Fix a test launcher hang when no tests are run.

base/test/test_launcher.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/test/test_launcher.h"
 
 #include "base/at_exit.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/environment.h"
@@ skipping 103 matching lines @@
 // detailed failure messages either.
 class ResultsPrinter {
  public:
   ResultsPrinter(const CommandLine& command_line,
                  const RunTestsCallback& callback);
   ~ResultsPrinter();
 
   // Called when test named |name| is scheduled to be started.
   void OnTestStarted(const std::string& name);
 
+  // Called when all tests that were to be started have been scheduled
+  // to be started.
+  void OnAllTestsStarted();
+
   // Adds |result| to the stored test results.
   void AddTestResult(const TestResult& result);
 
  private:
   // Prints a list of tests that finished with |status|.
   void PrintTestsByStatus(TestResult::Status status,
                           const std::string& description);
 
   // Test results grouped by test case name.
   typedef std::map<std::string, std::vector<TestResult> > ResultsMap;
@@ skipping 87 matching lines @@
   }
   fprintf(out_, "</testsuites>\n");
   fclose(out_);
 }
 
 void ResultsPrinter::OnTestStarted(const std::string& name) {
   DCHECK(thread_checker_.CalledOnValidThread());
   ++test_started_count_;
 }
 
+void ResultsPrinter::OnAllTestsStarted() {
+  if (test_started_count_ == 0) {
+    fprintf(stdout, "0 tests run\n");

[Ken Russell (switch to Gerrit), 2013/09/04 18:00:30]

Did you mean to leave this printf in here?

[Paweł Hajdan Jr., 2013/09/04 18:02:30]

Yes - it corresponds to "x tests run" below and explains a quick exit. :)

+    fflush(stdout);
+
+    // No tests have actually been started, so fire the callback
+    // to avoid a hang.
+    callback_.Run(true);
+    delete this;
+  }
+}
+
 void ResultsPrinter::AddTestResult(const TestResult& result) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   ++test_run_count_;
   results_[result.test_case_name].push_back(result);
 
   // TODO(phajdan.jr): Align counter (padding).
   std::string status_line(StringPrintf("[%" PRIuS "/%" PRIuS "] %s ",
                                        test_run_count_,
                                        test_started_count_,
@@ skipping 157 matching lines @@
                test_case,
                test_info,
                Bind(&ResultsPrinter::AddTestResult, Unretained(printer))));
     }
   }
 
   MessageLoop::current()->PostTask(
       FROM_HERE,
       Bind(&TestLauncherDelegate::RunRemainingTests,
       Unretained(launcher_delegate)));
+
+  MessageLoop::current()->PostTask(
+      FROM_HERE,
+      Bind(&ResultsPrinter::OnAllTestsStarted, Unretained(printer)));
 }
 
 void RunTestIteration(TestLauncherDelegate* launcher_delegate,
                       int32 total_shards,
                       int32 shard_index,
                       int cycles,
                       int* exit_code,
                       bool run_tests_success) {
   if (!run_tests_success) {
     *exit_code = 1;
@@ skipping 148 matching lines @@
            cycles,
            &exit_code,
            true));
 
   MessageLoop::current()->Run();
 
   return exit_code;
 }
 
 }  // namespace base