Code to collect issue 97285 debugging info for crash reports.

chrome/app/chrome_main_delegate.cc

 // Copyright (c) 2012 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 "chrome/app/chrome_main_delegate.h"
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/message_loop.h"
 #include "base/metrics/field_trial.h"
@@ skipping 12 matching lines @@
 #include "chrome/common/chrome_paths_internal.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/logging_chrome.h"
 #include "chrome/common/profiling.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/plugin/chrome_content_plugin_client.h"
 #include "chrome/renderer/chrome_content_renderer_client.h"
 #include "chrome/utility/chrome_content_utility_client.h"
 #include "content/public/common/content_client.h"
+#include "content/public/common/content_debug_logging.h"
 #include "content/public/common/content_paths.h"
 #include "content/public/common/content_switches.h"
 #include "ui/base/ui_base_switches.h"
 
 #if defined(OS_WIN)
 #include <algorithm>
 #include <atlbase.h>
 #include <malloc.h>
 #include "base/string_util.h"
 #include "base/win/registry.h"
@@ skipping 319 matching lines @@
 }
 #endif
 
 #endif  // OS_POSIX
 
 struct MainFunction {
   const char* name;
   int (*function)(const content::MainFunctionParams&);
 };
 
+// Limit message count and size to prevent rogue processes from
+// bloating memory use.
+const size_t kMaxBugMessages = 20;
+const size_t kMaxMessageSize = 64;
+
+// Locks g_messages.
+static base::LazyInstance<base::Lock>::Leaky
+    g_messages_lock = LAZY_INSTANCE_INITIALIZER;
+
+// Map bug ids to messages for that bug.
+// TODO(shess): Would multimap<> maintain the items in order added?
+base::LazyInstance<std::map<int, std::vector<std::string> > >
+    g_messages = LAZY_INSTANCE_INITIALIZER;
+
+void RecordMsg(int bug_id, const std::string& msg) {
+  // Only record information about specific bugs to prevent rogue
+  // processes from bloating memory usage.
+  CHECK(bug_id == 97285 || bug_id == 141055);
+
+  // Make sure legitimate clients know that things are getting too big
+  // to handle.
+  DCHECK_LE(msg.size(), kMaxMessageSize);
+
+  base::AutoLock pin(g_messages_lock.Get());
+  std::vector<std::string>& bug_messages = g_messages.Get()[bug_id];
+  bug_messages.push_back(msg.substr(0, kMaxMessageSize));
+
+  // Should only remove a single item.
+  while (bug_messages.size() > kMaxBugMessages)
+    bug_messages.erase(bug_messages.begin());
+}
+
+bool GetMessages(int bug_id, std::vector<std::string>* msgs) {
+  CHECK(bug_id == 97285 || bug_id == 141055);
+
+  base::AutoLock pin(g_messages_lock.Get());
+  std::vector<std::string>& bug_messages = g_messages.Get()[bug_id];
+  msgs->assign(bug_messages.begin(), bug_messages.end());

[Bernhard Bauer, 2012/09/05 15:04:55]

Could you just write `*msgs = g_messages.Get()[bug_id];`?

[Scott Hess - ex-Googler, 2012/09/05 17:17:05]

Done.  Sometimes it's harder to see the things which don't look right for C.

+  return !msgs->empty();
+}
+
 }  // namespace
 
 ChromeMainDelegate::ChromeMainDelegate() {
 }
 
 ChromeMainDelegate::~ChromeMainDelegate() {
 }
 
 bool ChromeMainDelegate::BasicStartupComplete(int* exit_code) {
 #if defined(OS_CHROMEOS)
@@ skipping 136 matching lines @@
   if (IsCrashReporterEnabled())
     InitCrashProcessInfo();
 }
 #endif  // defined(OS_MACOSX)
 
 void ChromeMainDelegate::PreSandboxStartup() {
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   std::string process_type =
       command_line.GetSwitchValueASCII(switches::kProcessType);
 
+  // TODO(shess): Could this be registered earlier?
+  if (process_type.empty())
+    content::debug::RegisterMessageHandlers(RecordMsg, GetMessages);
+
   chrome::RegisterPathProvider();
 
 #if defined(OS_MACOSX)
   // On the Mac, the child executable lives at a predefined location within
   // the app bundle's versioned directory.
   PathService::Override(content::CHILD_PROCESS_EXE,
                         chrome::GetVersionedDirectory().
                         Append(chrome::kHelperProcessExecutablePath));
 
   InitMacCrashReporter(command_line, process_type);
@@ skipping 178 matching lines @@
 
 content::ContentRendererClient*
     ChromeMainDelegate::CreateContentRendererClient() {
   return &g_chrome_content_renderer_client.Get();
 }
 
 content::ContentUtilityClient*
     ChromeMainDelegate::CreateContentUtilityClient() {
   return &g_chrome_content_utility_client.Get();
 }