package core_unix

lock mtx locks mtx, possibly waiting for it to be released first by another thread.

• raises Unix_error

  if lock attempts to acquire mtx recursively.

try_lock is like lock, but always returns immediately. If the calling thread or another one already has the mutex it returns `Already_held_by_me_or_other, otherwise it locks it and returns `Acquired.

unlock mtx unlocks mtx.

• raises Unix_error

  if unlock attempts to release an unacquired mutex or a mutex held by another thread.

critical_section t ~f locks t, runs f, unlocks t, and returns the result of f (or raises if f raised).

synchronize f creates a mutex and returns a new function that is identical to f except that the mutex is held during its execution.

update_signal mtx cnd ~f updates some state within a critical section protected by mutex mtx using function f and signals condition variable cnd after finishing. If f raises an exception, the condition will NOT be signaled!

update_broadcast mtx cnd ~f updates some state within a critical section protected by mutex mtx using function f and broadcasts condition variable cnd after finishing. If f raises an exception, the condition will NOT be broadcast!