1 /*
2  * Copyright (C) 2005 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ANDROID_IPC_THREAD_STATE_H
18 #define ANDROID_IPC_THREAD_STATE_H
19 
20 #include <utils/Errors.h>
21 #include <binder/Parcel.h>
22 #include <binder/ProcessState.h>
23 #include <utils/Vector.h>
24 
25 #if defined(_WIN32)
26 typedef  int  uid_t;
27 #endif
28 
29 // ---------------------------------------------------------------------------
30 namespace android {
31 
32 class IPCThreadState
33 {
34 public:
35     static  IPCThreadState*     self();
36     static  IPCThreadState*     selfOrNull();  // self(), but won't instantiate
37 
38             sp<ProcessState>    process();
39 
40             status_t            clearLastError();
41 
42             pid_t               getCallingPid() const;
43             uid_t               getCallingUid() const;
44 
45             void                setStrictModePolicy(int32_t policy);
46             int32_t             getStrictModePolicy() const;
47 
48             void                setLastTransactionBinderFlags(int32_t flags);
49             int32_t             getLastTransactionBinderFlags() const;
50 
51             int64_t             clearCallingIdentity();
52             void                restoreCallingIdentity(int64_t token);
53 
54             int                 setupPolling(int* fd);
55             status_t            handlePolledCommands();
56             void                flushCommands();
57 
58             void                joinThreadPool(bool isMain = true);
59 
60             // Stop the local process.
61             void                stopProcess(bool immediate = true);
62 
63             status_t            transact(int32_t handle,
64                                          uint32_t code, const Parcel& data,
65                                          Parcel* reply, uint32_t flags);
66 
67             void                incStrongHandle(int32_t handle);
68             void                decStrongHandle(int32_t handle);
69             void                incWeakHandle(int32_t handle);
70             void                decWeakHandle(int32_t handle);
71             status_t            attemptIncStrongHandle(int32_t handle);
72     static  void                expungeHandle(int32_t handle, IBinder* binder);
73             status_t            requestDeathNotification(   int32_t handle,
74                                                             BpBinder* proxy);
75             status_t            clearDeathNotification( int32_t handle,
76                                                         BpBinder* proxy);
77 
78     static  void                shutdown();
79 
80     // Call this to disable switching threads to background scheduling when
81     // receiving incoming IPC calls.  This is specifically here for the
82     // Android system process, since it expects to have background apps calling
83     // in to it but doesn't want to acquire locks in its services while in
84     // the background.
85     static  void                disableBackgroundScheduling(bool disable);
86 
87             // Call blocks until the number of executing binder threads is less than
88             // the maximum number of binder threads threads allowed for this process.
89             void                blockUntilThreadAvailable();
90 
91 private:
92                                 IPCThreadState();
93                                 ~IPCThreadState();
94 
95             status_t            sendReply(const Parcel& reply, uint32_t flags);
96             status_t            waitForResponse(Parcel *reply,
97                                                 status_t *acquireResult=NULL);
98             status_t            talkWithDriver(bool doReceive=true);
99             status_t            writeTransactionData(int32_t cmd,
100                                                      uint32_t binderFlags,
101                                                      int32_t handle,
102                                                      uint32_t code,
103                                                      const Parcel& data,
104                                                      status_t* statusBuffer);
105             status_t            getAndExecuteCommand();
106             status_t            executeCommand(int32_t command);
107             void                processPendingDerefs();
108 
109             void                clearCaller();
110 
111     static  void                threadDestructor(void *st);
112     static  void                freeBuffer(Parcel* parcel,
113                                            const uint8_t* data, size_t dataSize,
114                                            const binder_size_t* objects, size_t objectsSize,
115                                            void* cookie);
116 
117     const   sp<ProcessState>    mProcess;
118     const   pid_t               mMyThreadId;
119             Vector<BBinder*>    mPendingStrongDerefs;
120             Vector<RefBase::weakref_type*> mPendingWeakDerefs;
121 
122             Parcel              mIn;
123             Parcel              mOut;
124             status_t            mLastError;
125             pid_t               mCallingPid;
126             uid_t               mCallingUid;
127             int32_t             mStrictModePolicy;
128             int32_t             mLastTransactionBinderFlags;
129 };
130 
131 }; // namespace android
132 
133 // ---------------------------------------------------------------------------
134 
135 #endif // ANDROID_IPC_THREAD_STATE_H
136