memmap

package
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 Go to latest Published: Dec 10, 2024 License: Apache-2.0, MIT Imports: 8 Imported by: 74

Documentation

Overview

Package memmap defines semantics for memory mappings.

Index

Constants

View Source 
const (
	// minDegree is the minimum degree of an internal node in a Set B-tree.
	//
	//	- Any non-root node has at least minDegree-1 segments.
	//
	//	- Any non-root internal (non-leaf) node has at least minDegree children.
	//
	//	- The root node may have fewer than minDegree-1 segments, but it may
	// only have 0 segments if the tree is empty.
	//
	// Our implementation requires minDegree >= 3. Higher values of minDegree
	// usually improve performance, but increase memory usage for small sets.
	MappingminDegree = 3

	MappingmaxDegree = 2 * MappingminDegree
)
View Source 
const MappingtrackGaps = 0

trackGaps is an optional parameter.

If trackGaps is 1, the Set will track maximum gap size recursively, enabling the GapIterator.{Prev,Next}LargeEnoughGap functions. In this case, Key must be an unsigned integer.

trackGaps must be 0 or 1.

Variables

This section is empty.

Functions

func CheckTranslateResult 

func CheckTranslateResult(required, optional MappableRange, at hostarch.AccessType, ts []Translation, terr error) error

CheckTranslateResult returns an error if (ts, terr) does not satisfy all postconditions for Mappable.Translate(required, optional, at).

Preconditions: Same as Mappable.Translate.

func MappingzeroNodeSlice 

func MappingzeroNodeSlice(slice []*Mappingnode)

func MappingzeroValueSlice 

func MappingzeroValueSlice(slice []MappingsOfRange)

Types

type BufferedIOFallbackErr 

type BufferedIOFallbackErr struct{}

BufferedIOFallbackErr is returned (by value) by implementations of File.MapInternal() that cannot succeed, but can still support memory-mapped I/O by falling back to buffered reads and writes.

func (BufferedIOFallbackErr) Error 

func (BufferedIOFallbackErr) Error() string

Error implements error.Error.

type BusError 

type BusError struct {
	// Err is the original error.
	Err error
}

BusError may be returned by implementations of Mappable.Translate for errors that should result in SIGBUS delivery if they cause application page fault handling to fail.

func (*BusError) Error 

func (b *BusError) Error() string

Error implements error.Error.

type File 

type File interface {

	// IncRef increments the reference count on all pages in fr and
	// associates each page with a memCgID (memory cgroup id) to which it
	// belongs. memCgID will not be changed if the page already exists.
	//
	// Preconditions:
	//	* fr.Start and fr.End must be page-aligned.
	//	* fr.Length() > 0.
	//	* At least one reference must be held on all pages in fr. (The File
	//		interface does not provide a way to acquire an initial reference;
	//		implementors may define mechanisms for doing so.)
	IncRef(fr FileRange, memCgID uint32)

	// DecRef decrements the reference count on all pages in fr.
	//
	// Preconditions:
	//	* fr.Start and fr.End must be page-aligned.
	//	* fr.Length() > 0.
	//	* At least one reference must be held on all pages in fr.
	DecRef(fr FileRange)

	// MapInternal returns a mapping of the given file offsets in the invoking
	// process' address space for reading and writing.
	//
	// Note that fr.Start and fr.End need not be page-aligned.
	//
	// Preconditions:
	//	* fr.Length() > 0.
	//	* At least one reference must be held on all pages in fr.
	//
	// Postconditions: The returned mapping is valid as long as at least one
	// reference is held on the mapped pages.
	MapInternal(fr FileRange, at hostarch.AccessType) (safemem.BlockSeq, error)

	// DataFD blocks until offsets fr in the file contain valid data, then
	// returns the file descriptor represented by the File.
	//
	// Note that fr.Start and fr.End need not be page-aligned.
	//
	// Preconditions:
	//	* fr.Length() > 0.
	//	* At least one reference must be held on all pages in fr.
	DataFD(fr FileRange) (int, error)

	// BufferReadAt reads len(dst) bytes from the file into dst, starting at
	// file offset off. It returns the number of bytes read. Like
	// io.ReaderAt.ReadAt(), it never returns a short read with a nil error.
	//
	// Implementations of File for which MapInternal() never returns
	// BufferedIOFallbackErr can embed NoBufferedIOFallback to obtain an
	// appropriate implementation of BufferReadAt.
	//
	// Preconditions:
	//	* MapInternal() returned a BufferedIOFallbackErr.
	//	* At least one reference must be held on all read pages.
	BufferReadAt(off uint64, dst []byte) (uint64, error)

	// BufferWriteAt writes len(src) bytes src to the file, starting at file
	// offset off. It returns the number of bytes written. Like
	// io.WriterAt.WriteAt(), it never returns a short write with a nil error.
	//
	// Implementations of File for which MapInternal() never returns
	// BufferedIOFallbackErr can embed NoBufferedIOFallback to obtain an
	// appropriate implementation of BufferWriteAt.
	//
	// Preconditions:
	//	* MapInternal() returned a BufferedIOFallbackErr.
	//	* At least one reference must be held on all written pages.
	BufferWriteAt(off uint64, src []byte) (uint64, error)

	// FD returns the file descriptor represented by the File. The returned
	// file descriptor should not be used to implement
	// platform.AddressSpace.MapFile, since the contents of the File may not be
	// valid; use DataFD instead.
	FD() int
}

File represents a host file that may be mapped into an platform.AddressSpace.

type FileRange 

type FileRange struct {
	// Start is the inclusive start of the range.
	Start uint64

	// End is the exclusive end of the range.
	End uint64
}

A Range represents a contiguous range of T.

+stateify savable

func (FileRange) CanSplitAt 

func (r FileRange) CanSplitAt(x uint64) bool

CanSplitAt returns true if it is legal to split a segment spanning the range r at x; that is, splitting at x would produce two ranges, both of which have non-zero length.

func (FileRange) Contains 

func (r FileRange) Contains(x uint64) bool

Contains returns true if r contains x.

func (FileRange) Intersect 

func (r FileRange) Intersect(r2 FileRange) FileRange

Intersect returns a range consisting of the intersection between r and r2. If r and r2 do not overlap, Intersect returns a range with unspecified bounds, but for which Length() == 0.

func (FileRange) IsSupersetOf 

func (r FileRange) IsSupersetOf(r2 FileRange) bool

IsSupersetOf returns true if r is a superset of r2; that is, the range r2 is contained within r.

func (FileRange) Length 

func (r FileRange) Length() uint64

Length returns the length of the range.

func (FileRange) Overlaps 

func (r FileRange) Overlaps(r2 FileRange) bool

Overlaps returns true if r and r2 overlap.

func (*FileRange) StateFields 

func (fr *FileRange) StateFields() []string

func (*FileRange) StateLoad 

func (fr *FileRange) StateLoad(ctx context.Context, stateSourceObject state.Source)

+checklocksignore

func (*FileRange) StateSave 

func (fr *FileRange) StateSave(stateSinkObject state.Sink)

+checklocksignore

func (*FileRange) StateTypeName 

func (fr *FileRange) StateTypeName() string

func (FileRange) String 

func (fr FileRange) String() string

String implements fmt.Stringer.String.

func (FileRange) WellFormed 

func (r FileRange) WellFormed() bool

WellFormed returns true if r.Start <= r.End. All other methods on a Range require that the Range is well-formed.

type InvalidateOpts 

type InvalidateOpts struct {
	// InvalidatePrivate is true if private pages in the invalidated region
	// should also be discarded, causing their data to be lost.
	InvalidatePrivate bool
}

InvalidateOpts holds options to MappingSpace.Invalidate.

type MLockMode 

type MLockMode int

MLockMode specifies the memory locking behavior of a memory mapping. 

const (
	// MLockNone specifies that a mapping has no memory locking behavior.
	//
	// This must be the zero value for MLockMode.
	MLockNone MLockMode = iota

	// MLockEager specifies that a mapping is memory-locked, as by mlock() or
	// similar. Pages in the mapping should be made, and kept, resident in
	// physical memory as soon as possible.
	//
	// As of this writing, MLockEager does not cause memory-locking to be
	// requested from the host; it only affects the sentry's memory management
	// behavior.
	//
	// MLockEager is analogous to Linux's VM_LOCKED.
	MLockEager

	// MLockLazy specifies that a mapping is memory-locked, as by mlock() or
	// similar. Pages in the mapping should be kept resident in physical memory
	// once they have been made resident due to e.g. a page fault.
	//
	// As of this writing, MLockLazy does not cause memory-locking to be
	// requested from the host; in fact, it has virtually no effect, except for
	// interactions between mlocked pages and other syscalls.
	//
	// MLockLazy is analogous to Linux's VM_LOCKED | VM_LOCKONFAULT.
	MLockLazy
)

Note that the ordering of MLockModes is significant; see mm.MemoryManager.defMLockMode.

type MMapOpts 

type MMapOpts struct {
	// Length is the length of the mapping.
	Length uint64

	// MappingIdentity controls the lifetime of Mappable, and provides
	// properties of the mapping shown in /proc/[pid]/maps. If MMapOpts is used
	// to successfully create a memory mapping, a reference is taken on
	// MappingIdentity.
	MappingIdentity MappingIdentity

	// Mappable is the Mappable to be mapped. If Mappable is nil, the mapping
	// is anonymous. If Mappable is not nil, it must remain valid as long as a
	// reference is held on MappingIdentity.
	Mappable Mappable

	// Offset is the offset into Mappable to map. If Mappable is nil, Offset is
	// ignored.
	Offset uint64

	// Addr is the suggested address for the mapping.
	Addr hostarch.Addr

	// Fixed specifies whether this is a fixed mapping (it must be located at
	// Addr).
	Fixed bool

	// Unmap specifies whether existing mappings in the range being mapped may
	// be replaced. If Unmap is true, Fixed must be true.
	Unmap bool

	// If Map32Bit is true, all addresses in the created mapping must fit in a
	// 32-bit integer. (Note that the "end address" of the mapping, i.e. the
	// address of the first byte *after* the mapping, need not fit in a 32-bit
	// integer.) Map32Bit is ignored if Fixed is true.
	Map32Bit bool

	// Perms is the set of permissions to the applied to this mapping.
	Perms hostarch.AccessType

	// MaxPerms limits the set of permissions that may ever apply to this
	// mapping. If Mappable is not nil, all memmap.Translations returned by
	// Mappable.Translate must support all accesses in MaxPerms.
	//
	// Preconditions: MaxAccessType should be an effective AccessType, as
	// access cannot be limited beyond effective AccessTypes.
	MaxPerms hostarch.AccessType

	// Private is true if writes to the mapping should be propagated to a copy
	// that is exclusive to the MemoryManager.
	Private bool

	// GrowsDown is true if the mapping should be automatically expanded
	// downward on guard page faults.
	GrowsDown bool

	// Stack is equivalent to MAP_STACK, which has no mandatory semantics in
	// Linux.
	Stack bool

	// PlatformEffect controls the synchronous effect of this call on the
	// underlying platform.AddressSpace.
	PlatformEffect MMapPlatformEffect

	// MLockMode specifies the memory locking behavior of the mapping.
	MLockMode MLockMode

	// Name is the name used for the mapping in /proc/[pid]/maps. If Name is
	// empty, MappingIdentity.MappedName() will be used instead.
	//
	// TODO(jamieliu): Replace entirely with MappingIdentity?
	Name string

	// NameMut controls the effect of prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME)
	// on this mapping.
	NameMut NameMut

	// Force means to skip validation checks of Addr and Length. It can be
	// used to create special mappings below mm.layout.MinAddr and
	// mm.layout.MaxAddr. It has to be used with caution.
	//
	// If Force is true, Unmap and Fixed must be true.
	Force bool

	// If RequirePlatformEffect is false, PlatformEffect is best-effort;
	// failure to create mappings in the platform.AddressSpace are silently
	// ignored. If RequirePlatformEffect is true, failure to create mappings in
	// the platform.AddressSpace cause MMap() to fail. (If PlatformEffect is
	// PlatformEffectDefault, RequirePlatformEffect is ignored.)
	RequirePlatformEffect bool

	// SentryOwnedContent indicates the sentry exclusively controls the
	// underlying memory backing the mapping thus the memory content is
	// guaranteed not to be modified outside the sentry's purview.
	SentryOwnedContent bool
}

MMapOpts specifies a request to create a memory mapping.

type MMapPlatformEffect 

type MMapPlatformEffect uint8

MMapPlatformEffect is the type of MMapOpts.PlatformEffect. 

const (
	// PlatformEffectDefault indicates that no specific behavior is requested
	// from the platform.
	PlatformEffectDefault MMapPlatformEffect = iota

	// PlatformEffectPopulate indicates that platform mappings should be
	// established for all pages in the mapping.
	PlatformEffectPopulate

	// PlatformEffectCommit is like PlatformEffectPopulate, but also requests
	// that the platform eagerly commit resources to the mapping, as in
	// platform.AddressSpace.MapFile(precommit=true).
	PlatformEffectCommit
)

Possible values for MMapOpts.PlatformEffect:

type Mappable 

type Mappable interface {
	// AddMapping notifies the Mappable of a mapping from addresses ar in ms to
	// offsets [offset, offset+ar.Length()) in this Mappable.
	//
	// The writable flag indicates whether the backing data for a Mappable can
	// be modified through the mapping. Effectively, this means a shared mapping
	// where Translate may be called with at.Write == true. This is a property
	// established at mapping creation and must remain constant throughout the
	// lifetime of the mapping.
	//
	// Preconditions: offset+ar.Length() does not overflow.
	AddMapping(ctx context.Context, ms MappingSpace, ar hostarch.AddrRange, offset uint64, writable bool) error

	// RemoveMapping notifies the Mappable of the removal of a mapping from
	// addresses ar in ms to offsets [offset, offset+ar.Length()) in this
	// Mappable.
	//
	// Preconditions:
	//	* offset+ar.Length() does not overflow.
	//	* The removed mapping must exist. writable must match the
	//		corresponding call to AddMapping.
	RemoveMapping(ctx context.Context, ms MappingSpace, ar hostarch.AddrRange, offset uint64, writable bool)

	// CopyMapping notifies the Mappable of an attempt to copy a mapping in ms
	// from srcAR to dstAR. For most Mappables, this is equivalent to
	// AddMapping. Note that it is possible that srcAR.Length() != dstAR.Length(),
	// and also that srcAR.Length() == 0.
	//
	// CopyMapping is only called when a mapping is copied within a given
	// MappingSpace; it is analogous to Linux's vm_operations_struct::mremap.
	//
	// Preconditions:
	//	* offset+srcAR.Length() and offset+dstAR.Length() do not overflow.
	//	* The mapping at srcAR must exist. writable must match the
	//		corresponding call to AddMapping.
	CopyMapping(ctx context.Context, ms MappingSpace, srcAR, dstAR hostarch.AddrRange, offset uint64, writable bool) error

	// Translate returns the Mappable's current mappings for at least the range
	// of offsets specified by required, and at most the range of offsets
	// specified by optional. at is the set of access types that may be
	// performed using the returned Translations. If not all required offsets
	// are translated, it returns a non-nil error explaining why.
	//
	// Translations are valid until invalidated by a callback to
	// MappingSpace.Invalidate or until the caller removes its mapping of the
	// translated range. Mappable implementations must ensure that at least one
	// reference is held on all pages in a File that may be the result
	// of a valid Translation.
	//
	// Preconditions:
	//	* required.Length() > 0.
	//	* optional.IsSupersetOf(required).
	//	* required and optional must be page-aligned.
	//	* The caller must have established a mapping for all of the queried
	//		offsets via a previous call to AddMapping.
	//	* The caller is responsible for ensuring that calls to Translate
	//		synchronize with invalidation.
	//
	// Postconditions: See CheckTranslateResult.
	Translate(ctx context.Context, required, optional MappableRange, at hostarch.AccessType) ([]Translation, error)

	// InvalidateUnsavable requests that the Mappable invalidate Translations
	// that cannot be preserved across save/restore.
	//
	// Invariant: InvalidateUnsavable never races with concurrent calls to any
	// other Mappable methods.
	InvalidateUnsavable(ctx context.Context) error
}

Mappable represents a memory-mappable object, a mutable mapping from uint64 offsets to (File, uint64 File offset) pairs.

See mm/mm.go for Mappable's place in the lock order.

All Mappable methods have the following preconditions:

  • hostarch.AddrRanges and MappableRanges must be non-empty (Length() != 0).
  • hostarch.Addrs and Mappable offsets must be page-aligned.

type MappableRange 

type MappableRange struct {
	// Start is the inclusive start of the range.
	Start uint64

	// End is the exclusive end of the range.
	End uint64
}

A Range represents a contiguous range of T.

+stateify savable

func (MappableRange) CanSplitAt 

func (r MappableRange) CanSplitAt(x uint64) bool

CanSplitAt returns true if it is legal to split a segment spanning the range r at x; that is, splitting at x would produce two ranges, both of which have non-zero length.

func (MappableRange) Contains 

func (r MappableRange) Contains(x uint64) bool

Contains returns true if r contains x.

func (MappableRange) Intersect 

func (r MappableRange) Intersect(r2 MappableRange) MappableRange

Intersect returns a range consisting of the intersection between r and r2. If r and r2 do not overlap, Intersect returns a range with unspecified bounds, but for which Length() == 0.

func (MappableRange) IsSupersetOf 

func (r MappableRange) IsSupersetOf(r2 MappableRange) bool

IsSupersetOf returns true if r is a superset of r2; that is, the range r2 is contained within r.

func (MappableRange) Length 

func (r MappableRange) Length() uint64

Length returns the length of the range.

func (MappableRange) Overlaps 

func (r MappableRange) Overlaps(r2 MappableRange) bool

Overlaps returns true if r and r2 overlap.

func (*MappableRange) StateFields 

func (mr *MappableRange) StateFields() []string

func (*MappableRange) StateLoad 

func (mr *MappableRange) StateLoad(ctx context.Context, stateSourceObject state.Source)

+checklocksignore

func (*MappableRange) StateSave 

func (mr *MappableRange) StateSave(stateSinkObject state.Sink)

+checklocksignore

func (*MappableRange) StateTypeName 

func (mr *MappableRange) StateTypeName() string

func (MappableRange) String 

func (mr MappableRange) String() string

String implements fmt.Stringer.String.

func (MappableRange) WellFormed 

func (r MappableRange) WellFormed() bool

WellFormed returns true if r.Start <= r.End. All other methods on a Range require that the Range is well-formed.

type MappingFlatSegment 

type MappingFlatSegment struct {
	Start uint64
	End   uint64
	Value MappingsOfRange
}

FlatSegment represents a segment as a single object. FlatSegment is used as an intermediate representation for save/restore and tests.

+stateify savable

func (*MappingFlatSegment) StateFields 

func (m *MappingFlatSegment) StateFields() []string

func (*MappingFlatSegment) StateLoad 

func (m *MappingFlatSegment) StateLoad(ctx context.Context, stateSourceObject state.Source)

+checklocksignore

func (*MappingFlatSegment) StateSave 

func (m *MappingFlatSegment) StateSave(stateSinkObject state.Sink)

+checklocksignore

func (*MappingFlatSegment) StateTypeName 

func (m *MappingFlatSegment) StateTypeName() string

type MappingGapIterator 

type MappingGapIterator struct {
	// contains filtered or unexported fields
}

A GapIterator is conceptually one of:

  • A pointer to a position between two segments, before the first segment, or after the last segment in a set, called a *gap*; or

  • A terminal iterator, which is a sentinel indicating that the end of iteration has been reached.

Note that the gap between two adjacent segments exists (iterators to it are non-terminal), but has a length of zero. GapIterator.IsEmpty returns true for such gaps. An empty set contains a single gap, spanning the entire range of the set's keys.

GapIterators are copyable values and are meaningfully equality-comparable. The zero value of GapIterator is a terminal iterator.

Unless otherwise specified, any mutation of a set invalidates all existing iterators into the set.

func (MappingGapIterator) End 

func (gap MappingGapIterator) End() uint64

End is equivalent to Range().End, but should be preferred if only the end of the range is needed.

func (MappingGapIterator) IsEmpty 

func (gap MappingGapIterator) IsEmpty() bool

IsEmpty returns true if the iterated gap is empty (that is, the "gap" is between two adjacent segments.)

func (MappingGapIterator) NextGap 

func (gap MappingGapIterator) NextGap() MappingGapIterator

NextGap returns the iterated gap's successor. If no such gap exists, NextGap returns a terminal iterator.

func (MappingGapIterator) NextLargeEnoughGap 

func (gap MappingGapIterator) NextLargeEnoughGap(minSize uint64) MappingGapIterator

NextLargeEnoughGap returns the iterated gap's first next gap with larger length than minSize. If not found, return a terminal gap iterator (does NOT include this gap itself).

Precondition: trackGaps must be 1.

func (MappingGapIterator) NextSegment 

func (gap MappingGapIterator) NextSegment() MappingIterator

NextSegment returns the segment immediately after the iterated gap. If no such segment exists, NextSegment returns a terminal iterator.

func (MappingGapIterator) Ok 

func (gap MappingGapIterator) Ok() bool

Ok returns true if the iterator is not terminal. All other methods are only valid for non-terminal iterators.

func (MappingGapIterator) PrevGap 

func (gap MappingGapIterator) PrevGap() MappingGapIterator

PrevGap returns the iterated gap's predecessor. If no such gap exists, PrevGap returns a terminal iterator.

func (MappingGapIterator) PrevLargeEnoughGap 

func (gap MappingGapIterator) PrevLargeEnoughGap(minSize uint64) MappingGapIterator

PrevLargeEnoughGap returns the iterated gap's first prev gap with larger or equal length than minSize. If not found, return a terminal gap iterator (does NOT include this gap itself).

Precondition: trackGaps must be 1.

func (MappingGapIterator) PrevSegment 

func (gap MappingGapIterator) PrevSegment() MappingIterator

PrevSegment returns the segment immediately before the iterated gap. If no such segment exists, PrevSegment returns a terminal iterator.

func (MappingGapIterator) Range 

func (gap MappingGapIterator) Range() MappableRange

Range returns the range spanned by the iterated gap.

func (MappingGapIterator) Start 

func (gap MappingGapIterator) Start() uint64

Start is equivalent to Range().Start, but should be preferred if only the start of the range is needed.

type MappingIdentity 

type MappingIdentity interface {
	// IncRef increments the MappingIdentity's reference count.
	IncRef()

	// DecRef decrements the MappingIdentity's reference count.
	DecRef(ctx context.Context)

	// MappedName returns the application-visible name shown in
	// /proc/[pid]/maps.
	MappedName(ctx context.Context) string

	// DeviceID returns the device number shown in /proc/[pid]/maps.
	DeviceID() uint64

	// InodeID returns the inode number shown in /proc/[pid]/maps.
	InodeID() uint64

	// Msync has the same semantics as fs.FileOperations.Fsync(ctx,
	// int64(mr.Start), int64(mr.End-1), fs.SyncData).
	// (fs.FileOperations.Fsync() takes an inclusive end, but mr.End is
	// exclusive, hence mr.End-1.) It is defined rather than Fsync so that
	// implementors don't need to depend on the fs package for fs.SyncType.
	Msync(ctx context.Context, mr MappableRange) error
}

MappingIdentity controls the lifetime of a Mappable, and provides information about the Mappable for /proc/[pid]/maps. It is distinct from Mappable because all Mappables that are coherent must compare equal to support the implementation of shared futexes, but different MappingIdentities may represent the same Mappable, in the same way that multiple fs.Files may represent the same fs.Inode. (This similarity is not coincidental; fs.File implements MappingIdentity, and some fs.InodeOperations implement Mappable.)

type MappingIterator 

type MappingIterator struct {
	// contains filtered or unexported fields
}

A Iterator is conceptually one of:

  • A pointer to a segment in a set; or

  • A terminal iterator, which is a sentinel indicating that the end of iteration has been reached.

Iterators are copyable values and are meaningfully equality-comparable. The zero value of Iterator is a terminal iterator.

Unless otherwise specified, any mutation of a set invalidates all existing iterators into the set.

func MappingsegmentAfterPosition 

func MappingsegmentAfterPosition(n *Mappingnode, i int) MappingIterator

segmentAfterPosition returns the successor segment of the position given by n.children[i], which may or may not contain a child. If no such segment exists, segmentAfterPosition returns a terminal iterator.

func MappingsegmentBeforePosition 

func MappingsegmentBeforePosition(n *Mappingnode, i int) MappingIterator

segmentBeforePosition returns the predecessor segment of the position given by n.children[i], which may or may not contain a child. If no such segment exists, segmentBeforePosition returns a terminal iterator.

func (MappingIterator) End 

func (seg MappingIterator) End() uint64

End is equivalent to Range().End, but should be preferred if only the end of the range is needed.

func (MappingIterator) NextGap 

func (seg MappingIterator) NextGap() MappingGapIterator

NextGap returns the gap immediately after the iterated segment.

func (MappingIterator) NextNonEmpty 

func (seg MappingIterator) NextNonEmpty() (MappingIterator, MappingGapIterator)

NextNonEmpty returns the iterated segment's successor if it is adjacent, or the gap after the iterated segment otherwise. If seg.End() == Functions.MaxKey(), NextNonEmpty will return two terminal iterators. Otherwise, exactly one of the iterators returned by NextNonEmpty will be non-terminal.

func (MappingIterator) NextSegment 

func (seg MappingIterator) NextSegment() MappingIterator

NextSegment returns the iterated segment's successor. If there is no succeeding segment, NextSegment returns a terminal iterator.

func (MappingIterator) Ok 

func (seg MappingIterator) Ok() bool

Ok returns true if the iterator is not terminal. All other methods are only valid for non-terminal iterators.

func (MappingIterator) PrevGap 

func (seg MappingIterator) PrevGap() MappingGapIterator

PrevGap returns the gap immediately before the iterated segment.

func (MappingIterator) PrevNonEmpty 

func (seg MappingIterator) PrevNonEmpty() (MappingIterator, MappingGapIterator)

PrevNonEmpty returns the iterated segment's predecessor if it is adjacent, or the gap before the iterated segment otherwise. If seg.Start() == Functions.MinKey(), PrevNonEmpty will return two terminal iterators. Otherwise, exactly one of the iterators returned by PrevNonEmpty will be non-terminal.

func (MappingIterator) PrevSegment 

func (seg MappingIterator) PrevSegment() MappingIterator

PrevSegment returns the iterated segment's predecessor. If there is no preceding segment, PrevSegment returns a terminal iterator.

func (MappingIterator) Range 

func (seg MappingIterator) Range() MappableRange

Range returns the iterated segment's range key.

func (MappingIterator) SetEnd 

func (seg MappingIterator) SetEnd(end uint64)

SetEnd mutates the iterated segment's end. If the new end value would cause the iterated segment to overlap another segment, or would result in an invalid range, SetEnd panics. This operation does not invalidate any iterators.

func (MappingIterator) SetEndUnchecked 

func (seg MappingIterator) SetEndUnchecked(end uint64)

SetEndUnchecked mutates the iterated segment's end. This operation does not invalidate any iterators.

Preconditions: The new end must be valid:

  • end > seg.Start().
  • If seg.NextSegment().Ok(), then end <= seg.NextSegment().Start().

func (MappingIterator) SetRange 

func (seg MappingIterator) SetRange(r MappableRange)

SetRange mutates the iterated segment's range key. If the new range would cause the iterated segment to overlap another segment, or if the new range is invalid, SetRange panics. This operation does not invalidate any iterators.

func (MappingIterator) SetRangeUnchecked 

func (seg MappingIterator) SetRangeUnchecked(r MappableRange)

SetRangeUnchecked mutates the iterated segment's range key. This operation does not invalidate any iterators.

Preconditions: - r.Length() > 0. - The new range must not overlap an existing one:

  • If seg.NextSegment().Ok(), then r.end <= seg.NextSegment().Start().
  • If seg.PrevSegment().Ok(), then r.start >= seg.PrevSegment().End().

func (MappingIterator) SetStart 

func (seg MappingIterator) SetStart(start uint64)

SetStart mutates the iterated segment's start. If the new start value would cause the iterated segment to overlap another segment, or would result in an invalid range, SetStart panics. This operation does not invalidate any iterators.

func (MappingIterator) SetStartUnchecked 

func (seg MappingIterator) SetStartUnchecked(start uint64)

SetStartUnchecked mutates the iterated segment's start. This operation does not invalidate any iterators.

Preconditions: The new start must be valid:

  • start < seg.End()
  • If seg.PrevSegment().Ok(), then start >= seg.PrevSegment().End().

func (MappingIterator) SetValue 

func (seg MappingIterator) SetValue(val MappingsOfRange)

SetValue mutates the iterated segment's value. This operation does not invalidate any iterators.

func (MappingIterator) Start 

func (seg MappingIterator) Start() uint64

Start is equivalent to Range().Start, but should be preferred if only the start of the range is needed.

func (MappingIterator) Value 

func (seg MappingIterator) Value() MappingsOfRange

Value returns a copy of the iterated segment's value.

func (MappingIterator) ValuePtr 

func (seg MappingIterator) ValuePtr() *MappingsOfRange

ValuePtr returns a pointer to the iterated segment's value. The pointer is invalidated if the iterator is invalidated. This operation does not invalidate any iterators.

type MappingOfRange 

type MappingOfRange struct {
	MappingSpace MappingSpace
	AddrRange    hostarch.AddrRange
	Writable     bool
}

MappingOfRange represents a mapping of a MappableRange.

+stateify savable

func (*MappingOfRange) StateFields 

func (r *MappingOfRange) StateFields() []string

func (*MappingOfRange) StateLoad 

func (r *MappingOfRange) StateLoad(ctx context.Context, stateSourceObject state.Source)

+checklocksignore

func (*MappingOfRange) StateSave 

func (r *MappingOfRange) StateSave(stateSinkObject state.Sink)

+checklocksignore

func (*MappingOfRange) StateTypeName 

func (r *MappingOfRange) StateTypeName() string

func (MappingOfRange) String 

func (r MappingOfRange) String() string

String implements fmt.Stringer.String.

type MappingSet 

type MappingSet struct {
	// contains filtered or unexported fields
}

A Set is a mapping of segments with non-overlapping Range keys. The zero value for a Set is an empty set. Set values are not safely movable nor copyable. Set is thread-compatible.

+stateify savable

func (*MappingSet) AddMapping 

func (s *MappingSet) AddMapping(ms MappingSpace, ar hostarch.AddrRange, offset uint64, writable bool) []MappableRange

AddMapping adds the given mapping and returns the set of MappableRanges that previously had no mappings.

Preconditions: Same as Mappable.AddMapping.

func (*MappingSet) ExportSlice 

func (s *MappingSet) ExportSlice() []MappingFlatSegment

ExportSlice returns a copy of all segments in the given set, in ascending key order.

func (*MappingSet) Find 

func (s *MappingSet) Find(key uint64) (MappingIterator, MappingGapIterator)

Find returns the segment or gap whose range contains the given key. If a segment is found, the returned Iterator is non-terminal and the returned GapIterator is terminal. Otherwise, the returned Iterator is terminal and the returned GapIterator is non-terminal.

func (*MappingSet) FindGap 

func (s *MappingSet) FindGap(key uint64) MappingGapIterator

FindGap returns the gap containing the given key. If no such gap exists (i.e. the set contains a segment containing that key), FindGap returns a terminal iterator.

func (*MappingSet) FindSegment 

func (s *MappingSet) FindSegment(key uint64) MappingIterator

FindSegment returns the segment whose range contains the given key. If no such segment exists, FindSegment returns a terminal iterator.

func (*MappingSet) FirstGap 

func (s *MappingSet) FirstGap() MappingGapIterator

FirstGap returns the first gap in the set.

func (*MappingSet) FirstLargeEnoughGap 

func (s *MappingSet) FirstLargeEnoughGap(minSize uint64) MappingGapIterator

FirstLargeEnoughGap returns the first gap in the set with at least the given length. If no such gap exists, FirstLargeEnoughGap returns a terminal iterator.

Precondition: trackGaps must be 1.

func (*MappingSet) FirstSegment 

func (s *MappingSet) FirstSegment() MappingIterator

FirstSegment returns the first segment in the set. If the set is empty, FirstSegment returns a terminal iterator.

func (*MappingSet) ImportSlice 

func (s *MappingSet) ImportSlice(fs []MappingFlatSegment) error

ImportSlice initializes the given set from the given slice.

Preconditions:

  • s must be empty.
  • fs must represent a valid set (the segments in fs must have valid lengths that do not overlap).
  • The segments in fs must be sorted in ascending key order.

func (*MappingSet) Insert 

func (s *MappingSet) Insert(gap MappingGapIterator, r MappableRange, val MappingsOfRange) MappingIterator

Insert inserts the given segment into the given gap. If the new segment can be merged with adjacent segments, Insert will do so. Insert returns an iterator to the segment containing the inserted value (which may have been merged with other values). All existing iterators (including gap, but not including the returned iterator) are invalidated.

If the gap cannot accommodate the segment, or if r is invalid, Insert panics.

Insert is semantically equivalent to a InsertWithoutMerging followed by a Merge, but may be more efficient. Note that there is no unchecked variant of Insert since Insert must retrieve and inspect gap's predecessor and successor segments regardless.

func (*MappingSet) InsertRange 

func (s *MappingSet) InsertRange(r MappableRange, val MappingsOfRange) MappingIterator

InsertRange inserts the given segment into the set. If the new segment can be merged with adjacent segments, InsertRange will do so. InsertRange returns an iterator to the segment containing the inserted value (which may have been merged with other values). All existing iterators (excluding the returned iterator) are invalidated.

If the new segment would overlap an existing segment, or if r is invalid, InsertRange panics.

InsertRange searches the set to find the gap to insert into. If the caller already has the appropriate GapIterator, or if the caller needs to do additional work between finding the gap and insertion, use Insert instead.

func (*MappingSet) InsertWithoutMerging 

func (s *MappingSet) InsertWithoutMerging(gap MappingGapIterator, r MappableRange, val MappingsOfRange) MappingIterator

InsertWithoutMerging inserts the given segment into the given gap and returns an iterator to the inserted segment. All existing iterators (including gap, but not including the returned iterator) are invalidated.

If the gap cannot accommodate the segment, or if r is invalid, InsertWithoutMerging panics.

func (*MappingSet) InsertWithoutMergingRange 

func (s *MappingSet) InsertWithoutMergingRange(r MappableRange, val MappingsOfRange) MappingIterator

InsertWithoutMergingRange inserts the given segment into the set and returns an iterator to the inserted segment. All existing iterators (excluding the returned iterator) are invalidated.

If the new segment would overlap an existing segment, or if r is invalid, InsertWithoutMergingRange panics.

InsertWithoutMergingRange searches the set to find the gap to insert into. If the caller already has the appropriate GapIterator, or if the caller needs to do additional work between finding the gap and insertion, use InsertWithoutMerging instead.

func (*MappingSet) InsertWithoutMergingUnchecked 

func (s *MappingSet) InsertWithoutMergingUnchecked(gap MappingGapIterator, r MappableRange, val MappingsOfRange) MappingIterator

InsertWithoutMergingUnchecked inserts the given segment into the given gap and returns an iterator to the inserted segment. All existing iterators (including gap, but not including the returned iterator) are invalidated.

Preconditions:

  • r.Start >= gap.Start().
  • r.End <= gap.End().

func (*MappingSet) Invalidate 

func (s *MappingSet) Invalidate(mr MappableRange, opts InvalidateOpts)

Invalidate calls MappingSpace.Invalidate for all mappings of offsets in mr.

func (*MappingSet) InvalidateAll 

func (s *MappingSet) InvalidateAll(opts InvalidateOpts)

InvalidateAll calls MappingSpace.Invalidate for all mappings of s.

func (*MappingSet) IsEmpty 

func (s *MappingSet) IsEmpty() bool

IsEmpty returns true if the set contains no segments.

func (*MappingSet) IsEmptyRange 

func (s *MappingSet) IsEmptyRange(r MappableRange) bool

IsEmptyRange returns true iff no segments in the set overlap the given range. This is semantically equivalent to s.SpanRange(r) == 0, but may be more efficient.

func (*MappingSet) Isolate 

func (s *MappingSet) Isolate(seg MappingIterator, r MappableRange) MappingIterator

Isolate ensures that the given segment's range is a subset of r by splitting at r.Start and r.End if necessary, and returns an updated iterator to the bounded segment. All existing iterators (including seg, but not including the returned iterators) are invalidated.

Isolate is usually used when mutating part of a single segment, or when mutating segments in a range where the first segment is not necessarily split, making use of SplitBefore/SplitAfter complex.

Preconditions: seg.Range().Overlaps(r).

func (*MappingSet) LastGap 

func (s *MappingSet) LastGap() MappingGapIterator

LastGap returns the last gap in the set.

func (*MappingSet) LastLargeEnoughGap 

func (s *MappingSet) LastLargeEnoughGap(minSize uint64) MappingGapIterator

LastLargeEnoughGap returns the last gap in the set with at least the given length. If no such gap exists, LastLargeEnoughGap returns a terminal iterator.

Precondition: trackGaps must be 1.

func (*MappingSet) LastSegment 

func (s *MappingSet) LastSegment() MappingIterator

LastSegment returns the last segment in the set. If the set is empty, LastSegment returns a terminal iterator.

func (*MappingSet) LowerBoundGap 

func (s *MappingSet) LowerBoundGap(min uint64) MappingGapIterator

LowerBoundGap returns the gap with the lowest range that is greater than or equal to min.

func (*MappingSet) LowerBoundLargeEnoughGap 

func (s *MappingSet) LowerBoundLargeEnoughGap(min, minSize uint64) MappingGapIterator

LowerBoundLargeEnoughGap returns the first gap in the set with at least the given length and whose range contains a key greater than or equal to min. If no such gap exists, LowerBoundLargeEnoughGap returns a terminal iterator.

Precondition: trackGaps must be 1.

func (*MappingSet) LowerBoundSegment 

func (s *MappingSet) LowerBoundSegment(min uint64) MappingIterator

LowerBoundSegment returns the segment with the lowest range that contains a key greater than or equal to min. If no such segment exists, LowerBoundSegment returns a terminal iterator.

func (*MappingSet) LowerBoundSegmentSplitBefore 

func (s *MappingSet) LowerBoundSegmentSplitBefore(min uint64) MappingIterator

LowerBoundSegmentSplitBefore combines LowerBoundSegment and SplitBefore.

LowerBoundSegmentSplitBefore is usually used when mutating segments in a range while iterating them in order of increasing keys. In such cases, LowerBoundSegmentSplitBefore provides an iterator to the first segment to be mutated, suitable as the initial value for a loop variable.

func (*MappingSet) Merge 

func (s *MappingSet) Merge(first, second MappingIterator) MappingIterator

Merge attempts to merge two neighboring segments. If successful, Merge returns an iterator to the merged segment, and all existing iterators are invalidated. Otherwise, Merge returns a terminal iterator.

If first is not the predecessor of second, Merge panics.

func (*MappingSet) MergeAll 

func (s *MappingSet) MergeAll()

MergeAll merges all mergeable adjacent segments in the set. All existing iterators are invalidated.

func (*MappingSet) MergeInsideRange 

func (s *MappingSet) MergeInsideRange(r MappableRange)

MergeInsideRange attempts to merge all adjacent segments that contain a key in the specific range. All existing iterators are invalidated.

MergeInsideRange only makes sense after mutating the set in a way that may change the mergeability of modified segments; callers should prefer to use MergePrev or MergeNext during the mutating loop instead (depending on the direction of iteration), in order to avoid a redundant search.

func (*MappingSet) MergeNext 

func (s *MappingSet) MergeNext(seg MappingIterator) MappingIterator

MergeNext attempts to merge the given segment with its successor if possible, and returns an updated iterator to the extended segment. All existing iterators (including seg, but not including the returned iterator) are invalidated.

MergeNext is usually used when mutating segments while iterating them in order of decreasing keys, to attempt merging of each mutated segment with its previously-mutated successor. In such cases, merging a mutated segment with its unmutated predecessor would incorrectly cause the latter to be skipped.

func (*MappingSet) MergeOutsideRange 

func (s *MappingSet) MergeOutsideRange(r MappableRange)

MergeOutsideRange attempts to merge the segment containing r.Start with its predecessor, and the segment containing r.End-1 with its successor.

MergeOutsideRange only makes sense after mutating the set in a way that may change the mergeability of modified segments; callers should prefer to use MergePrev or MergeNext during the mutating loop instead (depending on the direction of iteration), in order to avoid two redundant searches.

func (*MappingSet) MergePrev 

func (s *MappingSet) MergePrev(seg MappingIterator) MappingIterator

MergePrev attempts to merge the given segment with its predecessor if possible, and returns an updated iterator to the extended segment. All existing iterators (including seg, but not including the returned iterator) are invalidated.

MergePrev is usually used when mutating segments while iterating them in order of increasing keys, to attempt merging of each mutated segment with its previously-mutated predecessor. In such cases, merging a mutated segment with its unmutated successor would incorrectly cause the latter to be skipped.

func (*MappingSet) MergeUnchecked 

func (s *MappingSet) MergeUnchecked(first, second MappingIterator) MappingIterator

MergeUnchecked attempts to merge two neighboring segments. If successful, MergeUnchecked returns an iterator to the merged segment, and all existing iterators are invalidated. Otherwise, MergeUnchecked returns a terminal iterator.

Precondition: first is the predecessor of second: first.NextSegment() == second, first == second.PrevSegment().

func (*MappingSet) MutateFullRange 

func (s *MappingSet) MutateFullRange(r MappableRange, f func(seg MappingIterator) bool)

MutateFullRange is equivalent to MutateRange, except that if any key in r that is visited before f returns false does not correspond to a segment, MutateFullRange panics.

func (*MappingSet) MutateRange 

func (s *MappingSet) MutateRange(r MappableRange, f func(seg MappingIterator) bool)

MutateRange applies the function f to all segments intersecting the range r, in order of ascending keys. Segments that lie partially outside r are split before f is called, such that f only observes segments entirely within r. Iterated segments are merged again after f is called. Non-empty gaps between segments are skipped. If a call to f returns false, MutateRange stops iteration immediately.

MutateRange invalidates all existing iterators.

N.B. f must not invalidate iterators into s.

func (*MappingSet) Remove 

func (s *MappingSet) Remove(seg MappingIterator) MappingGapIterator

Remove removes the given segment and returns an iterator to the vacated gap. All existing iterators (including seg, but not including the returned iterator) are invalidated.

func (*MappingSet) RemoveAll 

func (s *MappingSet) RemoveAll()

RemoveAll removes all segments from the set. All existing iterators are invalidated.

func (*MappingSet) RemoveFullRange 

func (s *MappingSet) RemoveFullRange(r MappableRange) MappingGapIterator

RemoveFullRange is equivalent to RemoveRange, except that if any key in the given range does not correspond to a segment, RemoveFullRange panics.

func (*MappingSet) RemoveFullRangeWith 

func (s *MappingSet) RemoveFullRangeWith(r MappableRange, f func(seg MappingIterator)) MappingGapIterator

RemoveFullRangeWith is equivalent to RemoveRangeWith, except that if any key in the given range does not correspond to a segment, RemoveFullRangeWith panics.

func (*MappingSet) RemoveMapping 

func (s *MappingSet) RemoveMapping(ms MappingSpace, ar hostarch.AddrRange, offset uint64, writable bool) []MappableRange

RemoveMapping removes the given mapping and returns the set of MappableRanges that now have no mappings.

Preconditions: Same as Mappable.RemoveMapping.

func (*MappingSet) RemoveRange 

func (s *MappingSet) RemoveRange(r MappableRange) MappingGapIterator

RemoveRange removes all segments in the given range. An iterator to the newly formed gap is returned, and all existing iterators are invalidated.

RemoveRange searches the set to find segments to remove. If the caller already has an iterator to either end of the range of segments to remove, or if the caller needs to do additional work before removing each segment, iterate segments and call Remove in a loop instead.

func (*MappingSet) RemoveRangeWith 

func (s *MappingSet) RemoveRangeWith(r MappableRange, f func(seg MappingIterator)) MappingGapIterator

RemoveRangeWith removes all segments in the given range. An iterator to the newly formed gap is returned, and all existing iterators are invalidated.

The function f is applied to each segment immediately before it is removed, in order of ascending keys. Segments that lie partially outside r are split before f is called, such that f only observes segments entirely within r. Non-empty gaps between segments are skipped.

RemoveRangeWith searches the set to find segments to remove. If the caller already has an iterator to either end of the range of segments to remove, or if the caller needs to do additional work before removing each segment, iterate segments and call Remove in a loop instead.

N.B. f must not invalidate iterators into s.

func (*MappingSet) Span 

func (s *MappingSet) Span() uint64

Span returns the total size of all segments in the set.

func (*MappingSet) SpanRange 

func (s *MappingSet) SpanRange(r MappableRange) uint64

SpanRange returns the total size of the intersection of segments in the set with the given range.

func (*MappingSet) Split 

func (s *MappingSet) Split(seg MappingIterator, split uint64) (MappingIterator, MappingIterator)

Split splits the given segment at the given key and returns iterators to the two resulting segments. All existing iterators (including seg, but not including the returned iterators) are invalidated.

If the segment cannot be split at split (because split is at the start or end of the segment's range, so splitting would produce a segment with zero length, or because split falls outside the segment's range altogether), Split panics.

func (*MappingSet) SplitAfter 

func (s *MappingSet) SplitAfter(seg MappingIterator, end uint64) MappingIterator

SplitAfter ensures that the given segment's end is at most end by splitting at end if necessary, and returns an updated iterator to the bounded segment. All existing iterators (including seg, but not including the returned iterator) are invalidated.

SplitAfter is usually used when mutating segments in a range. In such cases, when iterating segments in order of increasing keys, each iterated segment may extend beyond the end of the range to be mutated, and needs to be SplitAfter to ensure that only the part of the segment within the range is mutated. When iterating segments in order of decreasing keys, SplitBefore and SplitAfter exchange roles; i.e. SplitBefore needs to be invoked on each segment, while SplitAfter only needs to be invoked on the first.

Preconditions: seg.Start() < end.

func (*MappingSet) SplitBefore 

func (s *MappingSet) SplitBefore(seg MappingIterator, start uint64) MappingIterator

SplitBefore ensures that the given segment's start is at least start by splitting at start if necessary, and returns an updated iterator to the bounded segment. All existing iterators (including seg, but not including the returned iterator) are invalidated.

SplitBefore is usually when mutating segments in a range. In such cases, when iterating segments in order of increasing keys, the first segment may extend beyond the start of the range to be mutated, and needs to be SplitBefore to ensure that only the part of the segment within the range is mutated. When iterating segments in order of decreasing keys, SplitBefore and SplitAfter; i.e. SplitBefore needs to be invoked on each segment, while SplitAfter only needs to be invoked on the first.

Preconditions: start < seg.End().

func (*MappingSet) SplitUnchecked 

func (s *MappingSet) SplitUnchecked(seg MappingIterator, split uint64) (MappingIterator, MappingIterator)

SplitUnchecked splits the given segment at the given key and returns iterators to the two resulting segments. All existing iterators (including seg, but not including the returned iterators) are invalidated.

Preconditions: seg.Start() < key < seg.End().

func (*MappingSet) StateFields 

func (s *MappingSet) StateFields() []string

func (*MappingSet) StateLoad 

func (s *MappingSet) StateLoad(ctx context.Context, stateSourceObject state.Source)

+checklocksignore

func (*MappingSet) StateSave 

func (s *MappingSet) StateSave(stateSinkObject state.Sink)

+checklocksignore

func (*MappingSet) StateTypeName 

func (s *MappingSet) StateTypeName() string

func (*MappingSet) String 

func (s *MappingSet) String() string

String stringifies a Set for debugging.

func (*MappingSet) TryInsertRange 

func (s *MappingSet) TryInsertRange(r MappableRange, val MappingsOfRange) MappingIterator

TryInsertRange attempts to insert the given segment into the set. If the new segment can be merged with adjacent segments, TryInsertRange will do so. TryInsertRange returns an iterator to the segment containing the inserted value (which may have been merged with other values). All existing iterators (excluding the returned iterator) are invalidated.

If the new segment would overlap an existing segment, TryInsertRange does nothing and returns a terminal iterator.

TryInsertRange searches the set to find the gap to insert into. If the caller already has the appropriate GapIterator, or if the caller needs to do additional work between finding the gap and insertion, use Insert instead.

func (*MappingSet) TryInsertWithoutMergingRange 

func (s *MappingSet) TryInsertWithoutMergingRange(r MappableRange, val MappingsOfRange) MappingIterator

TryInsertWithoutMergingRange attempts to insert the given segment into the set. If successful, it returns an iterator to the inserted segment; all existing iterators (excluding the returned iterator) are invalidated. If the new segment would overlap an existing segment, TryInsertWithoutMergingRange does nothing and returns a terminal iterator.

TryInsertWithoutMergingRange searches the set to find the gap to insert into. If the caller already has the appropriate GapIterator, or if the caller needs to do additional work between finding the gap and insertion, use InsertWithoutMerging instead.

func (*MappingSet) Unisolate 

func (s *MappingSet) Unisolate(seg MappingIterator) MappingIterator

Unisolate attempts to merge the given segment with its predecessor and successor if possible, and returns an updated iterator to the extended segment. All existing iterators (including seg, but not including the returned iterator) are invalidated.

Unisolate is usually used in conjunction with Isolate when mutating part of a single segment in a way that may affect its mergeability. For the reasons described by MergePrev and MergeNext, it is usually incorrect to use the return value of Unisolate in a loop variable.

func (*MappingSet) UpperBoundGap 

func (s *MappingSet) UpperBoundGap(max uint64) MappingGapIterator

UpperBoundGap returns the gap with the highest range that is less than or equal to max.

func (*MappingSet) UpperBoundLargeEnoughGap 

func (s *MappingSet) UpperBoundLargeEnoughGap(max, minSize uint64) MappingGapIterator

UpperBoundLargeEnoughGap returns the last gap in the set with at least the given length and whose range contains a key less than or equal to max. If no such gap exists, UpperBoundLargeEnoughGap returns a terminal iterator.

Precondition: trackGaps must be 1.

func (*MappingSet) UpperBoundSegment 

func (s *MappingSet) UpperBoundSegment(max uint64) MappingIterator

UpperBoundSegment returns the segment with the highest range that contains a key less than or equal to max. If no such segment exists, UpperBoundSegment returns a terminal iterator.

func (*MappingSet) UpperBoundSegmentSplitAfter 

func (s *MappingSet) UpperBoundSegmentSplitAfter(max uint64) MappingIterator

UpperBoundSegmentSplitAfter combines UpperBoundSegment and SplitAfter.

UpperBoundSegmentSplitAfter is usually used when mutating segments in a range while iterating them in order of decreasing keys. In such cases, UpperBoundSegmentSplitAfter provides an iterator to the first segment to be mutated, suitable as the initial value for a loop variable.

func (*MappingSet) VisitFullRange 

func (s *MappingSet) VisitFullRange(r MappableRange, f func(seg MappingIterator) bool)

VisitFullRange is equivalent to VisitRange, except that if any key in r that is visited before f returns false does not correspond to a segment, VisitFullRange panics.

func (*MappingSet) VisitRange 

func (s *MappingSet) VisitRange(r MappableRange, f func(seg MappingIterator) bool)

VisitRange applies the function f to all segments intersecting the range r, in order of ascending keys. Segments will not be split, so f may be called on segments lying partially outside r. Non-empty gaps between segments are skipped. If a call to f returns false, VisitRange stops iteration immediately.

N.B. f must not invalidate iterators into s.

type MappingSpace 

type MappingSpace interface {
	// Invalidate is called to notify the MappingSpace that values returned by
	// previous calls to Mappable.Translate for offsets mapped by addresses in
	// ar are no longer valid.
	//
	// Invalidate must not take any locks preceding mm.MemoryManager.activeMu
	// in the lock order.
	//
	// Preconditions:
	//	* ar.Length() != 0.
	//	* ar must be page-aligned.
	Invalidate(ar hostarch.AddrRange, opts InvalidateOpts)
}

MappingSpace represents a mutable mapping from hostarch.Addrs to (Mappable, uint64 offset) pairs.

type MappingdynamicGap 

type MappingdynamicGap [MappingtrackGaps]uint64

dynamicGap is a type that disappears if trackGaps is 0.

func (*MappingdynamicGap) Get 

func (d *MappingdynamicGap) Get() uint64

Get returns the value of the gap.

Precondition: trackGaps must be non-zero.

func (*MappingdynamicGap) Set 

func (d *MappingdynamicGap) Set(v uint64)

Set sets the value of the gap.

Precondition: trackGaps must be non-zero.

type Mappingnode 

type Mappingnode struct {
	// contains filtered or unexported fields
}

+stateify savable

func (*Mappingnode) StateFields 

func (n *Mappingnode) StateFields() []string

func (*Mappingnode) StateLoad 

func (n *Mappingnode) StateLoad(ctx context.Context, stateSourceObject state.Source)

+checklocksignore

func (*Mappingnode) StateSave 

func (n *Mappingnode) StateSave(stateSinkObject state.Sink)

+checklocksignore

func (*Mappingnode) StateTypeName 

func (n *Mappingnode) StateTypeName() string

func (*Mappingnode) String 

func (n *Mappingnode) String() string

String stringifies a node (and all of its children) for debugging.

type MappingsOfRange 

type MappingsOfRange map[MappingOfRange]struct{}

MappingsOfRange is the value type of MappingSet, and represents the set of all mappings of the corresponding MappableRange.

Using a map offers O(1) lookups in RemoveMapping and mappingSetFunctions.Merge.

type NameMut 

type NameMut uint8

NameMut is the type of MMapOpts.NameMut. 

const (
	// NameMutDisallowed indicates that PR_SET_VMA_ANON_NAME should fail.
	NameMutDisallowed NameMut = iota

	// NameMutAnon indicates that PR_SET_VMA_ANON_NAME should succeed, and
	// treat the mapping as private anonymous memory.
	NameMutAnon

	// NameMutAnonShmem indicates that PR_SET_VMA_ANON_NAME should succeed, and
	// treat the mapping as shared anonymous memory.
	NameMutAnonShmem
)

Possible values for MMapOpts.NameMut:

type NoBufferedIOFallback 

type NoBufferedIOFallback struct{}

NoBufferedIOFallback implements File.BufferReadAt() and BufferWriteAt() for implementations of File for which MapInternal() never returns BufferedIOFallbackErr.

func (NoBufferedIOFallback) BufferReadAt 

func (NoBufferedIOFallback) BufferReadAt(off uint64, dst []byte) (uint64, error)

BufferReadAt implements File.BufferReadAt.

func (NoBufferedIOFallback) BufferWriteAt 

func (NoBufferedIOFallback) BufferWriteAt(off uint64, src []byte) (uint64, error)

BufferWriteAt implements File.BufferWriteAt.

type Translation 

type Translation struct {
	// Source is the translated range in the Mappable.
	Source MappableRange

	// File is the mapped file.
	File File

	// Offset is the offset into File at which this Translation begins.
	Offset uint64

	// Perms is the set of permissions for which platform.AddressSpace.MapFile
	// and platform.AddressSpace.MapInternal on this Translation is permitted.
	Perms hostarch.AccessType
}

Translations are returned by Mappable.Translate.

func (Translation) FileRange 

func (t Translation) FileRange() FileRange

FileRange returns the FileRange represented by t.

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