adb: move all cleanup to a function with defined ordering.

We want to explicitly define the order in which we teardown adb, so
move all of the at_quick_exits sprinkled throughout into one function
containing all of the cleanup functions.

Bug: http://b/37104408
Test: adb kill-server; adb start-server
Change-Id: I394f5782eb147e394d4b87df1ba364c061de4b90
diff --git a/adb/client/main.cpp b/adb/client/main.cpp
index fe5099c..bd9ad01 100644
--- a/adb/client/main.cpp
+++ b/adb/client/main.cpp
@@ -92,6 +92,16 @@
 }
 #endif
 
+void adb_server_cleanup() {
+    // Upon exit, we want to clean up in the following order:
+    //   1. close_smartsockets, so that we don't get any new clients
+    //   2. kick_all_transports, to avoid writing only part of a packet to a transport.
+    //   3. usb_cleanup, to tear down the USB stack.
+    close_smartsockets();
+    kick_all_transports();
+    usb_cleanup();
+}
+
 int adb_server_main(int is_daemon, const std::string& socket_spec, int ack_reply_fd) {
 #if defined(_WIN32)
     // adb start-server starts us up with stdout and stderr hooked up to
@@ -111,12 +121,13 @@
     SetConsoleCtrlHandler(ctrlc_handler, TRUE);
 #else
     signal(SIGINT, [](int) {
-        android::base::quick_exit(0);
+        fdevent_run_on_main_thread([]() { android::base::quick_exit(0); });
     });
 #endif
 
-    init_transport_registration();
+    android::base::at_quick_exit(adb_server_cleanup);
 
+    init_transport_registration();
     init_mdns_transport_discovery();
 
     usb_init();
diff --git a/adb/client/usb_dispatch.cpp b/adb/client/usb_dispatch.cpp
index 710a3ce..c4eed78 100644
--- a/adb/client/usb_dispatch.cpp
+++ b/adb/client/usb_dispatch.cpp
@@ -27,6 +27,12 @@
     }
 }
 
+void usb_cleanup() {
+    if (should_use_libusb()) {
+        libusb::usb_cleanup();
+    }
+}
+
 int usb_write(usb_handle* h, const void* data, int len) {
     return should_use_libusb()
                ? libusb::usb_write(reinterpret_cast<libusb::usb_handle*>(h), data, len)
diff --git a/adb/client/usb_libusb.cpp b/adb/client/usb_libusb.cpp
index 5a65865..18a8ff2 100644
--- a/adb/client/usb_libusb.cpp
+++ b/adb/client/usb_libusb.cpp
@@ -415,15 +415,21 @@
 
     // Spawn a thread to do device enumeration.
     // TODO: Use libusb_hotplug_* instead?
+    std::unique_lock<std::mutex> lock(device_poll_mutex);
     device_poll_thread = new std::thread(poll_for_devices);
-    android::base::at_quick_exit([]() {
-        {
-            std::unique_lock<std::mutex> lock(device_poll_mutex);
-            terminate_device_poll_thread = true;
+}
+
+void usb_cleanup() {
+    {
+        std::unique_lock<std::mutex> lock(device_poll_mutex);
+        terminate_device_poll_thread = true;
+
+        if (!device_poll_thread) {
+            return;
         }
-        device_poll_cv.notify_all();
-        device_poll_thread->join();
-    });
+    }
+    device_poll_cv.notify_all();
+    device_poll_thread->join();
 }
 
 // Dispatch a libusb transfer, unlock |device_lock|, and then wait for the result.
diff --git a/adb/client/usb_windows.cpp b/adb/client/usb_windows.cpp
index ec55b0e..1620e6e 100644
--- a/adb/client/usb_windows.cpp
+++ b/adb/client/usb_windows.cpp
@@ -265,6 +265,8 @@
   std::thread(_power_notification_thread).detach();
 }
 
+void usb_cleanup() {}
+
 usb_handle* do_usb_open(const wchar_t* interface_name) {
   unsigned long name_len = 0;