method protect
Documentation for method protect
assembled from the following types:
class Lock
From Lock
(Lock) method protect
Defined as:
method protect(Lock: )
Obtains the lock, runs &code
, and releases the lock afterwards. Care is taken to make sure the lock is released even if the code is left through an exception.
Note that the Lock itself needs to be created outside the portion of the code that gets threaded and it needs to protect. In the first example below, Lock is first created and assigned to $lock
, which is then used inside the Promises to protect the sensitive code. In the second example, a mistake is made: the Lock
is created right inside the Promise, so the code ends up with a bunch of separate locks, created in a bunch of threads, and thus they don't actually protect the code we want to protect.
# Right: $lock is instantiated outside the portion of the# code that will get threaded and be in need of protectionmy = Lock.new;await ^20 .map:# !!! WRONG !!! Lock is created inside threaded area!await ^20 .map:
class Lock::Async
From Lock::Async
(Lock::Async) method protect
Defined as:
method protect(Lock::Async: )
Calls lock
, does an await
to wait for the lock to be available, and reliably calls unlock
afterwards, even if the code throws an exception.
Note that the Lock::Async itself needs to be created outside the portion of the code that gets threaded and it needs to protect. In the first example below, Lock::Async is first created and assigned to $lock
, which is then used inside the Promises to protect the sensitive code. In the second example, a mistake is made, the Lock::Async
is created right inside the Promise, so the code ends up with a bunch of separate locks, created in a bunch of threads, and thus they don't actually protect the code we want to protect.
# Right: $lock is instantiated outside the portion of the# code that will get threaded and be in need of protectionmy = Lock::Async.new;await ^20 .map:# !!! WRONG !!! Lock::Async is instantiated inside threaded area!await ^20 .map: