Make selecting the asynchronous IO file-locking mode a runtime operation. Still untested. (CVS 6544)
FossilOrigin-Name: 577277e84a05707b8c21aa08bc5fc314c1ac38ac
diff --git a/ext/async/sqlite3async.c b/ext/async/sqlite3async.c
index f1fdb8d..586a749 100644
--- a/ext/async/sqlite3async.c
+++ b/ext/async/sqlite3async.c
@@ -10,7 +10,7 @@
**
*************************************************************************
**
-** $Id: sqlite3async.c,v 1.2 2009/04/24 09:27:16 danielk1977 Exp $
+** $Id: sqlite3async.c,v 1.3 2009/04/24 10:13:06 danielk1977 Exp $
**
** This file contains the implementation of an asynchronous IO backend
** for SQLite.
@@ -19,8 +19,10 @@
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ASYNCIO)
#include "sqlite3async.h"
-
-#define ENABLE_FILE_LOCKING
+#include "sqlite3.h"
+#include <stdarg.h>
+#include <string.h>
+#include <assert.h>
/* Useful macros used in several places */
#define MIN(x,y) ((x)<(y)?(x):(y))
@@ -34,6 +36,8 @@
typedef struct AsyncLock AsyncLock;
/* Enable for debugging */
+#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, ...){
@@ -45,6 +49,7 @@
fprintf(stderr, "[%d] %s", 0 /* (int)pthread_self() */, z);
sqlite3_free(z);
}
+#endif
/*
** THREAD SAFETY NOTES
@@ -374,9 +379,10 @@
AsyncLock *pLock; /* Linked list of all AsyncLock structures */
volatile int ioDelay; /* Extra delay between write operations */
volatile int eHalt; /* One of the SQLITEASYNC_HALT_XXX values */
+ volatile int bLockFiles; /* Current value of "lockfiles" parameter */
int ioError; /* True if an IO error has occurred */
int nFile; /* Number of open files (from sqlite pov) */
-} async = { 0,0,0,0,0,0,0 };
+} async = { 0,0,0,0,0,1,0,0 };
/* Possible values of AsyncWrite.op */
#define ASYNC_NOOP 0
@@ -456,11 +462,11 @@
** structures, one for each handle currently open on the file.
**
** If the opened file is not a main-database (the SQLITE_OPEN_MAIN_DB is
-** not passed to the sqlite3OsOpen() call), or if ENABLE_FILE_LOCKING is
-** not defined at compile time, variables AsyncLock.pFile and
-** AsyncLock.eLock are never used. Otherwise, pFile is a file handle
-** opened on the file in question and used to obtain the file-system
-** locks required by database connections within this process.
+** not passed to the sqlite3OsOpen() call), or if async.bLockFiles is
+** false, variables AsyncLock.pFile and AsyncLock.eLock are never used.
+** Otherwise, pFile is a file handle opened on the file in question and
+** used to obtain the file-system locks required by database connections
+** within this process.
**
** See comments above the asyncLock() function for more details on
** the implementation of database locking used by this backend.
@@ -1064,8 +1070,7 @@
pLock = (AsyncLock *)sqlite3_malloc(nByte);
if( pLock ){
memset(pLock, 0, nByte);
-#ifdef ENABLE_FILE_LOCKING
- if( flags&SQLITE_OPEN_MAIN_DB ){
+ 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 ){
@@ -1073,7 +1078,6 @@
pLock = 0;
}
}
-#endif
if( pLock ){
pLock->nFile = pData->nName;
pLock->zFile = &((char *)(&pLock[1]))[pVfs->szOsFile];
@@ -1607,7 +1611,7 @@
&& eWhen!=SQLITEASYNC_HALT_NOW
&& eWhen!=SQLITEASYNC_HALT_IDLE
){
- return SQLITE_ERROR;
+ return SQLITE_MISUSE;
}
async.eHalt = eWhen;
async_mutex_enter(ASYNC_MUTEX_QUEUE);
@@ -1618,9 +1622,24 @@
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 *);
@@ -1632,6 +1651,11 @@
*piDelay = async.ioDelay;
break;
}
+ case SQLITEASYNC_GET_LOCKFILES: {
+ int *piDelay = va_arg(ap, int *);
+ *piDelay = async.bLockFiles;
+ break;
+ }
default:
return SQLITE_ERROR;