/*
* This file is part of the Jikes RVM project (http://jikesrvm.org).
*
* This file is licensed to You under the Common Public License (CPL);
* You may not use this file except in compliance with the License. You
* may obtain a copy of the License at
*
* http://www.opensource.org/licenses/cpl1.0.php
*
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership.
*/
package org.jikesrvm.runtime;
import org.jikesrvm.VM;
import org.jikesrvm.VM_SizeConstants;
import org.vmmagic.pragma.Inline;
import org.vmmagic.pragma.Uninterruptible;
import org.vmmagic.unboxed.Address;
import org.vmmagic.unboxed.Extent;
import org.vmmagic.unboxed.LocalAddress;
import org.vmmagic.unboxed.Offset;
import org.vmmagic.unboxed.Word;
/**
* Low level memory management functions.
*
* Note that this class is "uninterruptible" - calling its methods will never
* cause the current thread to yield the cpu to another thread (one that
* might cause a gc, for example).
*/
@Uninterruptible
public class VM_Memory implements VM_SizeConstants {
////////////////////////
// (1) Utilities for copying/filling/zeroing memory
////////////////////////
/**
* How many bytes is considered large enough to justify the transition to
* C code to use memcpy?
*/
private static final int NATIVE_THRESHOLD = 512;
private static final boolean USE_NATIVE = true;
/**
* Low level copy of len elements from src[srcPos] to dst[dstPos].
*
* Assumptions: <code> src != dst || (scrPos >= dstPos + 4) </code>
* and src and dst are 8Bit arrays.
* @param src the source array
* @param srcPos index in the source array to begin copy
* @param dst the destination array
* @param dstPos index in the destination array to being copy
* @param len number of array elements to copy
*/
@Inline
public static void arraycopy8Bit(Object src, int srcPos, Object dst, int dstPos, int len) {
if (USE_NATIVE && len > NATIVE_THRESHOLD) {
memcopy(VM_Magic.objectAsAddress(dst).plus(dstPos), VM_Magic.objectAsAddress(src).plus(srcPos), len);
} else {
if (len >= BYTES_IN_ADDRESS && (srcPos & (BYTES_IN_ADDRESS - 1)) == (dstPos & (BYTES_IN_ADDRESS - 1))) {
// relative alignment is the same
int byteStart = srcPos;
int wordStart = alignUp(srcPos, BYTES_IN_ADDRESS);
int wordEnd = alignDown(srcPos + len, BYTES_IN_ADDRESS);
int byteEnd = srcPos + len;
int startDiff = wordStart - byteStart;
int endDiff = byteEnd - wordEnd;
int wordLen = wordEnd - wordStart;
Address srcPtr = VM_Magic.objectAsAddress(src).plus(srcPos + startDiff);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus(dstPos + startDiff);
if (VM.BuildFor64Addr) {
switch (startDiff) {
case 7: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(-7)), Offset.fromIntSignExtend(-7));
case 6: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(-6)), Offset.fromIntSignExtend(-6));
case 5: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(-5)), Offset.fromIntSignExtend(-5));
case 4: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(-4)), Offset.fromIntSignExtend(-4));
case 3: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(-3)), Offset.fromIntSignExtend(-3));
case 2: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(-2)), Offset.fromIntSignExtend(-2));
case 1: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(-1)), Offset.fromIntSignExtend(-1));
}
} else {
switch (startDiff) {
case 3: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(-3)), Offset.fromIntSignExtend(-3));
case 2: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(-2)), Offset.fromIntSignExtend(-2));
case 1: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(-1)), Offset.fromIntSignExtend(-1));
}
}
Address endPtr = srcPtr.plus(wordLen);
while (srcPtr.LT(endPtr)) {
dstPtr.store(srcPtr.loadWord());
srcPtr = srcPtr.plus(BYTES_IN_ADDRESS);
dstPtr = dstPtr.plus(BYTES_IN_ADDRESS);
}
if (VM.BuildFor64Addr) {
switch (endDiff) {
case 7: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(6)), Offset.fromIntSignExtend(6));
case 6: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(5)), Offset.fromIntSignExtend(5));
case 5: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(4)), Offset.fromIntSignExtend(4));
case 4: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(3)), Offset.fromIntSignExtend(3));
case 3: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(2)), Offset.fromIntSignExtend(2));
case 2: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(1)), Offset.fromIntSignExtend(1));
case 1: dstPtr.store(srcPtr.loadByte());
}
} else {
switch (endDiff) {
case 3: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(2)), Offset.fromIntSignExtend(2));
case 2: dstPtr.store(srcPtr.loadByte(Offset.fromIntSignExtend(1)), Offset.fromIntSignExtend(1));
case 1: dstPtr.store(srcPtr.loadByte());
}
}
} else {
Address srcPtr = VM_Magic.objectAsAddress(src).plus(srcPos);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus(dstPos);
Address endPtr = srcPtr.plus(len);
while (srcPtr.LT(endPtr)) {
dstPtr.store(srcPtr.loadByte());
srcPtr = srcPtr.plus(1);
dstPtr = dstPtr.plus(1);
}
}
}
}
/**
* Low level copy of len elements from src[srcPos] to dst[dstPos].
*
* Assumption src != dst || (srcPos >= dstPos + 2).
*
* @param src the source array
* @param srcPos index in the source array to begin copy
* @param dst the destination array
* @param dstPos index in the destination array to being copy
* @param len number of array elements to copy
*/
@Inline
public static void arraycopy16Bit(Object src, int srcPos, Object dst, int dstPos, int len) {
if (USE_NATIVE && len > (NATIVE_THRESHOLD >> LOG_BYTES_IN_SHORT)) {
memcopy(VM_Magic.objectAsAddress(dst).plus(dstPos << LOG_BYTES_IN_SHORT),
VM_Magic.objectAsAddress(src).plus(srcPos << LOG_BYTES_IN_SHORT),
len << LOG_BYTES_IN_SHORT);
} else {
if (len >= (BYTES_IN_ADDRESS >>> LOG_BYTES_IN_SHORT) &&
(srcPos & ((BYTES_IN_ADDRESS - 1) >>> LOG_BYTES_IN_SHORT)) ==
(dstPos & ((BYTES_IN_ADDRESS - 1) >>> LOG_BYTES_IN_SHORT))) {
// relative alignment is the same
int byteStart = srcPos << LOG_BYTES_IN_SHORT;
int wordStart = alignUp(byteStart, BYTES_IN_ADDRESS);
int wordEnd = alignDown(byteStart + (len << LOG_BYTES_IN_SHORT), BYTES_IN_ADDRESS);
int byteEnd = byteStart + (len << LOG_BYTES_IN_SHORT);
int startDiff = wordStart - byteStart;
int endDiff = byteEnd - wordEnd;
int wordLen = wordEnd - wordStart;
Address srcPtr = VM_Magic.objectAsAddress(src).plus((srcPos << LOG_BYTES_IN_SHORT) + startDiff);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus((dstPos << LOG_BYTES_IN_SHORT) + startDiff);
if (VM.BuildFor64Addr) {
switch (startDiff) {
case 6: dstPtr.store(srcPtr.loadChar(Offset.fromIntSignExtend(-6)), Offset.fromIntSignExtend(-6));
case 4: dstPtr.store(srcPtr.loadChar(Offset.fromIntSignExtend(-4)), Offset.fromIntSignExtend(-4));
case 2: dstPtr.store(srcPtr.loadChar(Offset.fromIntSignExtend(-2)), Offset.fromIntSignExtend(-2));
}
} else {
if (startDiff == 2) {
dstPtr.store(srcPtr.loadChar(Offset.fromIntSignExtend(-2)), Offset.fromIntSignExtend(-2));
}
}
Address endPtr = srcPtr.plus(wordLen);
while (srcPtr.LT(endPtr)) {
dstPtr.store(srcPtr.loadWord());
srcPtr = srcPtr.plus(BYTES_IN_ADDRESS);
dstPtr = dstPtr.plus(BYTES_IN_ADDRESS);
}
if (VM.BuildFor64Addr) {
switch (endDiff) {
case 6: dstPtr.store(srcPtr.loadChar(Offset.fromIntSignExtend(4)), Offset.fromIntSignExtend(4));
case 4: dstPtr.store(srcPtr.loadChar(Offset.fromIntSignExtend(2)), Offset.fromIntSignExtend(2));
case 2: dstPtr.store(srcPtr.loadChar());
}
} else {
if (endDiff == 2) {
dstPtr.store(srcPtr.loadChar());
}
}
} else {
Address srcPtr = VM_Magic.objectAsAddress(src).plus(srcPos << LOG_BYTES_IN_CHAR);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus(dstPos << LOG_BYTES_IN_CHAR);
Address endPtr = srcPtr.plus(len << LOG_BYTES_IN_CHAR);
while (srcPtr.LT(endPtr)) {
dstPtr.store(srcPtr.loadChar());
srcPtr = srcPtr.plus(2);
dstPtr = dstPtr.plus(2);
}
}
}
}
/**
* Low level copy of <code>len</code> elements from <code>src[srcPos]</code> to <code>dst[dstPos]</code>.
*
* Assumption: <code>src != dst || (srcPos >= dstPos)</code> and element size is 4 bytes.
*
* @param src the source array
* @param srcIdx index in the source array to begin copy
* @param dst the destination array
* @param dstIdx index in the destination array to being copy
* @param len number of array elements to copy
*/
@Inline
public static void arraycopy32Bit(Object src, int srcIdx, Object dst, int dstIdx, int len) {
Address srcPtr = VM_Magic.objectAsAddress(src).plus(srcIdx << LOG_BYTES_IN_INT);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus(dstIdx << LOG_BYTES_IN_INT);
int copyBytes = len << LOG_BYTES_IN_INT;
if (USE_NATIVE && len > (NATIVE_THRESHOLD >> LOG_BYTES_IN_INT)) {
memcopy(dstPtr, srcPtr, copyBytes);
} else {
// The elements of int[] and float[] are always 32 bit aligned
// therefore we can do 32 bit load/stores without worrying about alignment.
// TODO: do measurements to determine if on PPC it is a good idea to check
// for compatible doubleword alignment and handle that case via the FPRs in 64 bit chunks.
// Unclear if this will be a big enough win to justify checking because for big copies
// we are going into memcopy anyways and that will be faster than anything we do here.
Address endPtr = srcPtr.plus(copyBytes);
while (srcPtr.LT(endPtr)) {
dstPtr.store(srcPtr.loadInt());
srcPtr = srcPtr.plus(4);
dstPtr = dstPtr.plus(4);
}
}
}
/**
* Low level copy of <code>len</code> elements from <code>src[srcPos]</code> to <code>dst[dstPos]</code>.
*
* Assumption <code>src != dst || (srcPos >= dstPos)</code> and element size is 8 bytes.
*
* @param src the source array
* @param srcIdx index in the source array to begin copy
* @param dst the destination array
* @param dstIdx index in the destination array to being copy
* @param len number of array elements to copy
*/
@Inline
public static void arraycopy64Bit(Object src, int srcIdx, Object dst, int dstIdx, int len) {
Address srcPtr = VM_Magic.objectAsAddress(src).plus(srcIdx << LOG_BYTES_IN_DOUBLE);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus(dstIdx << LOG_BYTES_IN_DOUBLE);
int copyBytes = len << LOG_BYTES_IN_DOUBLE;
if (USE_NATIVE && len > (NATIVE_THRESHOLD >> LOG_BYTES_IN_DOUBLE)) {
memcopy(dstPtr, srcPtr, copyBytes);
} else {
// The elements of long[] and double[] are always doubleword aligned
// therefore we can do 64 bit load/stores without worrying about alignment.
Address endPtr = srcPtr.plus(copyBytes);
while (srcPtr.LT(endPtr)) {
// We generate abysmal code on IA32 if we try to use the FP registers,
// so use the gprs instead even though it results in more instructions.
if (VM.BuildForIA32) {
dstPtr.store(srcPtr.loadInt());
dstPtr.store(srcPtr.loadInt(Offset.fromIntSignExtend(4)), Offset.fromIntSignExtend(4));
} else {
dstPtr.store(srcPtr.loadDouble());
}
srcPtr = srcPtr.plus(8);
dstPtr = dstPtr.plus(8);
}
}
}
/**
* Copy numbytes from src to dst.
* Assumption either the ranges are non overlapping, or src >= dst + 4.
* Also, src and dst are 4 byte aligned and numBytes is a multiple of 4.
* @param dst the destination addr
* @param src the source addr
* @param numBytes the number of bytes top copy
*/
@Inline
public static void aligned32Copy(Address dst, Address src, Offset numBytes) {
if (USE_NATIVE && numBytes.sGT(Offset.fromIntSignExtend(NATIVE_THRESHOLD))) {
memcopy(dst, src, numBytes.toWord().toExtent());
} else {
if (VM.BuildFor64Addr) {
Word wordMask = Word.one().lsh(LOG_BYTES_IN_ADDRESS).minus(Word.one());
Word srcAlignment = src.toWord().and(wordMask);
if (srcAlignment.EQ(dst.toWord().and(wordMask))) {
Offset i = Offset.zero();
if (srcAlignment.EQ(Word.fromIntZeroExtend(BYTES_IN_INT))) {
dst.store(src.loadInt(i), i);
i = i.plus(BYTES_IN_INT);
}
Word endAlignment = srcAlignment.plus(numBytes).and(Word.fromIntSignExtend(BYTES_IN_ADDRESS - 1));
numBytes = numBytes.minus(endAlignment.toOffset());
for (; i.sLT(numBytes); i = i.plus(BYTES_IN_ADDRESS)) {
dst.store(src.loadWord(i), i);
}
if (!endAlignment.isZero()) {
dst.store(src.loadInt(i), i);
}
return;
}
}
//normal case: 32 bit or (64 bit not aligned)
for (Offset i = Offset.zero(); i.sLT(numBytes); i = i.plus(BYTES_IN_INT)) {
dst.store(src.loadInt(i), i);
}
}
}
@Inline
public static void aligned32Copy(Address dst, Address src, int numBytes) {
aligned32Copy(dst, src, Offset.fromIntSignExtend(numBytes));
}
/**
* Copy numbytes from src to dst.
* Assumption either the ranges are non overlapping, or src >= dst + BYTES_IN_ADDRESS.
* Also, src and dst are word aligned and numBytes is a multiple of BYTES_IN_ADDRESS.
* @param dst the destination addr
* @param src the source addr
* @param numBytes the number of bytes top copy
*/
@Inline
public static void alignedWordCopy(Address dst, Address src, int numBytes) {
if (USE_NATIVE && numBytes > NATIVE_THRESHOLD) {
memcopy(dst, src, numBytes);
} else {
internalAlignedWordCopy(dst, src, numBytes);
}
}
/**
* Copy <code>numbytes</code> from <code>src</code> to <code>dst</code>.
* Assumption either the ranges are non overlapping, or <code>src >= dst + BYTES_IN_ADDRESS</code>.
* @param dst The destination addr
* @param src The source addr
* @param numBytes The number of bytes to copy
*/
@Inline
private static void internalAlignedWordCopy(Address dst, Address src, int numBytes) {
Address end = src.plus(numBytes);
while (src.LT(end)) {
dst.store(src.loadWord());
src = src.plus(BYTES_IN_ADDRESS);
dst = dst.plus(BYTES_IN_ADDRESS);
}
}
/**
* Copy a region of memory.
* @param dst Destination address
* @param src Source address
* @param cnt Number of bytes to copy
* Assumption: source and destination regions do not overlap
*/
public static void memcopy(Address dst, Address src, Extent cnt) {
VM_SysCall.sysCall.sysCopy(dst, src, cnt);
}
public static void memcopy(Address dst, Address src, int cnt) {
VM_SysCall.sysCall.sysCopy(dst, src, Extent.fromIntSignExtend(cnt));
}
/**
* Copy a region of local memory.
* @param dst Destination address
* @param src Source address
* @param cnt Number of bytes to copy
* Assumption: source and destination regions do not overlap
*/
public static void memcopy(LocalAddress dst, LocalAddress src, Extent cnt) {
VM_SysCall.sysCall.sysCopy(VM_Magic.localAddressAsAddress(dst),
VM_Magic.localAddressAsAddress(src),
cnt);
}
public static void memcopy(LocalAddress dst, LocalAddress src, int cnt) {
VM_SysCall.sysCall.sysCopy(VM_Magic.localAddressAsAddress(dst),
VM_Magic.localAddressAsAddress(src),
Extent.fromIntSignExtend(cnt));
}
/**
* Zero a region of memory.
* @param start of address range (inclusive)
* @param len extent to zero.
*/
public static void zero(Address start, Extent len) {
VM_SysCall.sysCall.sysZero(start, len);
}
/**
* Zero a range of pages of memory.
* @param start Starting address (must be a page address)
* @param len Number of bytes (must be multiple of page size)
*/
public static void zeroPages(Address start, int len) {
if (VM.VerifyAssertions) VM._assert(isPageAligned(start) && isPageMultiple(len));
VM_SysCall.sysCall.sysZeroPages(start, len);
}
////////////////////////
// (2) Cache management
////////////////////////
/**
* Synchronize a region of memory: force data in dcache to be written out to main
* memory so that it will be seen by icache when instructions are fetched back.
* @param address Start of address range
* @param size Size of address range (bytes)
*/
public static void sync(Address address, int size) {
VM_SysCall.sysCall.sysSyncCache(address, size);
}
////////////////////////
// (3) MMap
////////////////////////
// constants for protection and mapping calls
public static final int PROT_NONE = 0;
public static final int PROT_READ = 1;
public static final int PROT_WRITE = 2;
public static final int PROT_EXEC = 4;
public static final int MAP_PRIVATE = 2;
public static final int MAP_FIXED = (VM.BuildForLinux) ? 16 : (VM.BuildForOsx) ? 16 : (VM.BuildForSolaris) ? 0x10 :256;
public static final int MAP_ANONYMOUS = (VM.BuildForLinux) ? 32 : (VM.BuildForOsx) ? 0x1000 : (VM.BuildForSolaris) ? 0x100 : 16;
public static boolean isPageMultiple(int val) {
int pagesizeMask = getPagesize() - 1;
return ((val & pagesizeMask) == 0);
}
public static boolean isPageMultiple(Extent val) {
Word pagesizeMask = Word.fromIntZeroExtend(getPagesize() - 1);
return val.toWord().and(pagesizeMask).isZero();
}
public static boolean isPageMultiple(Offset val) {
Word pagesizeMask = Word.fromIntZeroExtend(getPagesize() - 1);
return val.toWord().and(pagesizeMask).isZero();
}
public static boolean isPageAligned(Address addr) {
Word pagesizeMask = Word.fromIntZeroExtend(getPagesize() - 1);
return addr.toWord().and(pagesizeMask).isZero();
}
/**
* Do generic mmap non-file memory mapping call
* @param address Start of address range (Address)
* @param size Size of address range
* @param prot Protection (int)
* @param flags (int)
* @return Address (of region) if successful; errno (1 to 127) otherwise
*/
public static Address mmap(Address address, Extent size, int prot, int flags) {
if (VM.VerifyAssertions) {
VM._assert(isPageAligned(address) && isPageMultiple(size));
}
return VM_SysCall.sysCall.sysMMapErrno(address, size, prot, flags, -1, Offset.zero());
}
/**
* Do mmap demand zero fixed address memory mapping call
* @param address Start of address range
* @param size Size of address range
* @return Address (of region) if successful; errno (1 to 127) otherwise
*/
public static Address dzmmap(Address address, Extent size) {
if (VM.VerifyAssertions) {
VM._assert(isPageAligned(address) && isPageMultiple(size));
}
int prot = PROT_READ | PROT_WRITE | PROT_EXEC;
int flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED;
return mmap(address, size, prot, flags);
}
/**
* Do mprotect system call
* @param address Start of address range (Address)
* @param size Size of address range
* @param prot Protection (int)
* @return true iff success
*/
public static boolean mprotect(Address address, Extent size, int prot) {
if (VM.VerifyAssertions) {
VM._assert(isPageAligned(address) && isPageMultiple(size));
}
return VM_SysCall.sysCall.sysMProtect(address, size, prot) == 0;
}
private static int pagesize = -1;
private static int pagesizeLog = -1;
/**
* Do getpagesize call
* @return page size
*/
public static int getPagesize() {
if (pagesize == -1) {
pagesize = VM_SysCall.sysCall.sysGetPageSize();
pagesizeLog = -1;
int temp = pagesize;
while (temp > 0) {
temp >>>= 1;
pagesizeLog++;
}
if (VM.VerifyAssertions) VM._assert((1 << pagesizeLog) == pagesize);
}
return pagesize;
}
public static void dumpMemory(Address start, int beforeBytes, int afterBytes) {
beforeBytes = alignDown(beforeBytes, BYTES_IN_ADDRESS);
afterBytes = alignUp(afterBytes, BYTES_IN_ADDRESS);
VM.sysWrite("---- Dumping memory from ");
VM.sysWrite(start.minus(beforeBytes));
VM.sysWrite(" to ");
VM.sysWrite(start.plus(afterBytes));
VM.sysWrite(" ----\n");
for (int i = -beforeBytes; i < afterBytes; i += BYTES_IN_ADDRESS) {
VM.sysWrite(i, ": ");
VM.sysWrite(start.plus(i));
Word value = start.plus(i).loadWord();
VM.sysWriteln(" ", value);
}
}
@Inline
public static Address alignUp(Address address, int alignment) {
return address.plus(alignment - 1).toWord().and(Word.fromIntSignExtend(~(alignment - 1))).toAddress();
}
@Inline
public static Address alignDown(Address address, int alignment) {
return address.toWord().and(Word.fromIntSignExtend(~(alignment - 1))).toAddress();
}
// These versions are here to accommodate the boot image writer
@Inline
public static int alignUp(int address, int alignment) {
return ((address + alignment - 1) & ~(alignment - 1));
}
@Inline
public static int alignDown(int address, int alignment) {
return (address & ~(alignment - 1));
}
}