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
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
/*
* Copyright (C) 2010 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef WorkerFileWriterCallbacksBridge_h
#define WorkerFileWriterCallbacksBridge_h
#if ENABLE(FILE_SYSTEM)
#include "WebFileError.h"
#include "WebFileWriterClient.h"
#include "WorkerContext.h"
#include <wtf/PassOwnPtr.h>
#include <wtf/PassRefPtr.h>
#include <wtf/ThreadSafeShared.h>
namespace WebCore {
class AsyncFileWriterClient;
class KURL;
class WorkerLoaderProxy;
}
namespace WTF {
class String;
}
using WTF::String;
namespace WebKit {
class WebFileSystem;
class WebFileWriter;
class WebFileWriterClient;
class WebWorkerBase;
// This class is used as a mechanism to bridge calls between threads.
// Calls to a WebFileWriter must happen on the main thread, but they come from
// the context thread. The responses through the WebFileWriterClient interface
// start on the main thread, but must be sent via the worker context thread.
//
// A typical flow for write would look like this:
// Bridge::postWriteToMainThread() on WorkerThread
// --> Bridge::writeOnMainThread() is called on MainThread
// --> WebFileWriter::write()
// This makes an IPC; the actual operation is down in the browser.
// --> Bridge::didWrite is called on MainThread
// --> Bridge::didWriteOnWorkerThread is called on WorkerThread
// This calls the original client (m_clientOnWorkerThread).
//
// The bridge object is refcounted, so that it doesn't get deleted while there
// are cross-thread calls in flight. Each CrossThreadTask carries a reference
// to the bridge, which guarantees that the bridge will still be valid when the
// task is executed. In order to shut down the bridge, the WebFileWriterClient
// should call postShutdownToMainThread before dropping its reference to the
// bridge. This ensures that the WebFileWriter will be cleared on the main
// thread and that no further calls to the WebFileWriterClient will be made.
class WorkerFileWriterCallbacksBridge : public ThreadSafeShared<WorkerFileWriterCallbacksBridge>, public WebCore::WorkerContext::Observer, public WebFileWriterClient {
public:
~WorkerFileWriterCallbacksBridge();
// WorkerContext::Observer method.
virtual void notifyStop();
static PassRefPtr<WorkerFileWriterCallbacksBridge> create(const String& path, WebCore::WorkerLoaderProxy* proxy, WebCore::ScriptExecutionContext* workerContext, WebCore::AsyncFileWriterClient* client)
{
return adoptRef(new WorkerFileWriterCallbacksBridge(path, proxy, workerContext, client));
}
// Methods that create an instance and post an initial request task to the main thread. They must be called on the worker thread.
void postWriteToMainThread(long long position, const WebCore::KURL& data);
void postTruncateToMainThread(long long length);
void postAbortToMainThread();
// The owning WorkerAsyncFileWriterChromium should call this method before dropping its last reference to the bridge, on the context thread.
// The actual deletion of the WorkerFileWriterCallbacksBridge may happen on either the main or context thread, depending on where the last reference goes away; that's safe as long as this is called first.
void postShutdownToMainThread(PassRefPtr<WorkerFileWriterCallbacksBridge>);
// Callback methods that are called on the main thread.
// These are the implementation of WebKit::WebFileWriterClient.
void didWrite(long long bytes, bool complete);
void didFail(WebFileError);
void didTruncate();
private:
WorkerFileWriterCallbacksBridge(const String& path, WebCore::WorkerLoaderProxy*, WebCore::ScriptExecutionContext*, WebCore::AsyncFileWriterClient*);
void postInitToMainThread(const String& path);
// Methods that are to be called on the main thread.
static void writeOnMainThread(WebCore::ScriptExecutionContext*, PassRefPtr<WorkerFileWriterCallbacksBridge>, long long position, const WebCore::KURL& data);
static void truncateOnMainThread(WebCore::ScriptExecutionContext*, PassRefPtr<WorkerFileWriterCallbacksBridge>, long long length);
static void abortOnMainThread(WebCore::ScriptExecutionContext*, PassRefPtr<WorkerFileWriterCallbacksBridge>);
static void initOnMainThread(WebCore::ScriptExecutionContext*, PassRefPtr<WorkerFileWriterCallbacksBridge>, const String& path);
static void shutdownOnMainThread(WebCore::ScriptExecutionContext*, PassRefPtr<WorkerFileWriterCallbacksBridge>);
// Methods that dispatch to AsyncFileWriterClient on the worker threads.
static void didWriteOnWorkerThread(WebCore::ScriptExecutionContext*, PassRefPtr<WorkerFileWriterCallbacksBridge>, long long length, bool complete);
static void didFailOnWorkerThread(WebCore::ScriptExecutionContext*, PassRefPtr<WorkerFileWriterCallbacksBridge>, WebFileError);
static void didTruncateOnWorkerThread(WebCore::ScriptExecutionContext*, PassRefPtr<WorkerFileWriterCallbacksBridge>);
// Called on the main thread to run the supplied task.
static void runTaskOnMainThread(WebCore::ScriptExecutionContext*, PassRefPtr<WorkerFileWriterCallbacksBridge>, PassOwnPtr<WebCore::ScriptExecutionContext::Task>);
// Called on the worker thread to run the supplied task.
static void runTaskOnWorkerThread(WebCore::ScriptExecutionContext*, PassRefPtr<WorkerFileWriterCallbacksBridge>, PassOwnPtr<WebCore::ScriptExecutionContext::Task>);
// Called on the worker thread to dispatch to the main thread.
void dispatchTaskToMainThread(PassOwnPtr<WebCore::ScriptExecutionContext::Task>);
// Called on the main thread to dispatch to the worker thread.
void dispatchTaskToWorkerThread(PassOwnPtr<WebCore::ScriptExecutionContext::Task>);
// Used from the main thread to post tasks to the context thread.
WebCore::WorkerLoaderProxy* m_proxy;
// Used on the context thread, only to check that we're running on the context thread.
WebCore::ScriptExecutionContext* m_workerContext;
// Created and destroyed from the main thread.
OwnPtr<WebKit::WebFileWriter> m_writer;
// Used on the context thread to call back into the client.
WebCore::AsyncFileWriterClient* m_clientOnWorkerThread;
// Used to indicate that shutdown has started on the main thread, and hence the writer has been deleted.
bool m_writerDeleted;
};
} // namespace WebCore
#endif
#endif // WorkerFileWriterCallbacksBridge_h
|
