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Updated mutex and condition varable functions.

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This commit is contained in:
Marius Vollmer 2002-10-27 20:47:31 +00:00
parent e2d820a18c
commit 57c84ccd60
1 changed files with 28 additions and 6 deletions
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34
doc/ref/scheme-scheduling.texi
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@ -334,15 +334,25 @@ Create a new mutex object.
@deffn {Scheme Procedure} lock-mutex mutex @deffn {Scheme Procedure} lock-mutex mutex
Lock @var{mutex}. If the mutex is already locked, the calling thread Lock @var{mutex}. If the mutex is already locked, the calling thread
blocks until the mutex becomes available. The function returns when blocks until the mutex becomes available. The function returns when
the calling thread owns the lock on @var{mutex}. the calling thread owns the lock on @var{mutex}. Locking a mutex that
a thread already owns will succeed right away and will not block the
thread. That is, Guile's mutexes are @emph{recursive}.
@end deffn
@deffn {Scheme Procedure} try-mutex mutex
Try to lock @var{mutex}. If the mutex is already locked by someone
else, return @code{#f}. Else lock the mutex and return @code{#t}.
@end deffn @end deffn
@c begin (texi-doc-string "guile" "unlock-mutex") @c begin (texi-doc-string "guile" "unlock-mutex")
@deffn {Scheme Procedure} unlock-mutex mutex @deffn {Scheme Procedure} unlock-mutex mutex
Unlocks @var{mutex} if the calling thread owns the lock on @var{mutex}. Unlocks @var{mutex} if the calling thread owns the lock on
Calling unlock-mutex on a mutex not owned by the current thread results @var{mutex}. Calling unlock-mutex on a mutex not owned by the current
in undefined behaviour. Once a mutex has been unlocked, one thread thread results in undefined behaviour. Once a mutex has been unlocked,
blocked on @var{mutex} is awakened and grabs the mutex lock. one thread blocked on @var{mutex} is awakened and grabs the mutex
lock. Every call to @code{lock-mutex} by this thread must be matched
with a call to @code{unlock-mutex}. Only the last call to
@code{unlock-mutex} will actually unlock the mutex.
@end deffn @end deffn
@c begin (texi-doc-string "guile" "make-condition-variable") @c begin (texi-doc-string "guile" "make-condition-variable")
@ -350,13 +360,25 @@ blocked on @var{mutex} is awakened and grabs the mutex lock.
@end deffn @end deffn
@c begin (texi-doc-string "guile" "wait-condition-variable") @c begin (texi-doc-string "guile" "wait-condition-variable")
@deffn {Scheme Procedure} wait-condition-variable cond-var mutex @deffn {Scheme Procedure} wait-condition-variable cond-var mutex [time]
Wait until @var{cond-var} has been signalled. While waiting,
@var{mutex} is atomically unlocked (as with @code{unlock-mutex}) and
is locked again when this function returns. When @var{time} is given,
it specifies a point in time where the waiting should be aborted. It
can be either a integer as returned by @code{current-time} or a pair
as returned by @code{gettimeofday}. When the waiting is aborted the
mutex is locked and @code{#f} is returned. When the condition
variable is in fact signalled, the mutex is also locked and @code{#t}
is returned.
@end deffn @end deffn
@c begin (texi-doc-string "guile" "signal-condition-variable") @c begin (texi-doc-string "guile" "signal-condition-variable")
@deffn {Scheme Procedure} signal-condition-variable cond-var @deffn {Scheme Procedure} signal-condition-variable cond-var
@end deffn @end deffn
@c begin (texi-doc-string "guile" "broadcast-condition-variable")
@deffn {Scheme Procedure} signal-condition-variable cond-var
@end deffn
@node Higher level thread procedures @node Higher level thread procedures
@subsection Higher level thread procedures @subsection Higher level thread procedures