changeset 29798:80df04266a16

hgweb: profile HTTP requests Currently, running `hg serve --profile` doesn't yield anything useful: when the process is terminated the profiling output displays results from the main thread, which typically spends most of its time in select.select(). Furthermore, it has no meaningful results from mercurial.* modules because the threads serving HTTP requests don't actually get profiled. This patch teaches the hgweb wsgi applications to profile individual requests. If profiling is enabled, the profiler kicks in after HTTP/WSGI environment processing but before Mercurial's main request processing. The profile results are printed to the configured profiling output. If running `hg serve` from a shell, they will be printed to stderr, just before the HTTP request line is logged. If profiling to a file, we only write a single profile to the file because the file is not opened in append mode. We could add support for appending to files in a future patch if someone wants it. Per request profiling doesn't work with the statprof profiler because internally that profiler collects samples from the thread that *initially* requested profiling be enabled. I have plans to address this by vendoring Facebook's customized statprof and then improving it.
author Gregory Szorc <gregory.szorc@gmail.com>
date Sun, 14 Aug 2016 18:37:24 -0700
parents fc2442492606
children b1809f5d7630
files mercurial/hgweb/hgweb_mod.py mercurial/hgweb/hgwebdir_mod.py tests/test-profile.t
diffstat 3 files changed, 22 insertions(+), 3 deletions(-) [+]
line wrap: on
line diff
--- a/mercurial/hgweb/hgweb_mod.py	Sun Aug 14 16:03:30 2016 -0700
+++ b/mercurial/hgweb/hgweb_mod.py	Sun Aug 14 18:37:24 2016 -0700
@@ -28,6 +28,7 @@
     error,
     hg,
     hook,
+    profiling,
     repoview,
     templatefilters,
     templater,
@@ -305,8 +306,9 @@
         should be using instances of this class as the WSGI application.
         """
         with self._obtainrepo() as repo:
-            for r in self._runwsgi(req, repo):
-                yield r
+            with profiling.maybeprofile(repo.ui):
+                for r in self._runwsgi(req, repo):
+                    yield r
 
     def _runwsgi(self, req, repo):
         rctx = requestcontext(self, repo)
--- a/mercurial/hgweb/hgwebdir_mod.py	Sun Aug 14 16:03:30 2016 -0700
+++ b/mercurial/hgweb/hgwebdir_mod.py	Sun Aug 14 18:37:24 2016 -0700
@@ -31,6 +31,7 @@
     encoding,
     error,
     hg,
+    profiling,
     scmutil,
     templater,
     ui as uimod,
@@ -217,7 +218,9 @@
         return False
 
     def run_wsgi(self, req):
-        return self._runwsgi(req)
+        with profiling.maybeprofile(self.ui):
+            for r in self._runwsgi(req):
+                yield r
 
     def _runwsgi(self, req):
         try:
--- a/tests/test-profile.t	Sun Aug 14 16:03:30 2016 -0700
+++ b/tests/test-profile.t	Sun Aug 14 18:37:24 2016 -0700
@@ -31,4 +31,18 @@
 
 #endif
 
+#if lsprof serve
+
+Profiling of HTTP requests works
+
+  $ hg --profile --config profiling.format=text --config profiling.output=../profile.log serve -d -p $HGPORT --pid-file ../hg.pid -A ../access.log
+  $ cat ../hg.pid >> $DAEMON_PIDS
+  $ hg -q clone -U http://localhost:$HGPORT ../clone
+
+A single profile is logged because file logging doesn't append
+  $ grep CallCount ../profile.log | wc -l
+  \s*1 (re)
+
+#endif
+
   $ cd ..