void lock_ConvertRToW(osi_rwlock_t *lockp)
{
long i;
CRITICAL_SECTION *csp;
DWORD tid = thrd_Current();
if ((i = lockp->type) != 0) {
if (i >= 0 && i < OSI_NLOCKTYPES)
(osi_lockOps[i]->ConvertRToWProc)(lockp);
return;
}
/* otherwise we're the fast base type */
csp = &osi_baseAtomicCS[lockp->atomicIndex];
EnterCriticalSection(csp);
osi_assertx(!(lockp->flags & OSI_LOCKFLAG_EXCL), "write lock held");
osi_assertx(lockp->readers > 0, "read lock not held");
for ( i=0; i < lockp->readers; i++) {
if ( lockp->tid[i] == tid ) {
for ( ; i < lockp->readers - 1; i++)
lockp->tid[i] = lockp->tid[i+1];
lockp->tid[i] = 0;
break;
}
}
if (--(lockp->readers) == 0) {
/* convert read lock to write lock */
lockp->flags |= OSI_LOCKFLAG_EXCL;
lockp->tid[0] = tid;
} else {
osi_assertx(lockp->readers > 0, "read lock underflow");
lockp->waiters++;
osi_TWaitExt(&lockp->d.turn, OSI_SLEEPINFO_W4WRITE, &lockp->flags, lockp->tid, csp, FALSE);
lockp->waiters--;
osi_assertx(lockp->waiters >= 0, "waiters underflow");
osi_assert(lockp->readers == 0 && (lockp->flags & OSI_LOCKFLAG_EXCL));
}
LeaveCriticalSection(csp);
}
void osi_TWait(osi_turnstile_t *turnp, int waitFor, void *patchp, DWORD *tidp, CRITICAL_SECTION *releasep)
{
osi_TWaitExt(turnp, waitFor, patchp, tidp, releasep, TRUE);
}