| /* |
| * Copyright (C) 2007 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 |
| * |
| * http://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 com.android.internal.os; |
| |
| import static libcore.io.OsConstants.S_IRWXG; |
| import static libcore.io.OsConstants.S_IRWXO; |
| |
| import android.content.res.Resources; |
| import android.content.res.TypedArray; |
| import android.net.LocalServerSocket; |
| import android.opengl.EGL14; |
| import android.os.Debug; |
| import android.os.Process; |
| import android.os.SystemClock; |
| import android.os.SystemProperties; |
| import android.os.Trace; |
| import android.util.EventLog; |
| import android.util.Log; |
| |
| import dalvik.system.VMRuntime; |
| import dalvik.system.Zygote; |
| |
| import libcore.io.IoUtils; |
| import libcore.io.Libcore; |
| import libcore.io.OsConstants; |
| |
| import java.io.BufferedReader; |
| import java.io.FileDescriptor; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Modifier; |
| import java.util.ArrayList; |
| |
| /** |
| * Startup class for the zygote process. |
| * |
| * Pre-initializes some classes, and then waits for commands on a UNIX domain |
| * socket. Based on these commands, forks off child processes that inherit |
| * the initial state of the VM. |
| * |
| * Please see {@link ZygoteConnection.Arguments} for documentation on the |
| * client protocol. |
| * |
| * @hide |
| */ |
| public class ZygoteInit { |
| private static final String TAG = "Zygote"; |
| |
| private static final String PROPERTY_DISABLE_OPENGL_PRELOADING = "ro.zygote.disable_gl_preload"; |
| |
| private static final String ANDROID_SOCKET_ENV = "ANDROID_SOCKET_zygote"; |
| |
| private static final int LOG_BOOT_PROGRESS_PRELOAD_START = 3020; |
| private static final int LOG_BOOT_PROGRESS_PRELOAD_END = 3030; |
| |
| /** when preloading, GC after allocating this many bytes */ |
| private static final int PRELOAD_GC_THRESHOLD = 50000; |
| |
| public static final String USAGE_STRING = |
| " <\"start-system-server\"|\"\" for startSystemServer>"; |
| |
| private static LocalServerSocket sServerSocket; |
| |
| /** |
| * Used to pre-load resources. We hold a global reference on it so it |
| * never gets destroyed. |
| */ |
| private static Resources mResources; |
| |
| /** |
| * The number of times that the main Zygote loop |
| * should run before calling gc() again. |
| */ |
| static final int GC_LOOP_COUNT = 10; |
| |
| /** |
| * The name of a resource file that contains classes to preload. |
| */ |
| private static final String PRELOADED_CLASSES = "preloaded-classes"; |
| |
| /** Controls whether we should preload resources during zygote init. */ |
| private static final boolean PRELOAD_RESOURCES = true; |
| |
| /** |
| * Invokes a static "main(argv[]) method on class "className". |
| * Converts various failing exceptions into RuntimeExceptions, with |
| * the assumption that they will then cause the VM instance to exit. |
| * |
| * @param loader class loader to use |
| * @param className Fully-qualified class name |
| * @param argv Argument vector for main() |
| */ |
| static void invokeStaticMain(ClassLoader loader, |
| String className, String[] argv) |
| throws ZygoteInit.MethodAndArgsCaller { |
| Class<?> cl; |
| |
| try { |
| cl = loader.loadClass(className); |
| } catch (ClassNotFoundException ex) { |
| throw new RuntimeException( |
| "Missing class when invoking static main " + className, |
| ex); |
| } |
| |
| Method m; |
| try { |
| m = cl.getMethod("main", new Class[] { String[].class }); |
| } catch (NoSuchMethodException ex) { |
| throw new RuntimeException( |
| "Missing static main on " + className, ex); |
| } catch (SecurityException ex) { |
| throw new RuntimeException( |
| "Problem getting static main on " + className, ex); |
| } |
| |
| int modifiers = m.getModifiers(); |
| if (! (Modifier.isStatic(modifiers) && Modifier.isPublic(modifiers))) { |
| throw new RuntimeException( |
| "Main method is not public and static on " + className); |
| } |
| |
| /* |
| * This throw gets caught in ZygoteInit.main(), which responds |
| * by invoking the exception's run() method. This arrangement |
| * clears up all the stack frames that were required in setting |
| * up the process. |
| */ |
| throw new ZygoteInit.MethodAndArgsCaller(m, argv); |
| } |
| |
| /** |
| * Registers a server socket for zygote command connections |
| * |
| * @throws RuntimeException when open fails |
| */ |
| private static void registerZygoteSocket() { |
| if (sServerSocket == null) { |
| int fileDesc; |
| try { |
| String env = System.getenv(ANDROID_SOCKET_ENV); |
| fileDesc = Integer.parseInt(env); |
| } catch (RuntimeException ex) { |
| throw new RuntimeException( |
| ANDROID_SOCKET_ENV + " unset or invalid", ex); |
| } |
| |
| try { |
| sServerSocket = new LocalServerSocket( |
| createFileDescriptor(fileDesc)); |
| } catch (IOException ex) { |
| throw new RuntimeException( |
| "Error binding to local socket '" + fileDesc + "'", ex); |
| } |
| } |
| } |
| |
| /** |
| * Waits for and accepts a single command connection. Throws |
| * RuntimeException on failure. |
| */ |
| private static ZygoteConnection acceptCommandPeer() { |
| try { |
| return new ZygoteConnection(sServerSocket.accept()); |
| } catch (IOException ex) { |
| throw new RuntimeException( |
| "IOException during accept()", ex); |
| } |
| } |
| |
| /** |
| * Close and clean up zygote sockets. Called on shutdown and on the |
| * child's exit path. |
| */ |
| static void closeServerSocket() { |
| try { |
| if (sServerSocket != null) { |
| FileDescriptor fd = sServerSocket.getFileDescriptor(); |
| sServerSocket.close(); |
| if (fd != null) { |
| Libcore.os.close(fd); |
| } |
| } |
| } catch (IOException ex) { |
| Log.e(TAG, "Zygote: error closing sockets", ex); |
| } catch (libcore.io.ErrnoException ex) { |
| Log.e(TAG, "Zygote: error closing descriptor", ex); |
| } |
| |
| sServerSocket = null; |
| } |
| |
| /** |
| * Return the server socket's underlying file descriptor, so that |
| * ZygoteConnection can pass it to the native code for proper |
| * closure after a child process is forked off. |
| */ |
| |
| static FileDescriptor getServerSocketFileDescriptor() { |
| return sServerSocket.getFileDescriptor(); |
| } |
| |
| private static final int UNPRIVILEGED_UID = 9999; |
| private static final int UNPRIVILEGED_GID = 9999; |
| |
| private static final int ROOT_UID = 0; |
| private static final int ROOT_GID = 0; |
| |
| /** |
| * Sets effective user ID. |
| */ |
| private static void setEffectiveUser(int uid) { |
| int errno = setreuid(ROOT_UID, uid); |
| if (errno != 0) { |
| Log.e(TAG, "setreuid() failed. errno: " + errno); |
| } |
| } |
| |
| /** |
| * Sets effective group ID. |
| */ |
| private static void setEffectiveGroup(int gid) { |
| int errno = setregid(ROOT_GID, gid); |
| if (errno != 0) { |
| Log.e(TAG, "setregid() failed. errno: " + errno); |
| } |
| } |
| |
| static void preload() { |
| Log.d(TAG, "begin preload"); |
| preloadClasses(); |
| preloadResources(); |
| preloadOpenGL(); |
| Log.d(TAG, "end preload"); |
| } |
| |
| private static void preloadOpenGL() { |
| if (!SystemProperties.getBoolean(PROPERTY_DISABLE_OPENGL_PRELOADING, false)) { |
| EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY); |
| } |
| } |
| |
| /** |
| * Performs Zygote process initialization. Loads and initializes |
| * commonly used classes. |
| * |
| * Most classes only cause a few hundred bytes to be allocated, but |
| * a few will allocate a dozen Kbytes (in one case, 500+K). |
| */ |
| private static void preloadClasses() { |
| final VMRuntime runtime = VMRuntime.getRuntime(); |
| |
| InputStream is = ClassLoader.getSystemClassLoader().getResourceAsStream( |
| PRELOADED_CLASSES); |
| if (is == null) { |
| Log.e(TAG, "Couldn't find " + PRELOADED_CLASSES + "."); |
| } else { |
| Log.i(TAG, "Preloading classes..."); |
| long startTime = SystemClock.uptimeMillis(); |
| |
| // Drop root perms while running static initializers. |
| setEffectiveGroup(UNPRIVILEGED_GID); |
| setEffectiveUser(UNPRIVILEGED_UID); |
| |
| // Alter the target heap utilization. With explicit GCs this |
| // is not likely to have any effect. |
| float defaultUtilization = runtime.getTargetHeapUtilization(); |
| runtime.setTargetHeapUtilization(0.8f); |
| |
| // Start with a clean slate. |
| System.gc(); |
| runtime.runFinalizationSync(); |
| Debug.startAllocCounting(); |
| |
| try { |
| BufferedReader br |
| = new BufferedReader(new InputStreamReader(is), 256); |
| |
| int count = 0; |
| String line; |
| while ((line = br.readLine()) != null) { |
| // Skip comments and blank lines. |
| line = line.trim(); |
| if (line.startsWith("#") || line.equals("")) { |
| continue; |
| } |
| |
| try { |
| if (false) { |
| Log.v(TAG, "Preloading " + line + "..."); |
| } |
| Class.forName(line); |
| if (Debug.getGlobalAllocSize() > PRELOAD_GC_THRESHOLD) { |
| if (false) { |
| Log.v(TAG, |
| " GC at " + Debug.getGlobalAllocSize()); |
| } |
| System.gc(); |
| runtime.runFinalizationSync(); |
| Debug.resetGlobalAllocSize(); |
| } |
| count++; |
| } catch (ClassNotFoundException e) { |
| Log.w(TAG, "Class not found for preloading: " + line); |
| } catch (UnsatisfiedLinkError e) { |
| Log.w(TAG, "Problem preloading " + line + ": " + e); |
| } catch (Throwable t) { |
| Log.e(TAG, "Error preloading " + line + ".", t); |
| if (t instanceof Error) { |
| throw (Error) t; |
| } |
| if (t instanceof RuntimeException) { |
| throw (RuntimeException) t; |
| } |
| throw new RuntimeException(t); |
| } |
| } |
| |
| Log.i(TAG, "...preloaded " + count + " classes in " |
| + (SystemClock.uptimeMillis()-startTime) + "ms."); |
| } catch (IOException e) { |
| Log.e(TAG, "Error reading " + PRELOADED_CLASSES + ".", e); |
| } finally { |
| IoUtils.closeQuietly(is); |
| // Restore default. |
| runtime.setTargetHeapUtilization(defaultUtilization); |
| |
| // Fill in dex caches with classes, fields, and methods brought in by preloading. |
| runtime.preloadDexCaches(); |
| |
| Debug.stopAllocCounting(); |
| |
| // Bring back root. We'll need it later. |
| setEffectiveUser(ROOT_UID); |
| setEffectiveGroup(ROOT_GID); |
| } |
| } |
| } |
| |
| /** |
| * Load in commonly used resources, so they can be shared across |
| * processes. |
| * |
| * These tend to be a few Kbytes, but are frequently in the 20-40K |
| * range, and occasionally even larger. |
| */ |
| private static void preloadResources() { |
| final VMRuntime runtime = VMRuntime.getRuntime(); |
| |
| Debug.startAllocCounting(); |
| try { |
| System.gc(); |
| runtime.runFinalizationSync(); |
| mResources = Resources.getSystem(); |
| mResources.startPreloading(); |
| if (PRELOAD_RESOURCES) { |
| Log.i(TAG, "Preloading resources..."); |
| |
| long startTime = SystemClock.uptimeMillis(); |
| TypedArray ar = mResources.obtainTypedArray( |
| com.android.internal.R.array.preloaded_drawables); |
| int N = preloadDrawables(runtime, ar); |
| ar.recycle(); |
| Log.i(TAG, "...preloaded " + N + " resources in " |
| + (SystemClock.uptimeMillis()-startTime) + "ms."); |
| |
| startTime = SystemClock.uptimeMillis(); |
| ar = mResources.obtainTypedArray( |
| com.android.internal.R.array.preloaded_color_state_lists); |
| N = preloadColorStateLists(runtime, ar); |
| ar.recycle(); |
| Log.i(TAG, "...preloaded " + N + " resources in " |
| + (SystemClock.uptimeMillis()-startTime) + "ms."); |
| } |
| mResources.finishPreloading(); |
| } catch (RuntimeException e) { |
| Log.w(TAG, "Failure preloading resources", e); |
| } finally { |
| Debug.stopAllocCounting(); |
| } |
| } |
| |
| private static int preloadColorStateLists(VMRuntime runtime, TypedArray ar) { |
| int N = ar.length(); |
| for (int i=0; i<N; i++) { |
| if (Debug.getGlobalAllocSize() > PRELOAD_GC_THRESHOLD) { |
| if (false) { |
| Log.v(TAG, " GC at " + Debug.getGlobalAllocSize()); |
| } |
| System.gc(); |
| runtime.runFinalizationSync(); |
| Debug.resetGlobalAllocSize(); |
| } |
| int id = ar.getResourceId(i, 0); |
| if (false) { |
| Log.v(TAG, "Preloading resource #" + Integer.toHexString(id)); |
| } |
| if (id != 0) { |
| if (mResources.getColorStateList(id) == null) { |
| throw new IllegalArgumentException( |
| "Unable to find preloaded color resource #0x" |
| + Integer.toHexString(id) |
| + " (" + ar.getString(i) + ")"); |
| } |
| } |
| } |
| return N; |
| } |
| |
| |
| private static int preloadDrawables(VMRuntime runtime, TypedArray ar) { |
| int N = ar.length(); |
| for (int i=0; i<N; i++) { |
| if (Debug.getGlobalAllocSize() > PRELOAD_GC_THRESHOLD) { |
| if (false) { |
| Log.v(TAG, " GC at " + Debug.getGlobalAllocSize()); |
| } |
| System.gc(); |
| runtime.runFinalizationSync(); |
| Debug.resetGlobalAllocSize(); |
| } |
| int id = ar.getResourceId(i, 0); |
| if (false) { |
| Log.v(TAG, "Preloading resource #" + Integer.toHexString(id)); |
| } |
| if (id != 0) { |
| if (mResources.getDrawable(id) == null) { |
| throw new IllegalArgumentException( |
| "Unable to find preloaded drawable resource #0x" |
| + Integer.toHexString(id) |
| + " (" + ar.getString(i) + ")"); |
| } |
| } |
| } |
| return N; |
| } |
| |
| /** |
| * Runs several special GCs to try to clean up a few generations of |
| * softly- and final-reachable objects, along with any other garbage. |
| * This is only useful just before a fork(). |
| */ |
| /*package*/ static void gc() { |
| final VMRuntime runtime = VMRuntime.getRuntime(); |
| |
| /* runFinalizationSync() lets finalizers be called in Zygote, |
| * which doesn't have a HeapWorker thread. |
| */ |
| System.gc(); |
| runtime.runFinalizationSync(); |
| System.gc(); |
| runtime.runFinalizationSync(); |
| System.gc(); |
| runtime.runFinalizationSync(); |
| } |
| |
| /** |
| * Finish remaining work for the newly forked system server process. |
| */ |
| private static void handleSystemServerProcess( |
| ZygoteConnection.Arguments parsedArgs) |
| throws ZygoteInit.MethodAndArgsCaller { |
| |
| closeServerSocket(); |
| |
| // set umask to 0077 so new files and directories will default to owner-only permissions. |
| Libcore.os.umask(S_IRWXG | S_IRWXO); |
| |
| if (parsedArgs.niceName != null) { |
| Process.setArgV0(parsedArgs.niceName); |
| } |
| |
| if (parsedArgs.invokeWith != null) { |
| WrapperInit.execApplication(parsedArgs.invokeWith, |
| parsedArgs.niceName, parsedArgs.targetSdkVersion, |
| null, parsedArgs.remainingArgs); |
| } else { |
| /* |
| * Pass the remaining arguments to SystemServer. |
| */ |
| RuntimeInit.zygoteInit(parsedArgs.targetSdkVersion, parsedArgs.remainingArgs); |
| } |
| |
| /* should never reach here */ |
| } |
| |
| /** |
| * Prepare the arguments and fork for the system server process. |
| */ |
| private static boolean startSystemServer() |
| throws MethodAndArgsCaller, RuntimeException { |
| long capabilities = posixCapabilitiesAsBits( |
| OsConstants.CAP_BLOCK_SUSPEND, |
| OsConstants.CAP_KILL, |
| OsConstants.CAP_NET_ADMIN, |
| OsConstants.CAP_NET_BIND_SERVICE, |
| OsConstants.CAP_NET_BROADCAST, |
| OsConstants.CAP_NET_RAW, |
| OsConstants.CAP_SYS_MODULE, |
| OsConstants.CAP_SYS_NICE, |
| OsConstants.CAP_SYS_RESOURCE, |
| OsConstants.CAP_SYS_TIME, |
| OsConstants.CAP_SYS_TTY_CONFIG |
| ); |
| /* Hardcoded command line to start the system server */ |
| String args[] = { |
| "--setuid=1000", |
| "--setgid=1000", |
| "--setgroups=1001,1002,1003,1004,1005,1006,1007,1008,1009,1010,1018,1032,3001,3002,3003,3006,3007", |
| "--capabilities=" + capabilities + "," + capabilities, |
| "--runtime-init", |
| "--nice-name=system_server", |
| "com.android.server.SystemServer", |
| }; |
| ZygoteConnection.Arguments parsedArgs = null; |
| |
| int pid; |
| |
| try { |
| parsedArgs = new ZygoteConnection.Arguments(args); |
| ZygoteConnection.applyDebuggerSystemProperty(parsedArgs); |
| ZygoteConnection.applyInvokeWithSystemProperty(parsedArgs); |
| |
| /* Request to fork the system server process */ |
| pid = Zygote.forkSystemServer( |
| parsedArgs.uid, parsedArgs.gid, |
| parsedArgs.gids, |
| parsedArgs.debugFlags, |
| null, |
| parsedArgs.permittedCapabilities, |
| parsedArgs.effectiveCapabilities); |
| } catch (IllegalArgumentException ex) { |
| throw new RuntimeException(ex); |
| } |
| |
| /* For child process */ |
| if (pid == 0) { |
| handleSystemServerProcess(parsedArgs); |
| } |
| |
| return true; |
| } |
| |
| /** |
| * Gets the bit array representation of the provided list of POSIX capabilities. |
| */ |
| private static long posixCapabilitiesAsBits(int... capabilities) { |
| long result = 0; |
| for (int capability : capabilities) { |
| if ((capability < 0) || (capability > OsConstants.CAP_LAST_CAP)) { |
| throw new IllegalArgumentException(String.valueOf(capability)); |
| } |
| result |= (1L << capability); |
| } |
| return result; |
| } |
| |
| public static void main(String argv[]) { |
| try { |
| // Start profiling the zygote initialization. |
| SamplingProfilerIntegration.start(); |
| |
| registerZygoteSocket(); |
| EventLog.writeEvent(LOG_BOOT_PROGRESS_PRELOAD_START, |
| SystemClock.uptimeMillis()); |
| preload(); |
| EventLog.writeEvent(LOG_BOOT_PROGRESS_PRELOAD_END, |
| SystemClock.uptimeMillis()); |
| |
| // Finish profiling the zygote initialization. |
| SamplingProfilerIntegration.writeZygoteSnapshot(); |
| |
| // Do an initial gc to clean up after startup |
| gc(); |
| |
| // Disable tracing so that forked processes do not inherit stale tracing tags from |
| // Zygote. |
| Trace.setTracingEnabled(false); |
| |
| // If requested, start system server directly from Zygote |
| if (argv.length != 2) { |
| throw new RuntimeException(argv[0] + USAGE_STRING); |
| } |
| |
| if (argv[1].equals("start-system-server")) { |
| startSystemServer(); |
| } else if (!argv[1].equals("")) { |
| throw new RuntimeException(argv[0] + USAGE_STRING); |
| } |
| |
| Log.i(TAG, "Accepting command socket connections"); |
| |
| runSelectLoop(); |
| |
| closeServerSocket(); |
| } catch (MethodAndArgsCaller caller) { |
| caller.run(); |
| } catch (RuntimeException ex) { |
| Log.e(TAG, "Zygote died with exception", ex); |
| closeServerSocket(); |
| throw ex; |
| } |
| } |
| |
| /** |
| * Runs the zygote process's select loop. Accepts new connections as |
| * they happen, and reads commands from connections one spawn-request's |
| * worth at a time. |
| * |
| * @throws MethodAndArgsCaller in a child process when a main() should |
| * be executed. |
| */ |
| private static void runSelectLoop() throws MethodAndArgsCaller { |
| ArrayList<FileDescriptor> fds = new ArrayList<FileDescriptor>(); |
| ArrayList<ZygoteConnection> peers = new ArrayList<ZygoteConnection>(); |
| FileDescriptor[] fdArray = new FileDescriptor[4]; |
| |
| fds.add(sServerSocket.getFileDescriptor()); |
| peers.add(null); |
| |
| int loopCount = GC_LOOP_COUNT; |
| while (true) { |
| int index; |
| |
| /* |
| * Call gc() before we block in select(). |
| * It's work that has to be done anyway, and it's better |
| * to avoid making every child do it. It will also |
| * madvise() any free memory as a side-effect. |
| * |
| * Don't call it every time, because walking the entire |
| * heap is a lot of overhead to free a few hundred bytes. |
| */ |
| if (loopCount <= 0) { |
| gc(); |
| loopCount = GC_LOOP_COUNT; |
| } else { |
| loopCount--; |
| } |
| |
| |
| try { |
| fdArray = fds.toArray(fdArray); |
| index = selectReadable(fdArray); |
| } catch (IOException ex) { |
| throw new RuntimeException("Error in select()", ex); |
| } |
| |
| if (index < 0) { |
| throw new RuntimeException("Error in select()"); |
| } else if (index == 0) { |
| ZygoteConnection newPeer = acceptCommandPeer(); |
| peers.add(newPeer); |
| fds.add(newPeer.getFileDesciptor()); |
| } else { |
| boolean done; |
| done = peers.get(index).runOnce(); |
| |
| if (done) { |
| peers.remove(index); |
| fds.remove(index); |
| } |
| } |
| } |
| } |
| |
| /** |
| * The Linux syscall "setreuid()" |
| * @param ruid real uid |
| * @param euid effective uid |
| * @return 0 on success, non-zero errno on fail |
| */ |
| static native int setreuid(int ruid, int euid); |
| |
| /** |
| * The Linux syscall "setregid()" |
| * @param rgid real gid |
| * @param egid effective gid |
| * @return 0 on success, non-zero errno on fail |
| */ |
| static native int setregid(int rgid, int egid); |
| |
| /** |
| * Invokes the linux syscall "setpgid" |
| * |
| * @param pid pid to change |
| * @param pgid new process group of pid |
| * @return 0 on success or non-zero errno on fail |
| */ |
| static native int setpgid(int pid, int pgid); |
| |
| /** |
| * Invokes the linux syscall "getpgid" |
| * |
| * @param pid pid to query |
| * @return pgid of pid in question |
| * @throws IOException on error |
| */ |
| static native int getpgid(int pid) throws IOException; |
| |
| /** |
| * Invokes the syscall dup2() to copy the specified descriptors into |
| * stdin, stdout, and stderr. The existing stdio descriptors will be |
| * closed and errors during close will be ignored. The specified |
| * descriptors will also remain open at their original descriptor numbers, |
| * so the caller may want to close the original descriptors. |
| * |
| * @param in new stdin |
| * @param out new stdout |
| * @param err new stderr |
| * @throws IOException |
| */ |
| static native void reopenStdio(FileDescriptor in, |
| FileDescriptor out, FileDescriptor err) throws IOException; |
| |
| /** |
| * Toggles the close-on-exec flag for the specified file descriptor. |
| * |
| * @param fd non-null; file descriptor |
| * @param flag desired close-on-exec flag state |
| * @throws IOException |
| */ |
| static native void setCloseOnExec(FileDescriptor fd, boolean flag) |
| throws IOException; |
| |
| /** |
| * Invokes select() on the provider array of file descriptors (selecting |
| * for readability only). Array elements of null are ignored. |
| * |
| * @param fds non-null; array of readable file descriptors |
| * @return index of descriptor that is now readable or -1 for empty array. |
| * @throws IOException if an error occurs |
| */ |
| static native int selectReadable(FileDescriptor[] fds) throws IOException; |
| |
| /** |
| * Creates a file descriptor from an int fd. |
| * |
| * @param fd integer OS file descriptor |
| * @return non-null; FileDescriptor instance |
| * @throws IOException if fd is invalid |
| */ |
| static native FileDescriptor createFileDescriptor(int fd) |
| throws IOException; |
| |
| /** |
| * Class not instantiable. |
| */ |
| private ZygoteInit() { |
| } |
| |
| /** |
| * Helper exception class which holds a method and arguments and |
| * can call them. This is used as part of a trampoline to get rid of |
| * the initial process setup stack frames. |
| */ |
| public static class MethodAndArgsCaller extends Exception |
| implements Runnable { |
| /** method to call */ |
| private final Method mMethod; |
| |
| /** argument array */ |
| private final String[] mArgs; |
| |
| public MethodAndArgsCaller(Method method, String[] args) { |
| mMethod = method; |
| mArgs = args; |
| } |
| |
| public void run() { |
| try { |
| mMethod.invoke(null, new Object[] { mArgs }); |
| } catch (IllegalAccessException ex) { |
| throw new RuntimeException(ex); |
| } catch (InvocationTargetException ex) { |
| Throwable cause = ex.getCause(); |
| if (cause instanceof RuntimeException) { |
| throw (RuntimeException) cause; |
| } else if (cause instanceof Error) { |
| throw (Error) cause; |
| } |
| throw new RuntimeException(ex); |
| } |
| } |
| } |
| } |