Mutexes (mutual-exclusion locks) are used to implement critical sections
and protect shared mutable data structures against concurrent accesses.
The typical use is (if
m is the mutex associated with the data structure
RMutex.synchronize ~lock:m (fun () -> (* Critical section that operates over D *); ) ()
This module implements reentrant mutexes, i.e. a version of mutexes which may be locked again by their owner thread without blocking this thread. Reentrant mutexes are typically slower than regular mutexes but also safer.
The type of mutexes.
val create :
unit -> t
Return a new mutex.
val lock :
t -> unit
Lock the given mutex. Only one thread can have the mutex locked at any time. A thread that attempts to lock a mutex already locked will suspend until the other mutex is unlocked.
Note attempting to lock a mutex you already have locked from the same thread will not suspend your thread.
val try_lock :
t -> bool
RMutex.lock, but does not suspend the calling thread if
the mutex is already locked: just return
in that case. If the mutex is unlocked, lock it and
val unlock :
t -> unit
Unlock the given mutex. Other threads suspended trying to lock the mutex will restart. If the mutex wasn't locked, nothing happens.
val synchronize :
?lock:t -> ('a -> 'b) -> 'a -> 'b
Protect a function.
synchronize f returns a new function
f' with the same behavior
f but such that concurrenty calls to
f' are queued if
necessary to avoid races.
synchronize ~lock:l f behaves as
synchronize f but uses a
l, which may be useful to share a lock
between several function.
In either case, the lock is acquired when entering the function and released when the function call ends, whether this is due to normal termination or to some exception being raised.
val make :
unit -> BatConcurrent.lock
Create a new abstract lock based on Reentrant Mutexes.