/*
** 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
}
/*
** 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){
TID tid;
PID holder1;
ULONG holder2;
if( p==0 ) return;
assert( p->id==SQLITE_MUTEX_RECURSIVE || os2MutexNotheld(p) );
DosRequestMutexSem(p->mutex, SEM_INDEFINITE_WAIT);
DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
p->owner = tid;
p->nRef++;
}
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;
}
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) {
DosQueryMutexSem(p->mutex, &holder1, &tid, &holder2);
p->owner = tid;
p->nRef++;
rc = SQLITE_OK;
} else {
rc = SQLITE_BUSY;
}
return rc;
}