Android-Native-Server 启动和注册详细分析

sp<ProcessState> ProcessState::self()
{
Mutex::Autolock _l(gProcessMutex);
if (gProcess != NULL) {
return gProcess;
}
gProcess =new ProcessState;
return gProcess;
}

status_t BpBinder::transact(
uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
{
// Once a binder has died, it will never come back to life.
if (mAlive) {
status_t status = IPCThreadState::self()->transact(
mHandle, code, data, reply, flags);
if (status == DEAD_OBJECT) mAlive =0;
return status;
}
return DEAD_OBJECT;
}

status_t IPCThreadState::transact(int32_t handle,
uint32_t code, const Parcel& data,
Parcel* reply, uint32_t flags)
{
status_t err = data.errorCheck();
flags |= TF_ACCEPT_FDS;
IF_LOG_TRANSACTIONS() {
TextOutput::Bundle _b(alog);
alog <<"BC_TRANSACTION thr "<< (void*)pthread_self() <<" / hand "
<< handle <<" / code "<< TypeCode(code) <<": "
<< indent << data << dedent << endl;
}
if (err == NO_ERROR) {
LOG_ONEWAY(">>>> SEND from pid %d uid %d %s", getpid(), getuid(),
(flags & TF_ONE_WAY) ==0?"READ REPLY":"ONE WAY");
err = writeTransactionData(BC_TRANSACTION, flags, handle, code, data, NULL);
}
..............

.........省略部分代码.........

...............
return err;
}

status_t IPCThreadState::writeTransactionData(int32_t cmd, uint32_t binderFlags,
int32_t handle, uint32_t code, const Parcel& data, status_t* statusBuffer)
{
binder_transaction_data tr;
tr.target.handle = handle;
tr.code = code;
tr.flags = binderFlags;
tr.cookie =0;
tr.sender_pid =0;
tr.sender_euid =0;
const status_t err = data.errorCheck();
if (err == NO_ERROR) {
tr.data_size = data.ipcDataSize();
tr.data.ptr.buffer = data.ipcData();
tr.offsets_size = data.ipcObjectsCount()*sizeof(size_t);
tr.data.ptr.offsets = data.ipcObjects();
} elseif (statusBuffer) {
tr.flags |= TF_STATUS_CODE;
*statusBuffer = err;
tr.data_size =sizeof(status_t);
tr.data.ptr.buffer = statusBuffer;
tr.offsets_size =0;
tr.data.ptr.offsets = NULL;
} else {
return (mLastError = err);
}
mOut.writeInt32(cmd);
mOut.write(&tr, sizeof(tr));
return NO_ERROR;

status_t IPCThreadState::talkWithDriver(bool doReceive)
{
ALOG_ASSERT(mProcess->mDriverFD >=0, "Binder driver is not opened");
binder_write_read bwr;
// Is the read buffer empty?
constbool needRead = mIn.dataPosition() >= mIn.dataSize();
// We don't want to write anything if we are still reading
// from data left in the input buffer and the caller
// has requested to read the next data.
const size_t outAvail = (!doReceive || needRead) ? mOut.dataSize() :0;
bwr.write_size = outAvail;
bwr.write_buffer = (longunsignedint)mOut.data();
// This is what we'll read.
if (doReceive && needRead) {
bwr.read_size = mIn.dataCapacity();
bwr.read_buffer = (longunsignedint)mIn.data();
} else {
bwr.read_size =0;
bwr.read_buffer =0;
}
//用来打印日志的
IF_LOG_COMMANDS() {
TextOutput::Bundle _b(alog);
if (outAvail !=0) {
alog <<"Sending commands to driver: "<< indent;
constvoid* cmds = (constvoid*)bwr.write_buffer;
constvoid* end = ((const uint8_t*)cmds)+bwr.write_size;
alog << HexDump(cmds, bwr.write_size) << endl;
while (cmds < end) cmds = printCommand(alog, cmds);
alog << dedent;
}
alog <<"Size of receive buffer: "<< bwr.read_size
<<", needRead: "<< needRead <<", doReceive: "<< doReceive << endl;
}
// Return immediately if there is nothing to do.
if ((bwr.write_size ==0) && (bwr.read_size ==0)) return NO_ERROR;
bwr.write_consumed =0;
bwr.read_consumed =0;
status_t err;
do {
IF_LOG_COMMANDS() {
alog <<"About to read/write, write size = "<< mOut.dataSize() << endl;
}
#ifdefined(HAVE_ANDROID_OS)
if (ioctl(mProcess->mDriverFD, BINDER_WRITE_READ, &bwr) >=0)
err = NO_ERROR;
else
err =-errno;
#else
err = INVALID_OPERATION;
#endif
IF_LOG_COMMANDS() {
alog <<"Finished read/write, write size = "<< mOut.dataSize() << endl;
}
} while (err ==-EINTR);
IF_LOG_COMMANDS() {
alog <<"Our err: "<< (void*)err <<", write consumed: "
<< bwr.write_consumed <<" (of "<< mOut.dataSize()
<<"), read consumed: "<< bwr.read_consumed << endl;
}
if (err >= NO_ERROR) {
if (bwr.write_consumed >0) {
if (bwr.write_consumed < (ssize_t)mOut.dataSize())
mOut.remove(0, bwr.write_consumed);
else
mOut.setDataSize(0);
}
if (bwr.read_consumed >0) {
mIn.setDataSize(bwr.read_consumed);
mIn.setDataPosition(0);
}
IF_LOG_COMMANDS() {
TextOutput::Bundle _b(alog);
alog <<"Remaining data size: "<< mOut.dataSize() << endl;
alog <<"Received commands from driver: "<< indent;
constvoid* cmds = mIn.data();
constvoid* end = mIn.data() + mIn.dataSize();
alog << HexDump(cmds, mIn.dataSize()) << endl;
while (cmds < end) cmds = printReturnCommand(alog, cmds);
alog << dedent;
}
return NO_ERROR;
}
return err;
}

void ProcessState::startThreadPool()
{
AutoMutex _l(mLock);
if (!mThreadPoolStarted) {
mThreadPoolStarted =true;
spawnPooledThread(true);
}
}