Shared State Concurrency - Common Lisp.net

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wlock-name rwlockReturns the name of rwlock.Function8
Condition VariablesA condition variable is a synchronization mechanism used by threads to wait for andsignal changes in the state of shared data. Two operations are definied: a threadcan wait on a condition variable, blocking itself until a change in some shared datahappens; and a thread can signal a condition variable, unblocking some thread thatis waiting on it. Usually, a wait is done by a thread that wants to change the shareddata, and a signal is done by a thread that has just changed the data.A condition variable is always connected to the change of state of some shareddata. Because of this, it has an associated lock that is used to protected thecritical sections of those shared data.make-condvar lock &key name &allow-other-keysFunctionThis creates and returns a new condition variable with lock as its associated lock.wait-condvar condvarFunctionThis atomically unlocks condvar’s associated lock and blocks the current threadon the condition variable condvar. Before returning, after the current thread isunblocked, the function relocks condvar’s associated lock. This function returns anunspecified value. If this function is called by a thread that does not own condvar’sassociated lock, a lock-not-locked-error condition is signaled.wait-condvar/timeout condvar timeoutFunctionThis is similar to wait-condvar, but if the condition variable is not signaled beforetimeout seconds pass, this function returns :timeout. It returns an unspecifiedvalue, different from :timeout, if timeout seconds have not yet passed.signal-condvar condvar &key allpFunctionThis signals that something changed in the state of the shared resource protectedby the lock associated to condvar. This means that if some threads are waitingfor this condition, then one (if allp is nil) or all (if allp is not nil) of the blockedthreads should wake up. If there are no threads blocked on condvar then this hasno effect. This function returns an unspecified value. If this function is called bya thread that does not own condvar’s associated lock, a lock-not-locked-errorcondition is signaled.A spurious wakeup is the unblocking of a thread waiting on a conditionvariable that happens without other thread signaling the condition variable. Toallow greater flexibility, implementations are allowed to have this behavior. Becauseof this, the condition variable’s predicate must always be checked.condvar-lock condvarFunctionThis returns the mutual exclusion lock associated with condvar. It is an error ifcondvar is not a condition variable.condvarp objectThis is a predicate that is true if object is a condition variable.condvar-name condvarThis return the name of condvar.An idiomatic use of of the operations on a condition variable is9FunctionFunction
Page 1 and 2: Shared State ConcurrencyThis docume
Page 3 and 4: ThreadsA thread is useful only if i
Page 5 and 6: Mutual exclusion locksOne way to pr
Page 7: Read/Write LockA read/write lock is
Page 11 and 12: SemaphoresSemaphores are synchroniz
Page 13: Thread-mailboxFIX: Isn’t there a

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