Freezer: fix exception when parsing /proc/locks

The original code is based on /proc/locks manpage. Unfortunately, that
manpage is never correctly updated to include the new field for blocked
locks. The new code detects the extra field. As StringTokenizer is too
heavy, ProcFileReader is used for better performance.

Bug: 194756340
Test: FrameworksUtilTests com.android.internal.util.ProcFileReaderTest
Test: FrameworksCoreTests com.android.internal.os.ProcLocksReaderTest
Test: No /proc/locks parsing exception with blocked locks
Change-Id: I4c9763f9d3091f7d84d2e4b672d7e5cb78b33f59

1 files changed, 0 insertions, 42 deletions

diff --git a/core/java/android/os/Process.java b/core/java/android/os/Process.java
index 6bca336dae91..9f37c4877199 100644
--- a/core/java/android/os/Process.java
+++ b/core/java/android/os/Process.java
@@ -34,12 +34,9 @@ import dalvik.system.VMRuntime;
 
 import libcore.io.IoUtils;
 
-import java.io.BufferedReader;
 import java.io.FileDescriptor;
-import java.io.FileReader;
 import java.io.IOException;
 import java.util.Map;
-import java.util.StringTokenizer;
 import java.util.concurrent.TimeoutException;
 
 /**
@@ -1472,43 +1469,4 @@ public class Process {
     }
 
     private static native int nativePidFdOpen(int pid, int flags) throws ErrnoException;
-
-    /**
-     * Checks if a process corresponding to a specific pid owns any file locks.
-     * @param pid The process ID for which we want to know the existence of file locks.
-     * @return true If the process holds any file locks, false otherwise.
-     * @throws IOException if /proc/locks can't be accessed.
-     *
-     * @hide
-     */
-    public static boolean hasFileLocks(int pid) throws Exception {
-        BufferedReader br = null;
-
-        try {
-            br = new BufferedReader(new FileReader("/proc/locks"));
-            String line;
-
-            while ((line = br.readLine()) != null) {
-                StringTokenizer st = new StringTokenizer(line);
-
-                for (int i = 0; i < 5 && st.hasMoreTokens(); i++) {
-                    String str = st.nextToken();
-                    try {
-                        if (i == 4 && Integer.parseInt(str) == pid) {
-                            return true;
-                        }
-                    } catch (NumberFormatException nfe) {
-                        throw new Exception("Exception parsing /proc/locks at \" "
-                                + line +  " \", token #" + i);
-                    }
-                }
-            }
-
-            return false;
-        } finally {
-            if (br != null) {
-                br.close();
-            }
-        }
-    }
 }