From 7afabb8e93d6b8620604025733a47eec68c582ac Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Thu, 3 Dec 2015 11:17:35 -0800
Subject: [PATCH 2/2] add a tracepoint for PIC hit / miss

---
 include/ruby/ruby.h |  2 ++
 vm_insnhelper.c     |  8 ++++++++
 vm_trace.c          | 30 ++++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index e7f2f0d..f14a516 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -2060,6 +2060,8 @@ int ruby_native_thread_p(void);
 #define RUBY_EVENT_THREAD_BEGIN      0x0400
 #define RUBY_EVENT_THREAD_END        0x0800
 #define RUBY_EVENT_FIBER_SWITCH      0x1000
+#define RUBY_EVENT_INLINE_CACHE_HIT  0x2000
+#define RUBY_EVENT_INLINE_CACHE_MISS 0x4000
 #define RUBY_EVENT_TRACEPOINT_ALL    0xffff
 
 /* special events */
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 8692b7a..09a8fb2 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -1124,7 +1124,11 @@ vm_search_method(const struct rb_call_info *ci, struct rb_call_cache *cc, VALUE
 
 #if OPT_INLINE_METHOD_CACHE
     int i;
+    rb_thread_t *th = GET_THREAD();
+    VALUE ccid;
     if (LIKELY(GET_GLOBAL_METHOD_STATE() == cc->method_state && RCLASS_SERIAL(klass) == cc->class_serial)) {
+	ccid = INT2NUM(cc);
+	EXEC_EVENT_HOOK(th, RUBY_EVENT_INLINE_CACHE_HIT, recv, 0, 0, ccid);
 	/* cache hit! */
 	return;
 #   if OPT_POLYMORPHIC_INLINE_METHOD_CACHE
@@ -1137,6 +1141,8 @@ vm_search_method(const struct rb_call_info *ci, struct rb_call_cache *cc, VALUE
 		    cc->me = cc->mes[i];
 		    cc->class_serial = cc->class_serials[i];
 		    cc->call = cc->calls[i];
+		    ccid = INT2NUM(cc);
+		    EXEC_EVENT_HOOK(th, RUBY_EVENT_INLINE_CACHE_HIT, recv, 0, 0, ccid);
 		    /* cache hit! */
 		    return;
 		}
@@ -1156,6 +1162,8 @@ vm_search_method(const struct rb_call_info *ci, struct rb_call_cache *cc, VALUE
     VM_ASSERT(callable_method_entry_p(cc->me));
     cc->call = vm_call_general;
 #if OPT_INLINE_METHOD_CACHE
+    ccid = INT2NUM(cc);
+    EXEC_EVENT_HOOK(th, RUBY_EVENT_INLINE_CACHE_MISS, recv, 0, 0, ccid);
     cc->method_state = GET_GLOBAL_METHOD_STATE();
     cc->class_serial = RCLASS_SERIAL(klass);
 
diff --git a/vm_trace.c b/vm_trace.c
index 0515abf..4da76e8 100644
--- a/vm_trace.c
+++ b/vm_trace.c
@@ -598,6 +598,8 @@ get_event_id(rb_event_flag_t event)
 	C(thread_end, THREAD_END);
 	C(fiber_switch, FIBER_SWITCH);
 	C(specified_line, SPECIFIED_LINE);
+	C(inline_cache_hit, INLINE_CACHE_HIT);
+	C(inline_cache_miss, INLINE_CACHE_MISS);
       case RUBY_EVENT_LINE | RUBY_EVENT_SPECIFIED_LINE: CONST_ID(id, "line"); return id;
 #undef C
       default:
@@ -706,6 +708,8 @@ symbol2event_flag(VALUE v)
     C(specified_line, SPECIFIED_LINE);
     C(a_call, A_CALL);
     C(a_return, A_RETURN);
+    C(inline_cache_hit, INLINE_CACHE_HIT);
+    C(inline_cache_miss, INLINE_CACHE_MISS);
 #undef C
     rb_raise(rb_eArgError, "unknown event: %"PRIsVALUE, rb_sym2str(sym));
 }
@@ -832,6 +836,21 @@ rb_tracearg_self(rb_trace_arg_t *trace_arg)
 }
 
 VALUE
+rb_tracearg_callcache_id(rb_trace_arg_t *trace_arg)
+{
+    if (trace_arg->event & (RUBY_EVENT_INLINE_CACHE_HIT | RUBY_EVENT_INLINE_CACHE_MISS)) {
+	/* ok */
+    }
+    else {
+	rb_raise(rb_eRuntimeError, "not supported by this event");
+    }
+    if (trace_arg->data == Qundef) {
+	rb_bug("tp_attr_return_value_m: unreachable");
+    }
+    return trace_arg->data;
+}
+
+VALUE
 rb_tracearg_return_value(rb_trace_arg_t *trace_arg)
 {
     if (trace_arg->event & (RUBY_EVENT_RETURN | RUBY_EVENT_C_RETURN | RUBY_EVENT_B_RETURN)) {
@@ -985,6 +1004,16 @@ tracepoint_attr_return_value(VALUE tpval)
 }
 
 /*
+ *  Return call cache id for +:inline_cache_hit+ and +:inline_cache_miss+
+ */
+static VALUE
+tracepoint_callcache_id(VALUE tpval)
+{
+    return rb_tracearg_callcache_id(get_trace_arg());
+}
+
+
+/*
  * Value from exception raised on the +:raise+ event
  */
 static VALUE
@@ -1485,6 +1514,7 @@ Init_vm_trace(void)
     rb_define_method(rb_cTracePoint, "self", tracepoint_attr_self, 0);
     rb_define_method(rb_cTracePoint, "return_value", tracepoint_attr_return_value, 0);
     rb_define_method(rb_cTracePoint, "raised_exception", tracepoint_attr_raised_exception, 0);
+    rb_define_method(rb_cTracePoint, "callcache_id", tracepoint_callcache_id, 0);
 
     rb_define_singleton_method(rb_cTracePoint, "stat", tracepoint_stat_s, 0);
 
-- 
2.2.1