static void lock_W() {
LockState& ls = lockState();
if( ls.threadState == 't' ) {
DEV warning() << "W locking inside a temprelease, seems nonideal" << endl;
}
else if( ls.threadState ) {
log() << "can't lock_W, threadState=" << (int) ls.threadState << endl;
fassert(0,false);
}
getDur().commitIfNeeded(); // check before locking - will use an R lock for the commit if need to do one, which is better than W
threadState() = 'W';
{
Acquiring a('W');
q.lock_W();
}
locked_W();
}
Lock::GlobalWrite::GlobalWrite(bool sg, int timeoutms)
: ScopedLock('W') {
char ts = threadState();
noop = false;
if( ts == 'W' ) {
noop = true;
return;
}
dassert( ts == 0 );
Acquiring a(this,lockState());
if ( timeoutms != -1 ) {
bool success = qlk.lock_W_try( timeoutms );
if ( !success ) throw DBTryLockTimeoutException();
}
else {
qlk.lock_W();
}
}
void Lock::GlobalRead::_tempRelease() {
fassert(16127, !noop);
char ts = threadState();
fassert(16128, ts == 'R');
qlk.unlock_R();
}
bool Lock::isR() {
return threadState() == 'R';
}
bool Lock::isW() {
return threadState() == 'W';
}
bool Lock::isRW() {
return threadState() == 'W' || threadState() == 'R';
}
static void unlock_w() {
unlocking_w();
wassert( threadState() == 'w' );
threadState() = 0;
q.unlock_w();
}
int KNMusicStandardBackend::state() const
{
return threadState(m_main);
}
int Lock::isLocked() {
return threadState();
}
void Lock::ThreadSpanningOp::handoffR() {
threadState() = 0;
}
void Lock::ThreadSpanningOp::unsetR() {
assert( threadState() == 'R' || threadState() == 0 );
q.unlock_R();
q.start_greed();
threadState() = 0;
}
void Lock::ThreadSpanningOp::unsetW() { // note there is no unlocking_W() call here
assert( threadState() == 'W' );
q.unlock_W();
q.start_greed();
threadState() = 0;
}
void Lock::ThreadSpanningOp::W_to_R() {
assert( threadState() == 'W' );
dur::assertNothingSpooled();
q.W_to_R();
threadState() = 'R';
}
// these are safe for use ACROSS threads. i.e. one thread can lock and
// another unlock
void Lock::ThreadSpanningOp::setWLockedNongreedy() {
assert( threadState() == 0 ); // as this spans threads the tls wouldn't make sense
lock_W_stop_greed();
}
static void unlock_r() {
wassert( threadState() == 'r' );
threadState() = 0;
q.unlock_r();
}
void Lock::GlobalWrite::downgrade() {
verify( !noop );
verify( threadState() == 'W' );
qlk.W_to_R();
lockState().changeLockState( 'R' );
}
// you will deadlock if 2 threads doing this
void Lock::GlobalWrite::upgrade() {
verify( !noop );
verify( threadState() == 'R' );
qlk.R_to_W();
lockState().changeLockState( 'W' );
}
int Lock::isReadLocked() {
return threadState() == 'R' || threadState() == 'r';
}
int KNMusicStandardBackend::previewState() const
{
return threadState(m_preview);
}
int Lock::somethingWriteLocked() {
return threadState() == 'W' || threadState() == 'w';
}
