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]

1 files changed, 14 insertions, 0 deletions

diff --git a/scheduler.c b/scheduler.c
index 9821d07636..9ecc40cf6c 100644
--- a/scheduler.c
+++ b/scheduler.c
@@ -12,6 +12,8 @@
 #include "ruby/io.h"
 
 static ID id_kernel_sleep;
+static ID id_mutex_lock;
+static ID id_mutex_unlock;
 static ID id_io_read;
 static ID id_io_write;
 static ID id_io_wait;
@@ -20,6 +22,8 @@ void
 Init_Scheduler(void)
 {
     id_kernel_sleep = rb_intern_const("kernel_sleep");
+    id_mutex_lock = rb_intern_const("mutex_lock");
+    id_mutex_unlock = rb_intern_const("mutex_unlock");
     id_io_read = rb_intern_const("io_read");
     id_io_write = rb_intern_const("io_write");
     id_io_wait = rb_intern_const("io_wait");
@@ -44,6 +48,16 @@ VALUE rb_scheduler_kernel_sleepv(VALUE scheduler, int argc, VALUE * argv)
     return rb_funcallv(scheduler, id_kernel_sleep, argc, argv);
 }
 
+VALUE rb_scheduler_mutex_lock(VALUE scheduler, VALUE mutex)
+{
+    return rb_funcall(scheduler, id_mutex_lock, 1, mutex);
+}
+
+VALUE rb_scheduler_mutex_unlock(VALUE scheduler, VALUE mutex, VALUE fiber)
+{
+    return rb_funcall(scheduler, id_mutex_unlock, 2, mutex, fiber);
+}
+
 VALUE rb_scheduler_io_wait(VALUE scheduler, VALUE io, VALUE events, VALUE timeout)
 {
     return rb_funcall(scheduler, id_io_wait, 3, io, events, timeout);