cut posix semaphore polyfill

Summary: Prefer not to have polyfills. The class `NativeSemaphore` replaces this polyfill.

Reviewed By: Orvid

Differential Revision: D27971239

fbshipit-source-id: 39bd8b2d9be895a947faee4d522420535378fdc3

folly/portability/Semaphore.cpp

-/*
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * 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.
- */
-
-#include <folly/portability/Semaphore.h>
-
-#include <folly/portability/Windows.h>
-
-#include <cerrno>
-#include <mutex>
-
-#ifdef _WIN32
-namespace folly::portability::semaphore {
-struct sem_t_ {
-  std::mutex mtx{};
-  HANDLE sema{INVALID_HANDLE_VALUE};
-  int32_t value{0};
-};
-
-int sem_init(sem_t* s, int shared, unsigned int value) {
-  // Don't support cross-process shared semaphores.
-  if (shared != 0) {
-    return -1;
-  }
-  auto sem = CreateSemaphoreA(nullptr, 0, SEM_VALUE_MAX, nullptr);
-  if (sem == 0) {
-    return -1;
-  }
-  auto ret = new sem_t_();
-  ret->sema = sem;
-  ret->value = value;
-  *s = ret;
-  return 0;
-}
-
-int sem_destroy(sem_t* s) {
-  if (!CloseHandle((*s)->sema)) {
-    return -1;
-  }
-  delete *s;
-  *s = nullptr;
-  return 0;
-}
-
-int sem_post(sem_t* s) {
-  std::lock_guard<std::mutex> lock{(*s)->mtx};
-  if ((*s)->value < SEM_VALUE_MAX) {
-    if (++(*s)->value <= 0 && !ReleaseSemaphore((*s)->sema, 1, nullptr)) {
-      --(*s)->value;
-      errno = EINVAL;
-      return -1;
-    }
-  } else {
-    errno = ERANGE;
-    return -1;
-  }
-  return 0;
-}
-
-int sem_trywait(sem_t* s) {
-  std::lock_guard<std::mutex> lock{(*s)->mtx};
-  if ((*s)->value > 0) {
-    (*s)->value--;
-    return 0;
-  } else {
-    errno = EAGAIN;
-    return -1;
-  }
-}
-
-int sem_wait(sem_t* s) {
-  int32_t value = 0;
-  {
-    std::lock_guard<std::mutex> lock{(*s)->mtx};
-    value = --(*s)->value;
-  }
-
-  if (value < 0) {
-    if (WaitForSingleObject((*s)->sema, INFINITE) != WAIT_OBJECT_0) {
-      errno = EINVAL;
-      return -1;
-    }
-  }
-  return 0;
-}
-} // namespace folly::portability::semaphore
-#endif

folly/portability/Semaphore.h

-/*
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * 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.
- */
-
-#pragma once
-
-#ifndef _WIN32
-#include <semaphore.h>
-#else
-#include <limits.h>
-
-#include <folly/Portability.h>
-
-#define SEM_VALUE_MAX INT_MAX
-namespace folly::portability::semaphore {
-using sem_t = struct sem_t_*;
-int sem_init(sem_t* s, int shared, unsigned int value);
-int sem_destroy(sem_t* s);
-int sem_post(sem_t* s);
-int sem_trywait(sem_t* s);
-int sem_wait(sem_t* s);
-} // namespace folly::portability::semaphore
-
-FOLLY_PUSH_WARNING
-FOLLY_CLANG_DISABLE_WARNING("-Wheader-hygiene")
-/* using override */ using namespace folly::portability::semaphore;
-FOLLY_POP_WARNING
-#endif

folly/test/AtomicUnorderedMapTest.cpp

@@ -23,7 +23,6 @@
 #include <folly/Benchmark.h>
 #include <folly/portability/GFlags.h>
 #include <folly/portability/GTest.h>
-#include <folly/portability/Semaphore.h>
 #include <folly/test/DeterministicSchedule.h>
 
 using namespace folly;

folly/test/IndexedMemPoolTest.cpp

@@ -21,7 +21,6 @@
 
 #include <folly/portability/GMock.h>
 #include <folly/portability/GTest.h>
-#include <folly/portability/Semaphore.h>
 #include <folly/portability/Unistd.h>
 #include <folly/test/DeterministicSchedule.h>