);
if( primitives.aCond[0]==NULL ){
return 1;
}
InitializeCriticalSection(&primitives.aMutex[0]);
InitializeCriticalSection(&primitives.aMutex[1]);
InitializeCriticalSection(&primitives.aMutex[2]);
primitives.isInit = 1;
}
return 0;
}
static void async_os_shutdown(void){
if( primitives.isInit ){
DeleteCriticalSection(&primitives.aMutex[0]);
DeleteCriticalSection(&primitives.aMutex[1]);
DeleteCriticalSection(&primitives.aMutex[2]);
CloseHandle(primitives.aCond[0]);
primitives.isInit = 0;
}
}
static void async_mutex_enter(int eMutex){
assert( eMutex==0 || eMutex==1 || eMutex==2 );
assert( eMutex!=2 || (!mutex_held(0) && !mutex_held(1) && !mutex_held(2)) );
assert( eMutex!=1 || (!mutex_held(0) && !mutex_held(1)) );
assert( eMutex!=0 || (!mutex_held(0)) );
EnterCriticalSection(&primitives.aMutex[eMutex]);
TESTONLY( primitives.aHolder[eMutex] = GetCurrentThreadId(); )
}
static void async_mutex_leave(int eMutex){
assert( eMutex==0 || eMutex==1 || eMutex==2 );
assert( mutex_held(eMutex) );
TESTONLY( primitives.aHolder[eMutex] = 0; )
LeaveCriticalSection(&primitives.aMutex[eMutex]);
}
static void async_cond_wait(int eCond, int eMutex){
ResetEvent(primitives.aCond[eCond]);
async_mutex_leave(eMutex);
WaitForSingleObject(primitives.aCond[eCond], INFINITE);
async_mutex_enter(eMutex);
}
static void async_cond_signal(int eCond){
assert( mutex_held(ASYNC_MUTEX_QUEUE) );
SetEvent(primitives.aCond[eCond]);
}
static void async_sched_yield(void){
Sleep(0);
}
#else
#include <pthread.h>
#include <sched.h>
#define mutex_held(X) pthread_equal(primitives.aHolder[X], pthread_self())
static int async_os_initialize(void) {return 0;}
static void async_os_shutdown(void) {}
static struct AsyncPrimitives {
pthread_mutex_t aMutex[3];
pthread_cond_t aCond[1];
pthread_t aHolder[3];
} primitives = {
{ PTHREAD_MUTEX_INITIALIZER,
PTHREAD_MUTEX_INITIALIZER,
PTHREAD_MUTEX_INITIALIZER
} , {
PTHREAD_COND_INITIALIZER
} , { 0, 0, 0 }
};
static void async_mutex_enter(int eMutex){
assert( eMutex==0 || eMutex==1 || eMutex==2 );
assert( eMutex!=2 || (!mutex_held(0) && !mutex_held(1) && !mutex_held(2)) );
assert( eMutex!=1 || (!mutex_held(0) && !mutex_held(1)) );
assert( eMutex!=0 || (!mutex_held(0)) );
pthread_mutex_lock(&primitives.aMutex[eMutex]);
TESTONLY( primitives.aHolder[eMutex] = pthread_self(); )
}
static void async_mutex_leave(int eMutex){
assert( eMutex==0 || eMutex==1 || eMutex==2 );
assert( mutex_held(eMutex) );
TESTONLY( primitives.aHolder[eMutex] = 0; )
pthread_mutex_unlock(&primitives.aMutex[eMutex]);
}
static void async_cond_wait(int eCond, int eMutex){
assert( eMutex==0 || eMutex==1 || eMutex==2 );
assert( mutex_held(eMutex) );
TESTONLY( primitives.aHolder[eMutex] = 0; )
pthread_cond_wait(&primitives.aCond[eCond], &primitives.aMutex[eMutex]);
TESTONLY( primitives.aHolder[eMutex] = pthread_self(); )
}
static void async_cond_signal(int eCond){
assert( mutex_held(ASYNC_MUTEX_QUEUE) );
pthread_cond_signal(&primitives.aCond[eCond]);
}
static void async_sched_yield(void){
sched_yield();
}
#endif
#define assert_mutex_is_held(X) assert( mutex_held(X) )
#ifndef SQLITE_ASYNC_TWO_FILEHANDLES
#define SQLITE_ASYNC_TWO_FILEHANDLES 1
#endif
static struct TestAsyncStaticData {
AsyncWrite *pQueueFirst;
AsyncWrite *pQueueLast;
AsyncLock *pLock;
volatile int ioDelay;
volatile int eHalt;
volatile int bLockFiles;
int ioError;
int nFile;
} async = { 0,0,0,0,0,1,0,0 };
#define ASYNC_NOOP 0
#define ASYNC_WRITE 1
#define ASYNC_SYNC 2
#define ASYNC_TRUNCATE 3
#define ASYNC_CLOSE 4
#define ASYNC_DELETE 5
#define ASYNC_OPENEXCLUSIVE 6
#define ASYNC_UNLOCK 7
static const char *azOpcodeName[] = {
"NOOP", "WRITE", "SYNC", "TRUNCATE", "CLOSE", "DELETE", "OPENEX", "UNLOCK"
};
struct AsyncWrite {
AsyncFileData *pFileData;
int op;
sqlite_int64 iOffset;
int nByte;
char *zBuf;
AsyncWrite *pNext;
};
struct AsyncLock {
char *zFile;
int nFile;
sqlite3_file *pFile;
int eLock;
AsyncFileLock *pList;
AsyncLock *pNext;
};
struct AsyncFileLock {
int eLock;
int eAsyncLock;
AsyncFileLock *pNext;
};
struct AsyncFile {
sqlite3_io_methods *pMethod;
AsyncFileData *pData;
};
struct AsyncFileData {
char *zName;
int nName;
sqlite3_file *pBaseRead;
sqlite3_file *pBaseWrite;
AsyncFileLock lock;
AsyncLock *pLock;
AsyncWrite closeOp;
};
static void addAsyncWrite(AsyncWrite *pWrite){
if( pWrite->op!=ASYNC_UNLOCK ){
async_mutex_enter(ASYNC_MUTEX_QUEUE);
}
assert( !pWrite->pNext );
if( async.pQueueLast ){
assert( async.pQueueFirst );
async.pQueueLast->pNext = pWrite;
}else{
async.pQueueFirst = pWrite;
}
async.pQueueLast = pWrite;
ASYNC_TRACE(("PUSH %p (%s %s %d)\n", pWrite, azOpcodeName[pWrite->op],
pWrite->pFileData ? pWrite->pFileData->zName : "-", pWrite->iOffset));
if( pWrite->op==ASYNC_CLOSE ){
async.nFile--;
}
async_cond_signal(ASYNC_COND_QUEUE);
if( pWrite->op!=ASYNC_UNLOCK ){
async_mutex_leave(ASYNC_MUTEX_QUEUE);
}
}
static void incrOpenFileCount(void){
async_mutex_enter(ASYNC_MUTEX_QUEUE);
if( async.nFile==0 ){
async.ioError = SQLITE_OK;
}
async.nFile++;
async_mutex_leave(ASYNC_MUTEX_QUEUE);
}
static int addNewAsyncWrite(
AsyncFileData *pFileData,
int op,
sqlite3_int64 iOffset,
int nByte,
const char *zByte
){
AsyncWrite *p;
if( op!=ASYNC_CLOSE && async.ioError ){
return async.ioError;
}
p = sqlite3_malloc(sizeof(AsyncWrite) + (zByte?nByte:0));
if( !p ){
return SQLITE_IOERR;
}
p->op = op;
p->iOffset = iOffset;
p->nByte = nByte;
p->pFileData = pFileData;
p->pNext = 0;
if( zByte ){
p->zBuf = (char *)&p[1];
memcpy(p->zBuf, zByte, nByte);
}else{
p->zBuf = 0;
}
addAsyncWrite(p);
return SQLITE_OK;
}
static int asyncClose(sqlite3_file *pFile){
AsyncFileData *p = ((AsyncFile *)pFile)->pData;
async_mutex_enter(ASYNC_MUTEX_LOCK);
p->lock.eLock = 0;
async_mutex_leave(ASYNC_MUTEX_LOCK);
addAsyncWrite(&p->closeOp);
return SQLITE_OK;
}
static int asyncWrite(
sqlite3_file *pFile,
const void *pBuf,
int amt,
sqlite3_int64 iOff
){
AsyncFileData *p = ((AsyncFile *)pFile)->pData;
return addNewAsyncWrite(p, ASYNC_WRITE, iOff, amt, pBuf);
}
static int asyncRead(
sqlite3_file *pFile,
void *zOut,
int iAmt,
sqlite3_int64 iOffset
){
AsyncFileData *p = ((AsyncFile *)pFile)->pData;
int rc = SQLITE_OK;
sqlite3_int64 filesize = 0;
sqlite3_file *pBase = p->pBaseRead;
sqlite3_int64 iAmt64 = (sqlite3_int64)iAmt;
async_mutex_enter(ASYNC_MUTEX_QUEUE);
if( async.ioError!=SQLITE_OK ){
rc = async.ioError;
goto asyncread_out;
}
if( pBase->pMethods ){
sqlite3_int64 nRead;
rc = pBase->pMethods->xFileSize(pBase, &filesize);
if( rc!=SQLITE_OK ){
goto asyncread_out;
}
nRead = MIN(filesize - iOffset, iAmt64);
if( nRead>0 ){
rc = pBase->pMethods->xRead(pBase, zOut, (int)nRead, iOffset);
ASYNC_TRACE(("READ %s %d bytes at %d\n", p->zName, nRead, iOffset));
}
}
if( rc==SQLITE_OK ){
AsyncWrite *pWrite;
char *zName = p->zName;
for(pWrite=async.pQueueFirst; pWrite; pWrite = pWrite->pNext){
if( pWrite->op==ASYNC_WRITE && (
(pWrite->pFileData==p) ||
(zName && pWrite->pFileData->zName==zName)
)){
sqlite3_int64 nCopy;
sqlite3_int64 nByte64 = (sqlite3_int64)pWrite->nByte;
sqlite3_int64 iBeginOut = (pWrite->iOffset-iOffset);
sqlite3_int64 iBeginIn = -iBeginOut;
if( iBeginIn<0 ) iBeginIn = 0;
if( iBeginOut<0 ) iBeginOut = 0;
filesize = MAX(filesize, pWrite->iOffset+nByte64);
nCopy = MIN(nByte64-iBeginIn, iAmt64-iBeginOut);
if( nCopy>0 ){
memcpy(&((char *)zOut)[iBeginOut], &pWrite->zBuf[iBeginIn], (size_t)nCopy);
ASYNC_TRACE(("OVERREAD %d bytes at %d\n", nCopy, iBeginOut+iOffset));
}
}
}
}
asyncread_out:
async_mutex_leave(ASYNC_MUTEX_QUEUE);
if( rc==SQLITE_OK && filesize<(iOffset+iAmt) ){
rc = SQLITE_IOERR_SHORT_READ;
}
return rc;
}
static int asyncTruncate(sqlite3_file *pFile, sqlite3_int64 nByte){
AsyncFileData *p = ((AsyncFile *)pFile)->pData;
return addNewAsyncWrite(p, ASYNC_TRUNCATE, nByte, 0, 0);
}
static int asyncSync(sqlite3_file *pFile, int flags){
AsyncFileData *p = ((AsyncFile *)pFile)->pData;
return addNewAsyncWrite(p, ASYNC_SYNC, 0, flags, 0);
}
int asyncFileSize(sqlite3_file *pFile, sqlite3_int64 *piSize){
AsyncFileData *p = ((AsyncFile *)pFile)->pData;
int rc = SQLITE_OK;
sqlite3_int64 s = 0;
sqlite3_file *pBase;
async_mutex_enter(ASYNC_MUTEX_QUEUE);
pBase = p->pBaseRead;
if( pBase->pMethods ){
rc = pBase->pMethods->xFileSize(pBase, &s);
}
if( rc==SQLITE_OK ){
AsyncWrite *pWrite;
for(pWrite=async.pQueueFirst; pWrite; pWrite = pWrite->pNext){
if( pWrite->op==ASYNC_DELETE
&& p->zName
&& strcmp(p->zName, pWrite->zBuf)==0
){
s = 0;
}else if( pWrite->pFileData && (
(pWrite->pFileData==p)
|| (p->zName && pWrite->pFileData->zName==p->zName)
)){
switch( pWrite->op ){
case ASYNC_WRITE:
s = MAX(pWrite->iOffset + (sqlite3_int64)(pWrite->nByte), s);
break;
case ASYNC_TRUNCATE:
s = MIN(s, pWrite->iOffset);
break;
}
}
}
*piSize = s;
}
async_mutex_leave(ASYNC_MUTEX_QUEUE);
return rc;
}
static int getFileLock(AsyncLock *pLock){
int rc = SQLITE_OK;
AsyncFileLock *pIter;
int eRequired = 0;
if( pLock->pFile ){
for(pIter=pLock->pList; pIter; pIter=pIter->pNext){
assert(pIter->eAsyncLock>=pIter->eLock);
if( pIter->eAsyncLock>eRequired ){
eRequired = pIter->eAsyncLock;
assert(eRequired>=0 && eRequired<=SQLITE_LOCK_EXCLUSIVE);
}
}
if( eRequired>pLock->eLock ){
rc = pLock->pFile->pMethods->xLock(pLock->pFile, eRequired);
if( rc==SQLITE_OK ){
pLock->eLock = eRequired;
}
}
else if( eRequired<pLock->eLock && eRequired<=SQLITE_LOCK_SHARED ){
rc = pLock->pFile->pMethods->xUnlock(pLock->pFile, eRequired);
if( rc==SQLITE_OK ){
pLock->eLock = eRequired;
}
}
}
return rc;
}
static AsyncLock *findLock(const char *zName, int nName){
AsyncLock *p = async.pLock;
while( p && (p->nFile!=nName || memcmp(p->zFile, zName, nName)) ){
p = p->pNext;
}
return p;
}
static int asyncLock(sqlite3_file *pFile, int eLock){
int rc = SQLITE_OK;
AsyncFileData *p = ((AsyncFile *)pFile)->pData;
if( p->zName ){
async_mutex_enter(ASYNC_MUTEX_LOCK);
if( p->lock.eLock<eLock ){
AsyncLock *pLock = p->pLock;
AsyncFileLock *pIter;
assert(pLock && pLock->pList);
for(pIter=pLock->pList; pIter; pIter=pIter->pNext){
if( pIter!=&p->lock && (
(eLock==SQLITE_LOCK_EXCLUSIVE && pIter->eLock>=SQLITE_LOCK_SHARED) ||
(eLock==SQLITE_LOCK_PENDING && pIter->eLock>=SQLITE_LOCK_RESERVED) ||
(eLock==SQLITE_LOCK_RESERVED && pIter->eLock>=SQLITE_LOCK_RESERVED) ||
(eLock==SQLITE_LOCK_SHARED && pIter->eLock>=SQLITE_LOCK_PENDING)
)){
rc = SQLITE_BUSY;
}
}
if( rc==SQLITE_OK ){
p->lock.eLock = eLock;
p->lock.eAsyncLock = MAX(p->lock.eAsyncLock, eLock);
}
assert(p->lock.eAsyncLock>=p->lock.eLock);
if( rc==SQLITE_OK ){
rc = getFileLock(pLock);
}
}
async_mutex_leave(ASYNC_MUTEX_LOCK);
}
ASYNC_TRACE(("LOCK %d (%s) rc=%d\n", eLock, p->zName, rc));
return rc;
}
static int asyncUnlock(sqlite3_file *pFile, int eLock){
int rc = SQLITE_OK;
AsyncFileData *p = ((AsyncFile *)pFile)->pData;
if( p->zName ){
AsyncFileLock *pLock = &p->lock;
async_mutex_enter(ASYNC_MUTEX_QUEUE);
async_mutex_enter(ASYNC_MUTEX_LOCK);
pLock->eLock = MIN(pLock->eLock, eLock);
rc = addNewAsyncWrite(p, ASYNC_UNLOCK, 0, eLock, 0);
async_mutex_leave(ASYNC_MUTEX_LOCK);
async_mutex_leave(ASYNC_MUTEX_QUEUE);
}
return rc;
}
static int asyncCheckReservedLock(sqlite3_file *pFile, int *pResOut){
int ret = 0;
AsyncFileLock *pIter;
AsyncFileData *p = ((AsyncFile *)pFile)->pData;
async_mutex_enter(ASYNC_MUTEX_LOCK);
for(pIter=p->pLock->pList; pIter; pIter=pIter->pNext){
if( pIter->eLock>=SQLITE_LOCK_RESERVED ){
ret = 1;
break;
}
}
async_mutex_leave(ASYNC_MUTEX_LOCK);
ASYNC_TRACE(("CHECK-LOCK %d (%s)\n", ret, p->zName));
*pResOut = ret;
return SQLITE_OK;
}
static int asyncFileControl(sqlite3_file *id, int op, void *pArg){
switch( op ){
case SQLITE_FCNTL_LOCKSTATE: {
async_mutex_enter(ASYNC_MUTEX_LOCK);
*(int*)pArg = ((AsyncFile*)id)->pData->lock.eLock;
async_mutex_leave(ASYNC_MUTEX_LOCK);
return SQLITE_OK;
}
}
return SQLITE_ERROR;
}
static int asyncSectorSize(sqlite3_file *pFile){
UNUSED_PARAMETER(pFile);
return 512;
}
static int asyncDeviceCharacteristics(sqlite3_file *pFile){
UNUSED_PARAMETER(pFile);
return 0;
}
static int unlinkAsyncFile(AsyncFileData *pData){
AsyncFileLock **ppIter;
int rc = SQLITE_OK;
if( pData->zName ){
AsyncLock *pLock = pData->pLock;
for(ppIter=&pLock->pList; *ppIter; ppIter=&((*ppIter)->pNext)){
if( (*ppIter)==&pData->lock ){
*ppIter = pData->lock.pNext;
break;
}
}
if( !pLock->pList ){
AsyncLock **pp;
if( pLock->pFile ){
pLock->pFile->pMethods->xClose(pLock->pFile);
}
for(pp=&async.pLock; *pp!=pLock; pp=&((*pp)->pNext));
*pp = pLock->pNext;
sqlite3_free(pLock);
}else{
rc = getFileLock(pLock);
}
}
return rc;
}
static int doAsynchronousOpen(int flags){
return (flags&SQLITE_OPEN_CREATE) && (
(flags&SQLITE_OPEN_MAIN_JOURNAL) ||
(flags&SQLITE_OPEN_TEMP_JOURNAL) ||
(flags&SQLITE_OPEN_DELETEONCLOSE)
);
}
static int asyncOpen(
sqlite3_vfs *pAsyncVfs,
const char *zName,
sqlite3_file *pFile,
int flags,
int *pOutFlags
){
static sqlite3_io_methods async_methods = {
1,
asyncClose,
asyncRead,
asyncWrite,
asyncTruncate,
asyncSync,
asyncFileSize,
asyncLock,
asyncUnlock,
asyncCheckReservedLock,
asyncFileControl,
asyncSectorSize,
asyncDeviceCharacteristics
};
sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
AsyncFile *p = (AsyncFile *)pFile;
int nName = 0;
int rc = SQLITE_OK;
int nByte;
AsyncFileData *pData;
AsyncLock *pLock = 0;
char *z;
int isAsyncOpen = doAsynchronousOpen(flags);
if( zName ){
nName = (int)strlen(zName)+1;
}
nByte = (
sizeof(AsyncFileData) +
2 * pVfs->szOsFile +
nName
);
z = sqlite3_malloc(nByte);
if( !z ){
return SQLITE_NOMEM;
}
memset(z, 0, nByte);
pData = (AsyncFileData*)z;
z += sizeof(pData[0]);
pData->pBaseRead = (sqlite3_file*)z;
z += pVfs->szOsFile;
pData->pBaseWrite = (sqlite3_file*)z;
pData->closeOp.pFileData = pData;
pData->closeOp.op = ASYNC_CLOSE;
if( zName ){
z += pVfs->szOsFile;
pData->zName = z;
pData->nName = nName;
memcpy(pData->zName, zName, nName);
}
if( !isAsyncOpen ){
int flagsout;
rc = pVfs->xOpen(pVfs, pData->zName, pData->pBaseRead, flags, &flagsout);
if( rc==SQLITE_OK
&& (flagsout&SQLITE_OPEN_READWRITE)
&& (flags&SQLITE_OPEN_EXCLUSIVE)==0
){
rc = pVfs->xOpen(pVfs, pData->zName, pData->pBaseWrite, flags, 0);
}
if( pOutFlags ){
*pOutFlags = flagsout;
}
}
async_mutex_enter(ASYNC_MUTEX_LOCK);
if( zName && rc==SQLITE_OK ){
pLock = findLock(pData->zName, pData->nName);
if( !pLock ){
int nByte = pVfs->szOsFile + sizeof(AsyncLock) + pData->nName + 1;
pLock = (AsyncLock *)sqlite3_malloc(nByte);
if( pLock ){
memset(pLock, 0, nByte);
if( async.bLockFiles && (flags&SQLITE_OPEN_MAIN_DB) ){
pLock->pFile = (sqlite3_file *)&pLock[1];
rc = pVfs->xOpen(pVfs, pData->zName, pLock->pFile, flags, 0);
if( rc!=SQLITE_OK ){
sqlite3_free(pLock);
pLock = 0;
}
}
if( pLock ){
pLock->nFile = pData->nName;
pLock->zFile = &((char *)(&pLock[1]))[pVfs->szOsFile];
memcpy(pLock->zFile, pData->zName, pLock->nFile);
pLock->pNext = async.pLock;
async.pLock = pLock;
}
}else{
rc = SQLITE_NOMEM;
}
}
}
if( rc==SQLITE_OK ){
p->pMethod = &async_methods;
p->pData = pData;
if( zName ){
pData->lock.pNext = pLock->pList;
pLock->pList = &pData->lock;
pData->zName = pLock->zFile;
}
}else{
if( pData->pBaseRead->pMethods ){
pData->pBaseRead->pMethods->xClose(pData->pBaseRead);
}
if( pData->pBaseWrite->pMethods ){
pData->pBaseWrite->pMethods->xClose(pData->pBaseWrite);
}
sqlite3_free(pData);
}
async_mutex_leave(ASYNC_MUTEX_LOCK);
if( rc==SQLITE_OK ){
pData->pLock = pLock;
}
if( rc==SQLITE_OK && isAsyncOpen ){
rc = addNewAsyncWrite(pData, ASYNC_OPENEXCLUSIVE, (sqlite3_int64)flags,0,0);
if( rc==SQLITE_OK ){
if( pOutFlags ) *pOutFlags = flags;
}else{
async_mutex_enter(ASYNC_MUTEX_LOCK);
unlinkAsyncFile(pData);
async_mutex_leave(ASYNC_MUTEX_LOCK);
sqlite3_free(pData);
}
}
if( rc!=SQLITE_OK ){
p->pMethod = 0;
}else{
incrOpenFileCount();
}
return rc;
}
static int asyncDelete(sqlite3_vfs *pAsyncVfs, const char *z, int syncDir){
UNUSED_PARAMETER(pAsyncVfs);
return addNewAsyncWrite(0, ASYNC_DELETE, syncDir, (int)strlen(z)+1, z);
}
static int asyncAccess(
sqlite3_vfs *pAsyncVfs,
const char *zName,
int flags,
int *pResOut
){
int rc;
int ret;
AsyncWrite *p;
sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
assert(flags==SQLITE_ACCESS_READWRITE
|| flags==SQLITE_ACCESS_READ
|| flags==SQLITE_ACCESS_EXISTS
);
async_mutex_enter(ASYNC_MUTEX_QUEUE);
rc = pVfs->xAccess(pVfs, zName, flags, &ret);
if( rc==SQLITE_OK && flags==SQLITE_ACCESS_EXISTS ){
for(p=async.pQueueFirst; p; p = p->pNext){
if( p->op==ASYNC_DELETE && 0==strcmp(p->zBuf, zName) ){
ret = 0;
}else if( p->op==ASYNC_OPENEXCLUSIVE
&& p->pFileData->zName
&& 0==strcmp(p->pFileData->zName, zName)
){
ret = 1;
}
}
}
ASYNC_TRACE(("ACCESS(%s): %s = %d\n",
flags==SQLITE_ACCESS_READWRITE?"read-write":
flags==SQLITE_ACCESS_READ?"read":"exists"
, zName, ret)
);
async_mutex_leave(ASYNC_MUTEX_QUEUE);
*pResOut = ret;
return rc;
}
static int asyncFullPathname(
sqlite3_vfs *pAsyncVfs,
const char *zPath,
int nPathOut,
char *zPathOut
){
int rc;
sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
rc = pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);
if( rc==SQLITE_OK ){
int i, j;
char *z = zPathOut;
int n = (int)strlen(z);
while( n>1 && z[n-1]=='/' ){ n--; }
for(i=j=0; i<n; i++){
if( z[i]=='/' ){
if( z[i+1]=='/' ) continue;
if( z[i+1]=='.' && i+2<n && z[i+2]=='/' ){
i += 1;
continue;
}
if( z[i+1]=='.' && i+3<n && z[i+2]=='.' && z[i+3]=='/' ){
while( j>0 && z[j-1]!='/' ){ j--; }
if( j>0 ){ j--; }
i += 2;
continue;
}
}
z[j++] = z[i];
}
z[j] = 0;
}
return rc;
}
static void *asyncDlOpen(sqlite3_vfs *pAsyncVfs, const char *zPath){
sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
return pVfs->xDlOpen(pVfs, zPath);
}
static void asyncDlError(sqlite3_vfs *pAsyncVfs, int nByte, char *zErrMsg){
sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
pVfs->xDlError(pVfs, nByte, zErrMsg);
}
static void (*asyncDlSym(
sqlite3_vfs *pAsyncVfs,
void *pHandle,
const char *zSymbol
))(void){
sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
return pVfs->xDlSym(pVfs, pHandle, zSymbol);
}
static void asyncDlClose(sqlite3_vfs *pAsyncVfs, void *pHandle){
sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
pVfs->xDlClose(pVfs, pHandle);
}
static int asyncRandomness(sqlite3_vfs *pAsyncVfs, int nByte, char *zBufOut){
sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
return pVfs->xRandomness(pVfs, nByte, zBufOut);
}
static int asyncSleep(sqlite3_vfs *pAsyncVfs, int nMicro){
sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
return pVfs->xSleep(pVfs, nMicro);
}
static int asyncCurrentTime(sqlite3_vfs *pAsyncVfs, double *pTimeOut){
sqlite3_vfs *pVfs = (sqlite3_vfs *)pAsyncVfs->pAppData;
return pVfs->xCurrentTime(pVfs, pTimeOut);
}
static sqlite3_vfs async_vfs = {
1,
sizeof(AsyncFile),
0,
0,
SQLITEASYNC_VFSNAME,
0,
asyncOpen,
asyncDelete,
asyncAccess,
asyncFullPathname,
asyncDlOpen,
asyncDlError,
asyncDlSym,
asyncDlClose,
asyncRandomness,
asyncSleep,
asyncCurrentTime
};
static void asyncWriterThread(void){
sqlite3_vfs *pVfs = (sqlite3_vfs *)(async_vfs.pAppData);
AsyncWrite *p = 0;
int rc = SQLITE_OK;
int holdingMutex = 0;
async_mutex_enter(ASYNC_MUTEX_WRITER);
while( async.eHalt!=SQLITEASYNC_HALT_NOW ){
int doNotFree = 0;
sqlite3_file *pBase = 0;
if( !holdingMutex ){
async_mutex_enter(ASYNC_MUTEX_QUEUE);
}
while( (p = async.pQueueFirst)==0 ){
if( async.eHalt!=SQLITEASYNC_HALT_NEVER ){
async_mutex_leave(ASYNC_MUTEX_QUEUE);
break;
}else{
ASYNC_TRACE(("IDLE\n"));
async_cond_wait(ASYNC_COND_QUEUE, ASYNC_MUTEX_QUEUE);
ASYNC_TRACE(("WAKEUP\n"));
}
}
if( p==0 ) break;
holdingMutex = 1;
if( async.ioError!=SQLITE_OK && p->op!=ASYNC_CLOSE ){
p->op = ASYNC_NOOP;
}
if( p->pFileData ){
pBase = p->pFileData->pBaseWrite;
if(
p->op==ASYNC_CLOSE ||
p->op==ASYNC_OPENEXCLUSIVE ||
(pBase->pMethods && (p->op==ASYNC_SYNC || p->op==ASYNC_WRITE) )
){
async_mutex_leave(ASYNC_MUTEX_QUEUE);
holdingMutex = 0;
}
if( !pBase->pMethods ){
pBase = p->pFileData->pBaseRead;
}
}
switch( p->op ){
case ASYNC_NOOP:
break;
case ASYNC_WRITE:
assert( pBase );
ASYNC_TRACE(("WRITE %s %d bytes at %d\n",
p->pFileData->zName, p->nByte, p->iOffset));
rc = pBase->pMethods->xWrite(pBase, (void *)(p->zBuf), p->nByte, p->iOffset);
break;
case ASYNC_SYNC:
assert( pBase );
ASYNC_TRACE(("SYNC %s\n", p->pFileData->zName));
rc = pBase->pMethods->xSync(pBase, p->nByte);
break;
case ASYNC_TRUNCATE:
assert( pBase );
ASYNC_TRACE(("TRUNCATE %s to %d bytes\n",
p->pFileData->zName, p->iOffset));
rc = pBase->pMethods->xTruncate(pBase, p->iOffset);
break;
case ASYNC_CLOSE: {
AsyncFileData *pData = p->pFileData;
ASYNC_TRACE(("CLOSE %s\n", p->pFileData->zName));
if( pData->pBaseWrite->pMethods ){
pData->pBaseWrite->pMethods->xClose(pData->pBaseWrite);
}
if( pData->pBaseRead->pMethods ){
pData->pBaseRead->pMethods->xClose(pData->pBaseRead);
}
async_mutex_enter(ASYNC_MUTEX_LOCK);
rc = unlinkAsyncFile(pData);
async_mutex_leave(ASYNC_MUTEX_LOCK);
if( !holdingMutex ){
async_mutex_enter(ASYNC_MUTEX_QUEUE);
holdingMutex = 1;
}
assert_mutex_is_held(ASYNC_MUTEX_QUEUE);
async.pQueueFirst = p->pNext;
sqlite3_free(pData);
doNotFree = 1;
break;
}
case ASYNC_UNLOCK: {
AsyncWrite *pIter;
AsyncFileData *pData = p->pFileData;
int eLock = p->nByte;
assert( holdingMutex==1 );
assert( async.pQueueFirst==p );
for(pIter=async.pQueueFirst->pNext; pIter; pIter=pIter->pNext){
if( pIter->pFileData==pData && pIter->op==ASYNC_UNLOCK ) break;
}
if( !pIter ){
async_mutex_enter(ASYNC_MUTEX_LOCK);
pData->lock.eAsyncLock = MIN(
pData->lock.eAsyncLock, MAX(pData->lock.eLock, eLock)
);
assert(pData->lock.eAsyncLock>=pData->lock.eLock);
rc = getFileLock(pData->pLock);
async_mutex_leave(ASYNC_MUTEX_LOCK);
}
break;
}
case ASYNC_DELETE:
ASYNC_TRACE(("DELETE %s\n", p->zBuf));
rc = pVfs->xDelete(pVfs, p->zBuf, (int)p->iOffset);
break;
case ASYNC_OPENEXCLUSIVE: {
int flags = (int)p->iOffset;
AsyncFileData *pData = p->pFileData;
ASYNC_TRACE(("OPEN %s flags=%d\n", p->zBuf, (int)p->iOffset));
assert(pData->pBaseRead->pMethods==0 && pData->pBaseWrite->pMethods==0);
rc = pVfs->xOpen(pVfs, pData->zName, pData->pBaseRead, flags, 0);
assert( holdingMutex==0 );
async_mutex_enter(ASYNC_MUTEX_QUEUE);
holdingMutex = 1;
break;
}
default: assert(!"Illegal value for AsyncWrite.op");
}
if( !holdingMutex ){
async_mutex_enter(ASYNC_MUTEX_QUEUE);
holdingMutex = 1;
}
if( p==async.pQueueLast ){
async.pQueueLast = 0;
}
if( !doNotFree ){
assert_mutex_is_held(ASYNC_MUTEX_QUEUE);
async.pQueueFirst = p->pNext;
sqlite3_free(p);
}
assert( holdingMutex );
if( rc!=SQLITE_OK ){
async.ioError = rc;
}
if( async.ioError && !async.pQueueFirst ){
async_mutex_enter(ASYNC_MUTEX_LOCK);
if( 0==async.pLock ){
async.ioError = SQLITE_OK;
}
async_mutex_leave(ASYNC_MUTEX_LOCK);
}
if( !async.pQueueFirst || !async.ioError ){
async_mutex_leave(ASYNC_MUTEX_QUEUE);
holdingMutex = 0;
if( async.ioDelay>0 ){
pVfs->xSleep(pVfs, async.ioDelay*1000);
}else{
async_sched_yield();
}
}
}
async_mutex_leave(ASYNC_MUTEX_WRITER);
return;
}
int sqlite3async_initialize(const char *zParent, int isDefault){
int rc = SQLITE_OK;
if( async_vfs.pAppData==0 ){
sqlite3_vfs *pParent = sqlite3_vfs_find(zParent);
if( !pParent || async_os_initialize() ){
rc = SQLITE_ERROR;
}else if( SQLITE_OK!=(rc = sqlite3_vfs_register(&async_vfs, isDefault)) ){
async_os_shutdown();
}else{
async_vfs.pAppData = (void *)pParent;
async_vfs.mxPathname = ((sqlite3_vfs *)async_vfs.pAppData)->mxPathname;
}
}
return rc;
}
void sqlite3async_shutdown(void){
if( async_vfs.pAppData ){
async_os_shutdown();
sqlite3_vfs_unregister((sqlite3_vfs *)&async_vfs);
async_vfs.pAppData = 0;
}
}
void sqlite3async_run(void){
asyncWriterThread();
}
int sqlite3async_control(int op, ...){
va_list ap;
va_start(ap, op);
switch( op ){
case SQLITEASYNC_HALT: {
int eWhen = va_arg(ap, int);
if( eWhen!=SQLITEASYNC_HALT_NEVER
&& eWhen!=SQLITEASYNC_HALT_NOW
&& eWhen!=SQLITEASYNC_HALT_IDLE
){
return SQLITE_MISUSE;
}
async.eHalt = eWhen;
async_mutex_enter(ASYNC_MUTEX_QUEUE);
async_cond_signal(ASYNC_COND_QUEUE);
async_mutex_leave(ASYNC_MUTEX_QUEUE);
break;
}
case SQLITEASYNC_DELAY: {
int iDelay = va_arg(ap, int);
if( iDelay<0 ){
return SQLITE_MISUSE;
}
async.ioDelay = iDelay;
break;
}
case SQLITEASYNC_LOCKFILES: {
int bLock = va_arg(ap, int);
async_mutex_enter(ASYNC_MUTEX_QUEUE);
if( async.nFile || async.pQueueFirst ){
async_mutex_leave(ASYNC_MUTEX_QUEUE);
return SQLITE_MISUSE;
}
async.bLockFiles = bLock;
async_mutex_leave(ASYNC_MUTEX_QUEUE);
break;
}
case SQLITEASYNC_GET_HALT: {
int *peWhen = va_arg(ap, int *);
*peWhen = async.eHalt;
break;
}
case SQLITEASYNC_GET_DELAY: {
int *piDelay = va_arg(ap, int *);
*piDelay = async.ioDelay;
break;
}
case SQLITEASYNC_GET_LOCKFILES: {
int *piDelay = va_arg(ap, int *);
*piDelay = async.bLockFiles;
break;
}
default:
return SQLITE_ERROR;
}
return SQLITE_OK;
}
#endif