1.1 --- a/src/share/vm/prims/jvm.cpp Fri Nov 30 12:05:39 2018 +0000
1.2 +++ b/src/share/vm/prims/jvm.cpp Wed Dec 05 11:22:21 2018 +0000
1.3 @@ -759,6 +759,79 @@
1.4 JVM_END
1.5
1.6
1.7 +// java.nio.Bits ///////////////////////////////////////////////////////////////
1.8 +
1.9 +#define MAX_OBJECT_SIZE \
1.10 + ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
1.11 + + ((julong)max_jint * sizeof(double)) )
1.12 +
1.13 +static inline jlong field_offset_to_byte_offset(jlong field_offset) {
1.14 + return field_offset;
1.15 +}
1.16 +
1.17 +static inline void assert_field_offset_sane(oop p, jlong field_offset) {
1.18 +#ifdef ASSERT
1.19 + jlong byte_offset = field_offset_to_byte_offset(field_offset);
1.20 +
1.21 + if (p != NULL) {
1.22 + assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
1.23 + if (byte_offset == (jint)byte_offset) {
1.24 + void* ptr_plus_disp = (address)p + byte_offset;
1.25 + assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
1.26 + "raw [ptr+disp] must be consistent with oop::field_base");
1.27 + }
1.28 + jlong p_size = HeapWordSize * (jlong)(p->size());
1.29 + assert(byte_offset < p_size, err_msg("Unsafe access: offset " INT64_FORMAT
1.30 + " > object's size " INT64_FORMAT,
1.31 + (int64_t)byte_offset, (int64_t)p_size));
1.32 + }
1.33 +#endif
1.34 +}
1.35 +
1.36 +static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
1.37 + assert_field_offset_sane(p, field_offset);
1.38 + jlong byte_offset = field_offset_to_byte_offset(field_offset);
1.39 +
1.40 + if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
1.41 + return (address)p + (jint) byte_offset;
1.42 + } else {
1.43 + return (address)p + byte_offset;
1.44 + }
1.45 +}
1.46 +
1.47 +// This function is a leaf since if the source and destination are both in native memory
1.48 +// the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
1.49 +// If either source or destination (or both) are on the heap, the function will enter VM using
1.50 +// JVM_ENTRY_FROM_LEAF
1.51 +JVM_LEAF(void, JVM_CopySwapMemory(JNIEnv *env, jobject srcObj, jlong srcOffset,
1.52 + jobject dstObj, jlong dstOffset, jlong size,
1.53 + jlong elemSize)) {
1.54 +
1.55 + size_t sz = (size_t)size;
1.56 + size_t esz = (size_t)elemSize;
1.57 +
1.58 + if (srcObj == NULL && dstObj == NULL) {
1.59 + // Both src & dst are in native memory
1.60 + address src = (address)srcOffset;
1.61 + address dst = (address)dstOffset;
1.62 +
1.63 + Copy::conjoint_swap(src, dst, sz, esz);
1.64 + } else {
1.65 + // At least one of src/dst are on heap, transition to VM to access raw pointers
1.66 +
1.67 + JVM_ENTRY_FROM_LEAF(env, void, JVM_CopySwapMemory) {
1.68 + oop srcp = JNIHandles::resolve(srcObj);
1.69 + oop dstp = JNIHandles::resolve(dstObj);
1.70 +
1.71 + address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
1.72 + address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
1.73 +
1.74 + Copy::conjoint_swap(src, dst, sz, esz);
1.75 + } JVM_END
1.76 + }
1.77 +} JVM_END
1.78 +
1.79 +
1.80 // Misc. class handling ///////////////////////////////////////////////////////////
1.81
1.82
