blob: 51ad986a91632c17836a9fe46035fa661593506f (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
|
// 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 "net/disk_cache/in_flight_io.h"
#include "base/bind.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/threading/thread_restrictions.h"
namespace disk_cache {
BackgroundIO::BackgroundIO(InFlightIO* controller)
: result_(-1), io_completed_(true, false), controller_(controller) {
}
// Runs on the primary thread.
void BackgroundIO::OnIOSignalled() {
if (controller_)
controller_->InvokeCallback(this, false);
}
void BackgroundIO::Cancel() {
// controller_ may be in use from the background thread at this time.
base::AutoLock lock(controller_lock_);
DCHECK(controller_);
controller_ = NULL;
}
BackgroundIO::~BackgroundIO() {
}
// ---------------------------------------------------------------------------
InFlightIO::InFlightIO()
: callback_thread_(base::MessageLoopProxy::current()),
running_(false), single_thread_(false) {
}
InFlightIO::~InFlightIO() {
}
// Runs on the background thread.
void BackgroundIO::NotifyController() {
base::AutoLock lock(controller_lock_);
if (controller_)
controller_->OnIOComplete(this);
}
void InFlightIO::WaitForPendingIO() {
while (!io_list_.empty()) {
// Block the current thread until all pending IO completes.
IOList::iterator it = io_list_.begin();
InvokeCallback(*it, true);
}
}
void InFlightIO::DropPendingIO() {
while (!io_list_.empty()) {
IOList::iterator it = io_list_.begin();
BackgroundIO* operation = *it;
operation->Cancel();
DCHECK(io_list_.find(operation) != io_list_.end());
io_list_.erase(make_scoped_refptr(operation));
}
}
// Runs on a background thread.
void InFlightIO::OnIOComplete(BackgroundIO* operation) {
#ifndef NDEBUG
if (callback_thread_->BelongsToCurrentThread()) {
DCHECK(single_thread_ || !running_);
single_thread_ = true;
}
#endif
callback_thread_->PostTask(FROM_HERE,
base::Bind(&BackgroundIO::OnIOSignalled,
operation));
operation->io_completed()->Signal();
}
// Runs on the primary thread.
void InFlightIO::InvokeCallback(BackgroundIO* operation, bool cancel_task) {
{
// http://crbug.com/74623
base::ThreadRestrictions::ScopedAllowWait allow_wait;
operation->io_completed()->Wait();
}
running_ = true;
if (cancel_task)
operation->Cancel();
// Make sure that we remove the operation from the list before invoking the
// callback (so that a subsequent cancel does not invoke the callback again).
DCHECK(io_list_.find(operation) != io_list_.end());
DCHECK(!operation->HasOneRef());
io_list_.erase(make_scoped_refptr(operation));
OnOperationComplete(operation, cancel_task);
}
// Runs on the primary thread.
void InFlightIO::OnOperationPosted(BackgroundIO* operation) {
DCHECK(callback_thread_->BelongsToCurrentThread());
io_list_.insert(make_scoped_refptr(operation));
}
} // namespace disk_cache
|
