missing-file

ocaml/libs/xapi-stdext/lib/xapi-stdext-threads/runtime_lock_waiters.c

@@ -0,0 +1,49 @@
+#define CAML_INTERNALS
+#include <caml/signals.h>
+#include <caml/threads.h>
+#include <stdatomic.h>
+
+static void noop(void) {}
+
+static void (*old_enter_blocking_section_hook)(void) = noop;
+static void (*old_leave_blocking_section_hook)(void) = noop;
+
+static atomic_int waiting;
+
+static void my_enter_blocking_section(void)
+{
+  old_enter_blocking_section_hook();
+}
+
+static void my_leave_blocking_section(void)
+{
+  atomic_fetch_add(&waiting, 1);
+  old_leave_blocking_section_hook();
+  atomic_fetch_add(&waiting, -1);
+}
+
+CAMLprim value caml_runtime_lock_waiters_get(value)
+{
+  return Int_val(atomic_load(&waiting));
+}
+
+CAMLprim value caml_runtime_lock_waiters_init(value)
+{
+  void (*hook)(void);
+
+  hook = caml_enter_blocking_section_hook;
+  if (!hook)
+    return Val_false;
+  old_enter_blocking_section_hook = hook;
+
+  hook = caml_leave_blocking_section_hook;
+  if (!hook)
+    return Val_false;
+  old_leave_blocking_section_hook = hook;
+
+  atomic_init(&waiting, 0);
+
+  caml_enter_blocking_section_hook = my_enter_blocking_section;
+  caml_leave_blocking_section_hook = my_leave_blocking_section;
+  return Val_true;
+}