Tracing: Add lttng support for tracing on Linux.

This commit adds the ability to enable userspace tracing with lttng
in io.js. It adds tracepoints for all the equivalent dtrace and ETW
tracepoints. To use these tracepoints enable --with-lttng on linux.

Makefile

@@ -395,8 +395,9 @@ jslint:
 
 CPPLINT_EXCLUDE ?=
 CPPLINT_EXCLUDE += src/node_dtrace.cc
-CPPLINT_EXCLUDE += src/node_dtrace.cc
+CPPLINT_EXCLUDE += src/node_lttng.cc
 CPPLINT_EXCLUDE += src/node_root_certs.h
+CPPLINT_EXCLUDE += src/node_lttng_tp.h
 CPPLINT_EXCLUDE += src/node_win32_perfctr_provider.cc
 CPPLINT_EXCLUDE += src/queue.h
 CPPLINT_EXCLUDE += src/tree.h

configure

@@ -213,6 +213,11 @@ parser.add_option('--with-dtrace',
     dest='with_dtrace',
     help='build with DTrace (default is true on sunos)')
 
+parser.add_option('--with-lttng',
+    action='store_true',
+    dest='with_lttng',
+    help='build with Lttng (Only available to Linux)')
+
 parser.add_option('--with-etw',
     action='store_true',
     dest='with_etw',
@@ -524,6 +529,15 @@ def configure_node(o):
   else:
     o['variables']['node_use_dtrace'] = 'false'
 
+  # Enable Lttng if --with-lttng was defined. Use logic similar to
+  # ETW for windows. Lttng is only available on the Linux platform.
+  if flavor == 'linux':
+    o['variables']['node_use_lttng'] = b(options.with_lttng)
+  elif options.with_lttng:
+    raise Exception('lttng is only supported on Linux.')
+  else:
+    o['variables']['node_use_lttng'] = 'false'
+
   # if we're on illumos based systems wrap the helper library into the
   # executable
   if flavor == 'solaris':

lib/_http_client.js

@@ -155,6 +155,7 @@ ClientRequest.prototype.aborted = undefined;
 
 ClientRequest.prototype._finish = function() {
   DTRACE_HTTP_CLIENT_REQUEST(this, this.connection);
+  LTTNG_HTTP_CLIENT_REQUEST(this, this.connection);
   COUNTER_HTTP_CLIENT_REQUEST();
   OutgoingMessage.prototype._finish.call(this);
 };
@@ -386,6 +387,7 @@ function parserOnIncomingClient(res, shouldKeepAlive) {
 
 
   DTRACE_HTTP_CLIENT_RESPONSE(socket, req);
+  LTTNG_HTTP_CLIENT_RESPONSE(socket, req);
   COUNTER_HTTP_CLIENT_RESPONSE();
   req.res = res;
   res.req = req;

lib/_http_server.js

@@ -92,6 +92,7 @@ util.inherits(ServerResponse, OutgoingMessage);
 
 ServerResponse.prototype._finish = function() {
   DTRACE_HTTP_SERVER_RESPONSE(this.connection);
+  LTTNG_HTTP_SERVER_RESPONSE(this.connection);
   COUNTER_HTTP_SERVER_RESPONSE();
   OutgoingMessage.prototype._finish.call(this);
 };
@@ -416,6 +417,7 @@ function connectionListener(socket) {
 
     res.shouldKeepAlive = shouldKeepAlive;
     DTRACE_HTTP_SERVER_REQUEST(req, socket);
+    LTTNG_HTTP_SERVER_REQUEST(req, socket);
     COUNTER_HTTP_SERVER_REQUEST();
 
     if (socket._httpMessage) {

lib/net.js

@@ -387,6 +387,7 @@ Socket.prototype.end = function(data, encoding) {
   stream.Duplex.prototype.end.call(this, data, encoding);
   this.writable = false;
   DTRACE_NET_STREAM_END(this);
+  LTTNG_NET_STREAM_END(this);
 
   // just in case we're waiting for an EOF.
   if (this.readable && !this._readableState.endEmitted)
@@ -1324,6 +1325,7 @@ function onconnection(err, clientHandle) {
   socket.server = self;
 
   DTRACE_NET_SERVER_CONNECTION(socket);
+  LTTNG_NET_SERVER_CONNECTION(socket);
   COUNTER_NET_SERVER_CONNECTION(socket);
   self.emit('connection', socket);
 }

node.gyp

@@ -2,6 +2,7 @@
   'variables': {
     'v8_use_snapshot%': 'false',
     'node_use_dtrace%': 'false',
+    'node_use_lttng%': 'false',
     'node_use_etw%': 'false',
     'node_use_perfctr%': 'false',
     'node_has_winsdk%': 'false',
@@ -260,6 +261,14 @@
             }
           ] ]
         } ],
+        [ 'node_use_lttng=="true"', {
+          'defines': [ 'HAVE_LTTNG=1' ],
+          'include_dirs': [ '<(SHARED_INTERMEDIATE_DIR)' ],
+          'libraries': [ '-llttng-ust' ],
+          'sources': [
+            'src/node_lttng.cc'
+          ],
+        } ],
         [ 'node_use_mdb=="true"', {
           'dependencies': [ 'node_mdb' ],
           'include_dirs': [ '<(SHARED_INTERMEDIATE_DIR)' ],
@@ -450,6 +459,9 @@
             [ 'node_use_dtrace=="false" and node_use_etw=="false"', {
               'inputs': [ 'src/notrace_macros.py' ]
             }],
+            ['node_use_lttng=="false"', {
+              'inputs': [ 'src/nolttng_macros.py' ]
+            }],
             [ 'node_use_perfctr=="false"', {
               'inputs': [ 'src/perfctr_macros.py' ]
             }]

src/node.cc

@@ -23,6 +23,10 @@
 #include "node_dtrace.h"
 #endif
 
+#if defined HAVE_LTTNG
+#include "node_lttng.h"
+#endif
+
 #include "ares.h"
 #include "async-wrap.h"
 #include "async-wrap-inl.h"
@@ -2871,6 +2875,10 @@ void LoadEnvironment(Environment* env) {
   InitDTrace(env, global);
 #endif
 
+#if defined HAVE_LTTNG
+  InitLTTNG(env, global);
+#endif
+
 #if defined HAVE_PERFCTR
   InitPerfCounters(env, global);
 #endif