C++ (Cpp) UnaccessedPageUnmapped Examples

Example #1

bool
ARMVMTranslationMap32Bit::ClearAccessedAndModified(VMArea* area, addr_t address,
	bool unmapIfUnaccessed, bool& _modified)
{
	ASSERT(address % B_PAGE_SIZE == 0);

	page_directory_entry* pd = fPagingStructures->pgdir_virt;

	TRACE("ARMVMTranslationMap32Bit::ClearAccessedAndModified(%#" B_PRIxADDR
		")\n", address);

	RecursiveLocker locker(fLock);

	int index = VADDR_TO_PDENT(address);
	if ((pd[index] & ARM_PDE_TYPE_MASK) == 0)
		return false;

	ThreadCPUPinner pinner(thread_get_current_thread());

	page_table_entry* pt = (page_table_entry*)fPageMapper->GetPageTableAt(
		pd[index] & ARM_PDE_ADDRESS_MASK);

	index = VADDR_TO_PTENT(address);

	// perform the deed
	page_table_entry oldEntry;

	if (unmapIfUnaccessed) {
		while (true) {
			oldEntry = pt[index];
			if ((oldEntry & ARM_PTE_TYPE_MASK) == 0) {
				// page mapping not valid
				return false;
			}
#if 0 //IRA
			if (oldEntry & ARM_PTE_ACCESSED) {
				// page was accessed -- just clear the flags
				oldEntry = ARMPagingMethod32Bit::ClearPageTableEntryFlags(
					&pt[index], ARM_PTE_ACCESSED | ARM_PTE_DIRTY);
				break;
			}
#endif
			// page hasn't been accessed -- unmap it
			if (ARMPagingMethod32Bit::TestAndSetPageTableEntry(&pt[index], 0,
					oldEntry) == oldEntry) {
				break;
			}

			// something changed -- check again
		}
	} else {
#if 0 //IRA
		oldEntry = ARMPagingMethod32Bit::ClearPageTableEntryFlags(&pt[index],
			ARM_PTE_ACCESSED | ARM_PTE_DIRTY);
#else
		oldEntry = pt[index];
#endif
	}

	pinner.Unlock();

	_modified = true /* (oldEntry & ARM_PTE_DIRTY) != 0 */; // XXX IRA

	if (true /*(oldEntry & ARM_PTE_ACCESSED) != 0*/) {
		// Note, that we only need to invalidate the address, if the
		// accessed flags was set, since only then the entry could have been
		// in any TLB.
		InvalidatePage(address);

		Flush();

		return true;
	}

	if (!unmapIfUnaccessed)
		return false;

	// We have unmapped the address. Do the "high level" stuff.

	fMapCount--;

	locker.Detach();
		// UnaccessedPageUnmapped() will unlock for us

	UnaccessedPageUnmapped(area,
		(oldEntry & ARM_PTE_ADDRESS_MASK) / B_PAGE_SIZE);

	return false;
}

Example #2

File: X86VMTranslationMap64Bit.cpp Project: Barrett17/haiku-contacts-kit-old

bool
X86VMTranslationMap64Bit::ClearAccessedAndModified(VMArea* area, addr_t address,
	bool unmapIfUnaccessed, bool& _modified)
{
	ASSERT(address % B_PAGE_SIZE == 0);

	TRACE("X86VMTranslationMap64Bit::ClearAccessedAndModified(%#" B_PRIxADDR
		")\n", address);

	RecursiveLocker locker(fLock);
	ThreadCPUPinner pinner(thread_get_current_thread());

	uint64* entry = X86PagingMethod64Bit::PageTableEntryForAddress(
		fPagingStructures->VirtualPML4(), address, fIsKernelMap,
		false, NULL, fPageMapper, fMapCount);
	if (entry == NULL)
		return false;

	uint64 oldEntry;

	if (unmapIfUnaccessed) {
		while (true) {
			oldEntry = *entry;
			if ((oldEntry & X86_64_PTE_PRESENT) == 0) {
				// page mapping not valid
				return false;
			}

			if (oldEntry & X86_64_PTE_ACCESSED) {
				// page was accessed -- just clear the flags
				oldEntry = X86PagingMethod64Bit::ClearTableEntryFlags(entry,
					X86_64_PTE_ACCESSED | X86_64_PTE_DIRTY);
				break;
			}

			// page hasn't been accessed -- unmap it
			if (X86PagingMethod64Bit::TestAndSetTableEntry(entry, 0, oldEntry)
					== oldEntry) {
				break;
			}

			// something changed -- check again
		}
	} else {
		oldEntry = X86PagingMethod64Bit::ClearTableEntryFlags(entry,
			X86_64_PTE_ACCESSED | X86_64_PTE_DIRTY);
	}

	pinner.Unlock();

	_modified = (oldEntry & X86_64_PTE_DIRTY) != 0;

	if ((oldEntry & X86_64_PTE_ACCESSED) != 0) {
		// Note, that we only need to invalidate the address, if the
		// accessed flags was set, since only then the entry could have been
		// in any TLB.
		InvalidatePage(address);
		Flush();

		return true;
	}

	if (!unmapIfUnaccessed)
		return false;

	// We have unmapped the address. Do the "high level" stuff.

	fMapCount--;

	locker.Detach();
		// UnaccessedPageUnmapped() will unlock for us

	UnaccessedPageUnmapped(area,
		(oldEntry & X86_64_PTE_ADDRESS_MASK) / B_PAGE_SIZE);

	return false;
}