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Merge "Zygote: Poll with timeout for pid"

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Treehugger Robot
2017-07-20 05:25:24 +00:00
committed by Gerrit Code Review
parent d27a6d62c6 3fbde346ad
commit 89d119abe6
1 changed files with 57 additions and 9 deletions
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66
core/java/com/android/internal/os/ZygoteConnection.java
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@@ -18,6 +18,7 @@ package com.android.internal.os;
import static android.system.OsConstants.F_SETFD;
import static android.system.OsConstants.O_CLOEXEC;
import static android.system.OsConstants.POLLIN;
import static android.system.OsConstants.STDERR_FILENO;
import static android.system.OsConstants.STDIN_FILENO;
import static android.system.OsConstants.STDOUT_FILENO;
@@ -31,13 +32,14 @@ import android.os.SystemProperties;
import android.os.Trace;
import android.system.ErrnoException;
import android.system.Os;
import android.system.StructPollfd;
import android.util.Log;
import dalvik.system.VMRuntime;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
@@ -807,17 +809,63 @@ class ZygoteConnection {
boolean usingWrapper = false;
if (pipeFd != null && pid > 0) {
DataInputStream is = new DataInputStream(new FileInputStream(pipeFd));
int innerPid = -1;
try {
innerPid = is.readInt();
} catch (IOException ex) {
Log.w(TAG, "Error reading pid from wrapped process, child may have died", ex);
} finally {
try {
is.close();
} catch (IOException ex) {
// Do a busy loop here. We can't guarantee that a failure (and thus an exception
// bail) happens in a timely manner.
//
// We'll wait up to five seconds. This should give enough time for the fork to go
// through, but not to trigger the watchdog in the system server.
final int SLEEP_IN_MS = 5000;
final int BYTES_REQUIRED = 4; // Bytes in an int.
StructPollfd fds[] = new StructPollfd[] {
new StructPollfd()
};
byte data[] = new byte[BYTES_REQUIRED];
int remainingSleepTime = SLEEP_IN_MS;
int dataIndex = 0;
long startTime = System.nanoTime();
while (dataIndex < data.length && remainingSleepTime > 0) {
fds[0].fd = pipeFd;
fds[0].events = (short) POLLIN;
fds[0].revents = 0;
fds[0].userData = null;
int res = android.system.Os.poll(fds, remainingSleepTime);
long endTime = System.nanoTime();
remainingSleepTime = SLEEP_IN_MS - (int)((endTime - startTime) / 1000000l);
if (res > 0) {
if ((fds[0].revents & POLLIN) != 0) {
// Only read one byte, so as not to block.
int readBytes = android.system.Os.read(pipeFd, data, dataIndex, 1);
if (readBytes < 0) {
throw new RuntimeException("Some error");
}
dataIndex += readBytes;
} else {
// Error case. revents should contain one of the error bits.
break;
}
} else if (res == 0) {
Log.w(TAG, "Timed out waiting for child.");
}
}
if (dataIndex == data.length) {
DataInputStream is = new DataInputStream(new ByteArrayInputStream(data));
innerPid = is.readInt();
}
if (innerPid == -1) {
Log.w(TAG, "Error reading pid from wrapped process, child may have died");
}
} catch (Exception ex) {
Log.w(TAG, "Error reading pid from wrapped process, child may have died", ex);
}
// Ensure that the pid reported by the wrapped process is either the