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os_os2.c
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1924 lines (1698 loc) · 59.6 KB
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/*
** 2006 Feb 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 code that is specific to OS/2.
*/
#include "sqliteInt.h"
#if SQLITE_OS_OS2
/*
** A Note About Memory Allocation:
**
** This driver uses malloc()/free() directly rather than going through
** the SQLite-wrappers sqlite3_malloc()/sqlite3_free(). Those wrappers
** are designed for use on embedded systems where memory is scarce and
** malloc failures happen frequently. OS/2 does not typically run on
** embedded systems, and when it does the developers normally have bigger
** problems to worry about than running out of memory. So there is not
** a compelling need to use the wrappers.
**
** But there is a good reason to not use the wrappers. If we use the
** wrappers then we will get simulated malloc() failures within this
** driver. And that causes all kinds of problems for our tests. We
** could enhance SQLite to deal with simulated malloc failures within
** the OS driver, but the code to deal with those failure would not
** be exercised on Linux (which does not need to malloc() in the driver)
** and so we would have difficulty writing coverage tests for that
** code. Better to leave the code out, we think.
**
** The point of this discussion is as follows: When creating a new
** OS layer for an embedded system, if you use this file as an example,
** avoid the use of malloc()/free(). Those routines work ok on OS/2
** desktops but not so well in embedded systems.
*/
/*
** Macros used to determine whether or not to use threads.
*/
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE
# define SQLITE_OS2_THREADS 1
#endif
/*
** Include code that is common to all os_*.c files
*/
#include "os_common.h"
/* Forward references */
typedef struct os2File os2File; /* The file structure */
typedef struct os2ShmNode os2ShmNode; /* A shared descritive memory node */
typedef struct os2ShmLink os2ShmLink; /* A connection to shared-memory */
/*
** The os2File structure is subclass of sqlite3_file specific for the OS/2
** protability layer.
*/
struct os2File {
const sqlite3_io_methods *pMethod; /* Always the first entry */
HFILE h; /* Handle for accessing the file */
int flags; /* Flags provided to os2Open() */
int locktype; /* Type of lock currently held on this file */
int szChunk; /* Chunk size configured by FCNTL_CHUNK_SIZE */
char *zFullPathCp; /* Full path name of this file */
os2ShmLink *pShmLink; /* Instance of shared memory on this file */
};
#define LOCK_TIMEOUT 10L /* the default locking timeout */
/*
** Missing from some versions of the OS/2 toolkit -
** used to allocate from high memory if possible
*/
#ifndef OBJ_ANY
# define OBJ_ANY 0x00000400
#endif
/*****************************************************************************
** The next group of routines implement the I/O methods specified
** by the sqlite3_io_methods object.
******************************************************************************/
/*
** Close a file.
*/
static int os2Close( sqlite3_file *id ){
APIRET rc;
os2File *pFile = (os2File*)id;
assert( id!=0 );
OSTRACE(( "CLOSE %d (%s)\n", pFile->h, pFile->zFullPathCp ));
rc = DosClose( pFile->h );
if( pFile->flags & SQLITE_OPEN_DELETEONCLOSE )
DosForceDelete( (PSZ)pFile->zFullPathCp );
free( pFile->zFullPathCp );
pFile->zFullPathCp = NULL;
pFile->locktype = NO_LOCK;
pFile->h = (HFILE)-1;
pFile->flags = 0;
OpenCounter( -1 );
return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
}
/*
** Read data from a file into a buffer. Return SQLITE_OK if all
** bytes were read successfully and SQLITE_IOERR if anything goes
** wrong.
*/
static int os2Read(
sqlite3_file *id, /* File to read from */
void *pBuf, /* Write content into this buffer */
int amt, /* Number of bytes to read */
sqlite3_int64 offset /* Begin reading at this offset */
){
ULONG fileLocation = 0L;
ULONG got;
os2File *pFile = (os2File*)id;
assert( id!=0 );
SimulateIOError( return SQLITE_IOERR_READ );
OSTRACE(( "READ %d lock=%d\n", pFile->h, pFile->locktype ));
if( DosSetFilePtr(pFile->h, offset, FILE_BEGIN, &fileLocation) != NO_ERROR ){
return SQLITE_IOERR;
}
if( DosRead( pFile->h, pBuf, amt, &got ) != NO_ERROR ){
return SQLITE_IOERR_READ;
}
if( got == (ULONG)amt )
return SQLITE_OK;
else {
/* Unread portions of the input buffer must be zero-filled */
memset(&((char*)pBuf)[got], 0, amt-got);
return SQLITE_IOERR_SHORT_READ;
}
}
/*
** Write data from a buffer into a file. Return SQLITE_OK on success
** or some other error code on failure.
*/
static int os2Write(
sqlite3_file *id, /* File to write into */
const void *pBuf, /* The bytes to be written */
int amt, /* Number of bytes to write */
sqlite3_int64 offset /* Offset into the file to begin writing at */
){
ULONG fileLocation = 0L;
APIRET rc = NO_ERROR;
ULONG wrote;
os2File *pFile = (os2File*)id;
assert( id!=0 );
SimulateIOError( return SQLITE_IOERR_WRITE );
SimulateDiskfullError( return SQLITE_FULL );
OSTRACE(( "WRITE %d lock=%d\n", pFile->h, pFile->locktype ));
if( DosSetFilePtr(pFile->h, offset, FILE_BEGIN, &fileLocation) != NO_ERROR ){
return SQLITE_IOERR;
}
assert( amt>0 );
while( amt > 0 &&
( rc = DosWrite( pFile->h, (PVOID)pBuf, amt, &wrote ) ) == NO_ERROR &&
wrote > 0
){
amt -= wrote;
pBuf = &((char*)pBuf)[wrote];
}
return ( rc != NO_ERROR || amt > (int)wrote ) ? SQLITE_FULL : SQLITE_OK;
}
/*
** Truncate an open file to a specified size
*/
static int os2Truncate( sqlite3_file *id, i64 nByte ){
APIRET rc;
os2File *pFile = (os2File*)id;
assert( id!=0 );
OSTRACE(( "TRUNCATE %d %lld\n", pFile->h, nByte ));
SimulateIOError( return SQLITE_IOERR_TRUNCATE );
/* If the user has configured a chunk-size for this file, truncate the
** file so that it consists of an integer number of chunks (i.e. the
** actual file size after the operation may be larger than the requested
** size).
*/
if( pFile->szChunk ){
nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
}
rc = DosSetFileSize( pFile->h, nByte );
return rc == NO_ERROR ? SQLITE_OK : SQLITE_IOERR_TRUNCATE;
}
#ifdef SQLITE_TEST
/*
** Count the number of fullsyncs and normal syncs. This is used to test
** that syncs and fullsyncs are occuring at the right times.
*/
int sqlite3_sync_count = 0;
int sqlite3_fullsync_count = 0;
#endif
/*
** Make sure all writes to a particular file are committed to disk.
*/
static int os2Sync( sqlite3_file *id, int flags ){
os2File *pFile = (os2File*)id;
OSTRACE(( "SYNC %d lock=%d\n", pFile->h, pFile->locktype ));
#ifdef SQLITE_TEST
if( flags & SQLITE_SYNC_FULL){
sqlite3_fullsync_count++;
}
sqlite3_sync_count++;
#endif
/* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
** no-op
*/
#ifdef SQLITE_NO_SYNC
UNUSED_PARAMETER(pFile);
return SQLITE_OK;
#else
return DosResetBuffer( pFile->h ) == NO_ERROR ? SQLITE_OK : SQLITE_IOERR;
#endif
}
/*
** Determine the current size of a file in bytes
*/
static int os2FileSize( sqlite3_file *id, sqlite3_int64 *pSize ){
APIRET rc = NO_ERROR;
FILESTATUS3 fsts3FileInfo;
memset(&fsts3FileInfo, 0, sizeof(fsts3FileInfo));
assert( id!=0 );
SimulateIOError( return SQLITE_IOERR_FSTAT );
rc = DosQueryFileInfo( ((os2File*)id)->h, FIL_STANDARD, &fsts3FileInfo, sizeof(FILESTATUS3) );
if( rc == NO_ERROR ){
*pSize = fsts3FileInfo.cbFile;
return SQLITE_OK;
}else{
return SQLITE_IOERR_FSTAT;
}
}
/*
** Acquire a reader lock.
*/
static int getReadLock( os2File *pFile ){
FILELOCK LockArea,
UnlockArea;
APIRET res;
memset(&LockArea, 0, sizeof(LockArea));
memset(&UnlockArea, 0, sizeof(UnlockArea));
LockArea.lOffset = SHARED_FIRST;
LockArea.lRange = SHARED_SIZE;
UnlockArea.lOffset = 0L;
UnlockArea.lRange = 0L;
res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 1L );
OSTRACE(( "GETREADLOCK %d res=%d\n", pFile->h, res ));
return res;
}
/*
** Undo a readlock
*/
static int unlockReadLock( os2File *id ){
FILELOCK LockArea,
UnlockArea;
APIRET res;
memset(&LockArea, 0, sizeof(LockArea));
memset(&UnlockArea, 0, sizeof(UnlockArea));
LockArea.lOffset = 0L;
LockArea.lRange = 0L;
UnlockArea.lOffset = SHARED_FIRST;
UnlockArea.lRange = SHARED_SIZE;
res = DosSetFileLocks( id->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 1L );
OSTRACE(( "UNLOCK-READLOCK file handle=%d res=%d?\n", id->h, res ));
return res;
}
/*
** Lock the file with the lock specified by parameter locktype - one
** of the following:
**
** (1) SHARED_LOCK
** (2) RESERVED_LOCK
** (3) PENDING_LOCK
** (4) EXCLUSIVE_LOCK
**
** Sometimes when requesting one lock state, additional lock states
** are inserted in between. The locking might fail on one of the later
** transitions leaving the lock state different from what it started but
** still short of its goal. The following chart shows the allowed
** transitions and the inserted intermediate states:
**
** UNLOCKED -> SHARED
** SHARED -> RESERVED
** SHARED -> (PENDING) -> EXCLUSIVE
** RESERVED -> (PENDING) -> EXCLUSIVE
** PENDING -> EXCLUSIVE
**
** This routine will only increase a lock. The os2Unlock() routine
** erases all locks at once and returns us immediately to locking level 0.
** It is not possible to lower the locking level one step at a time. You
** must go straight to locking level 0.
*/
static int os2Lock( sqlite3_file *id, int locktype ){
int rc = SQLITE_OK; /* Return code from subroutines */
APIRET res = NO_ERROR; /* Result of an OS/2 lock call */
int newLocktype; /* Set pFile->locktype to this value before exiting */
int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
FILELOCK LockArea,
UnlockArea;
os2File *pFile = (os2File*)id;
memset(&LockArea, 0, sizeof(LockArea));
memset(&UnlockArea, 0, sizeof(UnlockArea));
assert( pFile!=0 );
OSTRACE(( "LOCK %d %d was %d\n", pFile->h, locktype, pFile->locktype ));
/* If there is already a lock of this type or more restrictive on the
** os2File, do nothing. Don't use the end_lock: exit path, as
** sqlite3_mutex_enter() hasn't been called yet.
*/
if( pFile->locktype>=locktype ){
OSTRACE(( "LOCK %d %d ok (already held)\n", pFile->h, locktype ));
return SQLITE_OK;
}
/* Make sure the locking sequence is correct
*/
assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
assert( locktype!=PENDING_LOCK );
assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
/* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
** a SHARED lock. If we are acquiring a SHARED lock, the acquisition of
** the PENDING_LOCK byte is temporary.
*/
newLocktype = pFile->locktype;
if( pFile->locktype==NO_LOCK
|| (locktype==EXCLUSIVE_LOCK && pFile->locktype==RESERVED_LOCK)
){
LockArea.lOffset = PENDING_BYTE;
LockArea.lRange = 1L;
UnlockArea.lOffset = 0L;
UnlockArea.lRange = 0L;
/* wait longer than LOCK_TIMEOUT here not to have to try multiple times */
res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, 100L, 0L );
if( res == NO_ERROR ){
gotPendingLock = 1;
OSTRACE(( "LOCK %d pending lock boolean set. res=%d\n", pFile->h, res ));
}
}
/* Acquire a shared lock
*/
if( locktype==SHARED_LOCK && res == NO_ERROR ){
assert( pFile->locktype==NO_LOCK );
res = getReadLock(pFile);
if( res == NO_ERROR ){
newLocktype = SHARED_LOCK;
}
OSTRACE(( "LOCK %d acquire shared lock. res=%d\n", pFile->h, res ));
}
/* Acquire a RESERVED lock
*/
if( locktype==RESERVED_LOCK && res == NO_ERROR ){
assert( pFile->locktype==SHARED_LOCK );
LockArea.lOffset = RESERVED_BYTE;
LockArea.lRange = 1L;
UnlockArea.lOffset = 0L;
UnlockArea.lRange = 0L;
res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
if( res == NO_ERROR ){
newLocktype = RESERVED_LOCK;
}
OSTRACE(( "LOCK %d acquire reserved lock. res=%d\n", pFile->h, res ));
}
/* Acquire a PENDING lock
*/
if( locktype==EXCLUSIVE_LOCK && res == NO_ERROR ){
newLocktype = PENDING_LOCK;
gotPendingLock = 0;
OSTRACE(( "LOCK %d acquire pending lock. pending lock boolean unset.\n",
pFile->h ));
}
/* Acquire an EXCLUSIVE lock
*/
if( locktype==EXCLUSIVE_LOCK && res == NO_ERROR ){
assert( pFile->locktype>=SHARED_LOCK );
res = unlockReadLock(pFile);
OSTRACE(( "unreadlock = %d\n", res ));
LockArea.lOffset = SHARED_FIRST;
LockArea.lRange = SHARED_SIZE;
UnlockArea.lOffset = 0L;
UnlockArea.lRange = 0L;
res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
if( res == NO_ERROR ){
newLocktype = EXCLUSIVE_LOCK;
}else{
OSTRACE(( "OS/2 error-code = %d\n", res ));
getReadLock(pFile);
}
OSTRACE(( "LOCK %d acquire exclusive lock. res=%d\n", pFile->h, res ));
}
/* If we are holding a PENDING lock that ought to be released, then
** release it now.
*/
if( gotPendingLock && locktype==SHARED_LOCK ){
int r;
LockArea.lOffset = 0L;
LockArea.lRange = 0L;
UnlockArea.lOffset = PENDING_BYTE;
UnlockArea.lRange = 1L;
r = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
OSTRACE(( "LOCK %d unlocking pending/is shared. r=%d\n", pFile->h, r ));
}
/* Update the state of the lock has held in the file descriptor then
** return the appropriate result code.
*/
if( res == NO_ERROR ){
rc = SQLITE_OK;
}else{
OSTRACE(( "LOCK FAILED %d trying for %d but got %d\n", pFile->h,
locktype, newLocktype ));
rc = SQLITE_BUSY;
}
pFile->locktype = newLocktype;
OSTRACE(( "LOCK %d now %d\n", pFile->h, pFile->locktype ));
return rc;
}
/*
** This routine checks if there is a RESERVED lock held on the specified
** file by this or any other process. If such a lock is held, return
** non-zero, otherwise zero.
*/
static int os2CheckReservedLock( sqlite3_file *id, int *pOut ){
int r = 0;
os2File *pFile = (os2File*)id;
assert( pFile!=0 );
if( pFile->locktype>=RESERVED_LOCK ){
r = 1;
OSTRACE(( "TEST WR-LOCK %d %d (local)\n", pFile->h, r ));
}else{
FILELOCK LockArea,
UnlockArea;
APIRET rc = NO_ERROR;
memset(&LockArea, 0, sizeof(LockArea));
memset(&UnlockArea, 0, sizeof(UnlockArea));
LockArea.lOffset = RESERVED_BYTE;
LockArea.lRange = 1L;
UnlockArea.lOffset = 0L;
UnlockArea.lRange = 0L;
rc = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
OSTRACE(( "TEST WR-LOCK %d lock reserved byte rc=%d\n", pFile->h, rc ));
if( rc == NO_ERROR ){
APIRET rcu = NO_ERROR; /* return code for unlocking */
LockArea.lOffset = 0L;
LockArea.lRange = 0L;
UnlockArea.lOffset = RESERVED_BYTE;
UnlockArea.lRange = 1L;
rcu = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
OSTRACE(( "TEST WR-LOCK %d unlock reserved byte r=%d\n", pFile->h, rcu ));
}
r = !(rc == NO_ERROR);
OSTRACE(( "TEST WR-LOCK %d %d (remote)\n", pFile->h, r ));
}
*pOut = r;
return SQLITE_OK;
}
/*
** Lower the locking level on file descriptor id to locktype. locktype
** must be either NO_LOCK or SHARED_LOCK.
**
** If the locking level of the file descriptor is already at or below
** the requested locking level, this routine is a no-op.
**
** It is not possible for this routine to fail if the second argument
** is NO_LOCK. If the second argument is SHARED_LOCK then this routine
** might return SQLITE_IOERR;
*/
static int os2Unlock( sqlite3_file *id, int locktype ){
int type;
os2File *pFile = (os2File*)id;
APIRET rc = SQLITE_OK;
APIRET res = NO_ERROR;
FILELOCK LockArea,
UnlockArea;
memset(&LockArea, 0, sizeof(LockArea));
memset(&UnlockArea, 0, sizeof(UnlockArea));
assert( pFile!=0 );
assert( locktype<=SHARED_LOCK );
OSTRACE(( "UNLOCK %d to %d was %d\n", pFile->h, locktype, pFile->locktype ));
type = pFile->locktype;
if( type>=EXCLUSIVE_LOCK ){
LockArea.lOffset = 0L;
LockArea.lRange = 0L;
UnlockArea.lOffset = SHARED_FIRST;
UnlockArea.lRange = SHARED_SIZE;
res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
OSTRACE(( "UNLOCK %d exclusive lock res=%d\n", pFile->h, res ));
if( locktype==SHARED_LOCK && getReadLock(pFile) != NO_ERROR ){
/* This should never happen. We should always be able to
** reacquire the read lock */
OSTRACE(( "UNLOCK %d to %d getReadLock() failed\n", pFile->h, locktype ));
rc = SQLITE_IOERR_UNLOCK;
}
}
if( type>=RESERVED_LOCK ){
LockArea.lOffset = 0L;
LockArea.lRange = 0L;
UnlockArea.lOffset = RESERVED_BYTE;
UnlockArea.lRange = 1L;
res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
OSTRACE(( "UNLOCK %d reserved res=%d\n", pFile->h, res ));
}
if( locktype==NO_LOCK && type>=SHARED_LOCK ){
res = unlockReadLock(pFile);
OSTRACE(( "UNLOCK %d is %d want %d res=%d\n",
pFile->h, type, locktype, res ));
}
if( type>=PENDING_LOCK ){
LockArea.lOffset = 0L;
LockArea.lRange = 0L;
UnlockArea.lOffset = PENDING_BYTE;
UnlockArea.lRange = 1L;
res = DosSetFileLocks( pFile->h, &UnlockArea, &LockArea, LOCK_TIMEOUT, 0L );
OSTRACE(( "UNLOCK %d pending res=%d\n", pFile->h, res ));
}
pFile->locktype = locktype;
OSTRACE(( "UNLOCK %d now %d\n", pFile->h, pFile->locktype ));
return rc;
}
/*
** Control and query of the open file handle.
*/
static int os2FileControl(sqlite3_file *id, int op, void *pArg){
switch( op ){
case SQLITE_FCNTL_LOCKSTATE: {
*(int*)pArg = ((os2File*)id)->locktype;
OSTRACE(( "FCNTL_LOCKSTATE %d lock=%d\n",
((os2File*)id)->h, ((os2File*)id)->locktype ));
return SQLITE_OK;
}
case SQLITE_FCNTL_CHUNK_SIZE: {
((os2File*)id)->szChunk = *(int*)pArg;
return SQLITE_OK;
}
case SQLITE_FCNTL_SIZE_HINT: {
sqlite3_int64 sz = *(sqlite3_int64*)pArg;
SimulateIOErrorBenign(1);
os2Truncate(id, sz);
SimulateIOErrorBenign(0);
return SQLITE_OK;
}
case SQLITE_FCNTL_SYNC_OMITTED: {
return SQLITE_OK;
}
}
return SQLITE_NOTFOUND;
}
/*
** Return the sector size in bytes of the underlying block device for
** the specified file. This is almost always 512 bytes, but may be
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and its journal file) that the sector size will be the
** same for both.
*/
static int os2SectorSize(sqlite3_file *id){
UNUSED_PARAMETER(id);
return SQLITE_DEFAULT_SECTOR_SIZE;
}
/*
** Return a vector of device characteristics.
*/
static int os2DeviceCharacteristics(sqlite3_file *id){
UNUSED_PARAMETER(id);
return SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN;
}
/*
** Character set conversion objects used by conversion routines.
*/
static UconvObject ucUtf8 = NULL; /* convert between UTF-8 and UCS-2 */
static UconvObject uclCp = NULL; /* convert between local codepage and UCS-2 */
/*
** Helper function to initialize the conversion objects from and to UTF-8.
*/
static void initUconvObjects( void ){
if( UniCreateUconvObject( UTF_8, &ucUtf8 ) != ULS_SUCCESS )
ucUtf8 = NULL;
if ( UniCreateUconvObject( (UniChar *)L"@path=yes", &uclCp ) != ULS_SUCCESS )
uclCp = NULL;
}
/*
** Helper function to free the conversion objects from and to UTF-8.
*/
static void freeUconvObjects( void ){
if ( ucUtf8 )
UniFreeUconvObject( ucUtf8 );
if ( uclCp )
UniFreeUconvObject( uclCp );
ucUtf8 = NULL;
uclCp = NULL;
}
/*
** Helper function to convert UTF-8 filenames to local OS/2 codepage.
** The two-step process: first convert the incoming UTF-8 string
** into UCS-2 and then from UCS-2 to the current codepage.
** The returned char pointer has to be freed.
*/
static char *convertUtf8PathToCp( const char *in ){
UniChar tempPath[CCHMAXPATH];
char *out = (char *)calloc( CCHMAXPATH, 1 );
if( !out )
return NULL;
if( !ucUtf8 || !uclCp )
initUconvObjects();
/* determine string for the conversion of UTF-8 which is CP1208 */
if( UniStrToUcs( ucUtf8, tempPath, (char *)in, CCHMAXPATH ) != ULS_SUCCESS )
return out; /* if conversion fails, return the empty string */
/* conversion for current codepage which can be used for paths */
UniStrFromUcs( uclCp, out, tempPath, CCHMAXPATH );
return out;
}
/*
** Helper function to convert filenames from local codepage to UTF-8.
** The two-step process: first convert the incoming codepage-specific
** string into UCS-2 and then from UCS-2 to the codepage of UTF-8.
** The returned char pointer has to be freed.
**
** This function is non-static to be able to use this in shell.c and
** similar applications that take command line arguments.
*/
char *convertCpPathToUtf8( const char *in ){
UniChar tempPath[CCHMAXPATH];
char *out = (char *)calloc( CCHMAXPATH, 1 );
if( !out )
return NULL;
if( !ucUtf8 || !uclCp )
initUconvObjects();
/* conversion for current codepage which can be used for paths */
if( UniStrToUcs( uclCp, tempPath, (char *)in, CCHMAXPATH ) != ULS_SUCCESS )
return out; /* if conversion fails, return the empty string */
/* determine string for the conversion of UTF-8 which is CP1208 */
UniStrFromUcs( ucUtf8, out, tempPath, CCHMAXPATH );
return out;
}
#ifndef SQLITE_OMIT_WAL
/*
** Use main database file for interprocess locking. If un-defined
** a separate file is created for this purpose. The file will be
** used only to set file locks. There will be no data written to it.
*/
#define SQLITE_OS2_NO_WAL_LOCK_FILE
#if 0
static void _ERR_TRACE( const char *fmt, ... ) {
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
fflush(stderr);
}
#define ERR_TRACE(rc, msg) \
if( (rc) != SQLITE_OK ) _ERR_TRACE msg;
#else
#define ERR_TRACE(rc, msg)
#endif
/*
** Helper functions to obtain and relinquish the global mutex. The
** global mutex is used to protect os2ShmNodeList.
**
** Function os2ShmMutexHeld() is used to assert() that the global mutex
** is held when required. This function is only used as part of assert()
** statements. e.g.
**
** os2ShmEnterMutex()
** assert( os2ShmMutexHeld() );
** os2ShmLeaveMutex()
*/
static void os2ShmEnterMutex(void){
sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
}
static void os2ShmLeaveMutex(void){
sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
}
#ifdef SQLITE_DEBUG
static int os2ShmMutexHeld(void) {
return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
}
int GetCurrentProcessId(void) {
PPIB pib;
DosGetInfoBlocks(NULL, &pib);
return (int)pib->pib_ulpid;
}
#endif
/*
** Object used to represent a the shared memory area for a single log file.
** When multiple threads all reference the same log-summary, each thread has
** its own os2File object, but they all point to a single instance of this
** object. In other words, each log-summary is opened only once per process.
**
** os2ShmMutexHeld() must be true when creating or destroying
** this object or while reading or writing the following fields:
**
** nRef
** pNext
**
** The following fields are read-only after the object is created:
**
** szRegion
** hLockFile
** shmBaseName
**
** Either os2ShmNode.mutex must be held or os2ShmNode.nRef==0 and
** os2ShmMutexHeld() is true when reading or writing any other field
** in this structure.
**
*/
struct os2ShmNode {
sqlite3_mutex *mutex; /* Mutex to access this object */
os2ShmNode *pNext; /* Next in list of all os2ShmNode objects */
int szRegion; /* Size of shared-memory regions */
int nRegion; /* Size of array apRegion */
void **apRegion; /* Array of pointers to shared-memory regions */
int nRef; /* Number of os2ShmLink objects pointing to this */
os2ShmLink *pFirst; /* First os2ShmLink object pointing to this */
HFILE hLockFile; /* File used for inter-process memory locking */
char shmBaseName[1]; /* Name of the memory object !!! must last !!! */
};
/*
** Structure used internally by this VFS to record the state of an
** open shared memory connection.
**
** The following fields are initialized when this object is created and
** are read-only thereafter:
**
** os2Shm.pShmNode
** os2Shm.id
**
** All other fields are read/write. The os2Shm.pShmNode->mutex must be held
** while accessing any read/write fields.
*/
struct os2ShmLink {
os2ShmNode *pShmNode; /* The underlying os2ShmNode object */
os2ShmLink *pNext; /* Next os2Shm with the same os2ShmNode */
u32 sharedMask; /* Mask of shared locks held */
u32 exclMask; /* Mask of exclusive locks held */
#ifdef SQLITE_DEBUG
u8 id; /* Id of this connection with its os2ShmNode */
#endif
};
/*
** A global list of all os2ShmNode objects.
**
** The os2ShmMutexHeld() must be true while reading or writing this list.
*/
static os2ShmNode *os2ShmNodeList = NULL;
/*
** Constants used for locking
*/
#ifdef SQLITE_OS2_NO_WAL_LOCK_FILE
#define OS2_SHM_BASE (PENDING_BYTE + 0x10000) /* first lock byte */
#else
#define OS2_SHM_BASE ((22+SQLITE_SHM_NLOCK)*4) /* first lock byte */
#endif
#define OS2_SHM_DMS (OS2_SHM_BASE+SQLITE_SHM_NLOCK) /* deadman switch */
/*
** Apply advisory locks for all n bytes beginning at ofst.
*/
#define _SHM_UNLCK 1 /* no lock */
#define _SHM_RDLCK 2 /* shared lock, no wait */
#define _SHM_WRLCK 3 /* exlusive lock, no wait */
#define _SHM_WRLCK_WAIT 4 /* exclusive lock, wait */
static int os2ShmSystemLock(
os2ShmNode *pNode, /* Apply locks to this open shared-memory segment */
int lockType, /* _SHM_UNLCK, _SHM_RDLCK, _SHM_WRLCK or _SHM_WRLCK_WAIT */
int ofst, /* Offset to first byte to be locked/unlocked */
int nByte /* Number of bytes to lock or unlock */
){
APIRET rc;
FILELOCK area;
ULONG mode, timeout;
/* Access to the os2ShmNode object is serialized by the caller */
assert( sqlite3_mutex_held(pNode->mutex) || pNode->nRef==0 );
mode = 1; /* shared lock */
timeout = 0; /* no wait */
area.lOffset = ofst;
area.lRange = nByte;
switch( lockType ) {
case _SHM_WRLCK_WAIT:
timeout = (ULONG)-1; /* wait forever */
case _SHM_WRLCK:
mode = 0; /* exclusive lock */
case _SHM_RDLCK:
rc = DosSetFileLocks(pNode->hLockFile,
NULL, &area, timeout, mode);
break;
/* case _SHM_UNLCK: */
default:
rc = DosSetFileLocks(pNode->hLockFile,
&area, NULL, 0, 0);
break;
}
OSTRACE(("SHM-LOCK %d %s %s 0x%08lx\n",
pNode->hLockFile,
rc==SQLITE_OK ? "ok" : "failed",
lockType==_SHM_UNLCK ? "Unlock" : "Lock",
rc));
ERR_TRACE(rc, ("os2ShmSystemLock: %d %s\n", rc, pNode->shmBaseName))
return ( rc == 0 ) ? SQLITE_OK : SQLITE_BUSY;
}
/*
** Find an os2ShmNode in global list or allocate a new one, if not found.
**
** This is not a VFS shared-memory method; it is a utility function called
** by VFS shared-memory methods.
*/
static int os2OpenSharedMemory( os2File *fd, int szRegion ) {
os2ShmLink *pLink;
os2ShmNode *pNode;
int cbShmName, rc = SQLITE_OK;
char shmName[CCHMAXPATH + 30];
#ifndef SQLITE_OS2_NO_WAL_LOCK_FILE
ULONG action;
#endif
/* We need some additional space at the end to append the region number */
cbShmName = sprintf(shmName, "\\SHAREMEM\\%s", fd->zFullPathCp );
if( cbShmName >= CCHMAXPATH-8 )
return SQLITE_IOERR_SHMOPEN;
/* Replace colon in file name to form a valid shared memory name */
shmName[10+1] = '!';
/* Allocate link object (we free it later in case of failure) */
pLink = sqlite3_malloc( sizeof(*pLink) );
if( !pLink )
return SQLITE_NOMEM;
/* Access node list */
os2ShmEnterMutex();
/* Find node by it's shared memory base name */
for( pNode = os2ShmNodeList;
pNode && stricmp(shmName, pNode->shmBaseName) != 0;
pNode = pNode->pNext ) ;
/* Not found: allocate a new node */
if( !pNode ) {
pNode = sqlite3_malloc( sizeof(*pNode) + cbShmName );
if( pNode ) {
memset(pNode, 0, sizeof(*pNode) );
pNode->szRegion = szRegion;
pNode->hLockFile = (HFILE)-1;
strcpy(pNode->shmBaseName, shmName);
#ifdef SQLITE_OS2_NO_WAL_LOCK_FILE
if( DosDupHandle(fd->h, &pNode->hLockFile) != 0 ) {
#else
sprintf(shmName, "%s-lck", fd->zFullPathCp);
if( DosOpen((PSZ)shmName, &pNode->hLockFile, &action, 0, FILE_NORMAL,
OPEN_ACTION_OPEN_IF_EXISTS | OPEN_ACTION_CREATE_IF_NEW,
OPEN_ACCESS_READWRITE | OPEN_SHARE_DENYNONE |
OPEN_FLAGS_NOINHERIT | OPEN_FLAGS_FAIL_ON_ERROR,
NULL) != 0 ) {
#endif
sqlite3_free(pNode);
rc = SQLITE_IOERR;
} else {
pNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
if( !pNode->mutex ) {
sqlite3_free(pNode);
rc = SQLITE_NOMEM;
}
}
} else {
rc = SQLITE_NOMEM;
}
if( rc == SQLITE_OK ) {
pNode->pNext = os2ShmNodeList;
os2ShmNodeList = pNode;
} else {
pNode = NULL;
}
} else if( pNode->szRegion != szRegion ) {
rc = SQLITE_IOERR_SHMSIZE;
pNode = NULL;
}
if( pNode ) {
sqlite3_mutex_enter(pNode->mutex);
memset(pLink, 0, sizeof(*pLink));
pLink->pShmNode = pNode;
pLink->pNext = pNode->pFirst;
pNode->pFirst = pLink;
pNode->nRef++;
fd->pShmLink = pLink;
sqlite3_mutex_leave(pNode->mutex);
} else {
/* Error occured. Free our link object. */
sqlite3_free(pLink);
}
os2ShmLeaveMutex();
ERR_TRACE(rc, ("os2OpenSharedMemory: %d %s\n", rc, fd->zFullPathCp))
return rc;
}
/*
** Purge the os2ShmNodeList list of all entries with nRef==0.
**
** This is not a VFS shared-memory method; it is a utility function called
** by VFS shared-memory methods.
*/
static void os2PurgeShmNodes( int deleteFlag ) {
os2ShmNode *pNode;
os2ShmNode **ppNode;
os2ShmEnterMutex();
ppNode = &os2ShmNodeList;
while( *ppNode ) {
pNode = *ppNode;
if( pNode->nRef == 0 ) {
*ppNode = pNode->pNext;
if( pNode->apRegion ) {