content: /*
   * Copyright (C) 2006 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * 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.
   */
  
  package android.os;
  
  import java.io.BufferedWriter;
  import java.io.DataInputStream;
  import java.io.IOException;
  import java.io.OutputStreamWriter;
  import java.util.ArrayList;
  
  import android.net.LocalSocket;
  import android.net.LocalSocketAddress;
  import android.util.Log;
  
  
  
  /*package*/ class ZygoteStartFailedEx extends Exception {
      /**
       * Something prevented the zygote process startup from happening normally
       */
  
      ZygoteStartFailedEx() {}
  
      ZygoteStartFailedEx(String s) {super(s);}
      ZygoteStartFailedEx(Throwable cause) {super(cause);}
  }
  
  /**
   * Tools for managing OS processes.
   */
  public class Process {
      public static final String LOG_TAG = "Process";
  
      public static final String ZYGOTE_SOCKET = "zygote";
  
      /**
       * Name of a process for running the platform's media services.
       * {@hide}
       */
      public static final String ANDROID_SHARED_MEDIA = "com.android.process.media";
  
      /**
       * Name of the process that Google content providers can share.
       * {@hide}
       */
      public static final String GOOGLE_SHARED_APP_CONTENT = "com.google.process.content";
  
      /**
       * Defines the UID/GID under which system code runs.
       */
      public static final int SYSTEM_UID = 1000;
  
      /**
       * Defines the UID/GID under which the telephony code runs.
       */
      public static final int PHONE_UID = 1001;
  
      /**
       * Defines the UID/GID for the user shell.
       */
      public static final int SHELL_UID = 2000;
  
      /**
       * Defines the UID/GID for the log group.
       */
      public static final int LOG_UID = 1007;
  
      /**
       * Defines the UID/GID for the WIFI supplicant process.
       */
      public static final int WIFI_UID = 1010;
  
      /**
       * Defines the UID/GID for the mediaserver process.
       */
      public static final int MEDIA_UID = 1013;
  
      /**
       * Defines the UID/GID for the DRM process.
       */
      public static final int DRM_UID = 1019;
  
      /**
       * Defines the UID/GID for the group that controls VPN services.
       */
      public static final int VPN_UID = 1016;
  
      /**
       * Defines the UID/GID for the NFC service process.
       */
      public static final int NFC_UID = 1027;
  
      /**
       * Defines the UID/GID for the Bluetooth service process.
       */
      public static final int BLUETOOTH_UID = 1002;
  
      /**
       * Defines the GID for the group that allows write access to the internal media storage.
       */
      public static final int MEDIA_RW_GID = 1023;
  
      /**
       * Access to installed package details
       */
      public static final int PACKAGE_INFO_GID = 1032;
  
      /**
       * Defines the start of a range of UIDs (and GIDs), going from this
       * number to {@link #LAST_APPLICATION_UID} that are reserved for assigning
       * to applications.
       */
      public static final int FIRST_APPLICATION_UID = 10000;
  
      /**
       * Last of application-specific UIDs starting at
       * {@link #FIRST_APPLICATION_UID}.
       */
      public static final int LAST_APPLICATION_UID = 19999;
  
      /**
       * First uid used for fully isolated sandboxed processes (with no permissions of their own)
       * @hide
       */
      public static final int FIRST_ISOLATED_UID = 99000;
  
      /**
       * Last uid used for fully isolated sandboxed processes (with no permissions of their own)
       * @hide
       */
      public static final int LAST_ISOLATED_UID = 99999;
  
      /**
       * First gid for applications to share resources. Used when forward-locking
       * is enabled but all UserHandles need to be able to read the resources.
       * @hide
       */
      public static final int FIRST_SHARED_APPLICATION_GID = 50000;
  
      /**
       * Last gid for applications to share resources. Used when forward-locking
       * is enabled but all UserHandles need to be able to read the resources.
       * @hide
       */
      public static final int LAST_SHARED_APPLICATION_GID = 59999;
  
      /**
       * Standard priority of application threads.
       * Use with {@link #setThreadPriority(int)} and
       * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
       * {@link java.lang.Thread} class.
       */
      public static final int THREAD_PRIORITY_DEFAULT = 0;
  
      /*
       * ***************************************
       * ** Keep in sync with utils/threads.h **
       * ***************************************
       */
      
      /**
       * Lowest available thread priority.  Only for those who really, really
       * don't want to run if anything else is happening.
       * Use with {@link #setThreadPriority(int)} and
       * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
       * {@link java.lang.Thread} class.
       */
      public static final int THREAD_PRIORITY_LOWEST = 19;
      
      /**
       * Standard priority background threads.  This gives your thread a slightly
       * lower than normal priority, so that it will have less chance of impacting
       * the responsiveness of the user interface.
       * Use with {@link #setThreadPriority(int)} and
       * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
       * {@link java.lang.Thread} class.
       */
      public static final int THREAD_PRIORITY_BACKGROUND = 10;
      
      /**
       * Standard priority of threads that are currently running a user interface
       * that the user is interacting with.  Applications can not normally
       * change to this priority; the system will automatically adjust your
       * application threads as the user moves through the UI.
       * Use with {@link #setThreadPriority(int)} and
       * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
       * {@link java.lang.Thread} class.
       */
      public static final int THREAD_PRIORITY_FOREGROUND = -2;
      
      /**
       * Standard priority of system display threads, involved in updating
       * the user interface.  Applications can not
       * normally change to this priority.
       * Use with {@link #setThreadPriority(int)} and
       * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
       * {@link java.lang.Thread} class.
       */
      public static final int THREAD_PRIORITY_DISPLAY = -4;
      
      /**
       * Standard priority of the most important display threads, for compositing
       * the screen and retrieving input events.  Applications can not normally
       * change to this priority.
       * Use with {@link #setThreadPriority(int)} and
       * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
       * {@link java.lang.Thread} class.
       */
      public static final int THREAD_PRIORITY_URGENT_DISPLAY = -8;
  
      /**
       * Standard priority of audio threads.  Applications can not normally
       * change to this priority.
       * Use with {@link #setThreadPriority(int)} and
       * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
       * {@link java.lang.Thread} class.
       */
      public static final int THREAD_PRIORITY_AUDIO = -16;
  
      /**
       * Standard priority of the most important audio threads.
       * Applications can not normally change to this priority.
       * Use with {@link #setThreadPriority(int)} and
       * {@link #setThreadPriority(int, int)}, <b>not</b> with the normal
       * {@link java.lang.Thread} class.
       */
      public static final int THREAD_PRIORITY_URGENT_AUDIO = -19;
  
      /**
       * Minimum increment to make a priority more favorable.
       */
      public static final int THREAD_PRIORITY_MORE_FAVORABLE = -1;
  
      /**
       * Minimum increment to make a priority less favorable.
       */
      public static final int THREAD_PRIORITY_LESS_FAVORABLE = +1;
  
      /**
       * Default scheduling policy
       * @hide
       */
      public static final int SCHED_OTHER = 0;
  
      /**
       * First-In First-Out scheduling policy
       * @hide
       */
      public static final int SCHED_FIFO = 1;
  
      /**
       * Round-Robin scheduling policy
       * @hide
       */
      public static final int SCHED_RR = 2;
  
      /**
       * Batch scheduling policy
       * @hide
       */
      public static final int SCHED_BATCH = 3;
  
      /**
       * Idle scheduling policy
       * @hide
       */
      public static final int SCHED_IDLE = 5;
  
      // Keep in sync with SP_* constants of enum type SchedPolicy
      // declared in system/core/include/cutils/sched_policy.h,
      // except THREAD_GROUP_DEFAULT does not correspond to any SP_* value.
  
      /**
       * Default thread group -
       * has meaning with setProcessGroup() only, cannot be used with setThreadGroup().
       * When used with setProcessGroup(), the group of each thread in the process
       * is conditionally changed based on that thread's current priority, as follows:
       * threads with priority numerically less than THREAD_PRIORITY_BACKGROUND
       * are moved to foreground thread group.  All other threads are left unchanged.
       * @hide
       */
      public static final int THREAD_GROUP_DEFAULT = -1;
  
      /**
       * Background thread group - All threads in
       * this group are scheduled with a reduced share of the CPU.
       * Value is same as constant SP_BACKGROUND of enum SchedPolicy.
       * FIXME rename to THREAD_GROUP_BACKGROUND.
       * @hide
       */
      public static final int THREAD_GROUP_BG_NONINTERACTIVE = 0;
  
      /**
       * Foreground thread group - All threads in
       * this group are scheduled with a normal share of the CPU.
       * Value is same as constant SP_FOREGROUND of enum SchedPolicy.
       * Not used at this level.
       * @hide
       **/
      public static final int THREAD_GROUP_FOREGROUND = 1;
  
      /**
       * System thread group.
       * @hide
       **/
      public static final int THREAD_GROUP_SYSTEM = 2;
  
      /**
       * Application audio thread group.
       * @hide
       **/
      public static final int THREAD_GROUP_AUDIO_APP = 3;
  
      /**
       * System audio thread group.
       * @hide
       **/
      public static final int THREAD_GROUP_AUDIO_SYS = 4;
  
      public static final int SIGNAL_QUIT = 3;
      public static final int SIGNAL_KILL = 9;
      public static final int SIGNAL_USR1 = 10;
      
      // State for communicating with zygote process
  
      static LocalSocket sZygoteSocket;
      static DataInputStream sZygoteInputStream;
      static BufferedWriter sZygoteWriter;
  
      /** true if previous zygote open failed */
      static boolean sPreviousZygoteOpenFailed;
  
      /**
       * Start a new process.
       * 
       * <p>If processes are enabled, a new process is created and the
       * static main() function of a <var>processClass</var> is executed there.
       * The process will continue running after this function returns.
       * 
       * <p>If processes are not enabled, a new thread in the caller's
       * process is created and main() of <var>processClass</var> called there.
       * 
       * <p>The niceName parameter, if not an empty string, is a custom name to
       * give to the process instead of using processClass.  This allows you to
       * make easily identifyable processes even if you are using the same base
       * <var>processClass</var> to start them.
       * 
       * @param processClass The class to use as the process's main entry
       *                     point.
       * @param niceName A more readable name to use for the process.
       * @param uid The user-id under which the process will run.
       * @param gid The group-id under which the process will run.
       * @param gids Additional group-ids associated with the process.
       * @param debugFlags Additional flags.
       * @param targetSdkVersion The target SDK version for the app.
       * @param seInfo null-ok SE Android information for the new process.
       * @param zygoteArgs Additional arguments to supply to the zygote process.
       * 
       * @return An object that describes the result of the attempt to start the process.
       * @throws RuntimeException on fatal start failure
       * 
       * {@hide}
       */
      public static final ProcessStartResult start(final String processClass,
                                    final String niceName,
                                    int uid, int gid, int[] gids,
                                    int debugFlags, int mountExternal,
                                    int targetSdkVersion,
                                    String seInfo,
                                    String[] zygoteArgs) {
          try {
              return startViaZygote(processClass, niceName, uid, gid, gids,
                      debugFlags, mountExternal, targetSdkVersion, seInfo, zygoteArgs);
          } catch (ZygoteStartFailedEx ex) {
              ex.printStackTrace();
              return null;
          }
      }
  
      /** retry interval for opening a zygote socket */
      static final int ZYGOTE_RETRY_MILLIS = 500;
  
      /**
       * Tries to open socket to Zygote process if not already open. If
       * already open, does nothing.  May block and retry.
       */
      public static void openZygoteSocketIfNeeded() 
              throws ZygoteStartFailedEx {
  
          int retryCount;
  
          if (sPreviousZygoteOpenFailed) {
              /*
               * If we've failed before, expect that we'll fail again and
               * don't pause for retries.
               */
              retryCount = 0;
          } else {
              retryCount = 10;            
          }
  
          /*
           * See bug #811181: Sometimes runtime can make it up before zygote.
           * Really, we'd like to do something better to avoid this condition,
           * but for now just wait a bit...
           */
          for (int retry = 0
                  ; (sZygoteSocket == null) && (retry < (retryCount + 1))
                  ; retry++ ) {
  
              if (retry > 0) {
                  try {
                  	Log.i("Zygote", "Zygote not up yet, sleeping...");
                      Thread.sleep(ZYGOTE_RETRY_MILLIS);
                  } catch (InterruptedException ex) {
                      // should never happen
                  }
              }
  
              try {
                  sZygoteSocket = new LocalSocket();
  
                  sZygoteSocket.connect(new LocalSocketAddress(ZYGOTE_SOCKET, 
                          LocalSocketAddress.Namespace.RESERVED));
  
                  sZygoteInputStream
                          = new DataInputStream(sZygoteSocket.getInputStream());
  
                  sZygoteWriter =
                      new BufferedWriter(
                              new OutputStreamWriter(
                                      sZygoteSocket.getOutputStream()),
                              256);
  
                  Log.i("Zygote", "Process: zygote socket opened");
  
                  sPreviousZygoteOpenFailed = false;
                  break;
              } catch (IOException ex) {
                  if (sZygoteSocket != null) {
                      try {
                          sZygoteSocket.close();
                      } catch (IOException ex2) {
                      	Log.e(LOG_TAG,"I/O exception on close after exception",
                                  ex2);
                      }
                  }
  
                  sZygoteSocket = null;
              }
          }
  
          if (sZygoteSocket == null) {
              sPreviousZygoteOpenFailed = true;
              throw new ZygoteStartFailedEx("connect failed");                 
          }
      }
  
      /**
       * Sends an argument list to the zygote process, which starts a new child
       * and returns the child's pid. Please note: the present implementation
       * replaces newlines in the argument list with spaces.
       * @param args argument list
       * @return An object that describes the result of the attempt to start the process.
       * @throws ZygoteStartFailedEx if process start failed for any reason
       */
      public static ProcessStartResult zygoteSendArgsAndGetResult(ArrayList<String> args)
              throws ZygoteStartFailedEx {
          openZygoteSocketIfNeeded();
  
          try {
              /**
               * See com.android.internal.os.ZygoteInit.readArgumentList()
               * Presently the wire format to the zygote process is:
               * a) a count of arguments (argc, in essence)
               * b) a number of newline-separated argument strings equal to count
               *
               * After the zygote process reads these it will write the pid of
               * the child or -1 on failure, followed by boolean to
               * indicate whether a wrapper process was used.
               */
  
              sZygoteWriter.write(Integer.toString(args.size()));
              sZygoteWriter.newLine();
  
              int sz = args.size();
              for (int i = 0; i < sz; i++) {
                  String arg = args.get(i);
                  if (arg.indexOf('\n') >= 0) {
                      throw new ZygoteStartFailedEx(
                              "embedded newlines not allowed");
                  }
                  sZygoteWriter.write(arg);
                  sZygoteWriter.newLine();
              }
  
              sZygoteWriter.flush();
  
              // Should there be a timeout on this?
              ProcessStartResult result = new ProcessStartResult();
              result.pid = sZygoteInputStream.readInt();
              if (result.pid < 0) {
                  throw new ZygoteStartFailedEx("fork() failed");
              }
              result.usingWrapper = sZygoteInputStream.readBoolean();
              return result;
          } catch (IOException ex) {
              try {
                  if (sZygoteSocket != null) {
                      sZygoteSocket.close();
                  }
              } catch (IOException ex2) {
                  // we're going to fail anyway
              	Log.e(LOG_TAG,"I/O exception on routine close", ex2);
              }
  
              sZygoteSocket = null;
  
              throw new ZygoteStartFailedEx(ex);
          }
      }
  
      /**
       * Starts a new process via the zygote mechanism.
       *
       * @param processClass Class name whose static main() to run
       * @param niceName 'nice' process name to appear in ps
       * @param uid a POSIX uid that the new process should setuid() to
       * @param gid a POSIX gid that the new process shuold setgid() to
       * @param gids null-ok; a list of supplementary group IDs that the
       * new process should setgroup() to.
       * @param debugFlags Additional flags.
       * @param targetSdkVersion The target SDK version for the app.
       * @param seInfo null-ok SE Android information for the new process.
       * @param extraArgs Additional arguments to supply to the zygote process.
       * @return An object that describes the result of the attempt to start the process.
       * @throws ZygoteStartFailedEx if process start failed for any reason
       */
      public static ProcessStartResult startViaZygote(final String processClass,
                                    final String niceName,
                                    final int uid, final int gid,
                                    final int[] gids,
                                    int debugFlags, int mountExternal,
                                    int targetSdkVersion,
                                    String seInfo,
                                    String[] extraArgs)
                                    throws ZygoteStartFailedEx {
          synchronized(Process.class) {
              ArrayList<String> argsForZygote = new ArrayList<String>();
              return zygoteSendArgsAndGetResult(argsForZygote);
          }
      }
      
      /**
       * Returns elapsed milliseconds of the time this process has run.
       * @return  Returns the number of milliseconds this process has return.
       */
      public static final native long getElapsedCpuTime();
      
      /**
       * Returns the identifier of this process, which can be used with
       * {@link #killProcess} and {@link #sendSignal}.
       */
      public static final int myPid() {
          return 0;
      }
  
      /**
       * Returns the identifier of this process' parent.
       * @hide
       */
      public static final int myPpid() {
          return 0;
      }
  
      /**
       * Returns the identifier of the calling thread, which be used with
       * {@link #setThreadPriority(int, int)}.
       */
      public static final int myTid() {
          return 0;
      }
  
      /**
       * Returns the identifier of this process's uid.  This is the kernel uid
       * that the process is running under, which is the identity of its
       * app-specific sandbox.  It is different from {@link #myUserHandle} in that
       * a uid identifies a specific app sandbox in a specific user.
       */
      public static final int myUid() {
          return 0;
      }
  
      /**
       * Returns this process's user handle.  This is the
       * user the process is running under.  It is distinct from
       * {@link #myUid()} in that a particular user will have multiple
       * distinct apps running under it each with their own uid.
       */
      public static final UserHandle myUserHandle() {
          return new UserHandle(null);
      }
  
      /**
       * Returns whether the current process is in an isolated sandbox.
       * @hide
       */
      public static final boolean isIsolated() {
          return true;
      }
  
      /**
       * Returns the UID assigned to a particular user name, or -1 if there is
       * none.  If the given string consists of only numbers, it is converted
       * directly to a uid.
       */
      public static final native int getUidForName(String name);
      
      /**
       * Returns the GID assigned to a particular user name, or -1 if there is
       * none.  If the given string consists of only numbers, it is converted
       * directly to a gid.
       */
      public static final native int getGidForName(String name);
  
      /**
       * Returns a uid for a currently running process.
       * @param pid the process id
       * @return the uid of the process, or -1 if the process is not running.
       * @hide pending API council review
       */
      public static final int getUidForPid(int pid) {
          String[] procStatusLabels = { "Uid:" };
          long[] procStatusValues = new long[1];
          procStatusValues[0] = -1;
          Process.readProcLines("/proc/" + pid + "/status", procStatusLabels, procStatusValues);
          return (int) procStatusValues[0];
      }
  
      /**
       * Returns the parent process id for a currently running process.
       * @param pid the process id
       * @return the parent process id of the process, or -1 if the process is not running.
       * @hide
       */
      public static final int getParentPid(int pid) {
          String[] procStatusLabels = { "PPid:" };
          long[] procStatusValues = new long[1];
          procStatusValues[0] = -1;
          Process.readProcLines("/proc/" + pid + "/status", procStatusLabels, procStatusValues);
          return (int) procStatusValues[0];
      }
  
      /**
       * Returns the thread group leader id for a currently running thread.
       * @param tid the thread id
       * @return the thread group leader id of the thread, or -1 if the thread is not running.
       *         This is same as what getpid(2) would return if called by tid.
       * @hide
       */
      public static final int getThreadGroupLeader(int tid) {
          String[] procStatusLabels = { "Tgid:" };
          long[] procStatusValues = new long[1];
          procStatusValues[0] = -1;
          Process.readProcLines("/proc/" + tid + "/status", procStatusLabels, procStatusValues);
          return (int) procStatusValues[0];
      }
  
      /**
       * Set the priority of a thread, based on Linux priorities.
       * 
       * @param tid The identifier of the thread/process to change.
       * @param priority A Linux priority level, from -20 for highest scheduling
       * priority to 19 for lowest scheduling priority.
       * 
       * @throws IllegalArgumentException Throws IllegalArgumentException if
       * <var>tid</var> does not exist.
       * @throws SecurityException Throws SecurityException if your process does
       * not have permission to modify the given thread, or to use the given
       * priority.
       */
      public static final native void setThreadPriority(int tid, int priority)
              throws IllegalArgumentException, SecurityException;
  
      /**
       * Call with 'false' to cause future calls to {@link #setThreadPriority(int)} to
       * throw an exception if passed a background-level thread priority.  This is only
       * effective if the JNI layer is built with GUARD_THREAD_PRIORITY defined to 1.
       *
       * @hide
       */
      public static final native void setCanSelfBackground(boolean backgroundOk);
  
      /**
       * Sets the scheduling group for a thread.
       * @hide
       * @param tid The identifier of the thread to change.
       * @param group The target group for this thread from THREAD_GROUP_*.
       * 
       * @throws IllegalArgumentException Throws IllegalArgumentException if
       * <var>tid</var> does not exist.
       * @throws SecurityException Throws SecurityException if your process does
       * not have permission to modify the given thread, or to use the given
       * priority.
       * If the thread is a thread group leader, that is it's gettid() == getpid(),
       * then the other threads in the same thread group are _not_ affected.
       */
      public static final native void setThreadGroup(int tid, int group)
              throws IllegalArgumentException, SecurityException;
  
      /**
       * Sets the scheduling group for a process and all child threads
       * @hide
       * @param pid The identifier of the process to change.
       * @param group The target group for this process from THREAD_GROUP_*.
       * 
       * @throws IllegalArgumentException Throws IllegalArgumentException if
       * <var>tid</var> does not exist.
       * @throws SecurityException Throws SecurityException if your process does
       * not have permission to modify the given thread, or to use the given
       * priority.
       *
       * group == THREAD_GROUP_DEFAULT means to move all non-background priority
       * threads to the foreground scheduling group, but to leave background
       * priority threads alone.  group == THREAD_GROUP_BG_NONINTERACTIVE moves all
       * threads, regardless of priority, to the background scheduling group.
       * group == THREAD_GROUP_FOREGROUND is not allowed.
       */
      public static final native void setProcessGroup(int pid, int group)
              throws IllegalArgumentException, SecurityException;
  
      /**
       * Return the scheduling group of requested process.
       *
       * @hide
       */
      public static final native int getProcessGroup(int pid)
              throws IllegalArgumentException, SecurityException;
  
      /**
       * Set the priority of the calling thread, based on Linux priorities.  See
       * {@link #setThreadPriority(int, int)} for more information.
       * 
       * @param priority A Linux priority level, from -20 for highest scheduling
       * priority to 19 for lowest scheduling priority.
       * 
       * @throws IllegalArgumentException Throws IllegalArgumentException if
       * <var>tid</var> does not exist.
       * @throws SecurityException Throws SecurityException if your process does
       * not have permission to modify the given thread, or to use the given
       * priority.
       * 
       * @see #setThreadPriority(int, int)
       */
      public static final native void setThreadPriority(int priority)
              throws IllegalArgumentException, SecurityException;
      
      /**
       * Return the current priority of a thread, based on Linux priorities.
       * 
       * @param tid The identifier of the thread/process to change.
       * 
       * @return Returns the current priority, as a Linux priority level,
       * from -20 for highest scheduling priority to 19 for lowest scheduling
       * priority.
       * 
       * @throws IllegalArgumentException Throws IllegalArgumentException if
       * <var>tid</var> does not exist.
       */
      public static final native int getThreadPriority(int tid)
              throws IllegalArgumentException;
      
      /**
       * Set the scheduling policy and priority of a thread, based on Linux.
       *
       * @param tid The identifier of the thread/process to change.
       * @param policy A Linux scheduling policy such as SCHED_OTHER etc.
       * @param priority A Linux priority level in a range appropriate for the given policy.
       *
       * @throws IllegalArgumentException Throws IllegalArgumentException if
       * <var>tid</var> does not exist, or if <var>priority</var> is out of range for the policy.
       * @throws SecurityException Throws SecurityException if your process does
       * not have permission to modify the given thread, or to use the given
       * scheduling policy or priority.
       *
       * {@hide}
       */
      public static final native void setThreadScheduler(int tid, int policy, int priority)
              throws IllegalArgumentException;
  
      /**
       * Determine whether the current environment supports multiple processes.
       * 
       * @return Returns true if the system can run in multiple processes, else
       * false if everything is running in a single process.
       *
       * @deprecated This method always returns true.  Do not use.
       */
      @Deprecated
      public static final boolean supportsProcesses() {
          return true;
      }
  
      /**
       * Set the out-of-memory badness adjustment for a process.
       * 
       * @param pid The process identifier to set.
       * @param amt Adjustment value -- linux allows -16 to +15.
       * 
       * @return Returns true if the underlying system supports this
       *         feature, else false.
       *         
       * {@hide}
       */
      public static final native boolean setOomAdj(int pid, int amt);
  
      /**
       * Adjust the swappiness level for a process.
       *
       * @param pid The process identifier to set.
       * @param is_increased Whether swappiness should be increased or default.
       *
       * @return Returns true if the underlying system supports this
       *         feature, else false.
       *
       * {@hide}
       */
      public static final native boolean setSwappiness(int pid, boolean is_increased);
  
      /**
       * Change this process's argv[0] parameter.  This can be useful to show
       * more descriptive information in things like the 'ps' command.
       * 
       * @param text The new name of this process.
       * 
       * {@hide}
       */
      public static final native void setArgV0(String text);
  
      /**
       * Kill the process with the given PID.
       * Note that, though this API allows us to request to
       * kill any process based on its PID, the kernel will
       * still impose standard restrictions on which PIDs you
       * are actually able to kill.  Typically this means only
       * the process running the caller's packages/application
       * and any additional processes created by that app; packages
       * sharing a common UID will also be able to kill each
       * other's processes.
       */
      public static final void killProcess(int pid) {
          sendSignal(pid, SIGNAL_KILL);
      }
  
      /** @hide */
      public static final native int setUid(int uid);
  
      /** @hide */
      public static final native int setGid(int uid);
  
      /**
       * Send a signal to the given process.
       * 
       * @param pid The pid of the target process.
       * @param signal The signal to send.
       */
      public static final native void sendSignal(int pid, int signal);
      
      /**
       * @hide
       * Private impl for avoiding a log message...  DO NOT USE without doing
       * your own log, or the Android Illuminati will find you some night and
       * beat you up.
       */
      public static final void killProcessQuiet(int pid) {
          sendSignalQuiet(pid, SIGNAL_KILL);
      }
  
      /**
       * @hide
       * Private impl for avoiding a log message...  DO NOT USE without doing
       * your own log, or the Android Illuminati will find you some night and
       * beat you up.
       */
      public static final native void sendSignalQuiet(int pid, int signal);
      
      /** @hide */
      public static final native long getFreeMemory();
      
      /** @hide */
      public static final native long getTotalMemory();
      
      /** @hide */
      public static final native void readProcLines(String path,
              String[] reqFields, long[] outSizes);
      
      /** @hide */
      public static final native int[] getPids(String path, int[] lastArray);
      
      /** @hide */
      public static final int PROC_TERM_MASK = 0xff;
      /** @hide */
      public static final int PROC_ZERO_TERM = 0;
      /** @hide */
      public static final int PROC_SPACE_TERM = (int)' ';
      /** @hide */
      public static final int PROC_TAB_TERM = (int)'\t';
      /** @hide */
      public static final int PROC_COMBINE = 0x100;
      /** @hide */
      public static final int PROC_PARENS = 0x200;
      /** @hide */
      public static final int PROC_QUOTES = 0x400;
      /** @hide */
      public static final int PROC_OUT_STRING = 0x1000;
      /** @hide */
      public static final int PROC_OUT_LONG = 0x2000;
      /** @hide */
      public static final int PROC_OUT_FLOAT = 0x4000;
      
      /** @hide */
      public static final native boolean readProcFile(String file, int[] format,
              String[] outStrings, long[] outLongs, float[] outFloats);
      
      /** @hide */
      public static final native boolean parseProcLine(byte[] buffer, int startIndex, 
              int endIndex, int[] format, String[] outStrings, long[] outLongs, float[] outFloats);
  
      /** @hide */
      public static final native int[] getPidsForCommands(String[] cmds);
  
      /**
       * Gets the total Pss value for a given process, in bytes.
       * 
       * @param pid the process to the Pss for
       * @return the total Pss value for the given process in bytes,
       *  or -1 if the value cannot be determined 
       * @hide
       */
      public static final native long getPss(int pid);
  
      /**
       * Specifies the outcome of having started a process.
       * @hide
       */
      public static final class ProcessStartResult {
          /**
           * The PID of the newly started process.
           * Always >= 0.  (If the start failed, an exception will have been thrown instead.)
           */
          public int pid;
  
          /**
           * True if the process was started with a wrapper attached.
           */
          public boolean usingWrapper;
      }
  }
  