Android HFP Profile 连接过程
packages/apps/Settings/src/com/android/settings/bluetooth/BluetoothDevicePreference.java
void onClicked() {
int bondState = mCachedDevice.getBondState();
if (mCachedDevice.isConnected()) {
askDisconnect();
} else if (bondState == BluetoothDevice.BOND_BONDED) { //已经配对，但是未连接
<span style="margin: 0px; padding: 0px; border: 0px; color: rgb(255, 0, 0); background: transparent;">mCachedDevice.connect(true);</span>
} else if (bondState == BluetoothDevice.BOND_NONE) { //没有配对
<span style="margin: 0px; padding: 0px; border: 0px; color: rgb(255, 0, 0); background: transparent;">pair();</span>
}
}
mCachedDevice.connect(true);方法会直接调用CachedBluetoothDevice.java的connect的方法。
packages/apps/Settings/src/com/android/settings/bluetooth/CachedBluetoothDevice.java
void connect(boolean connectAllProfiles) {
if (!ensurePaired()) { //配对处理暂时不关注
return;
}
mConnectAttempted = SystemClock.elapsedRealtime();
connectWithoutResettingTimer(connectAllProfiles);
}
代码执行到connectWithoutResettingTimer，注释就不粘贴了。
private void connectWithoutResettingTimer(boolean connectAllProfiles) {
......
// Reset the only-show-one-error-dialog tracking variable
mIsConnectingErrorPossible = true;
int preferredProfiles = 0;
for (LocalBluetoothProfile profile : mProfiles) {
if (connectAllProfiles ? profile.isConnectable() : profile.isAutoConnectable()) {
if (profile.isPreferred(mDevice)) {
++preferredProfiles;
connectInt(profile);
}
}
}
if (DEBUG) Log.d(TAG, "Preferred profiles = " + preferredProfiles);
if (preferredProfiles == 0) {
connectAutoConnectableProfiles();
}
}
不同的协议实现类，继承于LocalBluetoothProfile，以HeadsetProfile为例。
synchronized void connectInt(LocalBluetoothProfile profile) {
if (!ensurePaired()) {
return;
}
if (<span style="margin: 0px; padding: 0px; border: 0px; color: rgb(255, 0, 0); background: transparent;">profile.connect(mDevice)</span>) {
if (Utils.D) {
Log.d(TAG, "Command sent successfully:CONNECT " + describe(profile));
}
return;
}
Log.i(TAG, "Failed to connect " + profile.toString() + " to " + mName);
}
这个方法中,profile.connnect()，直接调用 HeadsetProfile的connnect()，其实headset/handsfree 是共用同一个service。
packages/apps/Settings/src/com/android/settings/bluetooth/HeadsetProfile.java
public boolean connect(BluetoothDevice device) {
if (mService == null) return false;
List<BluetoothDevice> sinks = mService.getConnectedDevices();
if (sinks != null) {//断开所有连接
for (BluetoothDevice sink : sinks) {
mService.disconnect(sink);
}
}
return mService.connect(device);
}
mService.connect 直接进入framwork层，调用Bluetooth Headset server的api。
frameworks/base/core/java/android/bluetooth/BluetoothHeadset.java
public boolean connect(BluetoothDevice device) {
if (DBG) log("connect(" + device + ")");
if (mService != null && isEnabled() &&
isValidDevice(device)) {
try {
return mService.connect(device);
} catch (RemoteException e) {
Log.e(TAG, Log.getStackTraceString(new Throwable()));
return false;
}
}
if (mService == null) Log.w(TAG, "Proxy not attached to service");
return false;
}
framework 中转了一下，利用Binder机制再次进入Bluetooth模块。
frameworks/base/core/java/android/bluetooth/IBluetoothHeadset.aidl，实现类是
packages/apps/Bluetooth/src/com/android/bluetooth/hfp/HeadsetService.java
注意顺序:Setting->framewrok->Bluetooth
public boolean connect(BluetoothDevice device) {
HeadsetService service = getService();
if (service == null) return false;
return service.connect(device);
}
IBluetoothHeadset.Sub仅仅是一个连接，什么都不做直接进入HeadsetService.java的connect 方法。
public boolean connect(BluetoothDevice device) {
enforceCallingOrSelfPermission(BLUETOOTH_ADMIN_PERM,
"Need BLUETOOTH ADMIN permission");
if (getPriority(device) == BluetoothProfile.PRIORITY_OFF) {
return false;
}
int connectionState = mStateMachine.getConnectionState(device);
if (connectionState == BluetoothProfile.STATE_CONNECTED ||
connectionState == BluetoothProfile.STATE_CONNECTING) {
return false;
}
mStateMachine.sendMessage(HeadsetStateMachine.CONNECT, device);//万恶的状态机开始工作
return true;
}
packages/apps/Bluetooth/src/com/android/bluetooth/hfp/HeadsetStateMachine.java
记住当前为 未连接状态，所以应该进入 Disconnected的状态，Disconnected的processMessage方法中：
switch(message.what) {
case CONNECT:
BluetoothDevice device = (BluetoothDevice) message.obj;
broadcastConnectionState(device, BluetoothProfile.STATE_CONNECTING,
BluetoothProfile.STATE_DISCONNECTED);
if (!<span style="margin: 0px; padding: 0px; border: 0px; color: rgb(255, 0, 0); background: transparent;">connectHfpNative(getByteAddress(device)) </span>) {
broadcastConnectionState(device, BluetoothProfile.STATE_DISCONNECTED,
BluetoothProfile.STATE_CONNECTING);
break;
}
synchronized (HeadsetStateMachine.this) {
mTargetDevice = device;
transitionTo(mPending);
}
connectHfpNative 连接，jni 方法 简单了。
packages\apps\bluetooth\jni\Com_android_bluetooth_hfp.cpp
{"connectHfpNative", "([B)Z", (void *) connectHfpNative},
static jboolean connectHfpNative(JNIEnv *env, jobject object, jbyteArray address) {
jbyte *addr;
bt_status_t status;
ALOGI("%s: sBluetoothHfpInterface: %p", __FUNCTION__, sBluetoothHfpInterface);
if (!sBluetoothHfpInterface) return JNI_FALSE;
addr = env->GetByteArrayElements(address, NULL);
if (!addr) {
jniThrowIOException(env, EINVAL);
return JNI_FALSE;
}
<span style="margin: 0px; padding: 0px; border: 0px; color: rgb(255, 0, 0); background: transparent;">if ((status = sBluetoothHfpInterface->connect((bt_bdaddr_t *)addr)) != BT_STATUS_SUCCESS) {</span>
ALOGE("Failed HF connection, status: %d", status);
}
env->ReleaseByteArrayElements(address, addr, 0);
return (status == BT_STATUS_SUCCESS) ? JNI_TRUE : JNI_FALSE;
}
关键函数是sBluetoothHfpInterface->connect((bt_bdaddr_t *)addr)， connect定义在 hardware/libhardware/include/hardware/bt_hf.h,
但是实现却在：external/bluetooth/bluedroid/btif/src/btif_hf.c 中实现
#include <hardware/bt_hf.h>
static bt_status_t connect( bt_bdaddr_t *bd_addr )
{
CHECK_BTHF_INIT();
return btif_queue_connect(UUID_SERVCLASS_AG_HANDSFREE, bd_addr, connect_int);
}
看定义，直接连接handsfree
#define UUID_SERVCLASS_AG_HANDSFREE 0X111F /* Handsfree profile */
btif_queue_connect的定义在下面文件中定义
external/bluetooth/bluedroid/btif/src/btif_profile_queue.c
进入bt_status_t btif_queue_connect看定义：
</pre><pre name="code" class="cpp" style="margin-top: 0px; margin-bottom: 10px; font-size: 13px; line-height: 24.05px; background-color: rgb(255, 255, 255);">bt_status_t btif_queue_connect(uint16_t uuid, const bt_bdaddr_t *bda,
btif_connect_cb_t *connect_cb)
{
connect_node_t node;
memset(&node, 0, sizeof(connect_node_t));
memcpy(&(node.bda), bda, sizeof(bt_bdaddr_t));
node.uuid = uuid;
node.p_cb = connect_cb;
return btif_transfer_context(queue_int_handle_evt, BTIF_QUEUE_CONNECT_EVT,
(char*)&node, sizeof(connect_node_t), NULL);
}
btif_transfer_context定义在如下文件中
external/bluetooth/bluedroid/btif/src/btif_core.c
btif_transfer_context内容就不粘贴了，里面发送消息，调用
external/bluetooth/bluedroid/gki/common/gki_buffer.c
void GKI_send_msg (UINT8 task_id, UINT8 mbox, void *msg)
GKI_send_msg发送一条GKI信息到BTA，GKI_send_msg有三个参数，第一个参数是线程id,也作为task id， 通过bta_sys_init获得，第二个参数是mailbox id,第三个是上一步封装好的p_msg