Implement WaitSetDispatcher::WaitSetWaitImpl().

mojo/edk/system/wait_set_dispatcher_unittest.cc

Index: mojo/edk/system/wait_set_dispatcher_unittest.cc
diff --git a/mojo/edk/system/wait_set_dispatcher_unittest.cc b/mojo/edk/system/wait_set_dispatcher_unittest.cc
index 41b6f59a3177f045bb1bd70dfc7f826a44326dbc..0c891e0591a0297bac347ad2d9b48f1cde749d03 100644
--- a/mojo/edk/system/wait_set_dispatcher_unittest.cc
+++ b/mojo/edk/system/wait_set_dispatcher_unittest.cc
@@ -13,38 +13,84 @@ namespace mojo {
 namespace system {
 namespace {
 
+// Helper to check if an array of |MojoWaitSetResult|s has a result |r| for the
+// given cookie, in which case:
+//    - |r.wait_result| must equal |wait_result|.
+//    - If |wait_result| is |MOJO_RESULT_OK| or
+//      |MOJO_RESULT_FAILED_PRECONDITION|, then
+//        - |r.signals_state.satisfied_signals & signals| must equal
+//          |signals_state.satisfied_signals & signals|, and
+//        - |r.signals_state.satisfiable & signals| must equal
+//          |signals_state.satisfiable_signals & signals|.
+//    - Otherwise, |r.signals_state| must equals |signals_state|.
+// (This doesn't check that the result is unique; you should check |num_results|
+// versus the expect number and exhaustively check every expected result.)
+bool CheckHasResult(uint32_t num_results,
+                    const MojoWaitSetResult* results,
+                    uint64_t cookie,
+                    MojoHandleSignals signals,
+                    MojoResult wait_result,
+                    const MojoHandleSignalsState& signals_state) {
+  for (uint32_t i = 0; i < num_results; i++) {
+    if (results[i].cookie == cookie) {
+      EXPECT_EQ(wait_result, results[i].wait_result) << cookie;
+      EXPECT_EQ(0u, results[i].reserved) << cookie;
+      if (wait_result == MOJO_RESULT_OK ||
+          wait_result == MOJO_RESULT_FAILED_PRECONDITION) {
+        EXPECT_EQ(signals_state.satisfied_signals & signals,
+                  results[i].signals_state.satisfied_signals & signals)
+            << cookie;
+        EXPECT_EQ(signals_state.satisfiable_signals & signals,
+                  results[i].signals_state.satisfiable_signals & signals)
+            << cookie;
+      } else {
+        EXPECT_EQ(signals_state.satisfied_signals,
+                  results[i].signals_state.satisfied_signals)
+            << cookie;
+        EXPECT_EQ(signals_state.satisfiable_signals,
+                  results[i].signals_state.satisfiable_signals)
+            << cookie;
+      }
+      return true;
+    }
+  }
+  return false;
+}
+
 TEST(WaitSetDispatcherTest, Basic) {
+  static constexpr auto kR = MOJO_HANDLE_SIGNAL_READABLE;
+  static constexpr auto kW = MOJO_HANDLE_SIGNAL_WRITABLE;
+
+  static constexpr auto kIndefinite = MOJO_DEADLINE_INDEFINITE;
+  static constexpr auto k10ms = static_cast<MojoDeadline>(10 * 1000u);
+
   auto d = WaitSetDispatcher::Create(WaitSetDispatcher::kDefaultCreateOptions);
 
   // These will be members of our wait set.
-  auto d_member0 = MakeRefCounted<test::MockSimpleDispatcher>(
-      MOJO_HANDLE_SIGNAL_NONE,
-      MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE);
-  auto d_member1 = MakeRefCounted<test::MockSimpleDispatcher>(
-      MOJO_HANDLE_SIGNAL_READABLE, MOJO_HANDLE_SIGNAL_READABLE);
+  auto d_member0 = MakeRefCounted<test::MockSimpleDispatcher>(kW, kR | kW);
+  auto d_member1 = MakeRefCounted<test::MockSimpleDispatcher>(kR, kR);
 
   // Add |d_member0|, for something not satisfied, but satisfiable.
-  const uint64_t kCookie0 = 0x123456789abcdef0ULL;
-  EXPECT_EQ(MOJO_RESULT_OK,
-            d->WaitSetAdd(NullUserPointer(), d_member0.Clone(),
-                          MOJO_HANDLE_SIGNAL_READABLE, kCookie0));
+  static constexpr uint64_t kCookie0 = 0x123456789abcdef0ULL;
+  static constexpr auto kSignals0 = kR;
+  EXPECT_EQ(MOJO_RESULT_OK, d->WaitSetAdd(NullUserPointer(), d_member0.Clone(),
+                                          kSignals0, kCookie0));
 
   // Add |d_member1|, for something satisfied.
-  const uint64_t kCookie1 = 0x23456789abcdef01ULL;
-  EXPECT_EQ(MOJO_RESULT_OK,
-            d->WaitSetAdd(NullUserPointer(), d_member1.Clone(),
-                          MOJO_HANDLE_SIGNAL_READABLE, kCookie1));
+  static constexpr uint64_t kCookie1 = 0x23456789abcdef01ULL;
+  static constexpr auto kSignals1 = kR;
+  EXPECT_EQ(MOJO_RESULT_OK, d->WaitSetAdd(NullUserPointer(), d_member1.Clone(),
+                                          kSignals1, kCookie1));
 
-  // Can add |d_member0| again, with a different cookie.
-  const uint64_t kCookie2 = 0x3456789abcdef012ULL;
-  EXPECT_EQ(MOJO_RESULT_OK,
-            d->WaitSetAdd(NullUserPointer(), d_member0.Clone(),
-                          MOJO_HANDLE_SIGNAL_WRITABLE, kCookie2));
+  // Can add |d_member0| again (satisfied), with a different cookie.
+  static constexpr uint64_t kCookie2 = 0x3456789abcdef012ULL;
+  static constexpr auto kSignals2 = kW;
+  EXPECT_EQ(MOJO_RESULT_OK, d->WaitSetAdd(NullUserPointer(), d_member0.Clone(),
+                                          kSignals2, kCookie2));
 
   // Adding something with the same cookie yields "already exists".
   EXPECT_EQ(MOJO_RESULT_ALREADY_EXISTS,
-            d->WaitSetAdd(NullUserPointer(), d_member1.Clone(),
-                          MOJO_HANDLE_SIGNAL_READABLE, kCookie2));
+            d->WaitSetAdd(NullUserPointer(), d_member1.Clone(), kR, kCookie2));
 
   // Can remove something based on a cookie.
   EXPECT_EQ(MOJO_RESULT_OK, d->WaitSetRemove(kCookie0));
@@ -52,17 +98,134 @@ TEST(WaitSetDispatcherTest, Basic) {
   // Trying to remove the same cookie again should fail.
   EXPECT_EQ(MOJO_RESULT_NOT_FOUND, d->WaitSetRemove(kCookie0));
 
-  // Can re-add it.
+  // Can re-add it (still not satisfied, but satisfiable).
   EXPECT_EQ(MOJO_RESULT_OK,
-            d->WaitSetAdd(NullUserPointer(), d_member0.Clone(),
-                          MOJO_HANDLE_SIGNAL_READABLE, kCookie0));
-
-  // TODO(vtl): Test waiting here.
-
-  // Can close a dispatcher that's "in" the wait set.
+            d->WaitSetAdd(NullUserPointer(), d_member0.Clone(), kR, kCookie0));
+
+  // Wait. Recall:
+  //   - |kCookie0| is for |d_member0| and is not satisfied (but satisfiable).
+  //   - |kCookie1| is for |d_member1| and is satisfied.
+  //   - |kCookie2| is for |d_member0| and is satisfied.
+  {
+    uint32_t num_results = 10u;
+    MojoWaitSetResult results[10] = {};
+    uint32_t max_results = static_cast<uint32_t>(-1);
+    EXPECT_EQ(MOJO_RESULT_OK,
+              d->WaitSetWait(k10ms, MakeUserPointer(&num_results),
+                             MakeUserPointer(results),
+                             MakeUserPointer(&max_results)));
+    EXPECT_EQ(2u, num_results);
+    EXPECT_EQ(2u, max_results);
+
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie1, kSignals1,
+                               MOJO_RESULT_OK,
+                               d_member1->GetHandleSignalsState()));
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie2, kSignals2,
+                               MOJO_RESULT_OK,
+                               d_member0->GetHandleSignalsState()));
+  }
+
+  // Do the same, but test the "indefinite" (forever) wait code path and only
+  // allow one result.
+  {
+    uint32_t num_results = 1u;
+    MojoWaitSetResult results[1] = {};
+    uint32_t max_results = static_cast<uint32_t>(-1);
+    EXPECT_EQ(MOJO_RESULT_OK,
+              d->WaitSetWait(kIndefinite, MakeUserPointer(&num_results),
+                             MakeUserPointer(results),
+                             MakeUserPointer(&max_results)));
+    EXPECT_EQ(1u, num_results);
+    EXPECT_EQ(2u, max_results);
+
+    // We should have *one* of the results.
+    EXPECT_TRUE(
+        CheckHasResult(num_results, results, kCookie1, kSignals1,
+                       MOJO_RESULT_OK, d_member1->GetHandleSignalsState()) ||
+        CheckHasResult(num_results, results, kCookie2, kSignals2,
+                       MOJO_RESULT_OK, d_member0->GetHandleSignalsState()));
+  }
+
+  // Change the state of |d_member0|. This makes |kCookie0| satisfied.
+  d_member0->SetSatisfiedSignals(kR | kW);
+
+  // Wait.
+  {
+    uint32_t num_results = 3u;
+    MojoWaitSetResult results[3] = {};
+    uint32_t max_results = static_cast<uint32_t>(-1);
+    EXPECT_EQ(MOJO_RESULT_OK,
+              d->WaitSetWait(k10ms, MakeUserPointer(&num_results),
+                             MakeUserPointer(results),
+                             MakeUserPointer(&max_results)));
+    EXPECT_EQ(3u, num_results);
+    EXPECT_EQ(3u, max_results);
+
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie0, kSignals0,
+                               MOJO_RESULT_OK,
+                               d_member0->GetHandleSignalsState()));
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie1, kSignals1,
+                               MOJO_RESULT_OK,
+                               d_member1->GetHandleSignalsState()));
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie2, kSignals2,
+                               MOJO_RESULT_OK,
+                               d_member0->GetHandleSignalsState()));
+  }
+
+  // Change the state of |d_member0| in two steps. |kCookie0| remains satisfied,
+  // but |kCookie2| becomes unsatisfiable.
+  d_member0->SetSatisfiedSignals(kR);
+  d_member0->SetSatisfiableSignals(kR);
+
+  // Wait.
+  {
+    uint32_t num_results = 10u;
+    MojoWaitSetResult results[10] = {};
+    uint32_t max_results = static_cast<uint32_t>(-1);
+    EXPECT_EQ(MOJO_RESULT_OK,
+              d->WaitSetWait(k10ms, MakeUserPointer(&num_results),
+                             MakeUserPointer(results),
+                             MakeUserPointer(&max_results)));
+    EXPECT_EQ(3u, num_results);
+    EXPECT_EQ(3u, max_results);
+
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie0, kSignals0,
+                               MOJO_RESULT_OK,
+                               d_member0->GetHandleSignalsState()));
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie1, kSignals1,
+                               MOJO_RESULT_OK,
+                               d_member1->GetHandleSignalsState()));
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie2, kSignals2,
+                               MOJO_RESULT_FAILED_PRECONDITION,
+                               d_member0->GetHandleSignalsState()));
+  }
+
+  // Can close a dispatcher that's "in" the wait set. This should make
+  // |kCookie1| "cancelled".
   EXPECT_EQ(MOJO_RESULT_OK, d_member1->Close());
 
-  // TODO(vtl): Test waiting here.
+  // Wait.
+  {
+    uint32_t num_results = 10u;
+    MojoWaitSetResult results[10] = {};
+    uint32_t max_results = static_cast<uint32_t>(-1);
+    EXPECT_EQ(MOJO_RESULT_OK,
+              d->WaitSetWait(k10ms, MakeUserPointer(&num_results),
+                             MakeUserPointer(results),
+                             MakeUserPointer(&max_results)));
+    EXPECT_EQ(3u, num_results);
+    EXPECT_EQ(3u, max_results);
+
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie0, kSignals0,
+                               MOJO_RESULT_OK,
+                               d_member0->GetHandleSignalsState()));
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie1, kSignals1,
+                               MOJO_RESULT_CANCELLED,
+                               MojoHandleSignalsState()));
+    EXPECT_TRUE(CheckHasResult(num_results, results, kCookie2, kSignals2,
+                               MOJO_RESULT_FAILED_PRECONDITION,
+                               d_member0->GetHandleSignalsState()));
+  }
 
   // Can remove something whose dispatcher has been closed.
   EXPECT_EQ(MOJO_RESULT_OK, d->WaitSetRemove(kCookie1));