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Commit 012ab8e9 authored by Daniel Colascione's avatar Daniel Colascione
Browse files

Mark common android.os.Parcel methods as FastNative 

Mark the marshaling functions for non-primitive parameters as being
@FastNative: they're all expected to complete quickly.

According to the table in CriticalNative.java, the difference between
a regular JNI call and a FastNative call is about 80ns, so this change
should shave about 160ns per non-primitive parameter off the latency
of a binder transaction. The actual savings will be greater as we also
use these Parcel methods to marshal and unmarshal complex objects like
PackageInfo sent as objects over Binder.

Bug: 142271139
Test: boots
Change-Id: I85c3ee8498640193b9c0777c8c5e7eb349c7b23c
parent ff3cf431

core/java/android/os/Parcel.java

+6 −0
Original line number Diff line number Diff line
@@ -305,8 +305,11 @@ public final class Parcel { 
    private static native void nativeWriteFloat(long nativePtr, float val);

    @FastNative

    private static native void nativeWriteDouble(long nativePtr, double val);

    @FastNative

    static native void nativeWriteString(long nativePtr, String val);

    @FastNative

    private static native void nativeWriteStrongBinder(long nativePtr, IBinder val);

    @FastNative

    private static native long nativeWriteFileDescriptor(long nativePtr, FileDescriptor val);



    private static native byte[] nativeCreateByteArray(long nativePtr);
@@ -320,8 +323,11 @@ public final class Parcel { 
    private static native float nativeReadFloat(long nativePtr);

    @CriticalNative

    private static native double nativeReadDouble(long nativePtr);

    @FastNative

    static native String nativeReadString(long nativePtr);

    @FastNative

    private static native IBinder nativeReadStrongBinder(long nativePtr);

    @FastNative

    private static native FileDescriptor nativeReadFileDescriptor(long nativePtr);



    private static native long nativeCreate();

core/jni/android_os_Parcel.cpp

+6 −0
Original line number Diff line number Diff line
@@ -721,8 +721,11 @@ static const JNINativeMethod gParcelMethods[] = { 
    {"nativeWriteFloat",          "(JF)V", (void*)android_os_Parcel_writeFloat},

    // @FastNative

    {"nativeWriteDouble",         "(JD)V", (void*)android_os_Parcel_writeDouble},

    // @FastNative

    {"nativeWriteString",         "(JLjava/lang/String;)V", (void*)android_os_Parcel_writeString},

    // @FastNative

    {"nativeWriteStrongBinder",   "(JLandroid/os/IBinder;)V", (void*)android_os_Parcel_writeStrongBinder},

    // @FastNative

    {"nativeWriteFileDescriptor", "(JLjava/io/FileDescriptor;)J", (void*)android_os_Parcel_writeFileDescriptor},



    {"nativeCreateByteArray",     "(J)[B", (void*)android_os_Parcel_createByteArray},
@@ -736,8 +739,11 @@ static const JNINativeMethod gParcelMethods[] = { 
    {"nativeReadFloat",           "(J)F", (void*)android_os_Parcel_readFloat},

    // @CriticalNative

    {"nativeReadDouble",          "(J)D", (void*)android_os_Parcel_readDouble},

    // @FastNative

    {"nativeReadString",          "(J)Ljava/lang/String;", (void*)android_os_Parcel_readString},

    // @FastNative

    {"nativeReadStrongBinder",    "(J)Landroid/os/IBinder;", (void*)android_os_Parcel_readStrongBinder},

    // @FastNative

    {"nativeReadFileDescriptor",  "(J)Ljava/io/FileDescriptor;", (void*)android_os_Parcel_readFileDescriptor},



    {"nativeCreate",              "()J", (void*)android_os_Parcel_create},

core/jni/android_util_Binder.cpp

+3 −0
Original line number Diff line number Diff line
@@ -697,6 +697,9 @@ BinderProxyNativeData* getBPNativeData(JNIEnv* env, jobject obj) { 
// same IBinder, and the original BinderProxy is still alive, return the same BinderProxy.

jobject javaObjectForIBinder(JNIEnv* env, const sp<IBinder>& val)

{

    // N.B. This function is called from a @FastNative JNI method, so don't take locks around

    // calls to Java code or block the calling thread for a long time for any reason.



    if (val == NULL) return NULL;



    if (val->checkSubclass(&gBinderOffsets)) {