void Mutex::acquire(pointer called_by)
{
if(unlikely(system_state != RUNNING))
return;
if(!called_by)
called_by = getCalledBefore(1);
// debug(LOCK, "Mutex::acquire: Mutex: %s (%p), currentThread: %s (%p).\n",
// getName(), this, currentThread->getName(), currentThread);
// if(kernel_debug_info)
// {
// debug(LOCK, "The acquire is called by: ");
// kernel_debug_info->printCallInformation(called_by);
// }
while(ArchThreads::testSetLock(mutex_, 1))
{
checkCurrentThreadStillWaitingOnAnotherLock();
lockWaitersList();
// Here we have to check for the lock again, in case some one released it in between, we might sleep forever.
if(!ArchThreads::testSetLock(mutex_, 1))
{
unlockWaitersList();
break;
}
// check for deadlocks, interrupts...
doChecksBeforeWaiting();
Scheduler::instance()->sleepAndRelease(*(Lock*)this);
// We have been waken up again.
currentThread->lock_waiting_on_ = 0;
}
assert(held_by_ == 0);
pushFrontToCurrentThreadHoldingList();
last_accessed_at_ = called_by;
held_by_ = currentThread;
}
void Mutex::acquire(const char* debug_info)
{
if(unlikely(system_state != RUNNING))
return;
//debug(LOCK, "Mutex::acquire: Mutex: %s (%p), currentThread: %s (%p).\n",
// getName(), this, currentThread->getName(), currentThread);
while(ArchThreads::testSetLock(mutex_, 1))
{
checkCurrentThreadStillWaitingOnAnotherLock(debug_info);
lockWaitersList();
// Here we have to check for the lock again, in case some one released it in between, we might sleep forever.
if(!ArchThreads::testSetLock(mutex_, 1))
{
unlockWaitersList();
break;
}
// check for deadlocks, interrupts...
doChecksBeforeWaiting(debug_info);
Scheduler::instance()->sleepAndRelease(*(Lock*)this);
// We have been waken up again.
currentThread->lock_waiting_on_ = 0;
}
assert(held_by_ == 0);
pushFrontToCurrentThreadHoldingList();
held_by_ = currentThread;
}
bool Mutex::acquireNonBlocking(pointer called_by)
{
if(unlikely(system_state != RUNNING))
return true;
if(!called_by)
called_by = getCalledBefore(1);
// debug(LOCK, "Mutex::acquireNonBlocking: Mutex: %s (%p), currentThread: %s (%p).\n",
// getName(), this, currentThread->getName(), currentThread);
// if(kernel_debug_info)
// {
// debug(LOCK, "The acquire is called by: ");
// kernel_debug_info->printCallInformation(called_by);
// }
// There may be some cases where the pre-checks may not be wished here.
// But these cases are usually dirty implemented, and it would not be necessary to call this method there.
// So in case you see this comment, re-think your implementation and don't just comment out this line!
doChecksBeforeWaiting();
if(ArchThreads::testSetLock(mutex_, 1))
{
// The mutex is already held by another thread,
// so we are not allowed to lock it.
return false;
}
assert(held_by_ == 0);
last_accessed_at_ = called_by;
held_by_ = currentThread;
pushFrontToCurrentThreadHoldingList();
return true;
}
