extensions/browser/api/async_api_function.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "extensions/browser/api/async_api_function.h"
   6
   7 #include "base/bind.h"
   8 #include "extensions/browser/extension_system.h"
   9
  10 using content::BrowserThread;
  11
  12 namespace extensions {
  13
  14 // AsyncApiFunction
  15 AsyncApiFunction::AsyncApiFunction() : work_thread_id_(BrowserThread::IO) {}
  16
  17 AsyncApiFunction::~AsyncApiFunction() {}
  18
  19 bool AsyncApiFunction::RunAsync() {
  20   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  21
  22   if (!PrePrepare() || !Prepare()) {
  23     return false;
  24   }
  25   bool rv = BrowserThread::PostTask(
  26       work_thread_id_,
  27       FROM_HERE,
  28       base::Bind(&AsyncApiFunction::WorkOnWorkThread, this));
  29   DCHECK(rv);
  30   return true;
  31 }
  32
  33 bool AsyncApiFunction::PrePrepare() { return true; }
  34
  35 void AsyncApiFunction::Work() {}
  36
  37 void AsyncApiFunction::AsyncWorkStart() {
  38   Work();
  39   AsyncWorkCompleted();
  40 }
  41
  42 void AsyncApiFunction::AsyncWorkCompleted() {
  43   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
  44     bool rv = BrowserThread::PostTask(
  45         BrowserThread::UI,
  46         FROM_HERE,
  47         base::Bind(&AsyncApiFunction::RespondOnUIThread, this));
  48     DCHECK(rv);
  49   } else {
  50     SendResponse(Respond());
  51   }
  52 }
  53
  54 void AsyncApiFunction::WorkOnWorkThread() {
  55   DCHECK_CURRENTLY_ON(work_thread_id_);
  56   DLOG_IF(ERROR, (work_thread_id_ == BrowserThread::UI))
  57       << "You have specified that AsyncApiFunction::Work() should happen on "
  58          "the UI thread. This nullifies the point of this class. Either "
  59          "specify a different thread or derive from a different class.";
  60   AsyncWorkStart();
  61 }
  62
  63 void AsyncApiFunction::RespondOnUIThread() {
  64   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  65   SendResponse(Respond());
  66 }
  67
  68 }  // namespace extensions