Make Mutex per-Fiber instead of per-Thread

* Enables Mutex to be used as synchronization between multiple Fibers
  of the same Thread.
* With a Fiber scheduler we can yield to another Fiber on contended
  Mutex#lock instead of blocking the entire thread.
* This also makes the behavior of Mutex consistent across CRuby, JRuby and TruffleRuby.
* [Feature #16792]

2 files changed, 5 insertions, 0 deletions

diff --git a/internal/cont.h b/internal/cont.h
index 81874aa5c7..a365cbe978 100644
--- a/internal/cont.h
+++ b/internal/cont.h
@@ -20,4 +20,6 @@ void rb_fiber_reset_root_local_storage(struct rb_thread_struct *);
 void ruby_register_rollback_func_for_ensure(VALUE (*ensure_func)(VALUE), VALUE (*rollback_func)(VALUE));
 void rb_fiber_init_mjit_cont(struct rb_fiber_struct *fiber);
 
+VALUE rb_fiberptr_self(struct rb_fiber_struct *fiber);
+
 #endif /* INTERNAL_CONT_H */
diff --git a/internal/scheduler.h b/internal/scheduler.h
index f5a41af064..44872e3b10 100644
--- a/internal/scheduler.h
+++ b/internal/scheduler.h
@@ -17,6 +17,9 @@ VALUE rb_scheduler_timeout(struct timeval *timeout);
 VALUE rb_scheduler_kernel_sleep(VALUE scheduler, VALUE duration);
 VALUE rb_scheduler_kernel_sleepv(VALUE scheduler, int argc, VALUE * argv);
 
+VALUE rb_scheduler_mutex_lock(VALUE scheduler, VALUE mutex);
+VALUE rb_scheduler_mutex_unlock(VALUE scheduler, VALUE mutex, VALUE fiber);
+
 VALUE rb_scheduler_io_wait(VALUE scheduler, VALUE io, VALUE events, VALUE timeout);
 VALUE rb_scheduler_io_wait_readable(VALUE scheduler, VALUE io);
 VALUE rb_scheduler_io_wait_writable(VALUE scheduler, VALUE io);