Don't round size to page size. Ashmem will do this internally as needed.

2 files changed, 9 insertions, 12 deletions

diff --git a/core/java/android/os/MemoryFile.java b/core/java/android/os/MemoryFile.java
index 03542dd..9742b05 100644
--- a/core/java/android/os/MemoryFile.java
+++ b/core/java/android/os/MemoryFile.java
@@ -52,7 +52,7 @@ public class MemoryFile
     private static native void native_write(FileDescriptor fd, int address, byte[] buffer,
             int srcOffset, int destOffset, int count, boolean isUnpinned) throws IOException;
     private static native void native_pin(FileDescriptor fd, boolean pin) throws IOException;
-    private static native int native_get_mapped_size(FileDescriptor fd) throws IOException;
+    private static native int native_get_size(FileDescriptor fd) throws IOException;
 
     private FileDescriptor mFD;        // ashmem file descriptor
     private int mAddress;   // address of ashmem memory
@@ -300,20 +300,19 @@ public class MemoryFile
      * @hide
      */
     public static boolean isMemoryFile(FileDescriptor fd) throws IOException {
-        return (native_get_mapped_size(fd) >= 0);
+        return (native_get_size(fd) >= 0);
     }
 
     /**
-     * Returns the size of the memory file, rounded up to a page boundary, that
-     * the file descriptor refers to, or -1 if the file descriptor does not
-     * refer to a memory file.
+     * Returns the size of the memory file that the file descriptor refers to,
+     * or -1 if the file descriptor does not refer to a memory file.
      *
      * @throws IOException If <code>fd</code> is not a valid file descriptor.
      *
      * @hide
      */
-    public static int getMappedSize(FileDescriptor fd) throws IOException {
-        return native_get_mapped_size(fd);
+    public static int getSize(FileDescriptor fd) throws IOException {
+        return native_get_size(fd);
     }
 
     /**
diff --git a/core/jni/android_os_MemoryFile.cpp b/core/jni/android_os_MemoryFile.cpp
index 1ae3ec7..ee8d836 100644
--- a/core/jni/android_os_MemoryFile.cpp
+++ b/core/jni/android_os_MemoryFile.cpp
@@ -30,8 +30,6 @@ static jobject android_os_MemoryFile_open(JNIEnv* env, jobject clazz, jstring na
 {
     const char* namestr = (name ? env->GetStringUTFChars(name, NULL) : NULL);
 
-    // round up length to page boundary
-    length = (((length - 1) / getpagesize()) + 1) * getpagesize();
     int result = ashmem_create_region(namestr, length);
 
     if (name)
@@ -118,7 +116,7 @@ static void android_os_MemoryFile_pin(JNIEnv* env, jobject clazz, jobject fileDe
     }
 }
 
-static jint android_os_MemoryFile_get_mapped_size(JNIEnv* env, jobject clazz,
+static jint android_os_MemoryFile_get_size(JNIEnv* env, jobject clazz,
         jobject fileDescriptor) {
     int fd = jniGetFDFromFileDescriptor(env, fileDescriptor);
     // Use ASHMEM_GET_SIZE to find out if the fd refers to an ashmem region.
@@ -146,8 +144,8 @@ static const JNINativeMethod methods[] = {
     {"native_read",  "(Ljava/io/FileDescriptor;I[BIIIZ)I", (void*)android_os_MemoryFile_read},
     {"native_write", "(Ljava/io/FileDescriptor;I[BIIIZ)V", (void*)android_os_MemoryFile_write},
     {"native_pin",   "(Ljava/io/FileDescriptor;Z)V", (void*)android_os_MemoryFile_pin},
-    {"native_get_mapped_size", "(Ljava/io/FileDescriptor;)I",
-            (void*)android_os_MemoryFile_get_mapped_size}
+    {"native_get_size", "(Ljava/io/FileDescriptor;)I",
+            (void*)android_os_MemoryFile_get_size}
 };
 
 static const char* const kClassPathName = "android/os/MemoryFile";