1 files changed, 80 insertions, 0 deletions
diff --git a/ext/-test-/tracepoint/gc_hook.c b/ext/-test-/tracepoint/gc_hook.c
new file mode 100644
index 0000000000..6d8485ecb1
--- /dev/null
+++ b/ext/-test-/tracepoint/gc_hook.c
@@ -0,0 +1,80 @@
+#include "ruby/ruby.h"
+#include "ruby/debug.h"
+
+static int invoking; /* TODO: should not be global variable */
+
+static VALUE
+invoke_proc_ensure(void *dmy)
+{
+    invoking = 0;
+    return Qnil;
+}
+
+static VALUE
+invoke_proc_begin(VALUE proc)
+{
+    return rb_proc_call(proc, rb_ary_new());
+}
+
+static void
+invoke_proc(void *data)
+{
+    VALUE proc = (VALUE)data;
+    invoking += 1;
+    rb_ensure(invoke_proc_begin, proc, invoke_proc_ensure, 0);
+}
+
+static void
+gc_start_end_i(VALUE tpval, void *data)
+{
+    if (0) {
+	rb_trace_arg_t *tparg = rb_tracearg_from_tracepoint(tpval);
+	fprintf(stderr, "trace: %s\n", rb_tracearg_event_flag(tparg) == RUBY_INTERNAL_EVENT_GC_START ? "gc_start" : "gc_end");
+    }
+
+    if (invoking == 0) {
+	rb_postponed_job_register(0, invoke_proc, data);
+    }
+}
+
+static VALUE
+set_gc_hook(VALUE module, VALUE proc, rb_event_flag_t event, const char *tp_str, const char *proc_str)
+{
+    VALUE tpval;
+    ID tp_key = rb_intern(tp_str);
+    ID proc_key = rb_intern(proc_str);
+
+    /* disable previous keys */
+    if (rb_ivar_defined(module, tp_key) != 0 &&
+	RTEST(tpval = rb_ivar_get(module, tp_key))) {
+	rb_tracepoint_disable(tpval);
+	rb_ivar_set(module, tp_key, Qnil);
+	rb_ivar_set(module, proc_key, Qnil);
+    }
+
+    if (RTEST(proc)) {
+	if (!rb_obj_is_proc(proc)) {
+	    rb_raise(rb_eTypeError, "trace_func needs to be Proc");
+	}
+
+	tpval = rb_tracepoint_new(0, event, gc_start_end_i, (void *)proc);
+	rb_ivar_set(module, tp_key, tpval);
+	rb_ivar_set(module, proc_key, proc); /* GC guard */
+	rb_tracepoint_enable(tpval);
+    }
+
+    return proc;
+}
+
+static VALUE
+set_after_gc_start(VALUE module, VALUE proc)
+{
+    return set_gc_hook(module, proc, RUBY_INTERNAL_EVENT_GC_START,
+		       "__set_after_gc_start_tpval__", "__set_after_gc_start_proc__");
+}
+
+void
+Init_gc_hook(VALUE module)
+{
+    rb_define_module_function(module, "after_gc_start_hook=", set_after_gc_start, 1);
+}