/*
** 2005 November 29
**
** 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 OS interface code that is common to all
** architectures.
*/
#define _SQLITE_OS_C_ 1
#include "sqliteInt.h"
#undef _SQLITE_OS_C_
/*
** If we compile with the SQLITE_TEST macro set, then the following block
** of code will give us the ability to simulate a disk I/O error. This
** is used for testing the I/O recovery logic.
*/
#if defined(SQLITE_TEST)
int sqlite3_io_error_hit = 0; /* Total number of I/O Errors */
int sqlite3_io_error_hardhit = 0; /* Number of non-benign errors */
int sqlite3_io_error_pending = 0; /* Count down to first I/O error */
int sqlite3_io_error_persist = 0; /* True if I/O errors persist */
int sqlite3_io_error_benign = 0; /* True if errors are benign */
int sqlite3_diskfull_pending = 0;
int sqlite3_diskfull = 0;
#endif /* defined(SQLITE_TEST) */
/*
** When testing, also keep a count of the number of open files.
*/
#if defined(SQLITE_TEST)
int sqlite3_open_file_count = 0;
#endif /* defined(SQLITE_TEST) */
/*
** The default SQLite sqlite3_vfs implementations do not allocate
** memory (actually, os_unix.c allocates a small amount of memory
** from within OsOpen()), but some third-party implementations may.
** So we test the effects of a malloc() failing and the sqlite3OsXXX()
** function returning SQLITE_IOERR_NOMEM using the DO_OS_MALLOC_TEST macro.
**
** The following functions are instrumented for malloc() failure
** testing:
**
** sqlite3OsRead()
** sqlite3OsWrite()
** sqlite3OsSync()
** sqlite3OsFileSize()
** sqlite3OsLock()
** sqlite3OsCheckReservedLock()
** sqlite3OsFileControl()
** sqlite3OsShmMap()
** sqlite3OsOpen()
** sqlite3OsDelete()
** sqlite3OsAccess()
** sqlite3OsFullPathname()
**
*/
#if defined(SQLITE_TEST)
int sqlite3_memdebug_vfs_oom_test = 1;
#define DO_OS_MALLOC_TEST(x) \
if (sqlite3_memdebug_vfs_oom_test && (!x || !sqlite3JournalIsInMemory(x))) { \
void *pTstAlloc = sqlite3Malloc(10); \
if (!pTstAlloc) return SQLITE_IOERR_NOMEM_BKPT; \
sqlite3_free(pTstAlloc); \
}
#else
#define DO_OS_MALLOC_TEST(x)
#endif
/*
** The following routines are convenience wrappers around methods
** of the sqlite3_file object. This is mostly just syntactic sugar. All
** of this would be completely automatic if SQLite were coded using
** C++ instead of plain old C.
*/
int sqlite3OsClose(sqlite3_file *pId){
int rc = SQLITE_OK;
if( pId->pMethods ){
rc = pId->pMethods->xClose(pId);
pId->pMethods = 0;
}
return rc;
}
int sqlite3OsRead(sqlite3_file *id, void *pBuf, int amt, i64 offset){
DO_OS_MALLOC_TEST(id);
return id->pMethods->xRead(id, pBuf, amt, offset);
}
int sqlite3OsWrite(sqlite3_file *id, const void *pBuf, int amt, i64 offset){
DO_OS_MALLOC_TEST(id);
return id->pMethods->xWrite(id, pBuf, amt, offset);
}
int sqlite3OsTruncate(sqlite3_file *id, i64 size){
return id->pMethods->xTruncate(id, size);
}
int sqlite3OsSync(sqlite3_file *id, int flags){
DO_OS_MALLOC_TEST(id);
return id->pMethods->xSync(id, flags);
}
int sqlite3OsFileSize(sqlite3_file *id, i64 *pSize){
DO_OS_MALLOC_TEST(id);
return id->pMethods->xFileSize(id, pSize);
}
int sqlite3OsLock(sqlite3_file *id, int lockType){
DO_OS_MALLOC_TEST(id);
return id->pMethods->xLock(id, lockType);
}
int sqlite3OsUnlock(sqlite3_file *id, int lockType){
return id->pMethods->xUnlock(id, lockType);
}
int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut){
DO_OS_MALLOC_TEST(id);
return id->pMethods->xCheckReservedLock(id, pResOut);
}
/*
** Use sqlite3OsFileControl() when we are doing something that might fail
** and we need to know about the failures. Use sqlite3OsFileControlHint()
** when simply tossing information over the wall to the VFS and we do not
** really care if the VFS receives and understands the information since it
** is only a hint and can be safely ignored. The sqlite3OsFileControlHint()
** routine has no return value since the return value would be meaningless.
*/
int sqlite3OsFileControl(sqlite3_file *id, int op, void *pArg){
#ifdef SQLITE_TEST
if( op!=SQLITE_FCNTL_COMMIT_PHASETWO ){
/* Faults are not injected into COMMIT_PHASETWO because, assuming SQLite
** is using a regular VFS, it is called after the corresponding
** transaction has been committed. Injecting a fault at this point
** confuses the test scripts - the COMMIT comand returns SQLITE_NOMEM
** but the transaction is committed anyway.
**
** The core must call OsFileControl() though, not OsFileControlHint(),
** as if a custom VFS (e.g. zipvfs) returns an error here, it probably
** means the commit really has failed and an error should be returned
** to the user. */
DO_OS_MALLOC_TEST(id);
}
#endif
return id->pMethods->xFileControl(id, op, pArg);
}
void sqlite3OsFileControlHint(sqlite3_file *id, int op, void *pArg){
(void)id->pMethods->xFileControl(id, op, pArg);
}
int sqlite3OsSectorSize(sqlite3_file *id){
int (*xSectorSize)(sqlite3_file*) = id->pMethods->xSectorSize;
return (xSectorSize ? xSectorSize(id) : SQLITE_DEFAULT_SECTOR_SIZE);
}
int sqlite3OsDeviceCharacteristics(sqlite3_file *id){
return id->pMethods->xDeviceCharacteristics(id);
}
int sqlite3OsShmLock(sqlite3_file *id, int offset, int n, int flags){
return id->pMethods->xShmLock(id, offset, n, flags);
}
void sqlite3OsShmBarrier(sqlite3_file *id){
id->pMethods->xShmBarrier(id);
}
int sqlite3OsShmUnmap(sqlite3_file *id, int deleteFlag){
return id->pMethods->xShmUnmap(id, deleteFlag);
}
int sqlite3OsShmMap(
sqlite3_file *id, /* Database file handle */
int iPage,
int pgsz,
int bExtend, /* True to extend file if necessary */
void volatile **pp /* OUT: Pointer to mapping */
){
DO_OS_MALLOC_TEST(id);
return id->pMethods->xShmMap(id, iPage, pgsz, bExtend, pp);
}
#if SQLITE_MAX_MMAP_SIZE>0
/* The real implementation of xFetch and xUnfetch */
int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){
DO_OS_MALLOC_TEST(id);
return id->pMethods->xFetch(id, iOff, iAmt, pp);
}
int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){
return id->pMethods->xUnfetch(id, iOff, p);
}
#else
/* No-op stubs to use when memory-mapped I/O is disabled */
int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){
*pp = 0;
return SQLITE_OK;
}
int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){
return SQLITE_OK;
}
#endif
/*
** The next group of routines are convenience wrappers around the
** VFS methods.
*/
int sqlite3OsOpen(
sqlite3_vfs *pVfs,
const char *zPath,
sqlite3_file *pFile,
int flags,
int *pFlagsOut
){
int rc;
DO_OS_MALLOC_TEST(0);
/* 0x87f7f is a mask of SQLITE_OPEN_ flags that are valid to be passed
** down into the VFS layer. Some SQLITE_OPEN_ flags (for example,
** SQLITE_OPEN_FULLMUTEX or SQLITE_OPEN_SHAREDCACHE) are blocked before
** reaching the VFS. */
rc = pVfs->xOpen(pVfs, zPath, pFile, flags & 0x87f7f, pFlagsOut);
assert( rc==SQLITE_OK || pFile->pMethods==0 );
return rc;
}
int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
DO_OS_MALLOC_TEST(0);
assert( dirSync==0 || dirSync==1 );
return pVfs->xDelete(pVfs, zPath, dirSync);
}
int sqlite3OsAccess(
sqlite3_vfs *pVfs,
const char *zPath,
int flags,
int *pResOut
){
DO_OS_MALLOC_TEST(0);
return pVfs->xAccess(pVfs, zPath, flags, pResOut);
}
int sqlite3OsFullPathname(
sqlite3_vfs *pVfs,
const char *zPath,
int nPathOut,
char *zPathOut
){
DO_OS_MALLOC_TEST(0);
zPathOut[0] = 0;
return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);
}
#ifndef SQLITE_OMIT_LOAD_EXTENSION
void *sqlite3OsDlOpen(sqlite3_vfs *pVfs, const char *zPath){
return pVfs->xDlOpen(pVfs, zPath);
}
void sqlite3OsDlError(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
pVfs->xDlError(pVfs, nByte, zBufOut);
}
void (*sqlite3OsDlSym(sqlite3_vfs *pVfs, void *pHdle, const char *zSym))(void){
return pVfs->xDlSym(pVfs, pHdle, zSym);
}
void sqlite3OsDlClose(sqlite3_vfs *pVfs, void *pHandle){
pVfs->xDlClose(pVfs, pHandle);
}
#endif /* SQLITE_OMIT_LOAD_EXTENSION */
int sqlite3OsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
return pVfs->xRandomness(pVfs, nByte, zBufOut);
}
int sqlite3OsSleep(sqlite3_vfs *pVfs, int nMicro){
return pVfs->xSleep(pVfs, nMicro);
}
int sqlite3OsCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *pTimeOut){
int rc;
/* IMPLEMENTATION-OF: R-49045-42493 SQLite will use the xCurrentTimeInt64()
** method to get the current date and time if that method is available
** (if iVersion is 2 or greater and the function pointer is not NULL) and
** will fall back to xCurrentTime() if xCurrentTimeInt64() is
** unavailable.
*/
if( pVfs->iVersion>=2 && pVfs->xCurrentTimeInt64 ){
rc = pVfs->xCurrentTimeInt64(pVfs, pTimeOut);
}else{
double r;
rc = pVfs->xCurrentTime(pVfs, &r);
*pTimeOut = (sqlite3_int64)(r*86400000.0);
}
return rc;
}
int sqlite3OsOpenMalloc(
sqlite3_vfs *pVfs,
const char *zFile,
sqlite3_file **ppFile,
int flags,
int *pOutFlags
){
int rc;
sqlite3_file *pFile;
pFile = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile);
if( pFile ){
rc = sqlite3OsOpen(pVfs, zFile, pFile, flags, pOutFlags);
if( rc!=SQLITE_OK ){
sqlite3_free(pFile);
}else{
*ppFile = pFile;
}
}else{
rc = SQLITE_NOMEM_BKPT;
}
return rc;
}
int sqlite3OsCloseFree(sqlite3_file *pFile){
int rc = SQLITE_OK;
assert( pFile );
rc = sqlite3OsClose(pFile);
sqlite3_free(pFile);
return rc;
}
/*
** This function is a wrapper around the OS specific implementation of
** sqlite3_os_init(). The purpose of the wrapper is to provide the
** ability to simulate a malloc failure, so that the handling of an
** error in sqlite3_os_init() by the upper layers can be tested.
*/
int sqlite3OsInit(void){
void *p = sqlite3_malloc(10);
if( p==0 ) return SQLITE_NOMEM_BKPT;
sqlite3_free(p);
return sqlite3_os_init();
}
/*
** The list of all registered VFS implementations.
*/
static sqlite3_vfs * SQLITE_WSD vfsList = 0;
#define vfsList GLOBAL(sqlite3_vfs *, vfsList)
/*
** Locate a VFS by name. If no name is given, simply return the
** first VFS on the list.
*/
sqlite3_vfs *sqlite3_vfs_find(const char *zVfs){
sqlite3_vfs *pVfs = 0;
#if SQLITE_THREADSAFE
sqlite3_mutex *mutex;
#endif
#ifndef SQLITE_OMIT_AUTOINIT
int rc = sqlite3_initialize();
if( rc ) return 0;
#endif
#if SQLITE_THREADSAFE
mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
#endif
sqlite3_mutex_enter(mutex);
for(pVfs = vfsList; pVfs; pVfs=pVfs->pNext){
if( zVfs==0 ) break;
if( strcmp(zVfs, pVfs->zName)==0 ) break;
}
sqlite3_mutex_leave(mutex);
return pVfs;
}
/*
** Unlink a VFS from the linked list
*/
static void vfsUnlink(sqlite3_vfs *pVfs){
assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)) );
if( pVfs==0 ){
/* No-op */
}else if( vfsList==pVfs ){
vfsList = pVfs->pNext;
}else if( vfsList ){
sqlite3_vfs *p = vfsList;
while( p->pNext && p->pNext!=pVfs ){
p = p->pNext;
}
if( p->pNext==pVfs ){
p->pNext = pVfs->pNext;
}
}
}
/*
** Register a VFS with the system. It is harmless to register the same
** VFS multiple times. The new VFS becomes the default if makeDflt is
** true.
*/
int sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){
MUTEX_LOGIC(sqlite3_mutex *mutex;)
#ifndef SQLITE_OMIT_AUTOINIT
int rc = sqlite3_initialize();
if( rc ) return rc;
#endif
#ifdef SQLITE_ENABLE_API_ARMOR
if( pVfs==0 ) return SQLITE_MISUSE_BKPT;
#endif
MUTEX_LOGIC( mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
sqlite3_mutex_enter(mutex);
vfsUnlink(pVfs);
if( makeDflt || vfsList==0 ){
pVfs->pNext = vfsList;
vfsList = pVfs;
}else{
pVfs->pNext = vfsList->pNext;
vfsList->pNext = pVfs;
}
assert(vfsList);
sqlite3_mutex_leave(mutex);
return SQLITE_OK;
}
/*
** Unregister a VFS so that it is no longer accessible.
*/
int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){
#if SQLITE_THREADSAFE
sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
#endif
sqlite3_mutex_enter(mutex);
vfsUnlink(pVfs);
sqlite3_mutex_leave(mutex);
return SQLITE_OK;
}