diff options
| -rw-r--r-- | fibers/internal.scm | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/fibers/internal.scm b/fibers/internal.scm index 5df25a9..bff342a 100644 --- a/fibers/internal.scm +++ b/fibers/internal.scm @@ -24,6 +24,7 @@ #:use-module (fibers psq) #:use-module (fibers nameset) #:use-module (ice-9 atomic) + #:use-module (ice-9 control) #:use-module (ice-9 match) #:use-module (ice-9 fdes-finalizers) #:use-module ((ice-9 threads) #:select (current-thread)) @@ -302,6 +303,10 @@ The fiber will be scheduled on the next turn." that this is currently unimplemented!" (error "kill-fiber is unimplemented")) +;; Shim for Guile 2.1.5. +(unless (defined? 'suspendable-continuation?) + (define! 'suspendable-continuation? (lambda (tag) #t))) + ;; The AFTER-SUSPEND thunk allows the user to suspend the current ;; fiber, saving its state, and then perform some other nonlocal ;; control flow. @@ -310,8 +315,10 @@ that this is currently unimplemented!" (after-suspend (lambda (fiber) #f))) "Suspend the current fiber. Call the optional @var{after-suspend} callback, if present, with the suspended thread as its argument." - ((abort-to-prompt (scheduler-prompt-tag (current-scheduler)) - after-suspend))) + (let ((tag (scheduler-prompt-tag (current-scheduler)))) + (unless (suspendable-continuation? tag) + (error "Attempt to suspend fiber within continuation barrier")) + ((abort-to-prompt tag after-suspend)))) (define* (resume-fiber fiber thunk) "Resume @var{fiber}, adding it to the run queue of its scheduler. |