| Index: third_party/sqlite/src/mutex_os2.c
|
| ===================================================================
|
| --- third_party/sqlite/src/mutex_os2.c (revision 56608)
|
| +++ third_party/sqlite/src/mutex_os2.c (working copy)
|
| @@ -1,273 +0,0 @@
|
| -/*
|
| -** 2007 August 28
|
| -**
|
| -** 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 the C functions that implement mutexes for OS/2
|
| -**
|
| -** $Id: mutex_os2.c,v 1.11 2008/11/22 19:50:54 pweilbacher Exp $
|
| -*/
|
| -#include "sqliteInt.h"
|
| -
|
| -/*
|
| -** The code in this file is only used if SQLITE_MUTEX_OS2 is defined.
|
| -** See the mutex.h file for details.
|
| -*/
|
| -#ifdef SQLITE_MUTEX_OS2
|
| -
|
| -/********************** OS/2 Mutex Implementation **********************
|
| -**
|
| -** This implementation of mutexes is built using the OS/2 API.
|
| -*/
|
| -
|
| -/*
|
| -** The mutex object
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| -** Each recursive mutex is an instance of the following structure.
|
| -*/
|
| -struct sqlite3_mutex {
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| - HMTX mutex; /* Mutex controlling the lock */
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| - int id; /* Mutex type */
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| - int nRef; /* Number of references */
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| - TID owner; /* Thread holding this mutex */
|
| -};
|
| -
|
| -#define OS2_MUTEX_INITIALIZER 0,0,0,0
|
| -
|
| -/*
|
| -** Initialize and deinitialize the mutex subsystem.
|
| -*/
|
| -static int os2MutexInit(void){ return SQLITE_OK; }
|
| -static int os2MutexEnd(void){ return SQLITE_OK; }
|
| -
|
| -/*
|
| -** The sqlite3_mutex_alloc() routine allocates a new
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| -** mutex and returns a pointer to it. If it returns NULL
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| -** that means that a mutex could not be allocated.
|
| -** SQLite will unwind its stack and return an error. The argument
|
| -** to sqlite3_mutex_alloc() is one of these integer constants:
|
| -**
|
| -** <ul>
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| -** <li> SQLITE_MUTEX_FAST 0
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| -** <li> SQLITE_MUTEX_RECURSIVE 1
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| -** <li> SQLITE_MUTEX_STATIC_MASTER 2
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| -** <li> SQLITE_MUTEX_STATIC_MEM 3
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| -** <li> SQLITE_MUTEX_STATIC_PRNG 4
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| -** </ul>
|
| -**
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| -** The first two constants cause sqlite3_mutex_alloc() to create
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| -** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
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| -** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
|
| -** The mutex implementation does not need to make a distinction
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| -** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
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| -** not want to. But SQLite will only request a recursive mutex in
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| -** cases where it really needs one. If a faster non-recursive mutex
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| -** implementation is available on the host platform, the mutex subsystem
|
| -** might return such a mutex in response to SQLITE_MUTEX_FAST.
|
| -**
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| -** The other allowed parameters to sqlite3_mutex_alloc() each return
|
| -** a pointer to a static preexisting mutex. Three static mutexes are
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| -** used by the current version of SQLite. Future versions of SQLite
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| -** may add additional static mutexes. Static mutexes are for internal
|
| -** use by SQLite only. Applications that use SQLite mutexes should
|
| -** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
|
| -** SQLITE_MUTEX_RECURSIVE.
|
| -**
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| -** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
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| -** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
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| -** returns a different mutex on every call. But for the static
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| -** mutex types, the same mutex is returned on every call that has
|
| -** the same type number.
|
| -*/
|
| -static sqlite3_mutex *os2MutexAlloc(int iType){
|
| - sqlite3_mutex *p = NULL;
|
| - switch( iType ){
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| - case SQLITE_MUTEX_FAST:
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| - case SQLITE_MUTEX_RECURSIVE: {
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| - p = sqlite3MallocZero( sizeof(*p) );
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| - if( p ){
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| - p->id = iType;
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| - if( DosCreateMutexSem( 0, &p->mutex, 0, FALSE ) != NO_ERROR ){
|
| - sqlite3_free( p );
|
| - p = NULL;
|
| - }
|
| - }
|
| - break;
|
| - }
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| - default: {
|
| - static volatile int isInit = 0;
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| - static sqlite3_mutex staticMutexes[] = {
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| - { OS2_MUTEX_INITIALIZER, },
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| - { OS2_MUTEX_INITIALIZER, },
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| - { OS2_MUTEX_INITIALIZER, },
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| - { OS2_MUTEX_INITIALIZER, },
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| - { OS2_MUTEX_INITIALIZER, },
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| - { OS2_MUTEX_INITIALIZER, },
|
| - };
|
| - if ( !isInit ){
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| - APIRET rc;
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| - PTIB ptib;
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| - PPIB ppib;
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| - HMTX mutex;
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| - char name[32];
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| - DosGetInfoBlocks( &ptib, &ppib );
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| - sqlite3_snprintf( sizeof(name), name, "\\SEM32\\SQLITE%04x",
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| - ppib->pib_ulpid );
|
| - while( !isInit ){
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| - mutex = 0;
|
| - rc = DosCreateMutexSem( name, &mutex, 0, FALSE);
|
| - if( rc == NO_ERROR ){
|
| - unsigned int i;
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| - if( !isInit ){
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| - for( i = 0; i < sizeof(staticMutexes)/sizeof(staticMutexes[0]); i++ ){
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| - DosCreateMutexSem( 0, &staticMutexes[i].mutex, 0, FALSE );
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| - }
|
| - isInit = 1;
|
| - }
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| - DosCloseMutexSem( mutex );
|
| - }else if( rc == ERROR_DUPLICATE_NAME ){
|
| - DosSleep( 1 );
|
| - }else{
|
| - return p;
|
| - }
|
| - }
|
| - }
|
| - assert( iType-2 >= 0 );
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| - assert( iType-2 < sizeof(staticMutexes)/sizeof(staticMutexes[0]) );
|
| - p = &staticMutexes[iType-2];
|
| - p->id = iType;
|
| - break;
|
| - }
|
| - }
|
| - return p;
|
| -}
|
| -
|
| -
|
| -/*
|
| -** This routine deallocates a previously allocated mutex.
|
| -** SQLite is careful to deallocate every mutex that it allocates.
|
| -*/
|
| -static void os2MutexFree(sqlite3_mutex *p){
|
| - if( p==0 ) return;
|
| - assert( p->nRef==0 );
|
| - assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
|
| - DosCloseMutexSem( p->mutex );
|
| - sqlite3_free( p );
|
| -}
|
| -
|
| -/*
|
| -** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
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| -** to enter a mutex. If another thread is already within the mutex,
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| -** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
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| -** SQLITE_BUSY. The sqlite3_mutex_try() interface returns SQLITE_OK
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| -** upon successful entry. Mutexes created using SQLITE_MUTEX_RECURSIVE can
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| -** be entered multiple times by the same thread. In such cases the,
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| -** mutex must be exited an equal number of times before another thread
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| -** can enter. If the same thread tries to enter any other kind of mutex
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| -** more than once, the behavior is undefined.
|
| -*/
|
| -static void os2MutexEnter(sqlite3_mutex *p){
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| - TID tid;
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| - PID holder1;
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| - ULONG holder2;
|
| - if( p==0 ) return;
|
| - assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) );
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| - DosRequestMutexSem(p->mutex, SEM_INDEFINITE_WAIT);
|
| - DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
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| - p->owner = tid;
|
| - p->nRef++;
|
| -}
|
| -static int os2MutexTry(sqlite3_mutex *p){
|
| - int rc;
|
| - TID tid;
|
| - PID holder1;
|
| - ULONG holder2;
|
| - if( p==0 ) return SQLITE_OK;
|
| - assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) );
|
| - if( DosRequestMutexSem(p->mutex, SEM_IMMEDIATE_RETURN) == NO_ERROR) {
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| - DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
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| - p->owner = tid;
|
| - p->nRef++;
|
| - rc = SQLITE_OK;
|
| - } else {
|
| - rc = SQLITE_BUSY;
|
| - }
|
| -
|
| - return rc;
|
| -}
|
| -
|
| -/*
|
| -** The sqlite3_mutex_leave() routine exits a mutex that was
|
| -** previously entered by the same thread. The behavior
|
| -** is undefined if the mutex is not currently entered or
|
| -** is not currently allocated. SQLite will never do either.
|
| -*/
|
| -static void os2MutexLeave(sqlite3_mutex *p){
|
| - TID tid;
|
| - PID holder1;
|
| - ULONG holder2;
|
| - if( p==0 ) return;
|
| - assert( p->nRef>0 );
|
| - DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
|
| - assert( p->owner==tid );
|
| - p->nRef--;
|
| - assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );
|
| - DosReleaseMutexSem(p->mutex);
|
| -}
|
| -
|
| -#ifdef SQLITE_DEBUG
|
| -/*
|
| -** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
|
| -** intended for use inside assert() statements.
|
| -*/
|
| -static int os2MutexHeld(sqlite3_mutex *p){
|
| - TID tid;
|
| - PID pid;
|
| - ULONG ulCount;
|
| - PTIB ptib;
|
| - if( p!=0 ) {
|
| - DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
|
| - } else {
|
| - DosGetInfoBlocks(&ptib, NULL);
|
| - tid = ptib->tib_ptib2->tib2_ultid;
|
| - }
|
| - return p==0 || (p->nRef!=0 && p->owner==tid);
|
| -}
|
| -static int os2MutexNotheld(sqlite3_mutex *p){
|
| - TID tid;
|
| - PID pid;
|
| - ULONG ulCount;
|
| - PTIB ptib;
|
| - if( p!= 0 ) {
|
| - DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount);
|
| - } else {
|
| - DosGetInfoBlocks(&ptib, NULL);
|
| - tid = ptib->tib_ptib2->tib2_ultid;
|
| - }
|
| - return p==0 || p->nRef==0 || p->owner!=tid;
|
| -}
|
| -#endif
|
| -
|
| -sqlite3_mutex_methods *sqlite3DefaultMutex(void){
|
| - static sqlite3_mutex_methods sMutex = {
|
| - os2MutexInit,
|
| - os2MutexEnd,
|
| - os2MutexAlloc,
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| - os2MutexFree,
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| - os2MutexEnter,
|
| - os2MutexTry,
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| - os2MutexLeave,
|
| -#ifdef SQLITE_DEBUG
|
| - os2MutexHeld,
|
| - os2MutexNotheld
|
| -#endif
|
| - };
|
| -
|
| - return &sMutex;
|
| -}
|
| -#endif /* SQLITE_MUTEX_OS2 */
|
|
|