skpbench: simplify adb and reduce number of invocations

tools/skpbench/_hardware_android.py

Index: tools/skpbench/_hardware_android.py
diff --git a/tools/skpbench/_hardware_android.py b/tools/skpbench/_hardware_android.py
index 68c8522e3e9e2e005f767c0961d09ff1f6a3ce14..ebaba0ab6d8a7324fe225bb03a56b88d2111a867 100644
--- a/tools/skpbench/_hardware_android.py
+++ b/tools/skpbench/_hardware_android.py
@@ -13,48 +13,42 @@ class HardwareAndroid(Hardware):
     Hardware.__init__(self)
     self.warmup_time = 5
     self._adb = adb
-    self._is_root = self._adb.attempt_root()
-    if self._is_root:
-      self._adb.remount()
-    self._initial_airplane_mode = None
-    self._initial_location_providers = None
-    self._initial_ASLR = None
 
-  def __enter__(self):
-    # turn on airplane mode.
-    self._initial_airplane_mode = \
-      self._adb.check('settings get global airplane_mode_on')
-    self._adb.shell('settings put global airplane_mode_on 1')
-
-    # disable GPS.
-    self._initial_location_providers = \
-      self._adb.check('settings get secure location_providers_allowed')
-    self._initial_location_providers = \
-      self._initial_location_providers.replace(',', ' ')
-    self._adb.shell('''\
-      for PROVIDER in %s; do
-        settings put secure location_providers_allowed -$PROVIDER
-      done''' % self._initial_location_providers)
-
-    if self._is_root:
-      # disable bluetooth, wifi, and mobile data.
-      # TODO: can we query these initial values?
-      self._adb.shell('''\
-        service call bluetooth_manager 8 &&
-        svc wifi disable &&
-        svc data disable''')
-
-      # kill the gui.
-      self._adb.shell('''\
-        setprop ctl.stop media &&
-        setprop ctl.stop zygote &&
-        setprop ctl.stop surfaceflinger &&
-        setprop ctl.stop drm''')
-
-      # disable ASLR.
+    if self._adb.root():
+      self._adb.remount()
       self._initial_ASLR = \
         self._adb.check('cat /proc/sys/kernel/randomize_va_space')
-      self._adb.shell('echo 0 > /proc/sys/kernel/randomize_va_space')
+
+  def __enter__(self):
+    self._adb.shell('\n'.join([
+      # turn on airplane mode.
+      '''
+      settings put global airplane_mode_on 1''',
+
+      # disable GPS.
+      '''
+      for MODE in gps wifi network; do
+        settings put secure location_providers_allowed -$MODE
+      done''']))
+
+    if self._adb.is_root():
+      self._adb.shell('\n'.join([
+        # disable bluetooth, wifi, and mobile data.
+        '''
+        service call bluetooth_manager 8
+        svc wifi disable
+        svc data disable''',
+
+        # kill the gui.
+        '''
+        setprop ctl.stop media
+        setprop ctl.stop zygote
+        setprop ctl.stop surfaceflinger
+        setprop ctl.stop drm''',
+
+        # disable ASLR
+        '''
+        echo 0 > /proc/sys/kernel/randomize_va_space''']))
     else:
       print("WARNING: no adb root access; results may be unreliable.",
             file=sys.stderr)
@@ -64,27 +58,18 @@ class HardwareAndroid(Hardware):
   def __exit__(self, exception_type, exception_value, traceback):
     Hardware.__exit__(self, exception_type, exception_value, traceback)
 
-    if self._is_root:
-      # restore ASLR.
-      self._adb.shell('echo %s > /proc/sys/kernel/randomize_va_space' %
-                      self._initial_ASLR)
-
-      # revive the gui.
-      self._adb.shell('''\
-        setprop ctl.start drm &&
-        setprop ctl.start surfaceflinger &&
-        setprop ctl.start zygote &&
-        setprop ctl.start media''')
-    else:
-      # restore GPS (doesn't seem to work if we killed the gui).
-      self._adb.shell('''\
-        for PROVIDER in %s; do
-          settings put secure location_providers_allowed +$PROVIDER
-        done''' % self._initial_location_providers)
-
-      # restore airplane mode (doesn't seem to work if we killed the gui).
-      self._adb.shell('settings put global airplane_mode_on %s' %
-                      self._initial_airplane_mode)
+    if self._adb.is_root():
+      self._adb.shell('\n'.join([
+        # restore ASLR.
+        '''
+        echo %s > /proc/sys/kernel/randomize_va_space''' % self._initial_ASLR,
+
+        # revive the gui.
+        '''
+        setprop ctl.start drm
+        setprop ctl.start surfaceflinger
+        setprop ctl.start zygote
+        setprop ctl.start media''']))
 
   def sanity_check(self):
     Hardware.sanity_check(self)