Migrate test-semaphore to base-unittests.

test/base-unittests/platform/semaphore-unittest.cc

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <cstring>
+
+#include "src/base/platform/platform.h"
+#include "src/base/platform/semaphore.h"
+#include "src/base/platform/time.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace v8 {
+namespace base {
+
+namespace {
+
+static const char kAlphabet[] = "XKOAD";
+static const size_t kAlphabetSize = sizeof(kAlphabet) - 1;
+static const size_t kBufferSize = 987;  // GCD(buffer size, alphabet size) = 1
+static const size_t kDataSize = kBufferSize * kAlphabetSize * 10;
+
+
+class ProducerThread V8_FINAL : public Thread {
+ public:
+  ProducerThread(char* buffer, Semaphore* free_space, Semaphore* used_space)
+      : Thread(Options("ProducerThread")),
+        buffer_(buffer),
+        free_space_(free_space),
+        used_space_(used_space) {}
+  virtual ~ProducerThread() {}
+
+  virtual void Run() V8_OVERRIDE {
+    for (size_t n = 0; n < kDataSize; ++n) {
+      free_space_->Wait();
+      buffer_[n % kBufferSize] = kAlphabet[n % kAlphabetSize];
+      used_space_->Signal();
+    }
+  }
+
+ private:
+  char* buffer_;
+  Semaphore* const free_space_;
+  Semaphore* const used_space_;
+};
+
+
+class ConsumerThread V8_FINAL : public Thread {
+ public:
+  ConsumerThread(const char* buffer, Semaphore* free_space,
+                 Semaphore* used_space)
+      : Thread(Options("ConsumerThread")),
+        buffer_(buffer),
+        free_space_(free_space),
+        used_space_(used_space) {}
+  virtual ~ConsumerThread() {}
+
+  virtual void Run() V8_OVERRIDE {
+    for (size_t n = 0; n < kDataSize; ++n) {
+      used_space_->Wait();
+      EXPECT_EQ(kAlphabet[n % kAlphabetSize], buffer_[n % kBufferSize]);
+      free_space_->Signal();
+    }
+  }
+
+ private:
+  const char* buffer_;
+  Semaphore* const free_space_;
+  Semaphore* const used_space_;
+};
+
+
+class WaitAndSignalThread V8_FINAL : public Thread {
+ public:
+  explicit WaitAndSignalThread(Semaphore* semaphore)
+      : Thread(Options("WaitAndSignalThread")), semaphore_(semaphore) {}
+  virtual ~WaitAndSignalThread() {}
+
+  virtual void Run() V8_OVERRIDE {
+    for (int n = 0; n < 100; ++n) {
+      semaphore_->Wait();
+      ASSERT_FALSE(semaphore_->WaitFor(TimeDelta::FromMicroseconds(1)));
+      semaphore_->Signal();
+    }
+  }
+
+ private:
+  Semaphore* const semaphore_;
+};
+
+}  // namespace
+
+
+TEST(Semaphore, ProducerConsumer) {
+  char buffer[kBufferSize];
+  std::memset(buffer, 0, sizeof(buffer));
+  Semaphore free_space(kBufferSize);
+  Semaphore used_space(0);
+  ProducerThread producer_thread(buffer, &free_space, &used_space);
+  ConsumerThread consumer_thread(buffer, &free_space, &used_space);
+  producer_thread.Start();
+  consumer_thread.Start();
+  producer_thread.Join();
+  consumer_thread.Join();
+}
+
+
+TEST(Semaphore, WaitAndSignal) {
+  Semaphore semaphore(0);
+  WaitAndSignalThread t1(&semaphore);
+  WaitAndSignalThread t2(&semaphore);
+
+  t1.Start();
+  t2.Start();
+
+  // Make something available.
+  semaphore.Signal();
+
+  t1.Join();
+  t2.Join();
+
+  semaphore.Wait();
+
+  EXPECT_FALSE(semaphore.WaitFor(TimeDelta::FromMicroseconds(1)));

[Michael Achenbach, 2014/08/22 08:21:07]

What's the difference to ASSERT_FALSE above?

[Benedikt Meurer, 2014/08/22 08:51:58]

EXPECT_* just record a failure, while ASSERT_* terminates the current test.

+}
+
+
+TEST(Semaphore, WaitFor) {
+  Semaphore semaphore(0);
+
+  // Semaphore not signalled - timeout.
+  ASSERT_FALSE(semaphore.WaitFor(TimeDelta::FromMicroseconds(0)));
+  ASSERT_FALSE(semaphore.WaitFor(TimeDelta::FromMicroseconds(100)));
+  ASSERT_FALSE(semaphore.WaitFor(TimeDelta::FromMicroseconds(1000)));

[Michael Achenbach, 2014/08/22 08:21:07]

Do we really need the last one? What could make that break?

+
+  // Semaphore signalled - no timeout.
+  semaphore.Signal();
+  ASSERT_TRUE(semaphore.WaitFor(TimeDelta::FromMicroseconds(0)));
+  semaphore.Signal();
+  ASSERT_TRUE(semaphore.WaitFor(TimeDelta::FromMicroseconds(100)));
+  semaphore.Signal();
+  ASSERT_TRUE(semaphore.WaitFor(TimeDelta::FromMicroseconds(1000)));
+}
+
+}  // namespace base
+}  // namespace v8