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/*
* Copyright (C) 2005 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.
*/
#ifndef ANDROID_HARDWARE_IPC_THREAD_STATE_H
#define ANDROID_HARDWARE_IPC_THREAD_STATE_H
#include <utils/Errors.h>
#include <hwbinder/Parcel.h>
#include <hwbinder/ProcessState.h>
#include <utils/Vector.h>
#include <functional>
#if defined(_WIN32)
typedef int uid_t;
#endif
// ---------------------------------------------------------------------------
namespace android {
class IPCThreadStateBase;
namespace hardware {
class IPCThreadState
{
public:
static IPCThreadState* self();
static IPCThreadState* selfOrNull(); // self(), but won't instantiate
sp<ProcessState> process();
status_t clearLastError();
pid_t getCallingPid() const;
// nullptr if unavailable
//
// this can't be restored once it's cleared, and it does not return the
// context of the current process when not in a binder call.
const char* getCallingSid() const;
uid_t getCallingUid() const;
void setStrictModePolicy(int32_t policy);
int32_t getStrictModePolicy() const;
void setLastTransactionBinderFlags(int32_t flags);
int32_t getLastTransactionBinderFlags() const;
int64_t clearCallingIdentity();
// Restores PID/UID (not SID)
void restoreCallingIdentity(int64_t token);
int setupPolling(int* fd);
status_t handlePolledCommands();
void flushCommands();
void joinThreadPool(bool isMain = true);
// Stop the local process.
void stopProcess(bool immediate = true);
status_t transact(int32_t handle,
uint32_t code, const Parcel& data,
Parcel* reply, uint32_t flags);
void incStrongHandle(int32_t handle, BpHwBinder *proxy);
void decStrongHandle(int32_t handle);
void incWeakHandle(int32_t handle, BpHwBinder *proxy);
void decWeakHandle(int32_t handle);
status_t attemptIncStrongHandle(int32_t handle);
static void expungeHandle(int32_t handle, IBinder* binder);
status_t requestDeathNotification( int32_t handle,
BpHwBinder* proxy);
status_t clearDeathNotification( int32_t handle,
BpHwBinder* proxy);
static void shutdown();
// Call blocks until the number of executing binder threads is less than
// the maximum number of binder threads threads allowed for this process.
void blockUntilThreadAvailable();
// Service manager registration
void setTheContextObject(sp<BHwBinder> obj);
bool isLooperThread();
bool isOnlyBinderThread();
// Is this thread currently serving a hwbinder call. This method
// returns true if while traversing backwards from the function call
// stack for this thread, we encounter a function serving a hwbinder
// call before encountering a binder call / hitting the end of the
// call stack.
// Eg: If thread T1 went through the following call pattern
// 1) T1 receives and executes binder call B1.
// 2) While handling B1, T1 makes hwbinder call H1.
// 3) The handler of H1, calls into T1 with a callback H2.
// If isServingCall() is called during B1 before 3), this method
// will return false, else true.
//
// ----
// | H2 | ---> While callback H2 is being handled during 3).
// ----
// | B1 | ---> While B1 is being handled, hwbinder call H1 made.
// ----
// Fig: Thread Call stack while handling H2.
//
// This is since after 3), while traversing the thread call stack,
// we hit a hwbinder call before a binder call / end of stack.
// This method may be typically used to determine whether to use
// hardware::IPCThreadState methods or IPCThreadState methods to
// infer information about thread state.
bool isServingCall() const;
// Tasks which are done on the binder thread after the thread returns to the
// threadpool.
void addPostCommandTask(const std::function<void(void)>& task);
private:
IPCThreadState();
~IPCThreadState();
status_t sendReply(const Parcel& reply, uint32_t flags);
status_t waitForResponse(Parcel *reply,
status_t *acquireResult=nullptr);
status_t talkWithDriver(bool doReceive=true);
status_t writeTransactionData(int32_t cmd,
uint32_t binderFlags,
int32_t handle,
uint32_t code,
const Parcel& data,
status_t* statusBuffer);
status_t getAndExecuteCommand();
status_t executeCommand(int32_t command);
void processPendingDerefs();
void processPostWriteDerefs();
void clearCaller();
static void threadDestructor(void *st);
static void freeBuffer(Parcel* parcel,
const uint8_t* data, size_t dataSize,
const binder_size_t* objects, size_t objectsSize,
void* cookie);
const sp<ProcessState> mProcess;
Vector<BHwBinder*> mPendingStrongDerefs;
Vector<RefBase::weakref_type*> mPendingWeakDerefs;
Vector<RefBase*> mPostWriteStrongDerefs;
Vector<RefBase::weakref_type*> mPostWriteWeakDerefs;
Parcel mIn;
Parcel mOut;
status_t mLastError;
pid_t mCallingPid;
const char* mCallingSid;
uid_t mCallingUid;
int32_t mStrictModePolicy;
int32_t mLastTransactionBinderFlags;
bool mIsLooper;
bool mIsPollingThread;
std::vector<std::function<void(void)>> mPostCommandTasks;
IPCThreadStateBase *mIPCThreadStateBase;
ProcessState::CallRestriction mCallRestriction;
};
} // namespace hardware
} // namespace android
// ---------------------------------------------------------------------------
#endif // ANDROID_HARDWARE_IPC_THREAD_STATE_H
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