| 1 | //go:build linux |
| 2 | |
| 3 | package cgroup |
| 4 | |
| 5 | import ( |
| 6 | "context" |
| 7 | "errors" |
| 8 | "sync" |
| 9 | "testing" |
| 10 | "time" |
| 11 | ) |
| 12 | |
| 13 | func TestPlacementsUnderCountsTheSubtree(t *testing.T) { |
| 14 | m := &Manager{root: "/r", logf: t.Logf} |
| 15 | done := m.beginPlacement("/r/carlos-exec@a.example/g2") |
| 16 | if m.placementsUnder("/r/carlos-exec@a.example") != 1 || m.placementsAt("/r/carlos-exec@a.example") != 0 { |
| 17 | t.Fatal("a child's placement is under its parent, not at it") |
| 18 | } |
| 19 | if m.placementsUnder("/r/carlos-exec@a.exampleX") != 0 { |
| 20 | t.Fatal("a prefix without a separator matched") |
| 21 | } |
| 22 | if m.placementsAt("/r/carlos-exec@a.example/g2/") != 1 || m.placementsUnder("/r") != 1 { |
| 23 | t.Fatal("the target itself or its root does not count it") |
| 24 | } |
| 25 | done() |
| 26 | done() // idempotent |
| 27 | if m.placementsUnder("/r/carlos-exec@a.example") != 0 { |
| 28 | t.Fatal("done did not drop the count") |
| 29 | } |
| 30 | } |
| 31 | |
| 32 | func TestPlacementsCountEachInFlight(t *testing.T) { |
| 33 | m := &Manager{root: "/r", logf: t.Logf} |
| 34 | a := m.beginPlacement("/r/h") |
| 35 | b := m.beginPlacement("/r/h") |
| 36 | if m.placementsAt("/r/h") != 2 { |
| 37 | t.Fatal("two placements at one target count as one") |
| 38 | } |
| 39 | a() |
| 40 | a() |
| 41 | if m.placementsAt("/r/h") != 1 { |
| 42 | t.Fatal("a repeated done dropped another placement's count") |
| 43 | } |
| 44 | b() |
| 45 | if m.placementsAt("/r/h") != 0 { |
| 46 | t.Fatal("the count did not reach zero") |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | func TestWaitPlacementsUnderWakes(t *testing.T) { |
| 51 | m := &Manager{root: "/r", logf: t.Logf} |
| 52 | if err := m.waitPlacementsUnder(context.Background(), "/r"); err != nil { |
| 53 | t.Fatalf("nothing in flight: %v", err) |
| 54 | } |
| 55 | done := m.beginPlacement("/r/h/g1") |
| 56 | |
| 57 | ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond) |
| 58 | defer cancel() |
| 59 | if err := m.waitPlacementsUnder(ctx, "/r/h"); !errors.Is(err, context.DeadlineExceeded) { |
| 60 | t.Fatalf("err=%v, want context.DeadlineExceeded", err) |
| 61 | } |
| 62 | |
| 63 | got := make(chan error, 1) |
| 64 | go func() { got <- m.waitPlacementsUnder(context.Background(), "/r/h") }() |
| 65 | // An unrelated placement ending wakes the waiter, which must keep waiting. |
| 66 | other := m.beginPlacement("/r/elsewhere") |
| 67 | other() |
| 68 | select { |
| 69 | case err := <-got: |
| 70 | t.Fatalf("the waiter returned %v while a placement was in flight", err) |
| 71 | case <-time.After(50 * time.Millisecond): |
| 72 | } |
| 73 | done() |
| 74 | select { |
| 75 | case err := <-got: |
| 76 | if err != nil { |
| 77 | t.Fatal(err) |
| 78 | } |
| 79 | case <-time.After(time.Second): |
| 80 | t.Fatal("the waiter did not wake within 1s of done") |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | func TestNilManagerPlacements(t *testing.T) { |
| 85 | var m *Manager |
| 86 | done := m.beginPlacement("/r/h") |
| 87 | done() |
| 88 | if m.placementsUnder("/r") != 0 || m.placementsAt("/r/h") != 0 { |
| 89 | t.Fatal("a nil manager counted a placement") |
| 90 | } |
| 91 | if err := m.waitPlacementsUnder(context.Background(), "/r"); err != nil { |
| 92 | t.Fatal(err) |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | // readQuiet answers quiet only when nothing under its directory was in |
| 97 | // flight at any moment of the read: not at its start, not registered or |
| 98 | // ended during it, not at its end. Placements elsewhere do not count. |
| 99 | func TestReadQuiet(t *testing.T) { |
| 100 | m := &Manager{root: "/r", logf: t.Logf} |
| 101 | if !m.readQuiet("/r/h", func() {}) { |
| 102 | t.Fatal("nothing in flight read as not quiet") |
| 103 | } |
| 104 | other := m.beginPlacement("/r/hx/g1") |
| 105 | defer other() |
| 106 | if !m.readQuiet("/r/h", func() { m.beginPlacement("/r/other")() }) { |
| 107 | t.Fatal("placements outside the directory made the read not quiet") |
| 108 | } |
| 109 | done := m.beginPlacement("/r/h/g1") |
| 110 | if m.readQuiet("/r/h", func() {}) { |
| 111 | t.Fatal("a placement in flight throughout read as quiet") |
| 112 | } |
| 113 | if m.readQuiet("/r/h", done) { |
| 114 | t.Fatal("a placement that ended during the read read as quiet") |
| 115 | } |
| 116 | var late func() |
| 117 | if m.readQuiet("/r/h", func() { late = m.beginPlacement("/r/h/g2"); late() }) { |
| 118 | t.Fatal("a placement that registered and ended during the read read as quiet") |
| 119 | } |
| 120 | if !m.readQuiet("/r/h", func() {}) { |
| 121 | t.Fatal("the read after everything ended is not quiet") |
| 122 | } |
| 123 | m.placeMu.Lock() |
| 124 | open := len(m.windows) |
| 125 | m.placeMu.Unlock() |
| 126 | if open != 0 { |
| 127 | t.Fatalf("%d windows left open", open) |
| 128 | } |
| 129 | var nilm *Manager |
| 130 | ran := false |
| 131 | if !nilm.readQuiet("/r", func() { ran = true }) || !ran { |
| 132 | t.Fatal("a nil manager's read did not run or was not quiet") |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | // holdPlacements stops registrations in and below its directory until it |
| 137 | // is released, counts the ones already in flight, and leaves others alone. |
| 138 | func TestHoldPlacementsBlocksRegistrationUntilReleased(t *testing.T) { |
| 139 | m := &Manager{root: "/r", logf: t.Logf} |
| 140 | before := m.beginPlacement("/r/h/g1") |
| 141 | at, under, release := m.holdPlacements("/r/h") |
| 142 | if at != 0 || under != 1 { |
| 143 | t.Fatalf("hold counted %d at, %d under: want 0, 1", at, under) |
| 144 | } |
| 145 | // A placement already in flight still ends under the hold. |
| 146 | before() |
| 147 | // One elsewhere is not held. |
| 148 | m.beginPlacement("/r/elsewhere")() |
| 149 | |
| 150 | blocked := make(chan struct{}) |
| 151 | var once sync.Once |
| 152 | orig := placementHeldHook |
| 153 | placementHeldHook = func(string) { once.Do(func() { close(blocked) }) } |
| 154 | t.Cleanup(func() { placementHeldHook = orig }) |
| 155 | got := make(chan func(), 1) |
| 156 | go func() { got <- m.beginPlacement("/r/h/g2") }() |
| 157 | select { |
| 158 | case <-blocked: |
| 159 | case d := <-got: |
| 160 | d() |
| 161 | t.Fatal("a placement registered under a hold") |
| 162 | case <-time.After(5 * time.Second): |
| 163 | t.Fatal("the registration neither registered nor waited") |
| 164 | } |
| 165 | if n := m.placementsUnder("/r/h"); n != 0 { |
| 166 | t.Fatalf("%d placements registered under the hold", n) |
| 167 | } |
| 168 | release() |
| 169 | release() // idempotent |
| 170 | select { |
| 171 | case d := <-got: |
| 172 | if n := m.placementsAt("/r/h/g2"); n != 1 { |
| 173 | t.Fatalf("after the release %d placements at g2, want 1", n) |
| 174 | } |
| 175 | d() |
| 176 | case <-time.After(5 * time.Second): |
| 177 | t.Fatal("the registration did not go ahead once the hold was released") |
| 178 | } |
| 179 | var nilm *Manager |
| 180 | if a, u, r := nilm.holdPlacements("/r"); a != 0 || u != 0 { |
| 181 | t.Fatal("a nil manager counted placements") |
| 182 | } else { |
| 183 | r() |
| 184 | } |
| 185 | } |
| 186 | |
amadan