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-rw-r--r--pkg/sentry/fs/lock/BUILD60
-rwxr-xr-xpkg/sentry/fs/lock/lock_range.go62
-rw-r--r--pkg/sentry/fs/lock/lock_range_test.go136
-rwxr-xr-xpkg/sentry/fs/lock/lock_set.go1270
-rwxr-xr-xpkg/sentry/fs/lock/lock_state_autogen.go106
-rw-r--r--pkg/sentry/fs/lock/lock_test.go1059
6 files changed, 1438 insertions, 1255 deletions
diff --git a/pkg/sentry/fs/lock/BUILD b/pkg/sentry/fs/lock/BUILD
deleted file mode 100644
index 5a7a5b8cd..000000000
--- a/pkg/sentry/fs/lock/BUILD
+++ /dev/null
@@ -1,60 +0,0 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_test")
-
-package(licenses = ["notice"])
-
-load("//tools/go_generics:defs.bzl", "go_template_instance")
-load("//tools/go_stateify:defs.bzl", "go_library")
-
-go_template_instance(
- name = "lock_range",
- out = "lock_range.go",
- package = "lock",
- prefix = "Lock",
- template = "//pkg/segment:generic_range",
- types = {
- "T": "uint64",
- },
-)
-
-go_template_instance(
- name = "lock_set",
- out = "lock_set.go",
- consts = {
- "minDegree": "3",
- },
- package = "lock",
- prefix = "Lock",
- template = "//pkg/segment:generic_set",
- types = {
- "Key": "uint64",
- "Range": "LockRange",
- "Value": "Lock",
- "Functions": "lockSetFunctions",
- },
-)
-
-go_library(
- name = "lock",
- srcs = [
- "lock.go",
- "lock_range.go",
- "lock_set.go",
- "lock_set_functions.go",
- ],
- importpath = "gvisor.dev/gvisor/pkg/sentry/fs/lock",
- visibility = ["//pkg/sentry:internal"],
- deps = [
- "//pkg/log",
- "//pkg/waiter",
- ],
-)
-
-go_test(
- name = "lock_test",
- size = "small",
- srcs = [
- "lock_range_test.go",
- "lock_test.go",
- ],
- embed = [":lock"],
-)
diff --git a/pkg/sentry/fs/lock/lock_range.go b/pkg/sentry/fs/lock/lock_range.go
new file mode 100755
index 000000000..7a6f77640
--- /dev/null
+++ b/pkg/sentry/fs/lock/lock_range.go
@@ -0,0 +1,62 @@
+package lock
+
+// A Range represents a contiguous range of T.
+//
+// +stateify savable
+type LockRange struct {
+ // Start is the inclusive start of the range.
+ Start uint64
+
+ // End is the exclusive end of the range.
+ End uint64
+}
+
+// WellFormed returns true if r.Start <= r.End. All other methods on a Range
+// require that the Range is well-formed.
+func (r LockRange) WellFormed() bool {
+ return r.Start <= r.End
+}
+
+// Length returns the length of the range.
+func (r LockRange) Length() uint64 {
+ return r.End - r.Start
+}
+
+// Contains returns true if r contains x.
+func (r LockRange) Contains(x uint64) bool {
+ return r.Start <= x && x < r.End
+}
+
+// Overlaps returns true if r and r2 overlap.
+func (r LockRange) Overlaps(r2 LockRange) bool {
+ return r.Start < r2.End && r2.Start < r.End
+}
+
+// IsSupersetOf returns true if r is a superset of r2; that is, the range r2 is
+// contained within r.
+func (r LockRange) IsSupersetOf(r2 LockRange) bool {
+ return r.Start <= r2.Start && r.End >= r2.End
+}
+
+// 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 (r LockRange) Intersect(r2 LockRange) LockRange {
+ if r.Start < r2.Start {
+ r.Start = r2.Start
+ }
+ if r.End > r2.End {
+ r.End = r2.End
+ }
+ if r.End < r.Start {
+ r.End = r.Start
+ }
+ return r
+}
+
+// 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 (r LockRange) CanSplitAt(x uint64) bool {
+ return r.Contains(x) && r.Start < x
+}
diff --git a/pkg/sentry/fs/lock/lock_range_test.go b/pkg/sentry/fs/lock/lock_range_test.go
deleted file mode 100644
index 6221199d1..000000000
--- a/pkg/sentry/fs/lock/lock_range_test.go
+++ /dev/null
@@ -1,136 +0,0 @@
-// Copyright 2018 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package lock
-
-import (
- "syscall"
- "testing"
-)
-
-func TestComputeRange(t *testing.T) {
- tests := []struct {
- // Description of test.
- name string
-
- // Requested start of the lock range.
- start int64
-
- // Requested length of the lock range,
- // can be negative :(
- length int64
-
- // Pre-computed file offset based on whence.
- // Will be added to start.
- offset int64
-
- // Expected error.
- err error
-
- // If error is nil, the expected LockRange.
- LockRange
- }{
- {
- name: "offset, start, and length all zero",
- LockRange: LockRange{Start: 0, End: LockEOF},
- },
- {
- name: "zero offset, zero start, positive length",
- start: 0,
- length: 4096,
- offset: 0,
- LockRange: LockRange{Start: 0, End: 4096},
- },
- {
- name: "zero offset, negative start",
- start: -4096,
- offset: 0,
- err: syscall.EINVAL,
- },
- {
- name: "large offset, negative start, positive length",
- start: -2048,
- length: 2048,
- offset: 4096,
- LockRange: LockRange{Start: 2048, End: 4096},
- },
- {
- name: "large offset, negative start, zero length",
- start: -2048,
- length: 0,
- offset: 4096,
- LockRange: LockRange{Start: 2048, End: LockEOF},
- },
- {
- name: "zero offset, zero start, negative length",
- start: 0,
- length: -4096,
- offset: 0,
- err: syscall.EINVAL,
- },
- {
- name: "large offset, zero start, negative length",
- start: 0,
- length: -4096,
- offset: 4096,
- LockRange: LockRange{Start: 0, End: 4096},
- },
- {
- name: "offset, start, and length equal, length is negative",
- start: 1024,
- length: -1024,
- offset: 1024,
- LockRange: LockRange{Start: 1024, End: 2048},
- },
- {
- name: "offset, start, and length equal, start is negative",
- start: -1024,
- length: 1024,
- offset: 1024,
- LockRange: LockRange{Start: 0, End: 1024},
- },
- {
- name: "offset, start, and length equal, offset is negative",
- start: 1024,
- length: 1024,
- offset: -1024,
- LockRange: LockRange{Start: 0, End: 1024},
- },
- {
- name: "offset, start, and length equal, all negative",
- start: -1024,
- length: -1024,
- offset: -1024,
- err: syscall.EINVAL,
- },
- {
- name: "offset, start, and length equal, all positive",
- start: 1024,
- length: 1024,
- offset: 1024,
- LockRange: LockRange{Start: 2048, End: 3072},
- },
- }
-
- for _, test := range tests {
- rng, err := ComputeRange(test.start, test.length, test.offset)
- if err != test.err {
- t.Errorf("%s: lockRange(%d, %d, %d) got error %v, want %v", test.name, test.start, test.length, test.offset, err, test.err)
- continue
- }
- if err == nil && rng != test.LockRange {
- t.Errorf("%s: lockRange(%d, %d, %d) got LockRange %v, want %v", test.name, test.start, test.length, test.offset, rng, test.LockRange)
- }
- }
-}
diff --git a/pkg/sentry/fs/lock/lock_set.go b/pkg/sentry/fs/lock/lock_set.go
new file mode 100755
index 000000000..2343ca0b4
--- /dev/null
+++ b/pkg/sentry/fs/lock/lock_set.go
@@ -0,0 +1,1270 @@
+package lock
+
+import (
+ "bytes"
+ "fmt"
+)
+
+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.
+ LockminDegree = 3
+
+ LockmaxDegree = 2 * LockminDegree
+)
+
+// 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
+type LockSet struct {
+ root Locknode `state:".(*LockSegmentDataSlices)"`
+}
+
+// IsEmpty returns true if the set contains no segments.
+func (s *LockSet) IsEmpty() bool {
+ return s.root.nrSegments == 0
+}
+
+// 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 (s *LockSet) IsEmptyRange(r LockRange) bool {
+ switch {
+ case r.Length() < 0:
+ panic(fmt.Sprintf("invalid range %v", r))
+ case r.Length() == 0:
+ return true
+ }
+ _, gap := s.Find(r.Start)
+ if !gap.Ok() {
+ return false
+ }
+ return r.End <= gap.End()
+}
+
+// Span returns the total size of all segments in the set.
+func (s *LockSet) Span() uint64 {
+ var sz uint64
+ for seg := s.FirstSegment(); seg.Ok(); seg = seg.NextSegment() {
+ sz += seg.Range().Length()
+ }
+ return sz
+}
+
+// SpanRange returns the total size of the intersection of segments in the set
+// with the given range.
+func (s *LockSet) SpanRange(r LockRange) uint64 {
+ switch {
+ case r.Length() < 0:
+ panic(fmt.Sprintf("invalid range %v", r))
+ case r.Length() == 0:
+ return 0
+ }
+ var sz uint64
+ for seg := s.LowerBoundSegment(r.Start); seg.Ok() && seg.Start() < r.End; seg = seg.NextSegment() {
+ sz += seg.Range().Intersect(r).Length()
+ }
+ return sz
+}
+
+// FirstSegment returns the first segment in the set. If the set is empty,
+// FirstSegment returns a terminal iterator.
+func (s *LockSet) FirstSegment() LockIterator {
+ if s.root.nrSegments == 0 {
+ return LockIterator{}
+ }
+ return s.root.firstSegment()
+}
+
+// LastSegment returns the last segment in the set. If the set is empty,
+// LastSegment returns a terminal iterator.
+func (s *LockSet) LastSegment() LockIterator {
+ if s.root.nrSegments == 0 {
+ return LockIterator{}
+ }
+ return s.root.lastSegment()
+}
+
+// FirstGap returns the first gap in the set.
+func (s *LockSet) FirstGap() LockGapIterator {
+ n := &s.root
+ for n.hasChildren {
+ n = n.children[0]
+ }
+ return LockGapIterator{n, 0}
+}
+
+// LastGap returns the last gap in the set.
+func (s *LockSet) LastGap() LockGapIterator {
+ n := &s.root
+ for n.hasChildren {
+ n = n.children[n.nrSegments]
+ }
+ return LockGapIterator{n, n.nrSegments}
+}
+
+// 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 (s *LockSet) Find(key uint64) (LockIterator, LockGapIterator) {
+ n := &s.root
+ for {
+
+ lower := 0
+ upper := n.nrSegments
+ for lower < upper {
+ i := lower + (upper-lower)/2
+ if r := n.keys[i]; key < r.End {
+ if key >= r.Start {
+ return LockIterator{n, i}, LockGapIterator{}
+ }
+ upper = i
+ } else {
+ lower = i + 1
+ }
+ }
+ i := lower
+ if !n.hasChildren {
+ return LockIterator{}, LockGapIterator{n, i}
+ }
+ n = n.children[i]
+ }
+}
+
+// FindSegment returns the segment whose range contains the given key. If no
+// such segment exists, FindSegment returns a terminal iterator.
+func (s *LockSet) FindSegment(key uint64) LockIterator {
+ seg, _ := s.Find(key)
+ return seg
+}
+
+// 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 (s *LockSet) LowerBoundSegment(min uint64) LockIterator {
+ seg, gap := s.Find(min)
+ if seg.Ok() {
+ return seg
+ }
+ return gap.NextSegment()
+}
+
+// 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 (s *LockSet) UpperBoundSegment(max uint64) LockIterator {
+ seg, gap := s.Find(max)
+ if seg.Ok() {
+ return seg
+ }
+ return gap.PrevSegment()
+}
+
+// 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 (s *LockSet) FindGap(key uint64) LockGapIterator {
+ _, gap := s.Find(key)
+ return gap
+}
+
+// LowerBoundGap returns the gap with the lowest range that is greater than or
+// equal to min.
+func (s *LockSet) LowerBoundGap(min uint64) LockGapIterator {
+ seg, gap := s.Find(min)
+ if gap.Ok() {
+ return gap
+ }
+ return seg.NextGap()
+}
+
+// UpperBoundGap returns the gap with the highest range that is less than or
+// equal to max.
+func (s *LockSet) UpperBoundGap(max uint64) LockGapIterator {
+ seg, gap := s.Find(max)
+ if gap.Ok() {
+ return gap
+ }
+ return seg.PrevGap()
+}
+
+// Add inserts the given segment into the set and returns true. If the new
+// segment can be merged with adjacent segments, Add will do so. If the new
+// segment would overlap an existing segment, Add returns false. If Add
+// succeeds, all existing iterators are invalidated.
+func (s *LockSet) Add(r LockRange, val Lock) bool {
+ if r.Length() <= 0 {
+ panic(fmt.Sprintf("invalid segment range %v", r))
+ }
+ gap := s.FindGap(r.Start)
+ if !gap.Ok() {
+ return false
+ }
+ if r.End > gap.End() {
+ return false
+ }
+ s.Insert(gap, r, val)
+ return true
+}
+
+// AddWithoutMerging inserts the given segment into the set and returns true.
+// If it would overlap an existing segment, AddWithoutMerging does nothing and
+// returns false. If AddWithoutMerging succeeds, all existing iterators are
+// invalidated.
+func (s *LockSet) AddWithoutMerging(r LockRange, val Lock) bool {
+ if r.Length() <= 0 {
+ panic(fmt.Sprintf("invalid segment range %v", r))
+ }
+ gap := s.FindGap(r.Start)
+ if !gap.Ok() {
+ return false
+ }
+ if r.End > gap.End() {
+ return false
+ }
+ s.InsertWithoutMergingUnchecked(gap, r, val)
+ return true
+}
+
+// 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 (s *LockSet) Insert(gap LockGapIterator, r LockRange, val Lock) LockIterator {
+ if r.Length() <= 0 {
+ panic(fmt.Sprintf("invalid segment range %v", r))
+ }
+ prev, next := gap.PrevSegment(), gap.NextSegment()
+ if prev.Ok() && prev.End() > r.Start {
+ panic(fmt.Sprintf("new segment %v overlaps predecessor %v", r, prev.Range()))
+ }
+ if next.Ok() && next.Start() < r.End {
+ panic(fmt.Sprintf("new segment %v overlaps successor %v", r, next.Range()))
+ }
+ if prev.Ok() && prev.End() == r.Start {
+ if mval, ok := (lockSetFunctions{}).Merge(prev.Range(), prev.Value(), r, val); ok {
+ prev.SetEndUnchecked(r.End)
+ prev.SetValue(mval)
+ if next.Ok() && next.Start() == r.End {
+ val = mval
+ if mval, ok := (lockSetFunctions{}).Merge(prev.Range(), val, next.Range(), next.Value()); ok {
+ prev.SetEndUnchecked(next.End())
+ prev.SetValue(mval)
+ return s.Remove(next).PrevSegment()
+ }
+ }
+ return prev
+ }
+ }
+ if next.Ok() && next.Start() == r.End {
+ if mval, ok := (lockSetFunctions{}).Merge(r, val, next.Range(), next.Value()); ok {
+ next.SetStartUnchecked(r.Start)
+ next.SetValue(mval)
+ return next
+ }
+ }
+ return s.InsertWithoutMergingUnchecked(gap, r, val)
+}
+
+// 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 (s *LockSet) InsertWithoutMerging(gap LockGapIterator, r LockRange, val Lock) LockIterator {
+ if r.Length() <= 0 {
+ panic(fmt.Sprintf("invalid segment range %v", r))
+ }
+ if gr := gap.Range(); !gr.IsSupersetOf(r) {
+ panic(fmt.Sprintf("cannot insert segment range %v into gap range %v", r, gr))
+ }
+ return s.InsertWithoutMergingUnchecked(gap, r, val)
+}
+
+// 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 (s *LockSet) InsertWithoutMergingUnchecked(gap LockGapIterator, r LockRange, val Lock) LockIterator {
+ gap = gap.node.rebalanceBeforeInsert(gap)
+ copy(gap.node.keys[gap.index+1:], gap.node.keys[gap.index:gap.node.nrSegments])
+ copy(gap.node.values[gap.index+1:], gap.node.values[gap.index:gap.node.nrSegments])
+ gap.node.keys[gap.index] = r
+ gap.node.values[gap.index] = val
+ gap.node.nrSegments++
+ return LockIterator{gap.node, gap.index}
+}
+
+// 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 (s *LockSet) Remove(seg LockIterator) LockGapIterator {
+
+ if seg.node.hasChildren {
+
+ victim := seg.PrevSegment()
+
+ seg.SetRangeUnchecked(victim.Range())
+ seg.SetValue(victim.Value())
+ return s.Remove(victim).NextGap()
+ }
+ copy(seg.node.keys[seg.index:], seg.node.keys[seg.index+1:seg.node.nrSegments])
+ copy(seg.node.values[seg.index:], seg.node.values[seg.index+1:seg.node.nrSegments])
+ lockSetFunctions{}.ClearValue(&seg.node.values[seg.node.nrSegments-1])
+ seg.node.nrSegments--
+ return seg.node.rebalanceAfterRemove(LockGapIterator{seg.node, seg.index})
+}
+
+// RemoveAll removes all segments from the set. All existing iterators are
+// invalidated.
+func (s *LockSet) RemoveAll() {
+ s.root = Locknode{}
+}
+
+// RemoveRange removes all segments in the given range. An iterator to the
+// newly formed gap is returned, and all existing iterators are invalidated.
+func (s *LockSet) RemoveRange(r LockRange) LockGapIterator {
+ seg, gap := s.Find(r.Start)
+ if seg.Ok() {
+ seg = s.Isolate(seg, r)
+ gap = s.Remove(seg)
+ }
+ for seg = gap.NextSegment(); seg.Ok() && seg.Start() < r.End; seg = gap.NextSegment() {
+ seg = s.Isolate(seg, r)
+ gap = s.Remove(seg)
+ }
+ return gap
+}
+
+// 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 (s *LockSet) Merge(first, second LockIterator) LockIterator {
+ if first.NextSegment() != second {
+ panic(fmt.Sprintf("attempt to merge non-neighboring segments %v, %v", first.Range(), second.Range()))
+ }
+ return s.MergeUnchecked(first, second)
+}
+
+// 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 (s *LockSet) MergeUnchecked(first, second LockIterator) LockIterator {
+ if first.End() == second.Start() {
+ if mval, ok := (lockSetFunctions{}).Merge(first.Range(), first.Value(), second.Range(), second.Value()); ok {
+
+ first.SetEndUnchecked(second.End())
+ first.SetValue(mval)
+ return s.Remove(second).PrevSegment()
+ }
+ }
+ return LockIterator{}
+}
+
+// MergeAll attempts to merge all adjacent segments in the set. All existing
+// iterators are invalidated.
+func (s *LockSet) MergeAll() {
+ seg := s.FirstSegment()
+ if !seg.Ok() {
+ return
+ }
+ next := seg.NextSegment()
+ for next.Ok() {
+ if mseg := s.MergeUnchecked(seg, next); mseg.Ok() {
+ seg, next = mseg, mseg.NextSegment()
+ } else {
+ seg, next = next, next.NextSegment()
+ }
+ }
+}
+
+// MergeRange attempts to merge all adjacent segments that contain a key in the
+// specific range. All existing iterators are invalidated.
+func (s *LockSet) MergeRange(r LockRange) {
+ seg := s.LowerBoundSegment(r.Start)
+ if !seg.Ok() {
+ return
+ }
+ next := seg.NextSegment()
+ for next.Ok() && next.Range().Start < r.End {
+ if mseg := s.MergeUnchecked(seg, next); mseg.Ok() {
+ seg, next = mseg, mseg.NextSegment()
+ } else {
+ seg, next = next, next.NextSegment()
+ }
+ }
+}
+
+// MergeAdjacent attempts to merge the segment containing r.Start with its
+// predecessor, and the segment containing r.End-1 with its successor.
+func (s *LockSet) MergeAdjacent(r LockRange) {
+ first := s.FindSegment(r.Start)
+ if first.Ok() {
+ if prev := first.PrevSegment(); prev.Ok() {
+ s.Merge(prev, first)
+ }
+ }
+ last := s.FindSegment(r.End - 1)
+ if last.Ok() {
+ if next := last.NextSegment(); next.Ok() {
+ s.Merge(last, next)
+ }
+ }
+}
+
+// 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 (s *LockSet) Split(seg LockIterator, split uint64) (LockIterator, LockIterator) {
+ if !seg.Range().CanSplitAt(split) {
+ panic(fmt.Sprintf("can't split %v at %v", seg.Range(), split))
+ }
+ return s.SplitUnchecked(seg, split)
+}
+
+// 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 (s *LockSet) SplitUnchecked(seg LockIterator, split uint64) (LockIterator, LockIterator) {
+ val1, val2 := (lockSetFunctions{}).Split(seg.Range(), seg.Value(), split)
+ end2 := seg.End()
+ seg.SetEndUnchecked(split)
+ seg.SetValue(val1)
+ seg2 := s.InsertWithoutMergingUnchecked(seg.NextGap(), LockRange{split, end2}, val2)
+
+ return seg2.PrevSegment(), seg2
+}
+
+// SplitAt splits the segment straddling split, if one exists. SplitAt returns
+// true if a segment was split and false otherwise. If SplitAt splits a
+// segment, all existing iterators are invalidated.
+func (s *LockSet) SplitAt(split uint64) bool {
+ if seg := s.FindSegment(split); seg.Ok() && seg.Range().CanSplitAt(split) {
+ s.SplitUnchecked(seg, split)
+ return true
+ }
+ return false
+}
+
+// Isolate ensures that the given segment's range does not escape 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.
+func (s *LockSet) Isolate(seg LockIterator, r LockRange) LockIterator {
+ if seg.Range().CanSplitAt(r.Start) {
+ _, seg = s.SplitUnchecked(seg, r.Start)
+ }
+ if seg.Range().CanSplitAt(r.End) {
+ seg, _ = s.SplitUnchecked(seg, r.End)
+ }
+ return seg
+}
+
+// ApplyContiguous applies a function to a contiguous range of segments,
+// splitting if necessary. The function is applied until the first gap is
+// encountered, at which point the gap is returned. If the function is applied
+// across the entire range, a terminal gap is returned. All existing iterators
+// are invalidated.
+//
+// N.B. The Iterator must not be invalidated by the function.
+func (s *LockSet) ApplyContiguous(r LockRange, fn func(seg LockIterator)) LockGapIterator {
+ seg, gap := s.Find(r.Start)
+ if !seg.Ok() {
+ return gap
+ }
+ for {
+ seg = s.Isolate(seg, r)
+ fn(seg)
+ if seg.End() >= r.End {
+ return LockGapIterator{}
+ }
+ gap = seg.NextGap()
+ if !gap.IsEmpty() {
+ return gap
+ }
+ seg = gap.NextSegment()
+ if !seg.Ok() {
+
+ return LockGapIterator{}
+ }
+ }
+}
+
+// +stateify savable
+type Locknode struct {
+ // An internal binary tree node looks like:
+ //
+ // K
+ // / \
+ // Cl Cr
+ //
+ // where all keys in the subtree rooted by Cl (the left subtree) are less
+ // than K (the key of the parent node), and all keys in the subtree rooted
+ // by Cr (the right subtree) are greater than K.
+ //
+ // An internal B-tree node's indexes work out to look like:
+ //
+ // K0 K1 K2 ... Kn-1
+ // / \/ \/ \ ... / \
+ // C0 C1 C2 C3 ... Cn-1 Cn
+ //
+ // where n is nrSegments.
+ nrSegments int
+
+ // parent is a pointer to this node's parent. If this node is root, parent
+ // is nil.
+ parent *Locknode
+
+ // parentIndex is the index of this node in parent.children.
+ parentIndex int
+
+ // Flag for internal nodes that is technically redundant with "children[0]
+ // != nil", but is stored in the first cache line. "hasChildren" rather
+ // than "isLeaf" because false must be the correct value for an empty root.
+ hasChildren bool
+
+ // Nodes store keys and values in separate arrays to maximize locality in
+ // the common case (scanning keys for lookup).
+ keys [LockmaxDegree - 1]LockRange
+ values [LockmaxDegree - 1]Lock
+ children [LockmaxDegree]*Locknode
+}
+
+// firstSegment returns the first segment in the subtree rooted by n.
+//
+// Preconditions: n.nrSegments != 0.
+func (n *Locknode) firstSegment() LockIterator {
+ for n.hasChildren {
+ n = n.children[0]
+ }
+ return LockIterator{n, 0}
+}
+
+// lastSegment returns the last segment in the subtree rooted by n.
+//
+// Preconditions: n.nrSegments != 0.
+func (n *Locknode) lastSegment() LockIterator {
+ for n.hasChildren {
+ n = n.children[n.nrSegments]
+ }
+ return LockIterator{n, n.nrSegments - 1}
+}
+
+func (n *Locknode) prevSibling() *Locknode {
+ if n.parent == nil || n.parentIndex == 0 {
+ return nil
+ }
+ return n.parent.children[n.parentIndex-1]
+}
+
+func (n *Locknode) nextSibling() *Locknode {
+ if n.parent == nil || n.parentIndex == n.parent.nrSegments {
+ return nil
+ }
+ return n.parent.children[n.parentIndex+1]
+}
+
+// rebalanceBeforeInsert splits n and its ancestors if they are full, as
+// required for insertion, and returns an updated iterator to the position
+// represented by gap.
+func (n *Locknode) rebalanceBeforeInsert(gap LockGapIterator) LockGapIterator {
+ if n.parent != nil {
+ gap = n.parent.rebalanceBeforeInsert(gap)
+ }
+ if n.nrSegments < LockmaxDegree-1 {
+ return gap
+ }
+ if n.parent == nil {
+
+ left := &Locknode{
+ nrSegments: LockminDegree - 1,
+ parent: n,
+ parentIndex: 0,
+ hasChildren: n.hasChildren,
+ }
+ right := &Locknode{
+ nrSegments: LockminDegree - 1,
+ parent: n,
+ parentIndex: 1,
+ hasChildren: n.hasChildren,
+ }
+ copy(left.keys[:LockminDegree-1], n.keys[:LockminDegree-1])
+ copy(left.values[:LockminDegree-1], n.values[:LockminDegree-1])
+ copy(right.keys[:LockminDegree-1], n.keys[LockminDegree:])
+ copy(right.values[:LockminDegree-1], n.values[LockminDegree:])
+ n.keys[0], n.values[0] = n.keys[LockminDegree-1], n.values[LockminDegree-1]
+ LockzeroValueSlice(n.values[1:])
+ if n.hasChildren {
+ copy(left.children[:LockminDegree], n.children[:LockminDegree])
+ copy(right.children[:LockminDegree], n.children[LockminDegree:])
+ LockzeroNodeSlice(n.children[2:])
+ for i := 0; i < LockminDegree; i++ {
+ left.children[i].parent = left
+ left.children[i].parentIndex = i
+ right.children[i].parent = right
+ right.children[i].parentIndex = i
+ }
+ }
+ n.nrSegments = 1
+ n.hasChildren = true
+ n.children[0] = left
+ n.children[1] = right
+ if gap.node != n {
+ return gap
+ }
+ if gap.index < LockminDegree {
+ return LockGapIterator{left, gap.index}
+ }
+ return LockGapIterator{right, gap.index - LockminDegree}
+ }
+
+ copy(n.parent.keys[n.parentIndex+1:], n.parent.keys[n.parentIndex:n.parent.nrSegments])
+ copy(n.parent.values[n.parentIndex+1:], n.parent.values[n.parentIndex:n.parent.nrSegments])
+ n.parent.keys[n.parentIndex], n.parent.values[n.parentIndex] = n.keys[LockminDegree-1], n.values[LockminDegree-1]
+ copy(n.parent.children[n.parentIndex+2:], n.parent.children[n.parentIndex+1:n.parent.nrSegments+1])
+ for i := n.parentIndex + 2; i < n.parent.nrSegments+2; i++ {
+ n.parent.children[i].parentIndex = i
+ }
+ sibling := &Locknode{
+ nrSegments: LockminDegree - 1,
+ parent: n.parent,
+ parentIndex: n.parentIndex + 1,
+ hasChildren: n.hasChildren,
+ }
+ n.parent.children[n.parentIndex+1] = sibling
+ n.parent.nrSegments++
+ copy(sibling.keys[:LockminDegree-1], n.keys[LockminDegree:])
+ copy(sibling.values[:LockminDegree-1], n.values[LockminDegree:])
+ LockzeroValueSlice(n.values[LockminDegree-1:])
+ if n.hasChildren {
+ copy(sibling.children[:LockminDegree], n.children[LockminDegree:])
+ LockzeroNodeSlice(n.children[LockminDegree:])
+ for i := 0; i < LockminDegree; i++ {
+ sibling.children[i].parent = sibling
+ sibling.children[i].parentIndex = i
+ }
+ }
+ n.nrSegments = LockminDegree - 1
+
+ if gap.node != n {
+ return gap
+ }
+ if gap.index < LockminDegree {
+ return gap
+ }
+ return LockGapIterator{sibling, gap.index - LockminDegree}
+}
+
+// rebalanceAfterRemove "unsplits" n and its ancestors if they are deficient
+// (contain fewer segments than required by B-tree invariants), as required for
+// removal, and returns an updated iterator to the position represented by gap.
+//
+// Precondition: n is the only node in the tree that may currently violate a
+// B-tree invariant.
+func (n *Locknode) rebalanceAfterRemove(gap LockGapIterator) LockGapIterator {
+ for {
+ if n.nrSegments >= LockminDegree-1 {
+ return gap
+ }
+ if n.parent == nil {
+
+ return gap
+ }
+
+ if sibling := n.prevSibling(); sibling != nil && sibling.nrSegments >= LockminDegree {
+ copy(n.keys[1:], n.keys[:n.nrSegments])
+ copy(n.values[1:], n.values[:n.nrSegments])
+ n.keys[0] = n.parent.keys[n.parentIndex-1]
+ n.values[0] = n.parent.values[n.parentIndex-1]
+ n.parent.keys[n.parentIndex-1] = sibling.keys[sibling.nrSegments-1]
+ n.parent.values[n.parentIndex-1] = sibling.values[sibling.nrSegments-1]
+ lockSetFunctions{}.ClearValue(&sibling.values[sibling.nrSegments-1])
+ if n.hasChildren {
+ copy(n.children[1:], n.children[:n.nrSegments+1])
+ n.children[0] = sibling.children[sibling.nrSegments]
+ sibling.children[sibling.nrSegments] = nil
+ n.children[0].parent = n
+ n.children[0].parentIndex = 0
+ for i := 1; i < n.nrSegments+2; i++ {
+ n.children[i].parentIndex = i
+ }
+ }
+ n.nrSegments++
+ sibling.nrSegments--
+ if gap.node == sibling && gap.index == sibling.nrSegments {
+ return LockGapIterator{n, 0}
+ }
+ if gap.node == n {
+ return LockGapIterator{n, gap.index + 1}
+ }
+ return gap
+ }
+ if sibling := n.nextSibling(); sibling != nil && sibling.nrSegments >= LockminDegree {
+ n.keys[n.nrSegments] = n.parent.keys[n.parentIndex]
+ n.values[n.nrSegments] = n.parent.values[n.parentIndex]
+ n.parent.keys[n.parentIndex] = sibling.keys[0]
+ n.parent.values[n.parentIndex] = sibling.values[0]
+ copy(sibling.keys[:sibling.nrSegments-1], sibling.keys[1:])
+ copy(sibling.values[:sibling.nrSegments-1], sibling.values[1:])
+ lockSetFunctions{}.ClearValue(&sibling.values[sibling.nrSegments-1])
+ if n.hasChildren {
+ n.children[n.nrSegments+1] = sibling.children[0]
+ copy(sibling.children[:sibling.nrSegments], sibling.children[1:])
+ sibling.children[sibling.nrSegments] = nil
+ n.children[n.nrSegments+1].parent = n
+ n.children[n.nrSegments+1].parentIndex = n.nrSegments + 1
+ for i := 0; i < sibling.nrSegments; i++ {
+ sibling.children[i].parentIndex = i
+ }
+ }
+ n.nrSegments++
+ sibling.nrSegments--
+ if gap.node == sibling {
+ if gap.index == 0 {
+ return LockGapIterator{n, n.nrSegments}
+ }
+ return LockGapIterator{sibling, gap.index - 1}
+ }
+ return gap
+ }
+
+ p := n.parent
+ if p.nrSegments == 1 {
+
+ left, right := p.children[0], p.children[1]
+ p.nrSegments = left.nrSegments + right.nrSegments + 1
+ p.hasChildren = left.hasChildren
+ p.keys[left.nrSegments] = p.keys[0]
+ p.values[left.nrSegments] = p.values[0]
+ copy(p.keys[:left.nrSegments], left.keys[:left.nrSegments])
+ copy(p.values[:left.nrSegments], left.values[:left.nrSegments])
+ copy(p.keys[left.nrSegments+1:], right.keys[:right.nrSegments])
+ copy(p.values[left.nrSegments+1:], right.values[:right.nrSegments])
+ if left.hasChildren {
+ copy(p.children[:left.nrSegments+1], left.children[:left.nrSegments+1])
+ copy(p.children[left.nrSegments+1:], right.children[:right.nrSegments+1])
+ for i := 0; i < p.nrSegments+1; i++ {
+ p.children[i].parent = p
+ p.children[i].parentIndex = i
+ }
+ } else {
+ p.children[0] = nil
+ p.children[1] = nil
+ }
+ if gap.node == left {
+ return LockGapIterator{p, gap.index}
+ }
+ if gap.node == right {
+ return LockGapIterator{p, gap.index + left.nrSegments + 1}
+ }
+ return gap
+ }
+ // Merge n and either sibling, along with the segment separating the
+ // two, into whichever of the two nodes comes first. This is the
+ // reverse of the non-root splitting case in
+ // node.rebalanceBeforeInsert.
+ var left, right *Locknode
+ if n.parentIndex > 0 {
+ left = n.prevSibling()
+ right = n
+ } else {
+ left = n
+ right = n.nextSibling()
+ }
+
+ if gap.node == right {
+ gap = LockGapIterator{left, gap.index + left.nrSegments + 1}
+ }
+ left.keys[left.nrSegments] = p.keys[left.parentIndex]
+ left.values[left.nrSegments] = p.values[left.parentIndex]
+ copy(left.keys[left.nrSegments+1:], right.keys[:right.nrSegments])
+ copy(left.values[left.nrSegments+1:], right.values[:right.nrSegments])
+ if left.hasChildren {
+ copy(left.children[left.nrSegments+1:], right.children[:right.nrSegments+1])
+ for i := left.nrSegments + 1; i < left.nrSegments+right.nrSegments+2; i++ {
+ left.children[i].parent = left
+ left.children[i].parentIndex = i
+ }
+ }
+ left.nrSegments += right.nrSegments + 1
+ copy(p.keys[left.parentIndex:], p.keys[left.parentIndex+1:p.nrSegments])
+ copy(p.values[left.parentIndex:], p.values[left.parentIndex+1:p.nrSegments])
+ lockSetFunctions{}.ClearValue(&p.values[p.nrSegments-1])
+ copy(p.children[left.parentIndex+1:], p.children[left.parentIndex+2:p.nrSegments+1])
+ for i := 0; i < p.nrSegments; i++ {
+ p.children[i].parentIndex = i
+ }
+ p.children[p.nrSegments] = nil
+ p.nrSegments--
+
+ n = p
+ }
+}
+
+// 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.
+type LockIterator struct {
+ // node is the node containing the iterated segment. If the iterator is
+ // terminal, node is nil.
+ node *Locknode
+
+ // index is the index of the segment in node.keys/values.
+ index int
+}
+
+// Ok returns true if the iterator is not terminal. All other methods are only
+// valid for non-terminal iterators.
+func (seg LockIterator) Ok() bool {
+ return seg.node != nil
+}
+
+// Range returns the iterated segment's range key.
+func (seg LockIterator) Range() LockRange {
+ return seg.node.keys[seg.index]
+}
+
+// Start is equivalent to Range().Start, but should be preferred if only the
+// start of the range is needed.
+func (seg LockIterator) Start() uint64 {
+ return seg.node.keys[seg.index].Start
+}
+
+// End is equivalent to Range().End, but should be preferred if only the end of
+// the range is needed.
+func (seg LockIterator) End() uint64 {
+ return seg.node.keys[seg.index].End
+}
+
+// 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 (seg LockIterator) SetRangeUnchecked(r LockRange) {
+ seg.node.keys[seg.index] = r
+}
+
+// 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 (seg LockIterator) SetRange(r LockRange) {
+ if r.Length() <= 0 {
+ panic(fmt.Sprintf("invalid segment range %v", r))
+ }
+ if prev := seg.PrevSegment(); prev.Ok() && r.Start < prev.End() {
+ panic(fmt.Sprintf("new segment range %v overlaps segment range %v", r, prev.Range()))
+ }
+ if next := seg.NextSegment(); next.Ok() && r.End > next.Start() {
+ panic(fmt.Sprintf("new segment range %v overlaps segment range %v", r, next.Range()))
+ }
+ seg.SetRangeUnchecked(r)
+}
+
+// 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 (seg LockIterator) SetStartUnchecked(start uint64) {
+ seg.node.keys[seg.index].Start = start
+}
+
+// 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 (seg LockIterator) SetStart(start uint64) {
+ if start >= seg.End() {
+ panic(fmt.Sprintf("new start %v would invalidate segment range %v", start, seg.Range()))
+ }
+ if prev := seg.PrevSegment(); prev.Ok() && start < prev.End() {
+ panic(fmt.Sprintf("new start %v would cause segment range %v to overlap segment range %v", start, seg.Range(), prev.Range()))
+ }
+ seg.SetStartUnchecked(start)
+}
+
+// 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 (seg LockIterator) SetEndUnchecked(end uint64) {
+ seg.node.keys[seg.index].End = end
+}
+
+// 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 (seg LockIterator) SetEnd(end uint64) {
+ if end <= seg.Start() {
+ panic(fmt.Sprintf("new end %v would invalidate segment range %v", end, seg.Range()))
+ }
+ if next := seg.NextSegment(); next.Ok() && end > next.Start() {
+ panic(fmt.Sprintf("new end %v would cause segment range %v to overlap segment range %v", end, seg.Range(), next.Range()))
+ }
+ seg.SetEndUnchecked(end)
+}
+
+// Value returns a copy of the iterated segment's value.
+func (seg LockIterator) Value() Lock {
+ return seg.node.values[seg.index]
+}
+
+// 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.
+func (seg LockIterator) ValuePtr() *Lock {
+ return &seg.node.values[seg.index]
+}
+
+// SetValue mutates the iterated segment's value. This operation does not
+// invalidate any iterators.
+func (seg LockIterator) SetValue(val Lock) {
+ seg.node.values[seg.index] = val
+}
+
+// PrevSegment returns the iterated segment's predecessor. If there is no
+// preceding segment, PrevSegment returns a terminal iterator.
+func (seg LockIterator) PrevSegment() LockIterator {
+ if seg.node.hasChildren {
+ return seg.node.children[seg.index].lastSegment()
+ }
+ if seg.index > 0 {
+ return LockIterator{seg.node, seg.index - 1}
+ }
+ if seg.node.parent == nil {
+ return LockIterator{}
+ }
+ return LocksegmentBeforePosition(seg.node.parent, seg.node.parentIndex)
+}
+
+// NextSegment returns the iterated segment's successor. If there is no
+// succeeding segment, NextSegment returns a terminal iterator.
+func (seg LockIterator) NextSegment() LockIterator {
+ if seg.node.hasChildren {
+ return seg.node.children[seg.index+1].firstSegment()
+ }
+ if seg.index < seg.node.nrSegments-1 {
+ return LockIterator{seg.node, seg.index + 1}
+ }
+ if seg.node.parent == nil {
+ return LockIterator{}
+ }
+ return LocksegmentAfterPosition(seg.node.parent, seg.node.parentIndex)
+}
+
+// PrevGap returns the gap immediately before the iterated segment.
+func (seg LockIterator) PrevGap() LockGapIterator {
+ if seg.node.hasChildren {
+
+ return seg.node.children[seg.index].lastSegment().NextGap()
+ }
+ return LockGapIterator{seg.node, seg.index}
+}
+
+// NextGap returns the gap immediately after the iterated segment.
+func (seg LockIterator) NextGap() LockGapIterator {
+ if seg.node.hasChildren {
+ return seg.node.children[seg.index+1].firstSegment().PrevGap()
+ }
+ return LockGapIterator{seg.node, seg.index + 1}
+}
+
+// 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 (seg LockIterator) PrevNonEmpty() (LockIterator, LockGapIterator) {
+ gap := seg.PrevGap()
+ if gap.Range().Length() != 0 {
+ return LockIterator{}, gap
+ }
+ return gap.PrevSegment(), LockGapIterator{}
+}
+
+// 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 (seg LockIterator) NextNonEmpty() (LockIterator, LockGapIterator) {
+ gap := seg.NextGap()
+ if gap.Range().Length() != 0 {
+ return LockIterator{}, gap
+ }
+ return gap.NextSegment(), LockGapIterator{}
+}
+
+// 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.
+type LockGapIterator struct {
+ // The representation of a GapIterator is identical to that of an Iterator,
+ // except that index corresponds to positions between segments in the same
+ // way as for node.children (see comment for node.nrSegments).
+ node *Locknode
+ index int
+}
+
+// Ok returns true if the iterator is not terminal. All other methods are only
+// valid for non-terminal iterators.
+func (gap LockGapIterator) Ok() bool {
+ return gap.node != nil
+}
+
+// Range returns the range spanned by the iterated gap.
+func (gap LockGapIterator) Range() LockRange {
+ return LockRange{gap.Start(), gap.End()}
+}
+
+// Start is equivalent to Range().Start, but should be preferred if only the
+// start of the range is needed.
+func (gap LockGapIterator) Start() uint64 {
+ if ps := gap.PrevSegment(); ps.Ok() {
+ return ps.End()
+ }
+ return lockSetFunctions{}.MinKey()
+}
+
+// End is equivalent to Range().End, but should be preferred if only the end of
+// the range is needed.
+func (gap LockGapIterator) End() uint64 {
+ if ns := gap.NextSegment(); ns.Ok() {
+ return ns.Start()
+ }
+ return lockSetFunctions{}.MaxKey()
+}
+
+// IsEmpty returns true if the iterated gap is empty (that is, the "gap" is
+// between two adjacent segments.)
+func (gap LockGapIterator) IsEmpty() bool {
+ return gap.Range().Length() == 0
+}
+
+// PrevSegment returns the segment immediately before the iterated gap. If no
+// such segment exists, PrevSegment returns a terminal iterator.
+func (gap LockGapIterator) PrevSegment() LockIterator {
+ return LocksegmentBeforePosition(gap.node, gap.index)
+}
+
+// NextSegment returns the segment immediately after the iterated gap. If no
+// such segment exists, NextSegment returns a terminal iterator.
+func (gap LockGapIterator) NextSegment() LockIterator {
+ return LocksegmentAfterPosition(gap.node, gap.index)
+}
+
+// PrevGap returns the iterated gap's predecessor. If no such gap exists,
+// PrevGap returns a terminal iterator.
+func (gap LockGapIterator) PrevGap() LockGapIterator {
+ seg := gap.PrevSegment()
+ if !seg.Ok() {
+ return LockGapIterator{}
+ }
+ return seg.PrevGap()
+}
+
+// NextGap returns the iterated gap's successor. If no such gap exists, NextGap
+// returns a terminal iterator.
+func (gap LockGapIterator) NextGap() LockGapIterator {
+ seg := gap.NextSegment()
+ if !seg.Ok() {
+ return LockGapIterator{}
+ }
+ return seg.NextGap()
+}
+
+// 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 LocksegmentBeforePosition(n *Locknode, i int) LockIterator {
+ for i == 0 {
+ if n.parent == nil {
+ return LockIterator{}
+ }
+ n, i = n.parent, n.parentIndex
+ }
+ return LockIterator{n, i - 1}
+}
+
+// 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 LocksegmentAfterPosition(n *Locknode, i int) LockIterator {
+ for i == n.nrSegments {
+ if n.parent == nil {
+ return LockIterator{}
+ }
+ n, i = n.parent, n.parentIndex
+ }
+ return LockIterator{n, i}
+}
+
+func LockzeroValueSlice(slice []Lock) {
+
+ for i := range slice {
+ lockSetFunctions{}.ClearValue(&slice[i])
+ }
+}
+
+func LockzeroNodeSlice(slice []*Locknode) {
+ for i := range slice {
+ slice[i] = nil
+ }
+}
+
+// String stringifies a Set for debugging.
+func (s *LockSet) String() string {
+ return s.root.String()
+}
+
+// String stringifies a node (and all of its children) for debugging.
+func (n *Locknode) String() string {
+ var buf bytes.Buffer
+ n.writeDebugString(&buf, "")
+ return buf.String()
+}
+
+func (n *Locknode) writeDebugString(buf *bytes.Buffer, prefix string) {
+ if n.hasChildren != (n.nrSegments > 0 && n.children[0] != nil) {
+ buf.WriteString(prefix)
+ buf.WriteString(fmt.Sprintf("WARNING: inconsistent value of hasChildren: got %v, want %v\n", n.hasChildren, !n.hasChildren))
+ }
+ for i := 0; i < n.nrSegments; i++ {
+ if child := n.children[i]; child != nil {
+ cprefix := fmt.Sprintf("%s- % 3d ", prefix, i)
+ if child.parent != n || child.parentIndex != i {
+ buf.WriteString(cprefix)
+ buf.WriteString(fmt.Sprintf("WARNING: inconsistent linkage to parent: got (%p, %d), want (%p, %d)\n", child.parent, child.parentIndex, n, i))
+ }
+ child.writeDebugString(buf, fmt.Sprintf("%s- % 3d ", prefix, i))
+ }
+ buf.WriteString(prefix)
+ buf.WriteString(fmt.Sprintf("- % 3d: %v => %v\n", i, n.keys[i], n.values[i]))
+ }
+ if child := n.children[n.nrSegments]; child != nil {
+ child.writeDebugString(buf, fmt.Sprintf("%s- % 3d ", prefix, n.nrSegments))
+ }
+}
+
+// SegmentDataSlices represents segments from a set as slices of start, end, and
+// values. SegmentDataSlices is primarily used as an intermediate representation
+// for save/restore and the layout here is optimized for that.
+//
+// +stateify savable
+type LockSegmentDataSlices struct {
+ Start []uint64
+ End []uint64
+ Values []Lock
+}
+
+// ExportSortedSlice returns a copy of all segments in the given set, in ascending
+// key order.
+func (s *LockSet) ExportSortedSlices() *LockSegmentDataSlices {
+ var sds LockSegmentDataSlices
+ for seg := s.FirstSegment(); seg.Ok(); seg = seg.NextSegment() {
+ sds.Start = append(sds.Start, seg.Start())
+ sds.End = append(sds.End, seg.End())
+ sds.Values = append(sds.Values, seg.Value())
+ }
+ sds.Start = sds.Start[:len(sds.Start):len(sds.Start)]
+ sds.End = sds.End[:len(sds.End):len(sds.End)]
+ sds.Values = sds.Values[:len(sds.Values):len(sds.Values)]
+ return &sds
+}
+
+// ImportSortedSlice initializes the given set from the given slice.
+//
+// Preconditions: s must be empty. sds must represent a valid set (the segments
+// in sds must have valid lengths that do not overlap). The segments in sds
+// must be sorted in ascending key order.
+func (s *LockSet) ImportSortedSlices(sds *LockSegmentDataSlices) error {
+ if !s.IsEmpty() {
+ return fmt.Errorf("cannot import into non-empty set %v", s)
+ }
+ gap := s.FirstGap()
+ for i := range sds.Start {
+ r := LockRange{sds.Start[i], sds.End[i]}
+ if !gap.Range().IsSupersetOf(r) {
+ return fmt.Errorf("segment overlaps a preceding segment or is incorrectly sorted: [%d, %d) => %v", sds.Start[i], sds.End[i], sds.Values[i])
+ }
+ gap = s.InsertWithoutMerging(gap, r, sds.Values[i]).NextGap()
+ }
+ return nil
+}
+func (s *LockSet) saveRoot() *LockSegmentDataSlices {
+ return s.ExportSortedSlices()
+}
+
+func (s *LockSet) loadRoot(sds *LockSegmentDataSlices) {
+ if err := s.ImportSortedSlices(sds); err != nil {
+ panic(err)
+ }
+}
diff --git a/pkg/sentry/fs/lock/lock_state_autogen.go b/pkg/sentry/fs/lock/lock_state_autogen.go
new file mode 100755
index 000000000..cb69e2cd0
--- /dev/null
+++ b/pkg/sentry/fs/lock/lock_state_autogen.go
@@ -0,0 +1,106 @@
+// automatically generated by stateify.
+
+package lock
+
+import (
+ "gvisor.dev/gvisor/pkg/state"
+)
+
+func (x *Lock) beforeSave() {}
+func (x *Lock) save(m state.Map) {
+ x.beforeSave()
+ m.Save("Readers", &x.Readers)
+ m.Save("HasWriter", &x.HasWriter)
+ m.Save("Writer", &x.Writer)
+}
+
+func (x *Lock) afterLoad() {}
+func (x *Lock) load(m state.Map) {
+ m.Load("Readers", &x.Readers)
+ m.Load("HasWriter", &x.HasWriter)
+ m.Load("Writer", &x.Writer)
+}
+
+func (x *Locks) beforeSave() {}
+func (x *Locks) save(m state.Map) {
+ x.beforeSave()
+ if !state.IsZeroValue(x.blockedQueue) { m.Failf("blockedQueue is %v, expected zero", x.blockedQueue) }
+ m.Save("locks", &x.locks)
+}
+
+func (x *Locks) afterLoad() {}
+func (x *Locks) load(m state.Map) {
+ m.Load("locks", &x.locks)
+}
+
+func (x *LockRange) beforeSave() {}
+func (x *LockRange) save(m state.Map) {
+ x.beforeSave()
+ m.Save("Start", &x.Start)
+ m.Save("End", &x.End)
+}
+
+func (x *LockRange) afterLoad() {}
+func (x *LockRange) load(m state.Map) {
+ m.Load("Start", &x.Start)
+ m.Load("End", &x.End)
+}
+
+func (x *LockSet) beforeSave() {}
+func (x *LockSet) save(m state.Map) {
+ x.beforeSave()
+ var root *LockSegmentDataSlices = x.saveRoot()
+ m.SaveValue("root", root)
+}
+
+func (x *LockSet) afterLoad() {}
+func (x *LockSet) load(m state.Map) {
+ m.LoadValue("root", new(*LockSegmentDataSlices), func(y interface{}) { x.loadRoot(y.(*LockSegmentDataSlices)) })
+}
+
+func (x *Locknode) beforeSave() {}
+func (x *Locknode) save(m state.Map) {
+ x.beforeSave()
+ m.Save("nrSegments", &x.nrSegments)
+ m.Save("parent", &x.parent)
+ m.Save("parentIndex", &x.parentIndex)
+ m.Save("hasChildren", &x.hasChildren)
+ m.Save("keys", &x.keys)
+ m.Save("values", &x.values)
+ m.Save("children", &x.children)
+}
+
+func (x *Locknode) afterLoad() {}
+func (x *Locknode) load(m state.Map) {
+ m.Load("nrSegments", &x.nrSegments)
+ m.Load("parent", &x.parent)
+ m.Load("parentIndex", &x.parentIndex)
+ m.Load("hasChildren", &x.hasChildren)
+ m.Load("keys", &x.keys)
+ m.Load("values", &x.values)
+ m.Load("children", &x.children)
+}
+
+func (x *LockSegmentDataSlices) beforeSave() {}
+func (x *LockSegmentDataSlices) save(m state.Map) {
+ x.beforeSave()
+ m.Save("Start", &x.Start)
+ m.Save("End", &x.End)
+ m.Save("Values", &x.Values)
+}
+
+func (x *LockSegmentDataSlices) afterLoad() {}
+func (x *LockSegmentDataSlices) load(m state.Map) {
+ m.Load("Start", &x.Start)
+ m.Load("End", &x.End)
+ m.Load("Values", &x.Values)
+}
+
+func init() {
+ state.Register("lock.Lock", (*Lock)(nil), state.Fns{Save: (*Lock).save, Load: (*Lock).load})
+ state.Register("lock.Locks", (*Locks)(nil), state.Fns{Save: (*Locks).save, Load: (*Locks).load})
+ state.Register("lock.LockRange", (*LockRange)(nil), state.Fns{Save: (*LockRange).save, Load: (*LockRange).load})
+ state.Register("lock.LockSet", (*LockSet)(nil), state.Fns{Save: (*LockSet).save, Load: (*LockSet).load})
+ state.Register("lock.Locknode", (*Locknode)(nil), state.Fns{Save: (*Locknode).save, Load: (*Locknode).load})
+ state.Register("lock.LockSegmentDataSlices", (*LockSegmentDataSlices)(nil), state.Fns{Save: (*LockSegmentDataSlices).save, Load: (*LockSegmentDataSlices).load})
+}
diff --git a/pkg/sentry/fs/lock/lock_test.go b/pkg/sentry/fs/lock/lock_test.go
deleted file mode 100644
index ba002aeb7..000000000
--- a/pkg/sentry/fs/lock/lock_test.go
+++ /dev/null
@@ -1,1059 +0,0 @@
-// Copyright 2018 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package lock
-
-import (
- "reflect"
- "testing"
-)
-
-type entry struct {
- Lock
- LockRange
-}
-
-func equals(e0, e1 []entry) bool {
- if len(e0) != len(e1) {
- return false
- }
- for i := range e0 {
- for k := range e0[i].Lock.Readers {
- if !e1[i].Lock.Readers[k] {
- return false
- }
- }
- for k := range e1[i].Lock.Readers {
- if !e0[i].Lock.Readers[k] {
- return false
- }
- }
- if !reflect.DeepEqual(e0[i].LockRange, e1[i].LockRange) {
- return false
- }
- if e0[i].Lock.HasWriter != e1[i].Lock.HasWriter {
- return false
- }
- if e0[i].Lock.Writer != e1[i].Lock.Writer {
- return false
- }
- }
- return true
-}
-
-// fill a LockSet with consecutive region locks. Will panic if
-// LockRanges are not consecutive.
-func fill(entries []entry) LockSet {
- l := LockSet{}
- for _, e := range entries {
- gap := l.FindGap(e.LockRange.Start)
- if !gap.Ok() {
- panic("cannot insert into existing segment")
- }
- l.Insert(gap, e.LockRange, e.Lock)
- }
- return l
-}
-
-func TestCanLockEmpty(t *testing.T) {
- l := LockSet{}
-
- // Expect to be able to take any locks given that the set is empty.
- eof := l.FirstGap().End()
- r := LockRange{0, eof}
- if !l.canLock(1, ReadLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", ReadLock, r, 1)
- }
- if !l.canLock(2, ReadLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", ReadLock, r, 2)
- }
- if !l.canLock(1, WriteLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", WriteLock, r, 1)
- }
- if !l.canLock(2, WriteLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", WriteLock, r, 2)
- }
-}
-
-func TestCanLock(t *testing.T) {
- // + -------------- + ---------- + -------------- + --------- +
- // | Readers 1 & 2 | Readers 1 | Readers 1 & 3 | Writer 1 |
- // + ------------- + ---------- + -------------- + --------- +
- // 0 1024 2048 3072 4096
- l := fill([]entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{1: true, 2: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{1: true}},
- LockRange: LockRange{1024, 2048},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{1: true, 3: true}},
- LockRange: LockRange{2048, 3072},
- },
- {
- Lock: Lock{HasWriter: true, Writer: 1},
- LockRange: LockRange{3072, 4096},
- },
- })
-
- // Now that we have a mildly interesting layout, try some checks on different
- // ranges, uids, and lock types.
- //
- // Expect to be able to extend the read lock, despite the writer lock, because
- // the writer has the same uid as the requested read lock.
- r := LockRange{0, 8192}
- if !l.canLock(1, ReadLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", ReadLock, r, 1)
- }
- // Expect to *not* be able to extend the read lock since there is an overlapping
- // writer region locked by someone other than the uid.
- if l.canLock(2, ReadLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got true, want false", ReadLock, r, 2)
- }
- // Expect to be able to extend the read lock if there are only other readers in
- // the way.
- r = LockRange{64, 3072}
- if !l.canLock(2, ReadLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", ReadLock, r, 2)
- }
- // Expect to be able to set a read lock beyond the range of any existing locks.
- r = LockRange{4096, 10240}
- if !l.canLock(2, ReadLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", ReadLock, r, 2)
- }
-
- // Expect to not be able to take a write lock with other readers in the way.
- r = LockRange{0, 8192}
- if l.canLock(1, WriteLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got true, want false", WriteLock, r, 1)
- }
- // Expect to be able to extend the write lock for the same uid.
- r = LockRange{3072, 8192}
- if !l.canLock(1, WriteLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", WriteLock, r, 1)
- }
- // Expect to not be able to overlap a write lock for two different uids.
- if l.canLock(2, WriteLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got true, want false", WriteLock, r, 2)
- }
- // Expect to be able to set a write lock that is beyond the range of any
- // existing locks.
- r = LockRange{8192, 10240}
- if !l.canLock(2, WriteLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", WriteLock, r, 2)
- }
- // Expect to be able to upgrade a read lock (any portion of it).
- r = LockRange{1024, 2048}
- if !l.canLock(1, WriteLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", WriteLock, r, 1)
- }
- r = LockRange{1080, 2000}
- if !l.canLock(1, WriteLock, r) {
- t.Fatalf("canLock type %d for range %v and uid %d got false, want true", WriteLock, r, 1)
- }
-}
-
-func TestSetLock(t *testing.T) {
- tests := []struct {
- // description of test.
- name string
-
- // LockSet entries to pre-fill.
- before []entry
-
- // Description of region to lock:
- //
- // start is the file offset of the lock.
- start uint64
- // end is the end file offset of the lock.
- end uint64
- // uid of lock attempter.
- uid UniqueID
- // lock type requested.
- lockType LockType
-
- // success is true if taking the above
- // lock should succeed.
- success bool
-
- // Expected layout of the set after locking
- // if success is true.
- after []entry
- }{
- {
- name: "set zero length ReadLock on empty set",
- start: 0,
- end: 0,
- uid: 0,
- lockType: ReadLock,
- success: true,
- },
- {
- name: "set zero length WriteLock on empty set",
- start: 0,
- end: 0,
- uid: 0,
- lockType: WriteLock,
- success: true,
- },
- {
- name: "set ReadLock on empty set",
- start: 0,
- end: LockEOF,
- uid: 0,
- lockType: ReadLock,
- success: true,
- // + ----------------------------------------- +
- // | Readers 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- },
- {
- name: "set WriteLock on empty set",
- start: 0,
- end: LockEOF,
- uid: 0,
- lockType: WriteLock,
- success: true,
- // + ----------------------------------------- +
- // | Writer 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- after: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, LockEOF},
- },
- },
- },
- {
- name: "set ReadLock on WriteLock same uid",
- // + ----------------------------------------- +
- // | Writer 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 0,
- end: 4096,
- uid: 0,
- lockType: ReadLock,
- success: true,
- // + ----------- + --------------------------- +
- // | Readers 0 | Writer 0 |
- // + ----------- + --------------------------- +
- // 0 4096 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, 4096},
- },
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "set WriteLock on ReadLock same uid",
- // + ----------------------------------------- +
- // | Readers 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 0,
- end: 4096,
- uid: 0,
- lockType: WriteLock,
- success: true,
- // + ----------- + --------------------------- +
- // | Writer 0 | Readers 0 |
- // + ----------- + --------------------------- +
- // 0 4096 max uint64
- after: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, 4096},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "set ReadLock on WriteLock different uid",
- // + ----------------------------------------- +
- // | Writer 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 0,
- end: 4096,
- uid: 1,
- lockType: ReadLock,
- success: false,
- },
- {
- name: "set WriteLock on ReadLock different uid",
- // + ----------------------------------------- +
- // | Readers 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 0,
- end: 4096,
- uid: 1,
- lockType: WriteLock,
- success: false,
- },
- {
- name: "split ReadLock for overlapping lock at start 0",
- // + ----------------------------------------- +
- // | Readers 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 0,
- end: 4096,
- uid: 1,
- lockType: ReadLock,
- success: true,
- // + -------------- + --------------------------- +
- // | Readers 0 & 1 | Readers 0 |
- // + -------------- + --------------------------- +
- // 0 4096 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{0, 4096},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "split ReadLock for overlapping lock at non-zero start",
- // + ----------------------------------------- +
- // | Readers 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 4096,
- end: 8192,
- uid: 1,
- lockType: ReadLock,
- success: true,
- // + ---------- + -------------- + ----------- +
- // | Readers 0 | Readers 0 & 1 | Readers 0 |
- // + ---------- + -------------- + ----------- +
- // 0 4096 8192 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, 4096},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{4096, 8192},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{8192, LockEOF},
- },
- },
- },
- {
- name: "fill front gap with ReadLock",
- // + --------- + ---------------------------- +
- // | gap | Readers 0 |
- // + --------- + ---------------------------- +
- // 0 1024 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{1024, LockEOF},
- },
- },
- start: 0,
- end: 8192,
- uid: 0,
- lockType: ReadLock,
- success: true,
- // + ----------------------------------------- +
- // | Readers 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- },
- {
- name: "fill end gap with ReadLock",
- // + ---------------------------- +
- // | Readers 0 |
- // + ---------------------------- +
- // 0 4096
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, 4096},
- },
- },
- start: 1024,
- end: LockEOF,
- uid: 0,
- lockType: ReadLock,
- success: true,
- // Note that this is not merged after lock does a Split. This is
- // fine because the two locks will still *behave* as one. In other
- // words we can fragment any lock all we want and semantically it
- // makes no difference.
- //
- // + ----------- + --------------------------- +
- // | Readers 0 | Readers 0 |
- // + ----------- + --------------------------- +
- // 0 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{1024, LockEOF},
- },
- },
- },
- {
- name: "fill gap with ReadLock and split",
- // + --------- + ---------------------------- +
- // | gap | Readers 0 |
- // + --------- + ---------------------------- +
- // 0 1024 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{1024, LockEOF},
- },
- },
- start: 0,
- end: 4096,
- uid: 1,
- lockType: ReadLock,
- success: true,
- // + --------- + ------------- + ------------- +
- // | Reader 1 | Readers 0 & 1 | Reader 0 |
- // + ----------+ ------------- + ------------- +
- // 0 1024 4096 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{1: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{1024, 4096},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "upgrade ReadLock to WriteLock for single uid fill gap",
- // + ------------- + --------- + --- + ------------- +
- // | Readers 0 & 1 | Readers 0 | gap | Readers 0 & 2 |
- // + ------------- + --------- + --- + ------------- +
- // 0 1024 2048 4096 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{1024, 2048},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 2: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- start: 1024,
- end: 4096,
- uid: 0,
- lockType: WriteLock,
- success: true,
- // + ------------- + -------- + ------------- +
- // | Readers 0 & 1 | Writer 0 | Readers 0 & 2 |
- // + ------------- + -------- + ------------- +
- // 0 1024 4096 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{1024, 4096},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 2: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "upgrade ReadLock to WriteLock for single uid keep gap",
- // + ------------- + --------- + --- + ------------- +
- // | Readers 0 & 1 | Readers 0 | gap | Readers 0 & 2 |
- // + ------------- + --------- + --- + ------------- +
- // 0 1024 2048 4096 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{1024, 2048},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 2: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- start: 1024,
- end: 3072,
- uid: 0,
- lockType: WriteLock,
- success: true,
- // + ------------- + -------- + --- + ------------- +
- // | Readers 0 & 1 | Writer 0 | gap | Readers 0 & 2 |
- // + ------------- + -------- + --- + ------------- +
- // 0 1024 3072 4096 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{1024, 3072},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 2: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "fail to upgrade ReadLock to WriteLock with conflicting Reader",
- // + ------------- + --------- +
- // | Readers 0 & 1 | Readers 0 |
- // + ------------- + --------- +
- // 0 1024 2048
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{1024, 2048},
- },
- },
- start: 0,
- end: 2048,
- uid: 0,
- lockType: WriteLock,
- success: false,
- },
- {
- name: "take WriteLock on whole file if all uids are the same",
- // + ------------- + --------- + --------- + ---------- +
- // | Writer 0 | Readers 0 | Readers 0 | Readers 0 |
- // + ------------- + --------- + --------- + ---------- +
- // 0 1024 2048 4096 max uint64
- before: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{1024, 2048},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{2048, 4096},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- start: 0,
- end: LockEOF,
- uid: 0,
- lockType: WriteLock,
- success: true,
- // We do not manually merge locks. Semantically a fragmented lock
- // held by the same uid will behave as one lock so it makes no difference.
- //
- // + ------------- + ---------------------------- +
- // | Writer 0 | Writer 0 |
- // + ------------- + ---------------------------- +
- // 0 1024 max uint64
- after: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{1024, LockEOF},
- },
- },
- },
- }
-
- for _, test := range tests {
- l := fill(test.before)
-
- r := LockRange{Start: test.start, End: test.end}
- success := l.lock(test.uid, test.lockType, r)
- var got []entry
- for seg := l.FirstSegment(); seg.Ok(); seg = seg.NextSegment() {
- got = append(got, entry{
- Lock: seg.Value(),
- LockRange: seg.Range(),
- })
- }
-
- if success != test.success {
- t.Errorf("%s: setlock(%v, %+v, %d, %d) got success %v, want %v", test.name, test.before, r, test.uid, test.lockType, success, test.success)
- continue
- }
-
- if success {
- if !equals(got, test.after) {
- t.Errorf("%s: got set %+v, want %+v", test.name, got, test.after)
- }
- }
- }
-}
-
-func TestUnlock(t *testing.T) {
- tests := []struct {
- // description of test.
- name string
-
- // LockSet entries to pre-fill.
- before []entry
-
- // Description of region to unlock:
- //
- // start is the file start of the lock.
- start uint64
- // end is the end file start of the lock.
- end uint64
- // uid of lock holder.
- uid UniqueID
-
- // Expected layout of the set after unlocking.
- after []entry
- }{
- {
- name: "unlock zero length on empty set",
- start: 0,
- end: 0,
- uid: 0,
- },
- {
- name: "unlock on empty set (no-op)",
- start: 0,
- end: LockEOF,
- uid: 0,
- },
- {
- name: "unlock uid not locked (no-op)",
- // + --------------------------- +
- // | Readers 1 & 2 |
- // + --------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{1: true, 2: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 1024,
- end: 4096,
- uid: 0,
- // + --------------------------- +
- // | Readers 1 & 2 |
- // + --------------------------- +
- // 0 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{1: true, 2: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- },
- {
- name: "unlock ReadLock over entire file",
- // + ----------------------------------------- +
- // | Readers 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 0,
- end: LockEOF,
- uid: 0,
- },
- {
- name: "unlock WriteLock over entire file",
- // + ----------------------------------------- +
- // | Writer 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 0,
- end: LockEOF,
- uid: 0,
- },
- {
- name: "unlock partial ReadLock (start)",
- // + ----------------------------------------- +
- // | Readers 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 0,
- end: 4096,
- uid: 0,
- // + ------ + --------------------------- +
- // | gap | Readers 0 |
- // +------- + --------------------------- +
- // 0 4096 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "unlock partial WriteLock (start)",
- // + ----------------------------------------- +
- // | Writer 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 0,
- end: 4096,
- uid: 0,
- // + ------ + --------------------------- +
- // | gap | Writer 0 |
- // +------- + --------------------------- +
- // 0 4096 max uint64
- after: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "unlock partial ReadLock (end)",
- // + ----------------------------------------- +
- // | Readers 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 4096,
- end: LockEOF,
- uid: 0,
- // + --------------------------- +
- // | Readers 0 |
- // +---------------------------- +
- // 0 4096
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true}},
- LockRange: LockRange{0, 4096},
- },
- },
- },
- {
- name: "unlock partial WriteLock (end)",
- // + ----------------------------------------- +
- // | Writer 0 |
- // + ----------------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 4096,
- end: LockEOF,
- uid: 0,
- // + --------------------------- +
- // | Writer 0 |
- // +---------------------------- +
- // 0 4096
- after: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, 4096},
- },
- },
- },
- {
- name: "unlock for single uid",
- // + ------------- + --------- + ------------------- +
- // | Readers 0 & 1 | Writer 0 | Readers 0 & 1 & 2 |
- // + ------------- + --------- + ------------------- +
- // 0 1024 4096 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{1024, 4096},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true, 2: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- start: 0,
- end: LockEOF,
- uid: 0,
- // + --------- + --- + --------------- +
- // | Readers 1 | gap | Readers 1 & 2 |
- // + --------- + --- + --------------- +
- // 0 1024 4096 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{1: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{1: true, 2: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "unlock subsection locked",
- // + ------------------------------- +
- // | Readers 0 & 1 & 2 |
- // + ------------------------------- +
- // 0 max uint64
- before: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true, 2: true}},
- LockRange: LockRange{0, LockEOF},
- },
- },
- start: 1024,
- end: 4096,
- uid: 0,
- // + ----------------- + ------------- + ----------------- +
- // | Readers 0 & 1 & 2 | Readers 1 & 2 | Readers 0 & 1 & 2 |
- // + ----------------- + ------------- + ----------------- +
- // 0 1024 4096 max uint64
- after: []entry{
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true, 2: true}},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{1: true, 2: true}},
- LockRange: LockRange{1024, 4096},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true, 2: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "unlock mid-gap to increase gap",
- // + --------- + ----- + ------------------- +
- // | Writer 0 | gap | Readers 0 & 1 |
- // + --------- + ----- + ------------------- +
- // 0 1024 4096 max uint64
- before: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- start: 8,
- end: 2048,
- uid: 0,
- // + --------- + ----- + ------------------- +
- // | Writer 0 | gap | Readers 0 & 1 |
- // + --------- + ----- + ------------------- +
- // 0 8 4096 max uint64
- after: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, 8},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- },
- {
- name: "unlock split region on uid mid-gap",
- // + --------- + ----- + ------------------- +
- // | Writer 0 | gap | Readers 0 & 1 |
- // + --------- + ----- + ------------------- +
- // 0 1024 4096 max uint64
- before: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{4096, LockEOF},
- },
- },
- start: 2048,
- end: 8192,
- uid: 0,
- // + --------- + ----- + --------- + ------------- +
- // | Writer 0 | gap | Readers 1 | Readers 0 & 1 |
- // + --------- + ----- + --------- + ------------- +
- // 0 1024 4096 8192 max uint64
- after: []entry{
- {
- Lock: Lock{HasWriter: true, Writer: 0},
- LockRange: LockRange{0, 1024},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{1: true}},
- LockRange: LockRange{4096, 8192},
- },
- {
- Lock: Lock{Readers: map[UniqueID]bool{0: true, 1: true}},
- LockRange: LockRange{8192, LockEOF},
- },
- },
- },
- }
-
- for _, test := range tests {
- l := fill(test.before)
-
- r := LockRange{Start: test.start, End: test.end}
- l.unlock(test.uid, r)
- var got []entry
- for seg := l.FirstSegment(); seg.Ok(); seg = seg.NextSegment() {
- got = append(got, entry{
- Lock: seg.Value(),
- LockRange: seg.Range(),
- })
- }
- if !equals(got, test.after) {
- t.Errorf("%s: got set %+v, want %+v", test.name, got, test.after)
- }
- }
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-04 18:13:14 +0000