[wasm] add no thread variant for freestanding environment

This implementation does nothing around preemptive context switching
because there is no native thread.

1 files changed, 17 insertions, 0 deletions

diff --git a/thread_none.h b/thread_none.h
new file mode 100644
index 0000000000..eac2635ca7
--- /dev/null
+++ b/thread_none.h
@@ -0,0 +1,17 @@
+#ifndef RUBY_THREAD_NONE_H
+#define RUBY_THREAD_NONE_H
+
+#define RB_NATIVETHREAD_LOCK_INIT (void)(0)
+#define RB_NATIVETHREAD_COND_INIT (void)(0)
+
+// no-thread impl doesn't use TLS but define this to avoid using tls key
+// based implementation in vm.c
+#define RB_THREAD_LOCAL_SPECIFIER
+
+typedef struct native_thread_data_struct {} native_thread_data_t;
+
+typedef struct rb_global_vm_lock_struct {} rb_global_vm_lock_t;
+
+RUBY_EXTERN struct rb_execution_context_struct *ruby_current_ec;
+
+#endif /* RUBY_THREAD_NONE_H */