Lines Matching full:counter

80 A ``QemuLockCnt`` comprises both a counter and a mutex; it has primitives
81 to increment and decrement the counter, and to take and release the
82 mutex.  The counter notes how many visits to the data structures are
85 governing the counter/mutex pair then are the following:
88   counter is zero and the mutex is taken.
90 - A new visit cannot be started while the counter is zero and the
104 This could be implemented simply by protecting the counter with the
135 counter to never become zero.  For this reason, this technique is
139 them for each modification of the counter.  ``QemuLockCnt`` ensures that
140 all modifications of the counter take the lock appropriately, and it
144   incrementing the counter while it is non-zero);
148   than simply managing a counter using atomic operations (see
154 inefficiencies; for example, a visit can never start if the counter is