Refactor CrashDump*Manager to use a shared CrashDumpObserver singleton.

components/crash/content/browser/crash_dump_manager_android.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 "components/crash/content/browser/crash_dump_manager_android.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/posix/global_descriptors.h"
 #include "base/process/process.h"
 #include "base/rand_util.h"
 #include "base/stl_util.h"
 #include "base/strings/stringprintf.h"
+#include "components/crash/content/app/breakpad_linux.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/child_process_data.h"
 #include "content/public/browser/file_descriptor_info.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
 
 using content::BrowserThread;
 
 namespace breakpad {
 
-// static
-CrashDumpManager* CrashDumpManager::instance_ = NULL;
+CrashDumpManager::CrashDumpManager(const base::FilePath& crash_dump_dir,
+                                   int descriptor_id)
+    : crash_dump_dir_(crash_dump_dir), descriptor_id_(descriptor_id) {}
 
-// static
-CrashDumpManager* CrashDumpManager::GetInstance() {
-  CHECK(instance_);
-  return instance_;
+CrashDumpManager::~CrashDumpManager() {
 }
 
-CrashDumpManager::CrashDumpManager(const base::FilePath& crash_dump_dir)
-    : crash_dump_dir_(crash_dump_dir) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  DCHECK(!instance_);
+void CrashDumpManager::OnChildStart(int child_process_id,
+                                    content::FileDescriptorInfo* mappings) {
+  DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
 
-  instance_ = this;
+  if (!breakpad::IsCrashReporterEnabled())
+    return;
 
-  notification_registrar_.Add(this,
-                              content::NOTIFICATION_RENDERER_PROCESS_TERMINATED,
-                              content::NotificationService::AllSources());
-  notification_registrar_.Add(this,
-                              content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
-                              content::NotificationService::AllSources());
-
-  BrowserChildProcessObserver::Add(this);
-}
-
-CrashDumpManager::~CrashDumpManager() {
-  instance_ = NULL;
-
-  BrowserChildProcessObserver::Remove(this);
-}
-
-base::File CrashDumpManager::CreateMinidumpFile(int child_process_id) {
-  DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
   base::FilePath minidump_path;
-  if (!base::CreateTemporaryFile(&minidump_path))
-    return base::File();
+  if (!base::CreateTemporaryFile(&minidump_path)) {
+    LOG(ERROR) << "Failed to create temporary file, crash won't be reported.";
+    return;
+  }
 
   // We need read permission as the minidump is generated in several phases
   // and needs to be read at some point.
   int flags = base::File::FLAG_OPEN | base::File::FLAG_READ |
               base::File::FLAG_WRITE;
   base::File minidump_file(minidump_path, flags);
   if (!minidump_file.IsValid()) {
-    LOG(ERROR) << "Failed to create temporary file, crash won't be reported.";
-    return base::File();
+    LOG(ERROR) << "Failed to open temporary file, crash won't be reported.";
+    return;
   }
 
   {
     base::AutoLock auto_lock(child_process_id_to_minidump_path_lock_);
     DCHECK(!base::ContainsKey(child_process_id_to_minidump_path_,
                               child_process_id));
     child_process_id_to_minidump_path_[child_process_id] = minidump_path;
   }
-  return minidump_file;
+  mappings->Transfer(descriptor_id_,
+                     base::ScopedFD(minidump_file.TakePlatformFile()));
 }
 
-// static
 void CrashDumpManager::ProcessMinidump(
     const base::FilePath& minidump_path,
     base::ProcessHandle pid,
     content::ProcessType process_type,
     base::TerminationStatus termination_status,
     base::android::ApplicationState app_state) {
-  DCHECK_CURRENTLY_ON(BrowserThread::FILE);

[Lei Zhang, 2016/10/05 18:00:00]

I'm curious what thread CrashDumpManager actually lives on.

[Tobias Sargeant, 2016/10/06 17:42:22]

It's created on the main thread, but callbacks occur on the process launcher
thread, and the blocking thread pool. Destruction thread could be any of these,
depending on who holds the last reference.

-  CHECK(instance_);
   int64_t file_size = 0;
   int r = base::GetFileSize(minidump_path, &file_size);
   DCHECK(r) << "Failed to retrieve size for minidump "
             << minidump_path.value();
 
   // TODO(wnwen): If these numbers match up to TabWebContentsObserver's
   //     TabRendererCrashStatus histogram, then remove that one as this is more
   //     accurate with more detail.
   if (process_type == content::PROCESS_TYPE_RENDERER &&
       app_state != base::android::APPLICATION_STATE_UNKNOWN) {
@@ skipping 33 matching lines @@
   if (file_size == 0) {
     // Empty minidump, this process did not crash. Just remove the file.
     r = base::DeleteFile(minidump_path, false);
     DCHECK(r) << "Failed to delete temporary minidump file "
               << minidump_path.value();
     return;
   }
 
   // We are dealing with a valid minidump. Copy it to the crash report
   // directory from where Java code will upload it later on.
-  if (instance_->crash_dump_dir_.empty()) {
+  if (crash_dump_dir_.empty()) {
     NOTREACHED() << "Failed to retrieve the crash dump directory.";
     return;
   }
   const uint64_t rand = base::RandUint64();
   const std::string filename =
       base::StringPrintf("chromium-renderer-minidump-%016" PRIx64 ".dmp%d",
                          rand, pid);
-  base::FilePath dest_path = instance_->crash_dump_dir_.Append(filename);
+  base::FilePath dest_path = crash_dump_dir_.Append(filename);
   r = base::Move(minidump_path, dest_path);
   if (!r) {
     LOG(ERROR) << "Failed to move crash dump from " << minidump_path.value()
                << " to " << dest_path.value();
     base::DeleteFile(minidump_path, false);
     return;
   }
-  VLOG(1) << "Crash minidump successfully generated: " <<
-      instance_->crash_dump_dir_.Append(filename).value();
-}
-
-void CrashDumpManager::BrowserChildProcessHostDisconnected(
-    const content::ChildProcessData& data) {
-  OnChildExit(data.id,
-              data.handle,
-              static_cast<content::ProcessType>(data.process_type),
-              base::TERMINATION_STATUS_MAX_ENUM,
-              base::android::APPLICATION_STATE_UNKNOWN);
-}
-
-void CrashDumpManager::BrowserChildProcessCrashed(
-    const content::ChildProcessData& data,
-    int exit_code) {
-  OnChildExit(data.id,
-              data.handle,
-              static_cast<content::ProcessType>(data.process_type),
-              base::TERMINATION_STATUS_ABNORMAL_TERMINATION,
-              base::android::APPLICATION_STATE_UNKNOWN);
-}
-
-void CrashDumpManager::Observe(int type,
-                               const content::NotificationSource& source,
-                               const content::NotificationDetails& details) {
-  content::RenderProcessHost* rph =
-      content::Source<content::RenderProcessHost>(source).ptr();
-  base::TerminationStatus term_status = base::TERMINATION_STATUS_MAX_ENUM;
-  base::android::ApplicationState app_state =
-      base::android::APPLICATION_STATE_UNKNOWN;
-  switch (type) {
-    case content::NOTIFICATION_RENDERER_PROCESS_TERMINATED: {
-      // NOTIFICATION_RENDERER_PROCESS_TERMINATED is sent when the renderer
-      // process is cleanly shutdown. However, we still need to close the
-      // minidump_fd we kept open.
-      term_status = base::TERMINATION_STATUS_NORMAL_TERMINATION;
-      break;
-    }
-    case content::NOTIFICATION_RENDERER_PROCESS_CLOSED: {
-      // We do not care about android fast shutdowns as it is a known case where
-      // the renderer is intentionally killed when we are done with it.
-      if (rph->FastShutdownStarted()) {
-        break;
-      }
-      content::RenderProcessHost::RendererClosedDetails* process_details =
-          content::Details<content::RenderProcessHost::RendererClosedDetails>(
-              details).ptr();
-      term_status = process_details->status;
-      app_state = base::android::ApplicationStatusListener::GetState();
-      break;
-    }
-    default:
-      NOTREACHED();
-      return;
-  }
-  OnChildExit(rph->GetID(),
-              rph->GetHandle(),
-              content::PROCESS_TYPE_RENDERER,
-              term_status,
-              app_state);
+  VLOG(1) << "Crash minidump successfully generated: "
+          << crash_dump_dir_.Append(filename).value();
 }
 
 void CrashDumpManager::OnChildExit(int child_process_id,
                                    base::ProcessHandle pid,
                                    content::ProcessType process_type,
                                    base::TerminationStatus termination_status,
                                    base::android::ApplicationState app_state) {
   base::FilePath minidump_path;
   {
     base::AutoLock auto_lock(child_process_id_to_minidump_path_lock_);
     ChildProcessIDToMinidumpPath::iterator iter =
         child_process_id_to_minidump_path_.find(child_process_id);
     if (iter == child_process_id_to_minidump_path_.end()) {
       // We might get a NOTIFICATION_RENDERER_PROCESS_TERMINATED and a
       // NOTIFICATION_RENDERER_PROCESS_CLOSED.
       return;
     }
     minidump_path = iter->second;
     child_process_id_to_minidump_path_.erase(iter);
   }
-  BrowserThread::PostTask(
-      BrowserThread::FILE, FROM_HERE,
-      base::Bind(&CrashDumpManager::ProcessMinidump,
-                 minidump_path,
-                 pid,
-                 process_type,
-                 termination_status,
-                 app_state));
+  ProcessMinidump(minidump_path, pid, process_type, termination_status,
+                  app_state);
 }
 
 }  // namespace breakpad