From 1b5ba8e022836fa8ab93bc90df1b34a29ea6e134 Mon Sep 17 00:00:00 2001 From: Hans-Christoph Steiner Date: Thu, 17 Jan 2013 14:18:26 -0500 Subject: Imported Upstream version 2.1.1 --- src/mutex_os2.c | 274 -------------------------------------------------------- 1 file changed, 274 deletions(-) delete mode 100644 src/mutex_os2.c (limited to 'src/mutex_os2.c') diff --git a/src/mutex_os2.c b/src/mutex_os2.c deleted file mode 100644 index ce650d9..0000000 --- a/src/mutex_os2.c +++ /dev/null @@ -1,274 +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 -*/ -#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 -** Each recursive mutex is an instance of the following structure. -*/ -struct sqlite3_mutex { - HMTX mutex; /* Mutex controlling the lock */ - int id; /* Mutex type */ -#ifdef SQLITE_DEBUG - int trace; /* True to trace changes */ -#endif -}; - -#ifdef SQLITE_DEBUG -#define SQLITE3_MUTEX_INITIALIZER { 0, 0, 0 } -#else -#define SQLITE3_MUTEX_INITIALIZER { 0, 0 } -#endif - -/* -** 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 -** mutex and returns a pointer to it. If it returns NULL -** 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: -** -** -** -** The first two constants cause sqlite3_mutex_alloc() to create -** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE -** is used but not necessarily so when SQLITE_MUTEX_FAST is used. -** The mutex implementation does not need to make a distinction -** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does -** not want to. But SQLite will only request a recursive mutex in -** cases where it really needs one. If a faster non-recursive mutex -** implementation is available on the host platform, the mutex subsystem -** might return such a mutex in response to SQLITE_MUTEX_FAST. -** -** The other allowed parameters to sqlite3_mutex_alloc() each return -** a pointer to a static preexisting mutex. Six static mutexes are -** used by the current version of SQLite. Future versions of SQLite -** 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. -** -** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST -** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() -** returns a different mutex on every call. But for the static -** 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 ){ - case SQLITE_MUTEX_FAST: - case SQLITE_MUTEX_RECURSIVE: { - p = sqlite3MallocZero( sizeof(*p) ); - if( p ){ - p->id = iType; - if( DosCreateMutexSem( 0, &p->mutex, 0, FALSE ) != NO_ERROR ){ - sqlite3_free( p ); - p = NULL; - } - } - break; - } - default: { - static volatile int isInit = 0; - static sqlite3_mutex staticMutexes[6] = { - SQLITE3_MUTEX_INITIALIZER, - SQLITE3_MUTEX_INITIALIZER, - SQLITE3_MUTEX_INITIALIZER, - SQLITE3_MUTEX_INITIALIZER, - SQLITE3_MUTEX_INITIALIZER, - SQLITE3_MUTEX_INITIALIZER, - }; - if ( !isInit ){ - APIRET rc; - PTIB ptib; - PPIB ppib; - HMTX mutex; - char name[32]; - DosGetInfoBlocks( &ptib, &ppib ); - sqlite3_snprintf( sizeof(name), name, "\\SEM32\\SQLITE%04x", - ppib->pib_ulpid ); - while( !isInit ){ - mutex = 0; - rc = DosCreateMutexSem( name, &mutex, 0, FALSE); - if( rc == NO_ERROR ){ - unsigned int i; - if( !isInit ){ - for( i = 0; i < sizeof(staticMutexes)/sizeof(staticMutexes[0]); i++ ){ - DosCreateMutexSem( 0, &staticMutexes[i].mutex, 0, FALSE ); - } - isInit = 1; - } - DosCloseMutexSem( mutex ); - }else if( rc == ERROR_DUPLICATE_NAME ){ - DosSleep( 1 ); - }else{ - return p; - } - } - } - assert( iType-2 >= 0 ); - 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){ -#ifdef SQLITE_DEBUG - TID tid; - PID pid; - ULONG ulCount; - DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount); - assert( ulCount==0 ); - assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE ); -#endif - DosCloseMutexSem( p->mutex ); - sqlite3_free( p ); -} - -#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; - DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount); - if( ulCount==0 || ( ulCount>1 && p->id!=SQLITE_MUTEX_RECURSIVE ) ) - return 0; - DosGetInfoBlocks(&ptib, NULL); - return tid==ptib->tib_ptib2->tib2_ultid; -} -static int os2MutexNotheld(sqlite3_mutex *p){ - TID tid; - PID pid; - ULONG ulCount; - PTIB ptib; - DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount); - if( ulCount==0 ) - return 1; - DosGetInfoBlocks(&ptib, NULL); - return tid!=ptib->tib_ptib2->tib2_ultid; -} -static void os2MutexTrace(sqlite3_mutex *p, char *pAction){ - TID tid; - PID pid; - ULONG ulCount; - DosQueryMutexSem(p->mutex, &pid, &tid, &ulCount); - printf("%s mutex %p (%d) with nRef=%ld\n", pAction, (void*)p, p->trace, ulCount); -} -#endif - -/* -** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt -** to enter a mutex. If another thread is already within the mutex, -** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return -** SQLITE_BUSY. The sqlite3_mutex_try() interface returns SQLITE_OK -** upon successful entry. Mutexes created using SQLITE_MUTEX_RECURSIVE can -** be entered multiple times by the same thread. In such cases the, -** mutex must be exited an equal number of times before another thread -** can enter. If the same thread tries to enter any other kind of mutex -** more than once, the behavior is undefined. -*/ -static void os2MutexEnter(sqlite3_mutex *p){ - assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) ); - DosRequestMutexSem(p->mutex, SEM_INDEFINITE_WAIT); -#ifdef SQLITE_DEBUG - if( p->trace ) os2MutexTrace(p, "enter"); -#endif -} -static int os2MutexTry(sqlite3_mutex *p){ - int rc = SQLITE_BUSY; - assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) ); - if( DosRequestMutexSem(p->mutex, SEM_IMMEDIATE_RETURN) == NO_ERROR ) { - rc = SQLITE_OK; -#ifdef SQLITE_DEBUG - if( p->trace ) os2MutexTrace(p, "try"); -#endif - } - 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){ - assert( os2MutexHeld(p) ); - DosReleaseMutexSem(p->mutex); -#ifdef SQLITE_DEBUG - if( p->trace ) os2MutexTrace(p, "leave"); -#endif -} - -sqlite3_mutex_methods const *sqlite3DefaultMutex(void){ - static const sqlite3_mutex_methods sMutex = { - os2MutexInit, - os2MutexEnd, - os2MutexAlloc, - os2MutexFree, - os2MutexEnter, - os2MutexTry, - os2MutexLeave, -#ifdef SQLITE_DEBUG - os2MutexHeld, - os2MutexNotheld -#else - 0, - 0 -#endif - }; - - return &sMutex; -} -#endif /* SQLITE_MUTEX_OS2 */ -- cgit v1.2.3