[Guile-commits] 14/17: cancel-thread can take arguments

[Andy Wingo]

wingo pushed a commit to branch master
in repository guile.

commit a7114ced5f062a92d34b07f2fcc5a05e8612482a
Author: Andy Wingo <address@hidden>
Date:   Mon Oct 31 22:11:01 2016 +0100

    cancel-thread can take arguments
    
    * doc/ref/api-scheduling.texi (Threads):
    * module/ice-9/threads.scm (cancel-thread): Additional args to
      cancel-thread will be returned by the thread.
---
 doc/ref/api-scheduling.texi |    5 +++--
 module/ice-9/threads.scm    |   11 ++++++-----
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/doc/ref/api-scheduling.texi b/doc/ref/api-scheduling.texi
index 45b5315..564d43f 100644
--- a/doc/ref/api-scheduling.texi
+++ b/doc/ref/api-scheduling.texi
@@ -112,12 +112,13 @@ If one or more threads are waiting to execute, calling 
yield forces an
 immediate context switch to one of them. Otherwise, yield has no effect.
 @end deffn
 
address@hidden {Scheme Procedure} cancel-thread thread
address@hidden {Scheme Procedure} cancel-thread thread . values
 @deffnx {C Function} scm_cancel_thread (thread)
 Asynchronously interrupt @var{thread} and ask it to terminate.
 @code{dynamic-wind} post thunks will run, but throw handlers will not.
 If @var{thread} has already terminated or been signaled to terminate,
-this function is a no-op.
+this function is a no-op.  Calling @code{join-thread} on the thread will
+return the given @var{values}, if the cancel succeeded.
 
 Under this hood, thread cancellation uses @code{system-async-mark} and
 @code{abort-to-prompt}.  @xref{Asyncs} for more on asynchronous
diff --git a/module/ice-9/threads.scm b/module/ice-9/threads.scm
index 4b2f6c6..5871e9a 100644
--- a/module/ice-9/threads.scm
+++ b/module/ice-9/threads.scm
@@ -88,16 +88,17 @@
 
 
 (define cancel-tag (make-prompt-tag "cancel"))
-(define (cancel-thread thread)
+(define (cancel-thread thread . values)
   "Asynchronously interrupt the target @var{thread} and ask it to
-terminate.  @code{dynamic-wind} post thunks will run, but throw handlers
-will not.  If @var{thread} has already terminated or been signaled to
-terminate, this function is a no-op."
+terminate, returning the given @var{values}.  @code{dynamic-wind} post
+thunks will run, but throw handlers will not.  If @var{thread} has
+already terminated or been signaled to terminate, this function is a
+no-op."
   (system-async-mark
    (lambda ()
      (catch #t
        (lambda ()
-         (abort-to-prompt cancel-tag))
+         (apply abort-to-prompt cancel-tag values))
        (lambda _
          (error "thread cancellation failed, throwing error instead???"))))
    thread))