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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.content;
import android.accounts.Account;
import android.os.Bundle;
import android.os.Process;
import java.util.concurrent.atomic.AtomicInteger;
/**
* An abstract implementation of a SyncAdapter that spawns a thread to invoke a sync operation.
* If a sync operation is already in progress when a startSync() request is received then an error
* will be returned to the new request and the existing request will be allowed to continue.
* When a startSync() is received and there is no sync operation in progress then a thread
* will be started to run the operation and {@link #performSync} will be invoked on that thread.
* If a cancelSync() is received that matches an existing sync operation then the thread
* that is running that sync operation will be interrupted, which will indicate to the thread
* that the sync has been canceled.
*
* @hide
*/
public abstract class AbstractThreadedSyncAdapter {
private final Context mContext;
private final AtomicInteger mNumSyncStarts;
private final ISyncAdapterImpl mISyncAdapterImpl;
// all accesses to this member variable must be synchronized on "this"
private SyncThread mSyncThread;
/** Kernel event log tag. Also listed in data/etc/event-log-tags. */
public static final int LOG_SYNC_DETAILS = 2743;
private final boolean mAutoInitialize;
/**
* Creates an {@link AbstractThreadedSyncAdapter}.
* @param context the {@link android.content.Context} that this is running within.
* @param autoInitialize if true then sync requests that have
* {@link ContentResolver#SYNC_EXTRAS_INITIALIZE} set will be internally handled by
* {@link AbstractThreadedSyncAdapter} by calling
* {@link ContentResolver#setIsSyncable(android.accounts.Account, String, int)} with 1 if it
* is currently set to <0.
*/
public AbstractThreadedSyncAdapter(Context context, boolean autoInitialize) {
mContext = context;
mISyncAdapterImpl = new ISyncAdapterImpl();
mNumSyncStarts = new AtomicInteger(0);
mSyncThread = null;
mAutoInitialize = autoInitialize;
}
class ISyncAdapterImpl extends ISyncAdapter.Stub {
public void startSync(ISyncContext syncContext, String authority, Account account,
Bundle extras) {
final SyncContext syncContextClient = new SyncContext(syncContext);
boolean alreadyInProgress;
// synchronize to make sure that mSyncThread doesn't change between when we
// check it and when we use it
synchronized (this) {
if (mSyncThread == null) {
if (mAutoInitialize
&& extras != null
&& extras.getBoolean(ContentResolver.SYNC_EXTRAS_INITIALIZE, false)) {
if (ContentResolver.getIsSyncable(account, authority) < 0) {
ContentResolver.setIsSyncable(account, authority, 1);
}
syncContextClient.onFinished(new SyncResult());
return;
}
mSyncThread = new SyncThread(
"SyncAdapterThread-" + mNumSyncStarts.incrementAndGet(),
syncContextClient, authority, account, extras);
mSyncThread.start();
alreadyInProgress = false;
} else {
alreadyInProgress = true;
}
}
// do this outside since we don't want to call back into the syncContext while
// holding the synchronization lock
if (alreadyInProgress) {
syncContextClient.onFinished(SyncResult.ALREADY_IN_PROGRESS);
}
}
public void cancelSync(ISyncContext syncContext) {
// synchronize to make sure that mSyncThread doesn't change between when we
// check it and when we use it
synchronized (this) {
if (mSyncThread != null
&& mSyncThread.mSyncContext.getISyncContext() == syncContext) {
mSyncThread.interrupt();
}
}
}
}
/**
* The thread that invokes performSync(). It also acquires the provider for this sync
* before calling performSync and releases it afterwards. Cancel this thread in order to
* cancel the sync.
*/
private class SyncThread extends Thread {
private final SyncContext mSyncContext;
private final String mAuthority;
private final Account mAccount;
private final Bundle mExtras;
private SyncThread(String name, SyncContext syncContext, String authority,
Account account, Bundle extras) {
super(name);
mSyncContext = syncContext;
mAuthority = authority;
mAccount = account;
mExtras = extras;
}
public void run() {
Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
if (isCanceled()) {
return;
}
SyncResult syncResult = new SyncResult();
ContentProviderClient provider = null;
try {
provider = mContext.getContentResolver().acquireContentProviderClient(mAuthority);
if (provider != null) {
AbstractThreadedSyncAdapter.this.performSync(mAccount, mExtras,
mAuthority, provider, syncResult);
} else {
// TODO(fredq) update the syncResults to indicate that we were unable to
// find the provider. maybe with a ProviderError?
}
} finally {
if (provider != null) {
provider.release();
}
if (!isCanceled()) {
mSyncContext.onFinished(syncResult);
}
// synchronize so that the assignment will be seen by other threads
// that also synchronize accesses to mSyncThread
synchronized (this) {
mSyncThread = null;
}
}
}
private boolean isCanceled() {
return Thread.currentThread().isInterrupted();
}
}
/**
* @return a reference to the ISyncAdapter interface into this SyncAdapter implementation.
*/
public final ISyncAdapter getISyncAdapter() {
return mISyncAdapterImpl;
}
/**
* Perform a sync for this account. SyncAdapter-specific parameters may
* be specified in extras, which is guaranteed to not be null. Invocations
* of this method are guaranteed to be serialized.
*
* @param account the account that should be synced
* @param extras SyncAdapter-specific parameters
* @param authority the authority of this sync request
* @param provider a ContentProviderClient that points to the ContentProvider for this
* authority
* @param syncResult SyncAdapter-specific parameters
*/
public abstract void performSync(Account account, Bundle extras,
String authority, ContentProviderClient provider, SyncResult syncResult);
}
|
