From d5936d5d182df752136c1cd8b0d4ac753d5348c6 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Fri, 15 May 2026 20:45:06 +0000
Subject: [PATCH 01/14] Optimize Android emulator initialization by batching
 reboots

This change reduces the number of reboots during Android device setup by:
- Adding a wait_for_reboot parameter to adb.write_data_to_file.
- Tracking reboot status in initialize_device to skip the final reboot if one already occurred.
- Disabling reboots when setting sanitizer options since the app restart is sufficient.

These optimizations improve bot startup efficiency and overall fuzzing throughput.
---
 .../_internal/platforms/android/adb.py          |  4 ++--
 .../_internal/platforms/android/device.py       | 17 +++++++++++------
 .../_internal/platforms/android/sanitizer.py    | 14 +++++++++-----
 3 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/src/clusterfuzz/_internal/platforms/android/adb.py b/src/clusterfuzz/_internal/platforms/android/adb.py
index 47c59b31c72..1f5eefcd861 100755
--- a/src/clusterfuzz/_internal/platforms/android/adb.py
+++ b/src/clusterfuzz/_internal/platforms/android/adb.py
@@ -880,7 +880,7 @@ def write_command_line_file(command_line, app_path):
   write_data_to_file(command_line_file_contents, command_line_path)
 
 
-def write_data_to_file(contents, file_path):
+def write_data_to_file(contents, file_path, wait_for_reboot=True):
   """Writes content to file."""
   # If this is a file in /system, we need to remount /system as read-write and
   # after file is written, revert it back to read-only.
@@ -895,6 +895,6 @@ def write_data_to_file(contents, file_path):
   # Make command line file is readable.
   run_shell_command('chmod 0644 %s' % file_path, root=True)
 
-  if is_system_file:
+  if is_system_file and wait_for_reboot:
     reboot()
     wait_until_fully_booted()
diff --git a/src/clusterfuzz/_internal/platforms/android/device.py b/src/clusterfuzz/_internal/platforms/android/device.py
index 0c8d81ca686..e13ddf6dca4 100755
--- a/src/clusterfuzz/_internal/platforms/android/device.py
+++ b/src/clusterfuzz/_internal/platforms/android/device.py
@@ -195,9 +195,9 @@ def configure_system_build_properties():
   current_md5 = adb.get_file_checksum(BUILD_PROP_PATH)
   if current_md5 is None:
     logs.error('Unable to find %s on device.' % BUILD_PROP_PATH)
-    return
+    return False
   if old_md5 == current_md5:
-    return
+    return False
 
   # Pull to tmp file.
   bot_tmp_directory = environment.get_value('BOT_TMPDIR')
@@ -205,7 +205,7 @@ def configure_system_build_properties():
   adb.run_command(['pull', BUILD_PROP_PATH, old_build_prop_path])
   if not os.path.exists(old_build_prop_path):
     logs.error('Unable to fetch %s from device.' % BUILD_PROP_PATH)
-    return
+    return False
 
   # Write new build.prop.
   new_build_prop_path = os.path.join(bot_tmp_directory, 'new.prop')
@@ -228,11 +228,13 @@ def configure_system_build_properties():
 
   # Keep verified boot disabled for M and higher releases. This makes it easy
   # to modify system's app_process to load asan libraries.
+  reboot_done = False
   build_version = settings.get_build_version()
   if is_build_at_least(build_version, 'M'):
     adb.run_as_root()
     adb.run_command('disable-verity')
     reboot()
+    reboot_done = True
 
   # Make /system writable.
   adb.run_as_root()
@@ -255,6 +257,8 @@ def configure_system_build_properties():
   current_md5 = adb.get_file_checksum(BUILD_PROP_PATH)
   persistent_cache.set_value(constants.BUILD_PROP_MD5_KEY, current_md5)
 
+  return reboot_done
+
 
 def get_debug_props_and_values():
   """Return debug property names and values based on |ENABLE_DEBUG_CHECKS|
@@ -306,16 +310,17 @@ def initialize_device():
   adb.setup_adb()
 
   # General device configuration settings.
-  configure_system_build_properties()
+  reboot_done = configure_system_build_properties()
   configure_device_settings()
   add_test_accounts_if_needed()
 
   # Setup AddressSanitizer if needed.
-  sanitizer.setup_asan_if_needed()
+  reboot_done = sanitizer.setup_asan_if_needed() or reboot_done
 
   # Reboot device as above steps would need it and also it brings device in a
   # good state.
-  reboot()
+  if not reboot_done:
+    reboot()
 
   # Make sure we are running as root after restart.
   adb.run_as_root()
diff --git a/src/clusterfuzz/_internal/platforms/android/sanitizer.py b/src/clusterfuzz/_internal/platforms/android/sanitizer.py
index 832f6a4a577..f5d954e0a2c 100644
--- a/src/clusterfuzz/_internal/platforms/android/sanitizer.py
+++ b/src/clusterfuzz/_internal/platforms/android/sanitizer.py
@@ -69,7 +69,9 @@ def set_options(sanitizer_tool_name, sanitizer_options):
   if not sanitizer_options_file_path:
     return
 
-  adb.write_data_to_file(sanitizer_options, sanitizer_options_file_path)
+  # Skip reboot as the app will pick up the options file on restart.
+  adb.write_data_to_file(
+      sanitizer_options, sanitizer_options_file_path, wait_for_reboot=False)
 
 
 def setup_asan_if_needed():
@@ -78,16 +80,16 @@ def setup_asan_if_needed():
     # Only do this step if explicitly enabled in the job type. This cannot be
     # determined from libraries in application directory since they can go
     # missing in a bad build, so we want to catch that.
-    return
+    return False
 
   if settings.get_sanitizer_tool_name():
     # If this is a sanitizer build, no need to setup ASAN (incompatible).
-    return
+    return False
 
   app_directory = environment.get_value('APP_DIR')
   if not app_directory:
     # No app directory -> No ASAN runtime library. No work to do, bail out.
-    return
+    return False
 
   # Initialize variables.
   android_directory = environment.get_platform_resources_directory()
@@ -108,7 +110,7 @@ def setup_asan_if_needed():
   result = process.run_and_wait()
   if result.return_code:
     logs.error('Failed to setup ASan on device.', output=result.output)
-    return
+    return False
 
   logs.info(
       'ASan device setup script successfully finished, waiting for boot.',
@@ -117,3 +119,5 @@ def setup_asan_if_needed():
   # Wait until fully booted as otherwise shell restart followed by a quick
   # reboot can trigger data corruption in /data/data.
   adb.wait_until_fully_booted()
+
+  return True

From 9b8833536b38dc9dd6f072eef8e7e4278553db40 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Sat, 16 May 2026 16:57:40 +0000
Subject: [PATCH 02/14] Fix reboot_done tracking to ensure device settings are
 applied

---
 src/clusterfuzz/_internal/platforms/android/device.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/clusterfuzz/_internal/platforms/android/device.py b/src/clusterfuzz/_internal/platforms/android/device.py
index e13ddf6dca4..da186f4060f 100755
--- a/src/clusterfuzz/_internal/platforms/android/device.py
+++ b/src/clusterfuzz/_internal/platforms/android/device.py
@@ -310,12 +310,12 @@ def initialize_device():
   adb.setup_adb()
 
   # General device configuration settings.
-  reboot_done = configure_system_build_properties()
+  configure_system_build_properties()
   configure_device_settings()
   add_test_accounts_if_needed()
 
   # Setup AddressSanitizer if needed.
-  reboot_done = sanitizer.setup_asan_if_needed() or reboot_done
+  reboot_done = sanitizer.setup_asan_if_needed()
 
   # Reboot device as above steps would need it and also it brings device in a
   # good state.

From 1aecb3abce4397cd145c8d46f0e78a591987e3f9 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Sat, 16 May 2026 17:05:15 +0000
Subject: [PATCH 03/14] Revert previous fix and use accumulated state for
 reboot_done

---
 src/clusterfuzz/_internal/platforms/android/device.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/clusterfuzz/_internal/platforms/android/device.py b/src/clusterfuzz/_internal/platforms/android/device.py
index da186f4060f..e13ddf6dca4 100755
--- a/src/clusterfuzz/_internal/platforms/android/device.py
+++ b/src/clusterfuzz/_internal/platforms/android/device.py
@@ -310,12 +310,12 @@ def initialize_device():
   adb.setup_adb()
 
   # General device configuration settings.
-  configure_system_build_properties()
+  reboot_done = configure_system_build_properties()
   configure_device_settings()
   add_test_accounts_if_needed()
 
   # Setup AddressSanitizer if needed.
-  reboot_done = sanitizer.setup_asan_if_needed()
+  reboot_done = sanitizer.setup_asan_if_needed() or reboot_done
 
   # Reboot device as above steps would need it and also it brings device in a
   # good state.

From 1482ba7d6ee89ac1925f48aa72291107f6e809c9 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Sat, 16 May 2026 17:12:12 +0000
Subject: [PATCH 04/14] Invert logic to needs_reboot and use bitwise OR
 operator to fix state tracking and short-circuit issues

---
 src/clusterfuzz/_internal/platforms/android/device.py | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/clusterfuzz/_internal/platforms/android/device.py b/src/clusterfuzz/_internal/platforms/android/device.py
index e13ddf6dca4..570edbde43e 100755
--- a/src/clusterfuzz/_internal/platforms/android/device.py
+++ b/src/clusterfuzz/_internal/platforms/android/device.py
@@ -228,13 +228,11 @@ def configure_system_build_properties():
 
   # Keep verified boot disabled for M and higher releases. This makes it easy
   # to modify system's app_process to load asan libraries.
-  reboot_done = False
   build_version = settings.get_build_version()
   if is_build_at_least(build_version, 'M'):
     adb.run_as_root()
     adb.run_command('disable-verity')
     reboot()
-    reboot_done = True
 
   # Make /system writable.
   adb.run_as_root()
@@ -257,7 +255,7 @@ def configure_system_build_properties():
   current_md5 = adb.get_file_checksum(BUILD_PROP_PATH)
   persistent_cache.set_value(constants.BUILD_PROP_MD5_KEY, current_md5)
 
-  return reboot_done
+  return True
 
 
 def get_debug_props_and_values():
@@ -310,16 +308,16 @@ def initialize_device():
   adb.setup_adb()
 
   # General device configuration settings.
-  reboot_done = configure_system_build_properties()
+  needs_reboot = configure_system_build_properties()
   configure_device_settings()
   add_test_accounts_if_needed()
 
   # Setup AddressSanitizer if needed.
-  reboot_done = sanitizer.setup_asan_if_needed() or reboot_done
+  needs_reboot |= sanitizer.setup_asan_if_needed()
 
   # Reboot device as above steps would need it and also it brings device in a
   # good state.
-  if not reboot_done:
+  if needs_reboot:
     reboot()
 
   # Make sure we are running as root after restart.

From f960945ae24a418fc6dc8dd34ceabf540608da4e Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Sat, 16 May 2026 17:14:42 +0000
Subject: [PATCH 05/14] Fix needs_reboot logic so ASan setup clears pending
 reboots

---
 src/clusterfuzz/_internal/platforms/android/device.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/clusterfuzz/_internal/platforms/android/device.py b/src/clusterfuzz/_internal/platforms/android/device.py
index 570edbde43e..a80826ba465 100755
--- a/src/clusterfuzz/_internal/platforms/android/device.py
+++ b/src/clusterfuzz/_internal/platforms/android/device.py
@@ -313,7 +313,10 @@ def initialize_device():
   add_test_accounts_if_needed()
 
   # Setup AddressSanitizer if needed.
-  needs_reboot |= sanitizer.setup_asan_if_needed()
+  if sanitizer.setup_asan_if_needed():
+    # ASan setup script performs a shell restart and waits for boot.
+    # This satisfies any pending reboot requirements from earlier steps.
+    needs_reboot = False
 
   # Reboot device as above steps would need it and also it brings device in a
   # good state.

From def65fa1ae506d18eeae606701e613442a1f220b Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Sat, 16 May 2026 17:17:37 +0000
Subject: [PATCH 06/14] Fix initialization reboot logic to correctly preserve
 base requirements

---
 src/clusterfuzz/_internal/platforms/android/device.py | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/src/clusterfuzz/_internal/platforms/android/device.py b/src/clusterfuzz/_internal/platforms/android/device.py
index a80826ba465..0cc1512c2ff 100755
--- a/src/clusterfuzz/_internal/platforms/android/device.py
+++ b/src/clusterfuzz/_internal/platforms/android/device.py
@@ -308,19 +308,16 @@ def initialize_device():
   adb.setup_adb()
 
   # General device configuration settings.
-  needs_reboot = configure_system_build_properties()
+  needs_full_reboot = configure_system_build_properties()
   configure_device_settings()
   add_test_accounts_if_needed()
 
   # Setup AddressSanitizer if needed.
-  if sanitizer.setup_asan_if_needed():
-    # ASan setup script performs a shell restart and waits for boot.
-    # This satisfies any pending reboot requirements from earlier steps.
-    needs_reboot = False
+  asan_reboot_done = sanitizer.setup_asan_if_needed()
 
   # Reboot device as above steps would need it and also it brings device in a
   # good state.
-  if needs_reboot:
+  if needs_full_reboot or not asan_reboot_done:
     reboot()
 
   # Make sure we are running as root after restart.

From ed141f17ed40855ae05cf31317fa9a02f0145817 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Sat, 16 May 2026 17:21:36 +0000
Subject: [PATCH 07/14] Add unit tests for android device reboot logic

---
 .../core/platforms/android/device_test.py     | 60 +++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py b/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
index e10051fb7ef..726739dcad7 100644
--- a/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
+++ b/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
@@ -13,6 +13,9 @@
 # limitations under the License.
 """Tests for device functions."""
 
+import unittest
+from unittest import mock
+
 from clusterfuzz._internal.platforms.android import device
 from clusterfuzz._internal.tests.test_libs import android_helpers
 
@@ -23,3 +26,60 @@ class InitializeEnvironmentTest(android_helpers.AndroidTest):
   def test(self):
     """Ensure that initialize_environment throws no exceptions."""
     device.initialize_environment()
+
+
+class InitializeDeviceRebootLogicTest(unittest.TestCase):
+  """Tests the reboot batching logic in initialize_device."""
+
+  def setUp(self):
+    # Mock environment to bypass the engine fuzzer check
+    mock.patch('clusterfuzz._internal.system.environment.is_engine_fuzzer_job', 
+               return_value=False).start()
+    
+    # Mock all the setup steps so we don't actually run ADB commands
+    self.mock_setup_adb = mock.patch('clusterfuzz._internal.platforms.android.adb.setup_adb').start()
+    self.mock_run_as_root = mock.patch('clusterfuzz._internal.platforms.android.adb.run_as_root').start()
+    self.mock_config_props = mock.patch('clusterfuzz._internal.platforms.android.device.configure_system_build_properties').start()
+    self.mock_config_settings = mock.patch('clusterfuzz._internal.platforms.android.device.configure_device_settings').start()
+    self.mock_add_accounts = mock.patch('clusterfuzz._internal.platforms.android.device.add_test_accounts_if_needed').start()
+    self.mock_setup_asan = mock.patch('clusterfuzz._internal.platforms.android.sanitizer.setup_asan_if_needed').start()
+    
+    # Mock the reboot function we are trying to track
+    self.mock_reboot = mock.patch('clusterfuzz._internal.platforms.android.device.reboot').start()
+    
+    # Mock the post-reboot steps
+    mock.patch('clusterfuzz._internal.platforms.android.wifi.configure').start()
+    mock.patch('clusterfuzz._internal.platforms.android.device.setup_host_and_device_forwarder_if_needed').start()
+    mock.patch('clusterfuzz._internal.platforms.android.settings.change_se_linux_to_permissive_mode').start()
+    mock.patch('clusterfuzz._internal.platforms.android.app.wait_until_optimization_complete').start()
+    mock.patch('clusterfuzz._internal.platforms.android.ui.clear_notifications').start()
+    mock.patch('clusterfuzz._internal.platforms.android.ui.unlock_screen').start()
+
+  def tearDown(self):
+    mock.patch.stopall()
+
+  def test_reboot_if_props_changed(self):
+    """Test that it reboots if build.prop changed, even if ASan didn't run."""
+    self.mock_config_props.return_value = True
+    self.mock_setup_asan.return_value = False
+    
+    device.initialize_device()
+    self.mock_reboot.assert_called_once()
+
+  def test_no_reboot_if_asan_ran(self):
+    """Test that the final reboot is skipped if ASan setup performed a shell restart."""
+    # If build.prop didn't change, the ASan restart handles the clean state.
+    self.mock_config_props.return_value = False 
+    self.mock_setup_asan.return_value = True
+    
+    device.initialize_device()
+    self.mock_reboot.assert_not_called()
+
+  def test_reboot_if_clean_slate_needed(self):
+    """Test that it still reboots to ensure a clean state if no other steps restarted it."""
+    self.mock_config_props.return_value = False
+    self.mock_setup_asan.return_value = False
+    
+    device.initialize_device()
+    self.mock_reboot.assert_called_once()
+

From a0d418e4081e78a6b71c28112a72813f9f1cb0f3 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Mon, 18 May 2026 19:23:24 +0000
Subject: [PATCH 08/14] Fix formatting issues from linter in device_test.py

---
 .../core/platforms/android/device_test.py     | 63 ++++++++++++-------
 1 file changed, 41 insertions(+), 22 deletions(-)

diff --git a/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py b/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
index 726739dcad7..7a5f792f545 100644
--- a/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
+++ b/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
@@ -33,27 +33,47 @@ class InitializeDeviceRebootLogicTest(unittest.TestCase):
 
   def setUp(self):
     # Mock environment to bypass the engine fuzzer check
-    mock.patch('clusterfuzz._internal.system.environment.is_engine_fuzzer_job', 
-               return_value=False).start()
-    
+    mock.patch(
+        'clusterfuzz._internal.system.environment.is_engine_fuzzer_job',
+        return_value=False).start()
+
     # Mock all the setup steps so we don't actually run ADB commands
-    self.mock_setup_adb = mock.patch('clusterfuzz._internal.platforms.android.adb.setup_adb').start()
-    self.mock_run_as_root = mock.patch('clusterfuzz._internal.platforms.android.adb.run_as_root').start()
-    self.mock_config_props = mock.patch('clusterfuzz._internal.platforms.android.device.configure_system_build_properties').start()
-    self.mock_config_settings = mock.patch('clusterfuzz._internal.platforms.android.device.configure_device_settings').start()
-    self.mock_add_accounts = mock.patch('clusterfuzz._internal.platforms.android.device.add_test_accounts_if_needed').start()
-    self.mock_setup_asan = mock.patch('clusterfuzz._internal.platforms.android.sanitizer.setup_asan_if_needed').start()
-    
+    self.mock_setup_adb = mock.patch(
+        'clusterfuzz._internal.platforms.android.adb.setup_adb').start()
+    self.mock_run_as_root = mock.patch(
+        'clusterfuzz._internal.platforms.android.adb.run_as_root').start()
+    self.mock_config_props = mock.patch(
+        'clusterfuzz._internal.platforms.android.device.configure_system_build_properties'
+    ).start()
+    self.mock_config_settings = mock.patch(
+        'clusterfuzz._internal.platforms.android.device.configure_device_settings'
+    ).start()
+    self.mock_add_accounts = mock.patch(
+        'clusterfuzz._internal.platforms.android.device.add_test_accounts_if_needed'
+    ).start()
+    self.mock_setup_asan = mock.patch(
+        'clusterfuzz._internal.platforms.android.sanitizer.setup_asan_if_needed'
+    ).start()
+
     # Mock the reboot function we are trying to track
-    self.mock_reboot = mock.patch('clusterfuzz._internal.platforms.android.device.reboot').start()
-    
+    self.mock_reboot = mock.patch(
+        'clusterfuzz._internal.platforms.android.device.reboot').start()
+
     # Mock the post-reboot steps
     mock.patch('clusterfuzz._internal.platforms.android.wifi.configure').start()
-    mock.patch('clusterfuzz._internal.platforms.android.device.setup_host_and_device_forwarder_if_needed').start()
-    mock.patch('clusterfuzz._internal.platforms.android.settings.change_se_linux_to_permissive_mode').start()
-    mock.patch('clusterfuzz._internal.platforms.android.app.wait_until_optimization_complete').start()
-    mock.patch('clusterfuzz._internal.platforms.android.ui.clear_notifications').start()
-    mock.patch('clusterfuzz._internal.platforms.android.ui.unlock_screen').start()
+    mock.patch(
+        'clusterfuzz._internal.platforms.android.device.setup_host_and_device_forwarder_if_needed'
+    ).start()
+    mock.patch(
+        'clusterfuzz._internal.platforms.android.settings.change_se_linux_to_permissive_mode'
+    ).start()
+    mock.patch(
+        'clusterfuzz._internal.platforms.android.app.wait_until_optimization_complete'
+    ).start()
+    mock.patch('clusterfuzz._internal.platforms.android.ui.clear_notifications'
+              ).start()
+    mock.patch(
+        'clusterfuzz._internal.platforms.android.ui.unlock_screen').start()
 
   def tearDown(self):
     mock.patch.stopall()
@@ -62,16 +82,16 @@ def test_reboot_if_props_changed(self):
     """Test that it reboots if build.prop changed, even if ASan didn't run."""
     self.mock_config_props.return_value = True
     self.mock_setup_asan.return_value = False
-    
+
     device.initialize_device()
     self.mock_reboot.assert_called_once()
 
   def test_no_reboot_if_asan_ran(self):
     """Test that the final reboot is skipped if ASan setup performed a shell restart."""
     # If build.prop didn't change, the ASan restart handles the clean state.
-    self.mock_config_props.return_value = False 
+    self.mock_config_props.return_value = False
     self.mock_setup_asan.return_value = True
-    
+
     device.initialize_device()
     self.mock_reboot.assert_not_called()
 
@@ -79,7 +99,6 @@ def test_reboot_if_clean_slate_needed(self):
     """Test that it still reboots to ensure a clean state if no other steps restarted it."""
     self.mock_config_props.return_value = False
     self.mock_setup_asan.return_value = False
-    
+
     device.initialize_device()
     self.mock_reboot.assert_called_once()
-

From 53bdbc80c295fafeb571331370d345dc50c1f976 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Mon, 18 May 2026 23:07:33 +0000
Subject: [PATCH 09/14] Address PR 5280 comments: Add return types and
 docstrings

Adds `-> bool` return type hints and explanatory docstrings to:
- `configure_system_build_properties`
- `setup_asan_if_needed`

These updates clarify that the returned boolean indicates whether a device reboot occurred during the setup step.
---
 src/clusterfuzz/_internal/platforms/android/device.py    | 8 ++++++--
 src/clusterfuzz/_internal/platforms/android/sanitizer.py | 8 ++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/clusterfuzz/_internal/platforms/android/device.py b/src/clusterfuzz/_internal/platforms/android/device.py
index 0cc1512c2ff..5a4461a84a5 100755
--- a/src/clusterfuzz/_internal/platforms/android/device.py
+++ b/src/clusterfuzz/_internal/platforms/android/device.py
@@ -183,9 +183,13 @@ def configure_device_settings():
   adb.write_data_to_file(local_properties_file_contents, LOCAL_PROP_PATH)
 
 
-def configure_system_build_properties():
+def configure_system_build_properties() -> bool:
   """Modifies system build properties in /system/build.prop for better boot
-  speed and power use."""
+  speed and power use.
+  
+  Returns:
+    True if the device was rebooted during configuration, False otherwise.
+  """
   adb.run_as_root()
 
   # Check md5 checksum of build.prop to see if already updated,
diff --git a/src/clusterfuzz/_internal/platforms/android/sanitizer.py b/src/clusterfuzz/_internal/platforms/android/sanitizer.py
index f5d954e0a2c..de51bd4207b 100644
--- a/src/clusterfuzz/_internal/platforms/android/sanitizer.py
+++ b/src/clusterfuzz/_internal/platforms/android/sanitizer.py
@@ -74,8 +74,12 @@ def set_options(sanitizer_tool_name, sanitizer_options):
       sanitizer_options, sanitizer_options_file_path, wait_for_reboot=False)
 
 
-def setup_asan_if_needed():
-  """Set up asan on device."""
+def setup_asan_if_needed() -> bool:
+  """Set up asan on device.
+  
+  Returns:
+    True if the device was rebooted or restarted during setup, False otherwise.
+  """
   if not environment.get_value('ASAN_DEVICE_SETUP'):
     # Only do this step if explicitly enabled in the job type. This cannot be
     # determined from libraries in application directory since they can go

From fd28f7b73bdbbd4b6399ed4034a90e4f57a3bb30 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Wed, 20 May 2026 04:48:00 +0000
Subject: [PATCH 10/14] Rename wait_for_reboot to should_reboot

---
 src/clusterfuzz/_internal/platforms/android/adb.py       | 4 ++--
 src/clusterfuzz/_internal/platforms/android/sanitizer.py | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/clusterfuzz/_internal/platforms/android/adb.py b/src/clusterfuzz/_internal/platforms/android/adb.py
index 1f5eefcd861..071922e084d 100755
--- a/src/clusterfuzz/_internal/platforms/android/adb.py
+++ b/src/clusterfuzz/_internal/platforms/android/adb.py
@@ -880,7 +880,7 @@ def write_command_line_file(command_line, app_path):
   write_data_to_file(command_line_file_contents, command_line_path)
 
 
-def write_data_to_file(contents, file_path, wait_for_reboot=True):
+def write_data_to_file(contents, file_path, should_reboot=True):
   """Writes content to file."""
   # If this is a file in /system, we need to remount /system as read-write and
   # after file is written, revert it back to read-only.
@@ -895,6 +895,6 @@ def write_data_to_file(contents, file_path, wait_for_reboot=True):
   # Make command line file is readable.
   run_shell_command('chmod 0644 %s' % file_path, root=True)
 
-  if is_system_file and wait_for_reboot:
+  if is_system_file and should_reboot:
     reboot()
     wait_until_fully_booted()
diff --git a/src/clusterfuzz/_internal/platforms/android/sanitizer.py b/src/clusterfuzz/_internal/platforms/android/sanitizer.py
index de51bd4207b..c602df87221 100644
--- a/src/clusterfuzz/_internal/platforms/android/sanitizer.py
+++ b/src/clusterfuzz/_internal/platforms/android/sanitizer.py
@@ -71,7 +71,7 @@ def set_options(sanitizer_tool_name, sanitizer_options):
 
   # Skip reboot as the app will pick up the options file on restart.
   adb.write_data_to_file(
-      sanitizer_options, sanitizer_options_file_path, wait_for_reboot=False)
+      sanitizer_options, sanitizer_options_file_path, should_reboot=False)
 
 
 def setup_asan_if_needed() -> bool:

From 169b8ae7ef0cfcbaa7cc700309c767ff83b0f346 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Wed, 20 May 2026 04:55:02 +0000
Subject: [PATCH 11/14] Update docstrings for test cases

---
 .../tests/core/platforms/android/device_test.py        | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py b/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
index 7a5f792f545..00811c5312a 100644
--- a/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
+++ b/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
@@ -79,7 +79,8 @@ def tearDown(self):
     mock.patch.stopall()
 
   def test_reboot_if_props_changed(self):
-    """Test that it reboots if build.prop changed, even if ASan didn't run."""
+    """Test that `initialize_device()` reboots the device if
+    `configure_system_build_properties()` did, and the ASan setup script did not."""
     self.mock_config_props.return_value = True
     self.mock_setup_asan.return_value = False
 
@@ -87,7 +88,9 @@ def test_reboot_if_props_changed(self):
     self.mock_reboot.assert_called_once()
 
   def test_no_reboot_if_asan_ran(self):
-    """Test that the final reboot is skipped if ASan setup performed a shell restart."""
+    """Test that `initialize_device()` skips calling `reboot()` if
+    `configure_system_build_properties()` did not cause a reboot but the ASan
+    setup script did."""
     # If build.prop didn't change, the ASan restart handles the clean state.
     self.mock_config_props.return_value = False
     self.mock_setup_asan.return_value = True
@@ -96,7 +99,8 @@ def test_no_reboot_if_asan_ran(self):
     self.mock_reboot.assert_not_called()
 
   def test_reboot_if_clean_slate_needed(self):
-    """Test that it still reboots to ensure a clean state if no other steps restarted it."""
+    """Test that `initialize_device()` calls `reboot()` if neither
+    `configure_system_build_properties()` nor the ASan setup script did."""
     self.mock_config_props.return_value = False
     self.mock_setup_asan.return_value = False
 

From 01dc2a9e21ef7eabd27efc662d176d27d6fa9951 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Wed, 20 May 2026 05:05:08 +0000
Subject: [PATCH 12/14] Simplify initialize_device logic and refactor tests

- Revert configure_system_build_properties to not return a bool.
- Simplify initialize_device to only reboot if ASan setup did not reboot the device. This fixes the bug where it would reboot even if no properties changed.
- Refactor device_test.py to use helpers.patch instead of manual mock setups, matching the codebase style.
---
 .../_internal/platforms/android/device.py     | 20 ++--
 .../core/platforms/android/device_test.py     | 93 ++++++-------------
 2 files changed, 33 insertions(+), 80 deletions(-)

diff --git a/src/clusterfuzz/_internal/platforms/android/device.py b/src/clusterfuzz/_internal/platforms/android/device.py
index 5a4461a84a5..6cf783e5a57 100755
--- a/src/clusterfuzz/_internal/platforms/android/device.py
+++ b/src/clusterfuzz/_internal/platforms/android/device.py
@@ -183,13 +183,9 @@ def configure_device_settings():
   adb.write_data_to_file(local_properties_file_contents, LOCAL_PROP_PATH)
 
 
-def configure_system_build_properties() -> bool:
+def configure_system_build_properties():
   """Modifies system build properties in /system/build.prop for better boot
-  speed and power use.
-  
-  Returns:
-    True if the device was rebooted during configuration, False otherwise.
-  """
+  speed and power use."""
   adb.run_as_root()
 
   # Check md5 checksum of build.prop to see if already updated,
@@ -199,9 +195,9 @@ def configure_system_build_properties() -> bool:
   current_md5 = adb.get_file_checksum(BUILD_PROP_PATH)
   if current_md5 is None:
     logs.error('Unable to find %s on device.' % BUILD_PROP_PATH)
-    return False
+    return
   if old_md5 == current_md5:
-    return False
+    return
 
   # Pull to tmp file.
   bot_tmp_directory = environment.get_value('BOT_TMPDIR')
@@ -209,7 +205,7 @@ def configure_system_build_properties() -> bool:
   adb.run_command(['pull', BUILD_PROP_PATH, old_build_prop_path])
   if not os.path.exists(old_build_prop_path):
     logs.error('Unable to fetch %s from device.' % BUILD_PROP_PATH)
-    return False
+    return
 
   # Write new build.prop.
   new_build_prop_path = os.path.join(bot_tmp_directory, 'new.prop')
@@ -259,8 +255,6 @@ def configure_system_build_properties() -> bool:
   current_md5 = adb.get_file_checksum(BUILD_PROP_PATH)
   persistent_cache.set_value(constants.BUILD_PROP_MD5_KEY, current_md5)
 
-  return True
-
 
 def get_debug_props_and_values():
   """Return debug property names and values based on |ENABLE_DEBUG_CHECKS|
@@ -312,7 +306,7 @@ def initialize_device():
   adb.setup_adb()
 
   # General device configuration settings.
-  needs_full_reboot = configure_system_build_properties()
+  configure_system_build_properties()
   configure_device_settings()
   add_test_accounts_if_needed()
 
@@ -321,7 +315,7 @@ def initialize_device():
 
   # Reboot device as above steps would need it and also it brings device in a
   # good state.
-  if needs_full_reboot or not asan_reboot_done:
+  if not asan_reboot_done:
     reboot()
 
   # Make sure we are running as root after restart.
diff --git a/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py b/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
index 00811c5312a..2c0b8fb9450 100644
--- a/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
+++ b/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
@@ -14,7 +14,6 @@
 """Tests for device functions."""
 
 import unittest
-from unittest import mock
 
 from clusterfuzz._internal.platforms.android import device
 from clusterfuzz._internal.tests.test_libs import android_helpers
@@ -32,77 +31,37 @@ class InitializeDeviceRebootLogicTest(unittest.TestCase):
   """Tests the reboot batching logic in initialize_device."""
 
   def setUp(self):
-    # Mock environment to bypass the engine fuzzer check
-    mock.patch(
+    from clusterfuzz._internal.tests.test_libs import helpers
+    helpers.patch(self, [
         'clusterfuzz._internal.system.environment.is_engine_fuzzer_job',
-        return_value=False).start()
-
-    # Mock all the setup steps so we don't actually run ADB commands
-    self.mock_setup_adb = mock.patch(
-        'clusterfuzz._internal.platforms.android.adb.setup_adb').start()
-    self.mock_run_as_root = mock.patch(
-        'clusterfuzz._internal.platforms.android.adb.run_as_root').start()
-    self.mock_config_props = mock.patch(
-        'clusterfuzz._internal.platforms.android.device.configure_system_build_properties'
-    ).start()
-    self.mock_config_settings = mock.patch(
-        'clusterfuzz._internal.platforms.android.device.configure_device_settings'
-    ).start()
-    self.mock_add_accounts = mock.patch(
-        'clusterfuzz._internal.platforms.android.device.add_test_accounts_if_needed'
-    ).start()
-    self.mock_setup_asan = mock.patch(
-        'clusterfuzz._internal.platforms.android.sanitizer.setup_asan_if_needed'
-    ).start()
-
-    # Mock the reboot function we are trying to track
-    self.mock_reboot = mock.patch(
-        'clusterfuzz._internal.platforms.android.device.reboot').start()
-
-    # Mock the post-reboot steps
-    mock.patch('clusterfuzz._internal.platforms.android.wifi.configure').start()
-    mock.patch(
-        'clusterfuzz._internal.platforms.android.device.setup_host_and_device_forwarder_if_needed'
-    ).start()
-    mock.patch(
-        'clusterfuzz._internal.platforms.android.settings.change_se_linux_to_permissive_mode'
-    ).start()
-    mock.patch(
-        'clusterfuzz._internal.platforms.android.app.wait_until_optimization_complete'
-    ).start()
-    mock.patch('clusterfuzz._internal.platforms.android.ui.clear_notifications'
-              ).start()
-    mock.patch(
-        'clusterfuzz._internal.platforms.android.ui.unlock_screen').start()
-
-  def tearDown(self):
-    mock.patch.stopall()
-
-  def test_reboot_if_props_changed(self):
-    """Test that `initialize_device()` reboots the device if
-    `configure_system_build_properties()` did, and the ASan setup script did not."""
-    self.mock_config_props.return_value = True
-    self.mock_setup_asan.return_value = False
+        'clusterfuzz._internal.platforms.android.adb.setup_adb',
+        'clusterfuzz._internal.platforms.android.adb.run_as_root',
+        'clusterfuzz._internal.platforms.android.device.configure_system_build_properties',
+        'clusterfuzz._internal.platforms.android.device.configure_device_settings',
+        'clusterfuzz._internal.platforms.android.device.add_test_accounts_if_needed',
+        'clusterfuzz._internal.platforms.android.sanitizer.setup_asan_if_needed',
+        'clusterfuzz._internal.platforms.android.device.reboot',
+        'clusterfuzz._internal.platforms.android.wifi.configure',
+        'clusterfuzz._internal.platforms.android.device.setup_host_and_device_forwarder_if_needed',
+        'clusterfuzz._internal.platforms.android.settings.change_se_linux_to_permissive_mode',
+        'clusterfuzz._internal.platforms.android.app.wait_until_optimization_complete',
+        'clusterfuzz._internal.platforms.android.ui.clear_notifications',
+        'clusterfuzz._internal.platforms.android.ui.unlock_screen',
+    ])
+    self.mock.is_engine_fuzzer_job.return_value = False
+
+  def test_reboot_if_asan_did_not_run(self):
+    """Test that `initialize_device()` calls `reboot()` if the ASan setup
+    script did not."""
+    self.mock.setup_asan_if_needed.return_value = False
 
     device.initialize_device()
-    self.mock_reboot.assert_called_once()
+    self.mock.reboot.assert_called_once()
 
   def test_no_reboot_if_asan_ran(self):
-    """Test that `initialize_device()` skips calling `reboot()` if
-    `configure_system_build_properties()` did not cause a reboot but the ASan
+    """Test that `initialize_device()` skips calling `reboot()` if the ASan
     setup script did."""
-    # If build.prop didn't change, the ASan restart handles the clean state.
-    self.mock_config_props.return_value = False
-    self.mock_setup_asan.return_value = True
-
-    device.initialize_device()
-    self.mock_reboot.assert_not_called()
-
-  def test_reboot_if_clean_slate_needed(self):
-    """Test that `initialize_device()` calls `reboot()` if neither
-    `configure_system_build_properties()` nor the ASan setup script did."""
-    self.mock_config_props.return_value = False
-    self.mock_setup_asan.return_value = False
+    self.mock.setup_asan_if_needed.return_value = True
 
     device.initialize_device()
-    self.mock_reboot.assert_called_once()
+    self.mock.reboot.assert_not_called()

From 450b66e9d04c4501517714837c57880c24bd9721 Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Wed, 20 May 2026 05:18:02 +0000
Subject: [PATCH 13/14] Add descriptive docstring for InitializeEnvironmentTest

---
 .../_internal/tests/core/platforms/android/device_test.py       | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py b/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
index 2c0b8fb9450..ebb6ba11a26 100644
--- a/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
+++ b/src/clusterfuzz/_internal/tests/core/platforms/android/device_test.py
@@ -20,7 +20,7 @@
 
 
 class InitializeEnvironmentTest(android_helpers.AndroidTest):
-  """Tests for """
+  """Tests for the device environment initialization process (`initialize_environment`)."""
 
   def test(self):
     """Ensure that initialize_environment throws no exceptions."""

From 2888eab0d76b96c94de826048d242a058745899c Mon Sep 17 00:00:00 2001
From: Diego Jardon <jardondiego@google.com>
Date: Wed, 20 May 2026 05:37:11 +0000
Subject: [PATCH 14/14] Add docstring to write_data_to_file

---
 src/clusterfuzz/_internal/platforms/android/adb.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/clusterfuzz/_internal/platforms/android/adb.py b/src/clusterfuzz/_internal/platforms/android/adb.py
index 071922e084d..0776ecfeb26 100755
--- a/src/clusterfuzz/_internal/platforms/android/adb.py
+++ b/src/clusterfuzz/_internal/platforms/android/adb.py
@@ -881,7 +881,14 @@ def write_command_line_file(command_line, app_path):
 
 
 def write_data_to_file(contents, file_path, should_reboot=True):
-  """Writes content to file."""
+  """Writes content to file.
+  
+  Args:
+    contents: The string content to write.
+    file_path: The path to the file on the Android device.
+    should_reboot: Whether to reboot the device if a system file is modified.
+        Defaults to True.
+  """
   # If this is a file in /system, we need to remount /system as read-write and
   # after file is written, revert it back to read-only.
   is_system_file = file_path.startswith('/system')