1 files changed, 114 insertions, 0 deletions

diff --git a/src/node_win32_etw_provider.cc b/src/node_win32_etw_provider.cc
index 78f465c466..26769b0e5a 100644
--- a/src/node_win32_etw_provider.cc
+++ b/src/node_win32_etw_provider.cc
@@ -22,6 +22,7 @@
 #include "node_dtrace.h"
 #include "node_win32_etw_provider.h"
 #include "node_etw_provider.h"
+#include "node_win32_etw_provider-inl.h"
 
 namespace node {
 
@@ -33,10 +34,110 @@ EventRegisterFunc event_register;
 EventUnregisterFunc event_unregister;
 EventWriteFunc event_write;
 int events_enabled;
+static uv_async_t dispatch_etw_events_change_async;
+
+struct v8tags {
+  char prefix[32 - sizeof(size_t)];
+  size_t prelen;
+};
+
+// The v8 CODE_ADDED event name has a prefix indicating the type of event.
+// Many of these are internal to v8.
+// The trace_codes array specifies which types are written.
+struct v8tags trace_codes[] = {
+#define MAKE_V8TAG(s) { s, sizeof(s) - 1 }
+  MAKE_V8TAG("LazyCompile:"),
+  MAKE_V8TAG("Script:"),
+  MAKE_V8TAG("Function:"),
+  MAKE_V8TAG("RegExp:"),
+  MAKE_V8TAG("Eval:")
+#undef MAKE_V8TAG
+};
+
+/* Below are some code prefixes which are not being written.
+ *    "Builtin:"
+ *    "Stub:"
+ *    "CallIC:"
+ *    "LoadIC:"
+ *    "KeyedLoadIC:"
+ *    "StoreIC:"
+ *    "KeyedStoreIC:"
+ *    "CallPreMonomorphic:"
+ *    "CallInitialize:"
+ *    "CallMiss:"
+ *    "CallMegamorphic:"
+ */
+
+// v8 sometimes puts a '*' or '~' in front of the name.
+#define V8_MARKER1 '*'
+#define V8_MARKER2 '~'
+
+
+// If prefix is not in filtered list return -1,
+// else return length of prefix and marker.
+int FilterCodeEvents(const char* name, size_t len) {
+  for (int i = 0; i < ARRAY_SIZE(trace_codes); i++) {
+    size_t prelen = trace_codes[i].prelen;
+    if (prelen < len) {
+      if (strncmp(name, trace_codes[i].prefix, prelen) == 0) {
+        if (name[prelen] == V8_MARKER1 || name[prelen] == V8_MARKER2)
+          prelen++;
+        return prelen;
+      }
+    }
+  }
+  return -1;
+}
+
+
+// callback from V8 module passes symbol and address info for stack walk
+void CodeAddressNotification(const JitCodeEvent* jevent) {
+  int pre_offset = 0;
+  if (NODE_V8SYMBOL_ENABLED()) {
+    switch (jevent->type) {
+    case JitCodeEvent::CODE_ADDED:
+      pre_offset = FilterCodeEvents(jevent->name.str, jevent->name.len);
+      if (pre_offset >= 0) {
+        // skip over prefix and marker
+        NODE_V8SYMBOL_ADD(jevent->name.str + pre_offset,
+                          jevent->name.len - pre_offset,
+                          jevent->code_start,
+                          jevent->code_len);
+      }
+      break;
+    case JitCodeEvent::CODE_REMOVED:
+      NODE_V8SYMBOL_REMOVE(jevent->code_start, 0);
+      break;
+    case JitCodeEvent::CODE_MOVED:
+      NODE_V8SYMBOL_MOVE(jevent->code_start, jevent->new_code_start);
+      break;
+    default:
+      break;
+    }
+  }
+}
+
+
+// Call v8 to enable or disable code event callbacks.
+// Must be on default thread to do this.
+// Note: It is possible to call v8 from ETW thread, but then
+//       event callbacks are received in the same thread. Attempts
+//       to write ETW events in this thread will fail.
+void etw_events_change_async(uv_async_t* handle, int status) {
+  if (events_enabled > 0) {
+    NODE_V8SYMBOL_RESET();
+    V8::SetJitCodeEventHandler(v8::kJitCodeEventEnumExisting,
+                               CodeAddressNotification);
+  } else {
+    V8::SetJitCodeEventHandler(v8::kJitCodeEventDefault, NULL);
+  }
+}
+
 
 // This callback is called by ETW when consumers of our provider
 // are enabled or disabled.
 // The callback is dispatched on ETW thread.
+// Before calling into V8 to enable code events, switch to default thread.
 void NTAPI etw_events_enable_callback(
   LPCGUID SourceId,
   ULONG IsEnabled,
@@ -47,8 +148,14 @@ void NTAPI etw_events_enable_callback(
   PVOID CallbackContext) {
   if (IsEnabled) {
     events_enabled++;
+    if (events_enabled == 1) {
+      uv_async_send(&dispatch_etw_events_change_async);
+    }
   } else {
     events_enabled--;
+    if (events_enabled == 0) {
+      uv_async_send(&dispatch_etw_events_change_async);
+    }
   }
 }
 
@@ -64,6 +171,12 @@ void init_etw() {
       GetProcAddress(advapi, "EventUnregister");
     event_write = (EventWriteFunc)GetProcAddress(advapi, "EventWrite");
 
+    // create async object used to invoke main thread from callback
+    uv_async_init(uv_default_loop(),
+                &dispatch_etw_events_change_async,
+                etw_events_change_async);
+    uv_unref((uv_handle_t*) &dispatch_etw_events_change_async);
+
     if (event_register) {    
       DWORD status = event_register(&NODE_ETW_PROVIDER,
                                     etw_events_enable_callback,
@@ -82,6 +195,7 @@ void shutdown_etw() {
   }
 
   events_enabled = 0;
+  V8::SetJitCodeEventHandler(v8::kJitCodeEventDefault, NULL);
 
   if (advapi) {
     FreeLibrary(advapi);