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#include "locks.hh"
#include "class_desc.hh" // for debugging
bool Locks::acquire(Lock lock) { // acquire lock Lock (add to lockset)
// return true if lock is new
monitor_table::iterator entry = monTable.find(lock);
if (entry == monTable.end()) { // new lock, insert
monTable.insert(monitor_table::value_type(lock, 1));
monStack.push_front(lock);
return true;
} else {
// lock exists, do nothing (for now); later version: incr. count
#ifdef DUMP_MONITOR
printf("Lock %s already acquired.\n", lock->name.as_asciz());
#endif
}
return false;
}
bool Locks::release(Lock lock) { // release lock Lock
// return true on success
if (getInnermost() == lock) {
monStack.pop_front();
monitor_table::iterator entry = monTable.find(lock);
if (entry != monTable.end()) { // ignore counter value for now
monTable.erase(entry);
}
return true;
} else {
#ifdef DUMP_MONITOR
Lock curr = getInnermost();
printf("Lock %s != %s could not be released.\n",
lock->name.as_asciz(), curr ? curr->name.as_asciz() : "<none>");
#endif
return false; // could not delete lock; was not innermost lock
}
}
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