Clean up orphaned testserver processes before launching a new one in net::TestServer

Several chrome tests have failed in recent days because some test cases crashed due to failures, leaving behind orphaned testserver processes. These test suites do not use out_of_proc_test_runner, and therefore, do not get the benefit of using the LaunchAppInNewProcessGroup()/KillProcessGroup() mechanism.

This patch implements an added layer of safety, by causing TestServer::LaunchPython() to first kill any remaining orphaned instances of testserver.py before launching a new one. The check for an orphaned testserver process on POSIX is a process with exe_name "python", a parent_pid of "1" (indicating that it's an orphan), and command line parameters that contain the strings "testserver.py" and "<port>" where <port> is the port that is being used by the test server instance.

BUG=55808,57253
TEST=Run a test that spawns a testserver and dies. Run another test. It shouldn't fail.

Review URL: http://codereview.chromium.org/3537002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@61584 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 51 insertions, 0 deletions

diff --git a/net/test/test_server_posix.cc b/net/test/test_server_posix.cc
index 262845c..6e65bcf 100644
--- a/net/test/test_server_posix.cc
+++ b/net/test/test_server_posix.cc
@@ -4,9 +4,52 @@
 
 #include "net/test/test_server.h"
 
+#include <vector>
+
 #include "base/file_util.h"
 #include "base/logging.h"
+#include "base/process_util.h"
 #include "base/string_number_conversions.h"
+#include "base/string_util.h"
+
+namespace {
+
+// Helper class used to detect and kill orphaned python test server processes.
+// Checks if the command line of a process contains |path_string| (the path
+// from which the test server was launched) and |port_string| (the port used by
+// the test server), and if the parent pid of the process is 1 (indicating that
+// it is an orphaned process).
+class OrphanedTestServerFilter : public base::ProcessFilter {
+ public:
+  OrphanedTestServerFilter(
+      const std::string& path_string, const std::string& port_string)
+      : path_string_(path_string),
+        port_string_(port_string) {}
+
+  virtual bool Includes(const base::ProcessEntry& entry) const {
+    if (entry.parent_pid() != 1)
+      return false;
+    bool found_path_string = false;
+    bool found_port_string = false;
+    for (std::vector<std::string>::const_iterator it =
+         entry.cmd_line_args().begin();
+         it != entry.cmd_line_args().end();
+         ++it) {
+      if (it->find(path_string_) != std::string::npos)
+        found_path_string = true;
+      if (it->find(port_string_) != std::string::npos)
+        found_port_string = true;
+    }
+    return found_path_string && found_port_string;
+  }
+
+ private:
+  std::string path_string_;
+  std::string port_string_;
+  DISALLOW_COPY_AND_ASSIGN(OrphanedTestServerFilter);
+};
+
+}  // namespace
 
 namespace net {
 bool TestServer::LaunchPython(const FilePath& testserver_path) {
@@ -47,6 +90,14 @@ bool TestServer::LaunchPython(const FilePath& testserver_path) {
 
   command_line.push_back("--startup-pipe=" + base::IntToString(pipefd[1]));
 
+  // Try to kill any orphaned testserver processes that may be running.
+  OrphanedTestServerFilter filter(testserver_path.value(),
+                                  base::IntToString(host_port_pair_.port()));
+  if (!base::KillProcesses(L"python", -1, &filter)) {
+    LOG(WARNING) << "Failed to clean up older orphaned testserver instances.";
+  }
+
+  // Launch a new testserver process.
   if (!base::LaunchApp(command_line, map_write_fd, false, &process_handle_)) {
     LOG(ERROR) << "Failed to launch " << command_line[0] << " ...";
     return false;