`TracePoint#enable(target_thraed:)` [Feature #15473]

* vm_trace.c (tracepoint_enable_m): `TracePoint#enable` supports
  `target_thread:` keyword to filter a target thread.
  [Feature #15473]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66640 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

prelude.rb

@@ -133,8 +133,8 @@ class IO
 end
 
 class TracePoint
-  def enable target: nil, target_line: nil, &blk
-    self.__enable target, target_line, &blk
+  def enable target: nil, target_line: nil, target_thread: nil, &blk
+    self.__enable target, target_line, target_thread, &blk
   end
 end
 

test/ruby/test_settracefunc.rb

@@ -2115,4 +2115,42 @@ class TestSetTraceFunc < Test::Unit::TestCase
     }
     assert_equal [], events
   end
+
+  def test_enable_target_thread
+    events = []
+    TracePoint.new(:line) do |tp|
+      events << Thread.current
+    end.enable(target_thread: Thread.current) do
+      a = 1
+      Thread.new{
+        b = 2
+        c = 3
+      }.join
+      d = 4
+    end
+    assert_equal Array.new(3){Thread.current}, events
+
+    events = []
+    tp = TracePoint.new(:line) do |tp|
+      events << Thread.current
+    end
+
+    q1 = Queue.new
+    q2 = Queue.new
+
+    th = Thread.new{
+      q1 << :ok; q2.pop
+      t1 = 1
+      t2 = 2
+    }
+    q1.pop
+    tp.enable(target_thread: th) do
+      q2 << 1
+      a = 1
+      b = 2
+      th.join
+    end
+
+    assert_equal Array.new(2){th}, events
+  end
 end

vm_trace.c

@@ -1327,6 +1327,7 @@ rb_tracepoint_disable(VALUE tpval)
         }
     }
     tp->tracing = 0;
+    tp->target_th = NULL;
     return Qundef;
 }
 
@@ -1398,11 +1399,22 @@ rb_hook_list_remove_tracepoint(rb_hook_list_t *list, VALUE tpval)
  *
  */
 static VALUE
-tracepoint_enable_m(VALUE tpval, VALUE target, VALUE target_line)
+tracepoint_enable_m(VALUE tpval, VALUE target, VALUE target_line, VALUE target_thread)
 {
     rb_tp_t *tp = tpptr(tpval);
     int previous_tracing = tp->tracing;
 
+    /* check target_thread */
+    if (RTEST(target_thread)) {
+        if (tp->target_th) {
+            rb_raise(rb_eArgError, "can not override target_thread filter");
+        }
+        tp->target_th = rb_thread_ptr(target_thread);
+    }
+    else {
+        tp->target_th = NULL;
+    }
+
     if (NIL_P(target)) {
         if (!NIL_P(target_line)) {
             rb_raise(rb_eArgError, "only target_line is specified");
@@ -1801,7 +1813,7 @@ Init_vm_trace(void)
      */
     rb_define_singleton_method(rb_cTracePoint, "trace", tracepoint_trace_s, -1);
 
-    rb_define_method(rb_cTracePoint, "__enable", tracepoint_enable_m, 2);
+    rb_define_method(rb_cTracePoint, "__enable", tracepoint_enable_m, 3);
     rb_define_method(rb_cTracePoint, "disable", tracepoint_disable_m, 0);
     rb_define_method(rb_cTracePoint, "enabled?", rb_tracepoint_enabled_p, 0);