/**
* Allows access to an area of virtual memory.
*
* @param start the address of the start of the area to be mapped
* @param size the size, in bytes, of the area to be mapped
* @return <code>true</code> if successful, otherwise <code>false</code>
*/
public final boolean munprotect(Address start, int size) {
return org.jikesrvm.runtime.Memory.mprotect(
start,
Extent.fromIntZeroExtend(size),
org.jikesrvm.runtime.Memory.PROT_READ
| org.jikesrvm.runtime.Memory.PROT_WRITE
| org.jikesrvm.runtime.Memory.PROT_EXEC);
}
/**
* Demand zero mmaps an area of virtual memory.
*
* @param start the address of the start of the area to be mapped
* @param size the size, in bytes, of the area to be mapped
* @return 0 if successful, otherwise the system errno
*/
public final int dzmmap(Address start, int size) {
Address result = org.jikesrvm.runtime.Memory.dzmmap(start, Extent.fromIntZeroExtend(size));
if (result.EQ(start)) return 0;
if (result.GT(Address.fromIntZeroExtend(127))) {
VM.sysWrite("demand zero mmap with MAP_FIXED on ", start);
VM.sysWriteln(" returned some other address", result);
VM.sysFail("mmap with MAP_FIXED has unexpected behavior");
}
return result.toInt();
}
/**
* Logs the contents of an address and the surrounding memory to the error output.
*
* @param start the address of the memory to be dumped
* @param beforeBytes the number of bytes before the address to be included
* @param afterBytes the number of bytes after the address to be included
*/
public final void dumpMemory(Address start, int beforeBytes, int afterBytes) {
org.jikesrvm.runtime.Memory.dumpMemory(start, beforeBytes, afterBytes);
}
/**
* Zero a range of pages of memory.
*
* @param start Start of address range (must be a page address)
* @param len Length in bytes of range (must be multiple of page size)
*/
public final void zeroPages(Address start, int len) {
/* AJG: Add assertions to check conditions documented above. */
org.jikesrvm.runtime.Memory.zeroPages(start, len);
}
/**
* Zero a region of memory.
*
* @param start Start of address range (inclusive)
* @param len Length in bytes of range to zero Returned: nothing
*/
public final void zero(Address start, Extent len) {
org.jikesrvm.runtime.Memory.zero(start, len);
}
/**
* Protects access to an area of virtual memory.
*
* @param start the address of the start of the area to be mapped
* @param size the size, in bytes, of the area to be mapped
* @return <code>true</code> if successful, otherwise <code>false</code>
*/
public final boolean mprotect(Address start, int size) {
return org.jikesrvm.runtime.Memory.mprotect(
start, Extent.fromIntZeroExtend(size), org.jikesrvm.runtime.Memory.PROT_NONE);
}