Rename Zygote -> ZygoteHooks.

The old Zygote class is moving to frameworks/base. The Zygote
class provides a set of callbacks that Zygote can call to allow
the runtime to perform pre/post fork work.

Change-Id: I7400e32906d32e80ffd196ef7a858a8733011ac3

2 files changed, 78 insertions, 187 deletions

diff --git a/dalvik/src/main/java/dalvik/system/Zygote.java b/dalvik/src/main/java/dalvik/system/Zygote.java
deleted file mode 100644
index aa9bf20..0000000
--- a/dalvik/src/main/java/dalvik/system/Zygote.java
+++ /dev/null
@@ -1,187 +0,0 @@
-/*
- * 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
- *
- *      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 dalvik.system;
-
-import libcore.io.ErrnoException;
-import libcore.io.Libcore;
-
-import java.io.File;
-
-/**
- * Provides access to the Dalvik "zygote" feature, which allows a VM instance to
- * be partially initialized and then fork()'d from the partially initialized
- * state.
- *
- * @hide
- */
-public class Zygote {
-    /*
-     * Bit values for "debugFlags" argument.  The definitions are duplicated
-     * in the native code.
-     */
-    /** enable debugging over JDWP */
-    public static final int DEBUG_ENABLE_DEBUGGER   = 1;
-    /** enable JNI checks */
-    public static final int DEBUG_ENABLE_CHECKJNI   = 1 << 1;
-    /** enable Java programming language "assert" statements */
-    public static final int DEBUG_ENABLE_ASSERT     = 1 << 2;
-    /** disable the JIT compiler */
-    public static final int DEBUG_ENABLE_SAFEMODE   = 1 << 3;
-    /** Enable logging of third-party JNI activity. */
-    public static final int DEBUG_ENABLE_JNI_LOGGING = 1 << 4;
-
-    /** No external storage should be mounted. */
-    public static final int MOUNT_EXTERNAL_NONE = 0;
-    /** Single-user external storage should be mounted. */
-    public static final int MOUNT_EXTERNAL_SINGLEUSER = 1;
-    /** Multi-user external storage should be mounted. */
-    public static final int MOUNT_EXTERNAL_MULTIUSER = 2;
-    /** All multi-user external storage should be mounted. */
-    public static final int MOUNT_EXTERNAL_MULTIUSER_ALL = 3;
-
-    private Zygote() {}
-
-    private static void preFork() {
-        Daemons.stop();
-        waitUntilAllThreadsStopped();
-    }
-
-    /**
-     * We must not fork until we're single-threaded again. Wait until /proc shows we're
-     * down to just one thread.
-     */
-    private static void waitUntilAllThreadsStopped() {
-        File tasks = new File("/proc/self/task");
-        while (tasks.list().length > 1) {
-            try {
-                // Experimentally, booting and playing about with a stingray, I never saw us
-                // go round this loop more than once with a 10ms sleep.
-                Thread.sleep(10);
-            } catch (InterruptedException ignored) {
-            }
-        }
-    }
-
-    private static void postFork() {
-        Daemons.start();
-    }
-
-    /**
-     * Forks a new VM instance.  The current VM must have been started
-     * with the -Xzygote flag. <b>NOTE: new instance keeps all
-     * root capabilities. The new process is expected to call capset()</b>.
-     *
-     * @param uid the UNIX uid that the new process should setuid() to after
-     * fork()ing and and before spawning any threads.
-     * @param gid the UNIX gid that the new process should setgid() to after
-     * fork()ing and and before spawning any threads.
-     * @param gids null-ok; a list of UNIX gids that the new process should
-     * setgroups() to after fork and before spawning any threads.
-     * @param debugFlags bit flags that enable debugging features.
-     * @param rlimits null-ok an array of rlimit tuples, with the second
-     * dimension having a length of 3 and representing
-     * (resource, rlim_cur, rlim_max). These are set via the posix
-     * setrlimit(2) call.
-     * @param seInfo null-ok a string specifying SELinux information for
-     * the new process.
-     * @param niceName null-ok a string specifying the process name.
-     * @param fdsToClose an array of ints, holding one or more POSIX
-     * file descriptor numbers that are to be closed by the child
-     * (and replaced by /dev/null) after forking.  An integer value
-     * of -1 in any entry in the array means "ignore this one".
-     *
-     * @return 0 if this is the child, pid of the child
-     * if this is the parent, or -1 on error.
-     */
-    public static int forkAndSpecialize(int uid, int gid, int[] gids, int debugFlags,
-          int[][] rlimits, int mountExternal, String seInfo, String niceName, int[] fdsToClose) {
-        preFork();
-        int pid = nativeForkAndSpecialize(
-                  uid, gid, gids, debugFlags, rlimits, mountExternal, seInfo, niceName, fdsToClose);
-        postFork();
-        return pid;
-    }
-
-    native public static int nativeForkAndSpecialize(int uid, int gid, int[] gids, int debugFlags,
-          int[][] rlimits, int mountExternal, String seInfo, String niceName, int[] fdsToClose);
-
-    /**
-     * Special method to start the system server process. In addition to the
-     * common actions performed in forkAndSpecialize, the pid of the child
-     * process is recorded such that the death of the child process will cause
-     * zygote to exit.
-     *
-     * @param uid the UNIX uid that the new process should setuid() to after
-     * fork()ing and and before spawning any threads.
-     * @param gid the UNIX gid that the new process should setgid() to after
-     * fork()ing and and before spawning any threads.
-     * @param gids null-ok; a list of UNIX gids that the new process should
-     * setgroups() to after fork and before spawning any threads.
-     * @param debugFlags bit flags that enable debugging features.
-     * @param rlimits null-ok an array of rlimit tuples, with the second
-     * dimension having a length of 3 and representing
-     * (resource, rlim_cur, rlim_max). These are set via the posix
-     * setrlimit(2) call.
-     * @param permittedCapabilities argument for setcap()
-     * @param effectiveCapabilities argument for setcap()
-     *
-     * @return 0 if this is the child, pid of the child
-     * if this is the parent, or -1 on error.
-     */
-    public static int forkSystemServer(int uid, int gid, int[] gids, int debugFlags,
-            int[][] rlimits, long permittedCapabilities, long effectiveCapabilities) {
-        preFork();
-        int pid = nativeForkSystemServer(
-                uid, gid, gids, debugFlags, rlimits, permittedCapabilities, effectiveCapabilities);
-        postFork();
-        return pid;
-    }
-
-    native public static int nativeForkSystemServer(int uid, int gid, int[] gids, int debugFlags,
-            int[][] rlimits, long permittedCapabilities, long effectiveCapabilities);
-
-    /**
-     * Executes "/system/bin/sh -c &lt;command&gt;" using the exec() system call.
-     * This method throws a runtime exception if exec() failed, otherwise, this
-     * method never returns.
-     *
-     * @param command The shell command to execute.
-     */
-    public static void execShell(String command) {
-        String[] args = { "/system/bin/sh", "-c", command };
-        try {
-            Libcore.os.execv(args[0], args);
-        } catch (ErrnoException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    /**
-     * Appends quotes shell arguments to the specified string builder.
-     * The arguments are quoted using single-quotes, escaped if necessary,
-     * prefixed with a space, and appended to the command.
-     *
-     * @param command A string builder for the shell command being constructed.
-     * @param args An array of argument strings to be quoted and appended to the command.
-     * @see #execShell(String)
-     */
-    public static void appendQuotedShellArgs(StringBuilder command, String[] args) {
-        for (String arg : args) {
-            command.append(" '").append(arg.replace("'", "'\\''")).append("'");
-        }
-    }
-}
diff --git a/dalvik/src/main/java/dalvik/system/ZygoteHooks.java b/dalvik/src/main/java/dalvik/system/ZygoteHooks.java
new file mode 100644
index 0000000..fa4f392
--- /dev/null
+++ b/dalvik/src/main/java/dalvik/system/ZygoteHooks.java
@@ -0,0 +1,78 @@
+/*
+ * 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
+ *
+ *      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 dalvik.system;
+
+import java.io.File;
+
+/**
+ * Provides hooks for the zygote to call back into the runtime to perform
+ * parent or child specific initialization..
+ *
+ * @hide
+ */
+public final class ZygoteHooks {
+    private long token;
+
+    /**
+     * Called by the zygote prior to every fork. Each call to {@code preFork}
+     * is followed by a matching call to {@link #postForkChild(int)} on the child
+     * process and {@link #postForkCommon()} on both the parent and the child
+     * process. {@code postForkCommon} is called after {@code postForkChild} in
+     * the child process.
+     */
+    public void preFork() {
+        Daemons.stop();
+        waitUntilAllThreadsStopped();
+        token = nativePreFork();
+    }
+
+    /**
+     * Called by the zygote in the child process after every fork. The debug
+     * flags from {@code debugFlags} are applied to the child process.
+     */
+    public void postForkChild(int debugFlags) {
+        nativePostForkChild(token, debugFlags);
+    }
+
+    /**
+     * Called by the zygote in both the parent and child processes after
+     * every fork. In the child process, this method is called after
+     * {@code postForkChild}.
+     */
+    public void postForkCommon() {
+        Daemons.start();
+    }
+
+    private static native long nativePreFork();
+    private static native void nativePostForkChild(long token, int debugFlags);
+
+    /**
+     * We must not fork until we're single-threaded again. Wait until /proc shows we're
+     * down to just one thread.
+     */
+    private static void waitUntilAllThreadsStopped() {
+        File tasks = new File("/proc/self/task");
+        while (tasks.list().length > 1) {
+            try {
+                // Experimentally, booting and playing about with a stingray, I never saw us
+                // go round this loop more than once with a 10ms sleep.
+                Thread.sleep(10);
+            } catch (InterruptedException ignored) {
+            }
+        }
+    }
+}