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Diffstat (limited to 'pkg/tcpip/faketime/faketime.go')
-rw-r--r--pkg/tcpip/faketime/faketime.go358
1 files changed, 0 insertions, 358 deletions
diff --git a/pkg/tcpip/faketime/faketime.go b/pkg/tcpip/faketime/faketime.go
deleted file mode 100644
index fb819d7a8..000000000
--- a/pkg/tcpip/faketime/faketime.go
+++ /dev/null
@@ -1,358 +0,0 @@
-// Copyright 2020 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 faketime provides a fake clock that implements tcpip.Clock interface.
-package faketime
-
-import (
- "container/heap"
- "fmt"
- "sync"
- "time"
-
- "gvisor.dev/gvisor/pkg/tcpip"
-)
-
-// NullClock implements a clock that never advances.
-type NullClock struct{}
-
-var _ tcpip.Clock = (*NullClock)(nil)
-
-// NowNanoseconds implements tcpip.Clock.NowNanoseconds.
-func (*NullClock) NowNanoseconds() int64 {
- return 0
-}
-
-// NowMonotonic implements tcpip.Clock.NowMonotonic.
-func (*NullClock) NowMonotonic() int64 {
- return 0
-}
-
-// AfterFunc implements tcpip.Clock.AfterFunc.
-func (*NullClock) AfterFunc(time.Duration, func()) tcpip.Timer {
- return nil
-}
-
-type notificationChannels struct {
- mu struct {
- sync.Mutex
-
- ch []<-chan struct{}
- }
-}
-
-func (n *notificationChannels) add(ch <-chan struct{}) {
- n.mu.Lock()
- defer n.mu.Unlock()
- n.mu.ch = append(n.mu.ch, ch)
-}
-
-// wait returns once all the notification channels are readable.
-//
-// Channels that are added while waiting on existing channels will be waited on
-// as well.
-func (n *notificationChannels) wait() {
- for {
- n.mu.Lock()
- ch := n.mu.ch
- n.mu.ch = nil
- n.mu.Unlock()
-
- if len(ch) == 0 {
- break
- }
-
- for _, c := range ch {
- <-c
- }
- }
-}
-
-// ManualClock implements tcpip.Clock and only advances manually with Advance
-// method.
-type ManualClock struct {
- // runningTimers tracks the completion of timer callbacks that began running
- // immediately upon their scheduling. It is used to ensure the proper ordering
- // of timer callback dispatch.
- runningTimers notificationChannels
-
- mu struct {
- sync.RWMutex
-
- // now is the current (fake) time of the clock.
- now time.Time
-
- // times is min-heap of times.
- times timeHeap
-
- // timers holds the timers scheduled for each time.
- timers map[time.Time]map[*manualTimer]struct{}
- }
-}
-
-// NewManualClock creates a new ManualClock instance.
-func NewManualClock() *ManualClock {
- c := &ManualClock{}
-
- c.mu.Lock()
- defer c.mu.Unlock()
-
- // Set the initial time to a non-zero value since the zero value is used to
- // detect inactive timers.
- c.mu.now = time.Unix(0, 0)
- c.mu.timers = make(map[time.Time]map[*manualTimer]struct{})
-
- return c
-}
-
-var _ tcpip.Clock = (*ManualClock)(nil)
-
-// NowNanoseconds implements tcpip.Clock.NowNanoseconds.
-func (mc *ManualClock) NowNanoseconds() int64 {
- mc.mu.RLock()
- defer mc.mu.RUnlock()
- return mc.mu.now.UnixNano()
-}
-
-// NowMonotonic implements tcpip.Clock.NowMonotonic.
-func (mc *ManualClock) NowMonotonic() int64 {
- return mc.NowNanoseconds()
-}
-
-// AfterFunc implements tcpip.Clock.AfterFunc.
-func (mc *ManualClock) AfterFunc(d time.Duration, f func()) tcpip.Timer {
- mt := &manualTimer{
- clock: mc,
- f: f,
- }
-
- mc.mu.Lock()
- defer mc.mu.Unlock()
-
- mt.mu.Lock()
- defer mt.mu.Unlock()
-
- mc.resetTimerLocked(mt, d)
- return mt
-}
-
-// resetTimerLocked schedules a timer to be fired after the given duration.
-//
-// Precondition: mc.mu and mt.mu must be locked.
-func (mc *ManualClock) resetTimerLocked(mt *manualTimer, d time.Duration) {
- if !mt.mu.firesAt.IsZero() {
- panic("tried to reset an active timer")
- }
-
- t := mc.mu.now.Add(d)
-
- if !mc.mu.now.Before(t) {
- // If the timer is scheduled to fire immediately, call its callback
- // in a new goroutine immediately.
- //
- // It needs to be called in its own goroutine to escape its current
- // execution context - like an actual timer.
- ch := make(chan struct{})
- mc.runningTimers.add(ch)
-
- go func() {
- defer close(ch)
-
- mt.f()
- }()
-
- return
- }
-
- mt.mu.firesAt = t
-
- timers, ok := mc.mu.timers[t]
- if !ok {
- timers = make(map[*manualTimer]struct{})
- mc.mu.timers[t] = timers
- heap.Push(&mc.mu.times, t)
- }
-
- timers[mt] = struct{}{}
-}
-
-// stopTimerLocked stops a timer from firing.
-//
-// Precondition: mc.mu and mt.mu must be locked.
-func (mc *ManualClock) stopTimerLocked(mt *manualTimer) {
- t := mt.mu.firesAt
- mt.mu.firesAt = time.Time{}
-
- if t.IsZero() {
- panic("tried to stop an inactive timer")
- }
-
- timers, ok := mc.mu.timers[t]
- if !ok {
- err := fmt.Sprintf("tried to stop an active timer but the clock does not have anything scheduled for the timer @ t = %s %p\nScheduled timers @:", t.UTC(), mt)
- for t := range mc.mu.timers {
- err += fmt.Sprintf("%s\n", t.UTC())
- }
- panic(err)
- }
-
- if _, ok := timers[mt]; !ok {
- panic(fmt.Sprintf("did not have an entry in timers for an active timer @ t = %s", t.UTC()))
- }
-
- delete(timers, mt)
-
- if len(timers) == 0 {
- delete(mc.mu.timers, t)
- }
-}
-
-// Advance executes all work that have been scheduled to execute within d from
-// the current time. Blocks until all work has completed execution.
-func (mc *ManualClock) Advance(d time.Duration) {
- // We spawn goroutines for timers that were scheduled to fire at the time of
- // being reset. Wait for those goroutines to complete before proceeding so
- // that timer callbacks are called in the right order.
- mc.runningTimers.wait()
-
- mc.mu.Lock()
- defer mc.mu.Unlock()
-
- until := mc.mu.now.Add(d)
- for mc.mu.times.Len() > 0 {
- t := heap.Pop(&mc.mu.times).(time.Time)
- if t.After(until) {
- // No work to do
- heap.Push(&mc.mu.times, t)
- break
- }
-
- timers := mc.mu.timers[t]
- delete(mc.mu.timers, t)
-
- mc.mu.now = t
-
- // Mark the timers as inactive since they will be fired.
- //
- // This needs to be done while holding mc's lock because we remove the entry
- // in the map of timers for the current time. If an attempt to stop a
- // timer is made after mc's lock was dropped but before the timer is
- // marked inactive, we would panic since no entry exists for the time when
- // the timer was expected to fire.
- for mt := range timers {
- mt.mu.Lock()
- mt.mu.firesAt = time.Time{}
- mt.mu.Unlock()
- }
-
- // Release the lock before calling the timer's callback fn since the
- // callback fn might try to schedule a timer which requires obtaining
- // mc's lock.
- mc.mu.Unlock()
-
- for mt := range timers {
- mt.f()
- }
-
- // The timer callbacks may have scheduled a timer to fire immediately.
- // We spawn goroutines for these timers and need to wait for them to
- // finish before proceeding so that timer callbacks are called in the
- // right order.
- mc.runningTimers.wait()
- mc.mu.Lock()
- }
-
- mc.mu.now = until
-}
-
-func (mc *ManualClock) resetTimer(mt *manualTimer, d time.Duration) {
- mc.mu.Lock()
- defer mc.mu.Unlock()
-
- mt.mu.Lock()
- defer mt.mu.Unlock()
-
- if !mt.mu.firesAt.IsZero() {
- mc.stopTimerLocked(mt)
- }
-
- mc.resetTimerLocked(mt, d)
-}
-
-func (mc *ManualClock) stopTimer(mt *manualTimer) bool {
- mc.mu.Lock()
- defer mc.mu.Unlock()
-
- mt.mu.Lock()
- defer mt.mu.Unlock()
-
- if mt.mu.firesAt.IsZero() {
- return false
- }
-
- mc.stopTimerLocked(mt)
- return true
-}
-
-type manualTimer struct {
- clock *ManualClock
- f func()
-
- mu struct {
- sync.Mutex
-
- // firesAt is the time when the timer will fire.
- //
- // Zero only when the timer is not active.
- firesAt time.Time
- }
-}
-
-var _ tcpip.Timer = (*manualTimer)(nil)
-
-// Reset implements tcpip.Timer.Reset.
-func (mt *manualTimer) Reset(d time.Duration) {
- mt.clock.resetTimer(mt, d)
-}
-
-// Stop implements tcpip.Timer.Stop.
-func (mt *manualTimer) Stop() bool {
- return mt.clock.stopTimer(mt)
-}
-
-type timeHeap []time.Time
-
-var _ heap.Interface = (*timeHeap)(nil)
-
-func (h timeHeap) Len() int {
- return len(h)
-}
-
-func (h timeHeap) Less(i, j int) bool {
- return h[i].Before(h[j])
-}
-
-func (h timeHeap) Swap(i, j int) {
- h[i], h[j] = h[j], h[i]
-}
-
-func (h *timeHeap) Push(x interface{}) {
- *h = append(*h, x.(time.Time))
-}
-
-func (h *timeHeap) Pop() interface{} {
- last := (*h)[len(*h)-1]
- *h = (*h)[:len(*h)-1]
- return last
-}