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rocksdb/port/port_posix.h

216 lines
5.9 KiB

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
//
// See port_example.h for documentation for the following types/functions.
#pragma once
#include <thread>
#include "rocksdb/rocksdb_namespace.h"
// size_t printf formatting named in the manner of C99 standard formatting
// strings such as PRIu64
// in fact, we could use that one
#define ROCKSDB_PRIszt "zu"
#define __declspec(S)
#define ROCKSDB_NOEXCEPT noexcept
#undef PLATFORM_IS_LITTLE_ENDIAN
#if defined(OS_MACOSX)
#include <machine/endian.h>
#if defined(__DARWIN_LITTLE_ENDIAN) && defined(__DARWIN_BYTE_ORDER)
#define PLATFORM_IS_LITTLE_ENDIAN \
(__DARWIN_BYTE_ORDER == __DARWIN_LITTLE_ENDIAN)
#endif
#elif defined(OS_SOLARIS)
#include <sys/isa_defs.h>
#ifdef _LITTLE_ENDIAN
#define PLATFORM_IS_LITTLE_ENDIAN true
#else
#define PLATFORM_IS_LITTLE_ENDIAN false
#endif
#include <alloca.h>
#elif defined(OS_AIX)
#include <sys/types.h>
#include <arpa/nameser_compat.h>
#define PLATFORM_IS_LITTLE_ENDIAN (BYTE_ORDER == LITTLE_ENDIAN)
#include <alloca.h>
#elif defined(OS_FREEBSD) || defined(OS_OPENBSD) || defined(OS_NETBSD) || \
defined(OS_DRAGONFLYBSD) || defined(OS_ANDROID)
#include <sys/endian.h>
#include <sys/types.h>
#define PLATFORM_IS_LITTLE_ENDIAN (_BYTE_ORDER == _LITTLE_ENDIAN)
#else
#include <endian.h>
#endif
#include <pthread.h>
#include <stdint.h>
#include <string.h>
#include <limits>
#include <string>
#ifndef PLATFORM_IS_LITTLE_ENDIAN
#define PLATFORM_IS_LITTLE_ENDIAN (__BYTE_ORDER == __LITTLE_ENDIAN)
#endif
#if defined(OS_MACOSX) || defined(OS_SOLARIS) || defined(OS_FREEBSD) ||\
defined(OS_NETBSD) || defined(OS_OPENBSD) || defined(OS_DRAGONFLYBSD) ||\
defined(OS_ANDROID) || defined(CYGWIN) || defined(OS_AIX)
// Use fread/fwrite/fflush on platforms without _unlocked variants
#define fread_unlocked fread
#define fwrite_unlocked fwrite
#define fflush_unlocked fflush
#endif
#if defined(OS_MACOSX) || defined(OS_FREEBSD) ||\
defined(OS_OPENBSD) || defined(OS_DRAGONFLYBSD)
// Use fsync() on platforms without fdatasync()
#define fdatasync fsync
#endif
#if defined(OS_ANDROID) && __ANDROID_API__ < 9
// fdatasync() was only introduced in API level 9 on Android. Use fsync()
// when targeting older platforms.
#define fdatasync fsync
#endif
namespace ROCKSDB_NAMESPACE {
extern const bool kDefaultToAdaptiveMutex;
namespace port {
// For use at db/file_indexer.h kLevelMaxIndex
const uint32_t kMaxUint32 = std::numeric_limits<uint32_t>::max();
const int kMaxInt32 = std::numeric_limits<int32_t>::max();
const int kMinInt32 = std::numeric_limits<int32_t>::min();
const uint64_t kMaxUint64 = std::numeric_limits<uint64_t>::max();
const int64_t kMaxInt64 = std::numeric_limits<int64_t>::max();
const int64_t kMinInt64 = std::numeric_limits<int64_t>::min();
const size_t kMaxSizet = std::numeric_limits<size_t>::max();
static const bool kLittleEndian = PLATFORM_IS_LITTLE_ENDIAN;
#undef PLATFORM_IS_LITTLE_ENDIAN
class CondVar;
class Mutex {
public:
explicit Mutex(bool adaptive = kDefaultToAdaptiveMutex);
// No copying
Mutex(const Mutex&) = delete;
void operator=(const Mutex&) = delete;
~Mutex();
void Lock();
void Unlock();
// this will assert if the mutex is not locked
// it does NOT verify that mutex is held by a calling thread
void AssertHeld();
private:
friend class CondVar;
pthread_mutex_t mu_;
#ifndef NDEBUG
bool locked_;
#endif
};
class RWMutex {
public:
RWMutex();
// No copying allowed
RWMutex(const RWMutex&) = delete;
void operator=(const RWMutex&) = delete;
~RWMutex();
void ReadLock();
void WriteLock();
void ReadUnlock();
void WriteUnlock();
void AssertHeld() { }
private:
pthread_rwlock_t mu_; // the underlying platform mutex
};
class CondVar {
public:
explicit CondVar(Mutex* mu);
~CondVar();
void Wait();
// Timed condition wait. Returns true if timeout occurred.
bool TimedWait(uint64_t abs_time_us);
void Signal();
void SignalAll();
private:
pthread_cond_t cv_;
Mutex* mu_;
};
using Thread = std::thread;
static inline void AsmVolatilePause() {
#if defined(__i386__) || defined(__x86_64__)
asm volatile("pause");
#elif defined(__aarch64__)
asm volatile("wfe");
#elif defined(__powerpc64__)
asm volatile("or 27,27,27");
#endif
// it's okay for other platforms to be no-ops
}
// Returns -1 if not available on this platform
extern int PhysicalCoreID();
typedef pthread_once_t OnceType;
#define LEVELDB_ONCE_INIT PTHREAD_ONCE_INIT
extern void InitOnce(OnceType* once, void (*initializer)());
#ifndef CACHE_LINE_SIZE
// To test behavior with non-native cache line size, e.g. for
// Bloom filters, set TEST_CACHE_LINE_SIZE to the desired test size.
// This disables ALIGN_AS to keep it from failing compilation.
#ifdef TEST_CACHE_LINE_SIZE
#define CACHE_LINE_SIZE TEST_CACHE_LINE_SIZE
#define ALIGN_AS(n) /*empty*/
#else
#if defined(__s390__)
#define CACHE_LINE_SIZE 256U
#elif defined(__powerpc__) || defined(__aarch64__)
#define CACHE_LINE_SIZE 128U
#else
#define CACHE_LINE_SIZE 64U
#endif
#define ALIGN_AS(n) alignas(n)
#endif
#endif
static_assert((CACHE_LINE_SIZE & (CACHE_LINE_SIZE - 1)) == 0,
"Cache line size must be a power of 2 number of bytes");
extern void *cacheline_aligned_alloc(size_t size);
extern void cacheline_aligned_free(void *memblock);
#define PREFETCH(addr, rw, locality) __builtin_prefetch(addr, rw, locality)
extern void Crash(const std::string& srcfile, int srcline);
extern int GetMaxOpenFiles();
} // namespace port
} // namespace ROCKSDB_NAMESPACE