diff --git a/ci/build_device_and_tests b/ci/build_device_and_tests
index 9d11268..63d3ce3 100755
--- a/ci/build_device_and_tests
+++ b/ci/build_device_and_tests
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+set -euo pipefail
 
-build/soong/soong_ui.bash --make-mode build_test_suites || exit $?
-$(build/soong/soong_ui.bash --dumpvar-mode HOST_OUT)/bin/build_test_suites $@ || exit $?
+build/soong/soong_ui.bash --make-mode build_test_suites
+$(build/soong/soong_ui.bash --dumpvar-mode HOST_OUT)/bin/build_test_suites --device-build $@
diff --git a/ci/build_test_suites b/ci/build_test_suites
index 9d11268..74470a8 100755
--- a/ci/build_test_suites
+++ b/ci/build_test_suites
@@ -13,6 +13,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+set -euo pipefail
 
-build/soong/soong_ui.bash --make-mode build_test_suites || exit $?
-$(build/soong/soong_ui.bash --dumpvar-mode HOST_OUT)/bin/build_test_suites $@ || exit $?
+build/soong/soong_ui.bash --make-mode build_test_suites
+$(build/soong/soong_ui.bash --dumpvar-mode HOST_OUT)/bin/build_test_suites $@
diff --git a/ci/build_test_suites.py b/ci/build_test_suites.py
index 623d256..b67ecec 100644
--- a/ci/build_test_suites.py
+++ b/ci/build_test_suites.py
@@ -30,9 +30,10 @@
 import test_discovery_agent
 
 
-REQUIRED_ENV_VARS = frozenset(['TARGET_PRODUCT', 'TARGET_RELEASE', 'TOP'])
+REQUIRED_ENV_VARS = frozenset(['TARGET_PRODUCT', 'TARGET_RELEASE', 'TOP', 'DIST_DIR'])
 SOONG_UI_EXE_REL_PATH = 'build/soong/soong_ui.bash'
 LOG_PATH = 'logs/build_test_suites.log'
+REQUIRED_BUILD_TARGETS = frozenset(['dist'])
 
 
 class Error(Exception):
@@ -73,34 +74,46 @@
 
     build_targets = set()
     packaging_commands_getters = []
-    test_discovery_zip_regexes = set()
-    optimization_rationale = ''
-    try:
-      # Do not use these regexes for now, only run this to collect data on what
-      # would be optimized.
-      test_discovery_zip_regexes = self._get_test_discovery_zip_regexes()
-      logging.info(f'Discovered test discovery regexes: {test_discovery_zip_regexes}')
-    except test_discovery_agent.TestDiscoveryError as e:
-      optimization_rationale = e.message
-      logging.warning(f'Unable to perform test discovery: {optimization_rationale}')
-    for target in self.args.extra_targets:
-      if optimization_rationale:
-        get_metrics_agent().report_unoptimized_target(target, optimization_rationale)
-      else:
+    # In order to roll optimizations out differently between test suites and
+    # device builds, we have separate flags.
+    if (
+        'test_suites_zip_test_discovery'
+        in self.build_context.enabled_build_features
+        and not self.args.device_build
+    ) or (
+        'device_zip_test_discovery'
+        in self.build_context.enabled_build_features
+        and self.args.device_build
+    ):
+      preliminary_build_targets = self._collect_preliminary_build_targets()
+    else:
+      preliminary_build_targets = self._legacy_collect_preliminary_build_targets()
+
+      # Keep reporting metrics when test discovery is disabled.
+      # To be removed once test discovery is fully rolled out.
+      optimization_rationale = ''
+      test_discovery_zip_regexes = set()
+      try:
+        test_discovery_zip_regexes = self._get_test_discovery_zip_regexes()
+        logging.info(f'Discovered test discovery regexes: {test_discovery_zip_regexes}')
+      except test_discovery_agent.TestDiscoveryError as e:
+        optimization_rationale = e.message
+        logging.warning(f'Unable to perform test discovery: {optimization_rationale}')
+
+      for target in self.args.extra_targets:
+        if optimization_rationale:
+          get_metrics_agent().report_unoptimized_target(target, optimization_rationale)
+          continue
         try:
-          regex = r'\b(%s)\b' % re.escape(target)
+          regex = r'\b(%s.*)\b' % re.escape(target)
           if any(re.search(regex, opt) for opt in test_discovery_zip_regexes):
             get_metrics_agent().report_unoptimized_target(target, 'Test artifact used.')
-          else:
-            get_metrics_agent().report_optimized_target(target)
+            continue
+          get_metrics_agent().report_optimized_target(target)
         except Exception as e:
           logging.error(f'unable to parse test discovery output: {repr(e)}')
 
-      if self._unused_target_exclusion_enabled(
-          target
-      ) and not self.build_context.build_target_used(target):
-        continue
-
+    for target in preliminary_build_targets:
       target_optimizer_getter = self.target_optimizations.get(target, None)
       if not target_optimizer_getter:
         build_targets.add(target)
@@ -116,6 +129,51 @@
 
     return BuildPlan(build_targets, packaging_commands_getters)
 
+  def _collect_preliminary_build_targets(self):
+    build_targets = set()
+    try:
+      test_discovery_zip_regexes = self._get_test_discovery_zip_regexes()
+      logging.info(f'Discovered test discovery regexes: {test_discovery_zip_regexes}')
+    except test_discovery_agent.TestDiscoveryError as e:
+      optimization_rationale = e.message
+      logging.warning(f'Unable to perform test discovery: {optimization_rationale}')
+
+      for target in self.args.extra_targets:
+        get_metrics_agent().report_unoptimized_target(target, optimization_rationale)
+      return self._legacy_collect_preliminary_build_targets()
+
+    for target in self.args.extra_targets:
+      if target in REQUIRED_BUILD_TARGETS:
+        build_targets.add(target)
+        continue
+
+      regex = r'\b(%s.*)\b' % re.escape(target)
+      for opt in test_discovery_zip_regexes:
+        try:
+          if re.search(regex, opt):
+            get_metrics_agent().report_unoptimized_target(target, 'Test artifact used.')
+            build_targets.add(target)
+            continue
+          get_metrics_agent().report_optimized_target(target)
+        except Exception as e:
+          # In case of exception report as unoptimized
+          build_targets.add(target)
+          get_metrics_agent().report_unoptimized_target(target, f'Error in parsing test discovery output for {target}: {repr(e)}')
+          logging.error(f'unable to parse test discovery output: {repr(e)}')
+
+    return build_targets
+
+  def _legacy_collect_preliminary_build_targets(self):
+    build_targets = set()
+    for target in self.args.extra_targets:
+      if self._unused_target_exclusion_enabled(
+          target
+      ) and not self.build_context.build_target_used(target):
+        continue
+
+      build_targets.add(target)
+    return build_targets
+
   def _unused_target_exclusion_enabled(self, target: str) -> bool:
     return (
         f'{target}_unused_exclusion'
@@ -197,6 +255,11 @@
   argparser.add_argument(
       'extra_targets', nargs='*', help='Extra test suites to build.'
   )
+  argparser.add_argument(
+      '--device-build',
+      action='store_true',
+      help='Flag to indicate running a device build.',
+  )
 
   return argparser.parse_args(argv)
 
diff --git a/ci/build_test_suites_test.py b/ci/build_test_suites_test.py
index 26f4316..29d268e 100644
--- a/ci/build_test_suites_test.py
+++ b/ci/build_test_suites_test.py
@@ -78,6 +78,12 @@
     with self.assert_raises_word(build_test_suites.Error, 'TOP'):
       build_test_suites.main([])
 
+  def test_missing_dist_dir_env_var_raises(self):
+    del os.environ['DIST_DIR']
+
+    with self.assert_raises_word(build_test_suites.Error, 'DIST_DIR'):
+      build_test_suites.main([])
+
   def test_invalid_arg_raises(self):
     invalid_args = ['--invalid_arg']
 
@@ -114,6 +120,9 @@
     self.soong_ui_dir = self.fake_top.joinpath('build/soong')
     self.soong_ui_dir.mkdir(parents=True, exist_ok=True)
 
+    self.logs_dir = self.fake_top.joinpath('dist/logs')
+    self.logs_dir.mkdir(parents=True, exist_ok=True)
+
     self.soong_ui = self.soong_ui_dir.joinpath('soong_ui.bash')
     self.soong_ui.touch()
 
@@ -121,6 +130,7 @@
         'TARGET_RELEASE': 'release',
         'TARGET_PRODUCT': 'product',
         'TOP': str(self.fake_top),
+        'DIST_DIR': str(self.fake_top.joinpath('dist')),
     })
 
     self.mock_subprocess_run.return_value = 0
diff --git a/core/soong_extra_config.mk b/core/soong_extra_config.mk
index 2ff83a1..8eee50a 100644
--- a/core/soong_extra_config.mk
+++ b/core/soong_extra_config.mk
@@ -80,7 +80,7 @@
 
 $(call add_json_str, ScreenDensity, $(TARGET_SCREEN_DENSITY))
 
-$(call add_json_bool, UsesVulkan, $(filter true,$(TARGET_USES_VULKAN)))
+$(call add_json_str, UsesVulkan, $(TARGET_USES_VULKAN))
 
 $(call add_json_bool, ZygoteForce64, $(filter true,$(ZYGOTE_FORCE_64)))
 
diff --git a/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/ByteBufferReader.java b/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/ByteBufferReader.java
index 9571568..1fbcb85 100644
--- a/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/ByteBufferReader.java
+++ b/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/ByteBufferReader.java
@@ -63,4 +63,8 @@
     public void position(int newPosition) {
         mByteBuffer.position(newPosition);
     }
+
+    public int position() {
+        return mByteBuffer.position();
+    }
 }
diff --git a/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/PackageTable.java b/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/PackageTable.java
index a45d12a..1e7c2ca 100644
--- a/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/PackageTable.java
+++ b/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/PackageTable.java
@@ -19,10 +19,16 @@
 import static java.nio.charset.StandardCharsets.UTF_8;
 
 import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Objects;
 
 public class PackageTable {
 
+    private static final int FINGERPRINT_BYTES = 8;
+    // int: mPackageId + int: mBooleanStartIndex + int: mNextOffset
+    private static final int NODE_SKIP_BYTES = 12;
+
     private Header mHeader;
     private ByteBufferReader mReader;
 
@@ -60,6 +66,18 @@
         return null;
     }
 
+    public List<String> getPackageList() {
+        List<String> list = new ArrayList<>(mHeader.mNumPackages);
+        mReader.position(mHeader.mNodeOffset);
+        int fingerprintBytes = mHeader.mVersion == 1 ? 0 : FINGERPRINT_BYTES;
+        int skipBytes = fingerprintBytes + NODE_SKIP_BYTES;
+        for (int i = 0; i < mHeader.mNumPackages; i++) {
+            list.add(mReader.readString());
+            mReader.position(mReader.position() + skipBytes);
+        }
+        return list;
+    }
+
     public Header getHeader() {
         return mHeader;
     }
diff --git a/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/StorageFileProvider.java b/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/StorageFileProvider.java
index f1a4e26..f75ac36 100644
--- a/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/StorageFileProvider.java
+++ b/tools/aconfig/aconfig_storage_file/srcs/android/aconfig/storage/StorageFileProvider.java
@@ -39,13 +39,15 @@
     private static final String PMAP_FILE_EXT = ".package.map";
     private static final String FMAP_FILE_EXT = ".flag.map";
     private static final String VAL_FILE_EXT = ".val";
+    private static final StorageFileProvider DEFAULT_INSTANCE =
+            new StorageFileProvider(DEFAULT_MAP_PATH, DEFAULT_BOOT_PATH);
 
     private final String mMapPath;
     private final String mBootPath;
 
     /** @hide */
     public static StorageFileProvider getDefaultProvider() {
-        return new StorageFileProvider(DEFAULT_MAP_PATH, DEFAULT_BOOT_PATH);
+        return DEFAULT_INSTANCE;
     }
 
     /** @hide */
@@ -82,7 +84,9 @@
 
     /** @hide */
     public PackageTable getPackageTable(String container) {
-        return getPackageTable(Paths.get(mMapPath, container + PMAP_FILE_EXT));
+        return PackageTable.fromBytes(
+                mapStorageFile(
+                        Paths.get(mMapPath, container + PMAP_FILE_EXT), FileType.PACKAGE_MAP));
     }
 
     /** @hide */
@@ -97,11 +101,6 @@
                 mapStorageFile(Paths.get(mBootPath, container + VAL_FILE_EXT), FileType.FLAG_VAL));
     }
 
-    /** @hide */
-    public static PackageTable getPackageTable(Path path) {
-        return PackageTable.fromBytes(mapStorageFile(path, FileType.PACKAGE_MAP));
-    }
-
     // Map a storage file given file path
     private static MappedByteBuffer mapStorageFile(Path file, FileType type) {
         FileChannel channel = null;
diff --git a/tools/aconfig/aconfig_storage_file/tests/srcs/PackageTableTest.java b/tools/aconfig/aconfig_storage_file/tests/srcs/PackageTableTest.java
index 5906d8b..812ce35 100644
--- a/tools/aconfig/aconfig_storage_file/tests/srcs/PackageTableTest.java
+++ b/tools/aconfig/aconfig_storage_file/tests/srcs/PackageTableTest.java
@@ -27,6 +27,9 @@
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
+import java.util.HashSet;
+import java.util.Set;
+
 @RunWith(JUnit4.class)
 public class PackageTableTest {
 
@@ -121,4 +124,22 @@
         assertEquals(4431940502274857964L, node2.getPackageFingerprint());
         assertEquals(-2213514155997929241L, node4.getPackageFingerprint());
     }
+
+    @Test
+    public void testPackageTable_getPackageList() throws Exception {
+        PackageTable packageTable =
+                PackageTable.fromBytes(TestDataUtils.getTestPackageMapByteBuffer(2));
+        Set<String> packages = new HashSet<>(packageTable.getPackageList());
+        assertEquals(3, packages.size());
+        assertTrue(packages.contains("com.android.aconfig.storage.test_1"));
+        assertTrue(packages.contains("com.android.aconfig.storage.test_2"));
+        assertTrue(packages.contains("com.android.aconfig.storage.test_4"));
+
+        packageTable = PackageTable.fromBytes(TestDataUtils.getTestPackageMapByteBuffer(1));
+        packages = new HashSet<>(packageTable.getPackageList());
+        assertEquals(3, packages.size());
+        assertTrue(packages.contains("com.android.aconfig.storage.test_1"));
+        assertTrue(packages.contains("com.android.aconfig.storage.test_2"));
+        assertTrue(packages.contains("com.android.aconfig.storage.test_4"));
+    }
 }
diff --git a/tools/edit_monitor/daemon_manager.py b/tools/edit_monitor/daemon_manager.py
index a352e30..7d666fe 100644
--- a/tools/edit_monitor/daemon_manager.py
+++ b/tools/edit_monitor/daemon_manager.py
@@ -13,6 +13,8 @@
 # limitations under the License.
 
 
+import errno
+import fcntl
 import getpass
 import hashlib
 import logging
@@ -100,16 +102,32 @@
       logging.warning("Edit monitor for cog is not supported, exiting...")
       return
 
-    try:
-      self._stop_any_existing_instance()
-      self._write_pid_to_pidfile()
-      self._start_daemon_process()
-    except Exception as e:
-      logging.exception("Failed to start daemon manager with error %s", e)
-      self._send_error_event_to_clearcut(
-          edit_event_pb2.EditEvent.FAILED_TO_START_EDIT_MONITOR
-      )
-      raise e
+    setup_lock_file = pathlib.Path(tempfile.gettempdir()).joinpath(
+        self.pid_file_path.name + ".setup"
+    )
+    logging.info("setup lock file: %s", setup_lock_file)
+    with open(setup_lock_file, "w") as f:
+      try:
+        # Acquire an exclusive lock
+        fcntl.flock(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
+        self._stop_any_existing_instance()
+        self._write_pid_to_pidfile()
+        self._start_daemon_process()
+      except Exception as e:
+        if (
+            isinstance(e, IOError) and e.errno == errno.EAGAIN
+        ):  # Failed to acquire the file lock.
+          logging.warning("Another edit monitor is starting, exitinng...")
+          return
+        else:
+          logging.exception("Failed to start daemon manager with error %s", e)
+          self._send_error_event_to_clearcut(
+              edit_event_pb2.EditEvent.FAILED_TO_START_EDIT_MONITOR
+          )
+          raise e
+      finally:
+        # Release the lock
+        fcntl.flock(f, fcntl.LOCK_UN)
 
   def monitor_daemon(
       self,
@@ -413,13 +431,19 @@
   def _find_all_instances_pids(self) -> list[int]:
     pids = []
 
-    for file in os.listdir(self.pid_file_path.parent):
-      if file.endswith(".lock"):
-        try:
-          with open(self.pid_file_path.parent.joinpath(file), "r") as f:
-            pids.append(int(f.read().strip()))
-        except (FileNotFoundError, IOError, ValueError, TypeError):
-          logging.exception("Failed to get pid from file path: %s", file)
+    try:
+      output = subprocess.check_output(["ps", "-ef", "--no-headers"], text=True)
+      for line in output.splitlines():
+        parts = line.split()
+        process_path = parts[7]
+        if pathlib.Path(process_path).name == "edit_monitor":
+          pid = int(parts[1])
+          if pid != self.pid:  # exclude the current process
+            pids.append(pid)
+    except Exception:
+      logging.exception(
+          "Failed to get pids of existing edit monitors from ps command."
+      )
 
     return pids
 
diff --git a/tools/edit_monitor/daemon_manager_test.py b/tools/edit_monitor/daemon_manager_test.py
index 350739d..be28965 100644
--- a/tools/edit_monitor/daemon_manager_test.py
+++ b/tools/edit_monitor/daemon_manager_test.py
@@ -14,6 +14,7 @@
 
 """Unittests for DaemonManager."""
 
+import fcntl
 import logging
 import multiprocessing
 import os
@@ -82,7 +83,8 @@
     # tests will be cleaned.
     tempfile.tempdir = self.working_dir.name
     self.patch = mock.patch.dict(
-        os.environ, {'ENABLE_ANDROID_EDIT_MONITOR': 'true'})
+        os.environ, {'ENABLE_ANDROID_EDIT_MONITOR': 'true'}
+    )
     self.patch.start()
 
   def tearDown(self):
@@ -102,6 +104,7 @@
     p = self._create_fake_deamon_process()
 
     self.assert_run_simple_daemon_success()
+    self.assert_no_subprocess_running()
 
   def test_start_success_with_existing_instance_already_dead(self):
     # Create a pidfile with pid that does not exist.
@@ -137,7 +140,9 @@
     # Verify no daemon process is started.
     self.assertIsNone(dm.daemon_process)
 
-  @mock.patch.dict(os.environ, {'ENABLE_ANDROID_EDIT_MONITOR': 'false'}, clear=True)
+  @mock.patch.dict(
+      os.environ, {'ENABLE_ANDROID_EDIT_MONITOR': 'false'}, clear=True
+  )
   def test_start_return_directly_if_disabled(self):
     dm = daemon_manager.DaemonManager(TEST_BINARY_FILE)
     dm.start()
@@ -154,6 +159,25 @@
     # Verify no daemon process is started.
     self.assertIsNone(dm.daemon_process)
 
+  def test_start_failed_other_instance_is_starting(self):
+    f = open(
+        pathlib.Path(self.working_dir.name).joinpath(
+            TEST_PID_FILE_PATH + '.setup'
+        ),
+        'w',
+    )
+    # Acquire an exclusive lock
+    fcntl.flock(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
+
+    dm = daemon_manager.DaemonManager(TEST_BINARY_FILE)
+    dm.start()
+
+    # Release the lock
+    fcntl.flock(f, fcntl.LOCK_UN)
+    f.close()
+    # Verify no daemon process is started.
+    self.assertIsNone(dm.daemon_process)
+
   @mock.patch('os.kill')
   def test_start_failed_to_kill_existing_instance(self, mock_kill):
     mock_kill.side_effect = OSError('Unknown OSError')
@@ -177,6 +201,7 @@
         'edit_monitor'
     )
     pid_file_path_dir.mkdir(parents=True, exist_ok=True)
+
     # Makes the directory read-only so write pidfile will fail.
     os.chmod(pid_file_path_dir, 0o555)
 
@@ -216,7 +241,7 @@
         cclient=fake_cclient,
     )
     # set the fake total_memory_size
-    dm.total_memory_size = 100 * 1024 *1024
+    dm.total_memory_size = 100 * 1024 * 1024
     dm.start()
     dm.monitor_daemon(interval=1)
 
@@ -367,6 +392,26 @@
         fake_cclient, edit_event_pb2.EditEvent.FAILED_TO_REBOOT_EDIT_MONITOR
     )
 
+  @mock.patch('subprocess.check_output')
+  def test_cleanup_success(self, mock_check_output):
+    p = self._create_fake_deamon_process()
+    fake_cclient = FakeClearcutClient()
+    mock_check_output.return_value = f'user {p.pid} 1 1 1 1 1 edit_monitor arg'
+
+    dm = daemon_manager.DaemonManager(
+        TEST_BINARY_FILE,
+        daemon_target=long_running_daemon,
+        cclient=fake_cclient,
+    )
+    dm.cleanup()
+
+    self.assertFalse(p.is_alive())
+    self.assertTrue(
+        pathlib.Path(self.working_dir.name)
+        .joinpath(daemon_manager.BLOCK_SIGN_FILE)
+        .exists()
+    )
+
   def assert_run_simple_daemon_success(self):
     damone_output_file = tempfile.NamedTemporaryFile(
         dir=self.working_dir.name, delete=False
@@ -432,7 +477,7 @@
         pass
 
   def _create_fake_deamon_process(
-      self, name: str = ''
+      self, name: str = TEST_PID_FILE_PATH
   ) -> multiprocessing.Process:
     # Create a long running subprocess
     p = multiprocessing.Process(target=long_running_daemon)
@@ -443,7 +488,7 @@
         'edit_monitor'
     )
     pid_file_path_dir.mkdir(parents=True, exist_ok=True)
-    with open(pid_file_path_dir.joinpath(name + 'pid.lock'), 'w') as f:
+    with open(pid_file_path_dir.joinpath(name), 'w') as f:
       f.write(str(p.pid))
     return p
 
diff --git a/tools/edit_monitor/main.py b/tools/edit_monitor/main.py
index 7ca0daa..3c2d183 100644
--- a/tools/edit_monitor/main.py
+++ b/tools/edit_monitor/main.py
@@ -102,12 +102,12 @@
       daemon_args=(args.path, args.dry_run),
   )
 
-  if args.force_cleanup:
-    dm.cleanup()
-
   try:
-    dm.start()
-    dm.monitor_daemon()
+    if args.force_cleanup:
+      dm.cleanup()
+    else:
+      dm.start()
+      dm.monitor_daemon()
   except Exception:
     logging.exception('Unexpected exception raised when run daemon.')
   finally: