GBBopen 1.5 Reference -- with-lock-held

with-lock-held

with-lock-held (lock &key whostate) form* => result* [Macro]

Purpose
After acquiring a lock or a recursive lock, execute forms and then release the lock.

Package :portable-threads

Module :portable-threads

Arguments and values

lock		A lock, a recursive lock, or a condition variable
whostate		A string (default `"With Lock Held"`)
forms		An implicit progn of forms to be evaluated
results		The values returned by evaluating the last `form`

Returns
The values returned by evaluating the last form.

Errors
A thread attempts to re-acquire a (non-recursive) lock that it holds.

Description
If a thread executes a with-lock-held that is dynamically inside another with-lock-held involving the same recursive lock, the inner with-lock-held simply proceeds as if it had acquired the lock.

Examples
Acquire the lock controlling access to a critical section of code:

  (with-lock-held (lock :whostate "Waiting for Critical Lock")
    (critical-section))

A silly example showing a recursive re-acquisition of a recursive lock:

  (with-lock-held (recursive-lock :whostate "Waiting for Critical Lock")
    (with-lock-held (recursive-lock :whostate "Again Waiting for Critical Lock")
      (critical-section)))

Acquire the lock associated with condition-variable and then signal all blocked threads that are waiting on it:

  (with-lock-held (condition-variable)
    (condition-variable-signal condition-variable))

Note
The whostate value is ignored by SBCL.

The GBBopen Project

with-lock-held