rocksdb/env/env_posix.cc
Siying Dong 926f3a78a6 In delete scheduler, before ftruncate file for slow delete, check whether there is other hard links (#4093)
Summary:
Right now slow deletion with ftruncate doesn't work well with checkpoints because it ruin hard linked files in checkpoints. To fix it, check the file has no other hard link before ftruncate it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4093

Differential Revision: D8730360

Pulled By: siying

fbshipit-source-id: 756eea5bce8a87b9a2ea3a5bfa190b2cab6f75df
2018-07-09 15:28:12 -07:00

1080 lines
33 KiB
C++

// 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
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#if defined(OS_LINUX)
#include <linux/fs.h>
#endif
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#if defined(OS_LINUX) || defined(OS_SOLARIS)
#include <sys/statfs.h>
#include <sys/syscall.h>
#include <sys/sysmacros.h>
#endif
#include <sys/time.h>
#include <sys/types.h>
#include <time.h>
#include <algorithm>
// Get nano time includes
#if defined(OS_LINUX) || defined(OS_FREEBSD)
#elif defined(__MACH__)
#include <mach/clock.h>
#include <mach/mach.h>
#else
#include <chrono>
#endif
#include <deque>
#include <set>
#include <vector>
#include "env/io_posix.h"
#include "env/posix_logger.h"
#include "monitoring/iostats_context_imp.h"
#include "monitoring/thread_status_updater.h"
#include "port/port.h"
#include "rocksdb/options.h"
#include "rocksdb/slice.h"
#include "util/coding.h"
#include "util/compression_context_cache.h"
#include "util/logging.h"
#include "util/random.h"
#include "util/string_util.h"
#include "util/sync_point.h"
#include "util/thread_local.h"
#include "util/threadpool_imp.h"
#if !defined(TMPFS_MAGIC)
#define TMPFS_MAGIC 0x01021994
#endif
#if !defined(XFS_SUPER_MAGIC)
#define XFS_SUPER_MAGIC 0x58465342
#endif
#if !defined(EXT4_SUPER_MAGIC)
#define EXT4_SUPER_MAGIC 0xEF53
#endif
namespace rocksdb {
namespace {
ThreadStatusUpdater* CreateThreadStatusUpdater() {
return new ThreadStatusUpdater();
}
inline mode_t GetDBFileMode(bool allow_non_owner_access) {
return allow_non_owner_access ? 0644 : 0600;
}
// list of pathnames that are locked
static std::set<std::string> lockedFiles;
static port::Mutex mutex_lockedFiles;
static int LockOrUnlock(int fd, bool lock) {
errno = 0;
struct flock f;
memset(&f, 0, sizeof(f));
f.l_type = (lock ? F_WRLCK : F_UNLCK);
f.l_whence = SEEK_SET;
f.l_start = 0;
f.l_len = 0; // Lock/unlock entire file
int value = fcntl(fd, F_SETLK, &f);
return value;
}
class PosixFileLock : public FileLock {
public:
int fd_;
std::string filename;
};
class PosixEnv : public Env {
public:
PosixEnv();
virtual ~PosixEnv() {
for (const auto tid : threads_to_join_) {
pthread_join(tid, nullptr);
}
for (int pool_id = 0; pool_id < Env::Priority::TOTAL; ++pool_id) {
thread_pools_[pool_id].JoinAllThreads();
}
// Delete the thread_status_updater_ only when the current Env is not
// Env::Default(). This is to avoid the free-after-use error when
// Env::Default() is destructed while some other child threads are
// still trying to update thread status.
if (this != Env::Default()) {
delete thread_status_updater_;
}
}
void SetFD_CLOEXEC(int fd, const EnvOptions* options) {
if ((options == nullptr || options->set_fd_cloexec) && fd > 0) {
fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
}
}
virtual Status NewSequentialFile(const std::string& fname,
unique_ptr<SequentialFile>* result,
const EnvOptions& options) override {
result->reset();
int fd = -1;
int flags = O_RDONLY;
FILE* file = nullptr;
if (options.use_direct_reads && !options.use_mmap_reads) {
#ifdef ROCKSDB_LITE
return Status::IOError(fname, "Direct I/O not supported in RocksDB lite");
#endif // !ROCKSDB_LITE
#if !defined(OS_MACOSX) && !defined(OS_OPENBSD) && !defined(OS_SOLARIS)
flags |= O_DIRECT;
#endif
}
do {
IOSTATS_TIMER_GUARD(open_nanos);
fd = open(fname.c_str(), flags, GetDBFileMode(allow_non_owner_access_));
} while (fd < 0 && errno == EINTR);
if (fd < 0) {
return IOError("While opening a file for sequentially reading", fname,
errno);
}
SetFD_CLOEXEC(fd, &options);
if (options.use_direct_reads && !options.use_mmap_reads) {
#ifdef OS_MACOSX
if (fcntl(fd, F_NOCACHE, 1) == -1) {
close(fd);
return IOError("While fcntl NoCache", fname, errno);
}
#endif
} else {
do {
IOSTATS_TIMER_GUARD(open_nanos);
file = fdopen(fd, "r");
} while (file == nullptr && errno == EINTR);
if (file == nullptr) {
close(fd);
return IOError("While opening file for sequentially read", fname,
errno);
}
}
result->reset(new PosixSequentialFile(fname, file, fd, options));
return Status::OK();
}
virtual Status NewRandomAccessFile(const std::string& fname,
unique_ptr<RandomAccessFile>* result,
const EnvOptions& options) override {
result->reset();
Status s;
int fd;
int flags = O_RDONLY;
if (options.use_direct_reads && !options.use_mmap_reads) {
#ifdef ROCKSDB_LITE
return Status::IOError(fname, "Direct I/O not supported in RocksDB lite");
#endif // !ROCKSDB_LITE
#if !defined(OS_MACOSX) && !defined(OS_OPENBSD) && !defined(OS_SOLARIS)
flags |= O_DIRECT;
TEST_SYNC_POINT_CALLBACK("NewRandomAccessFile:O_DIRECT", &flags);
#endif
}
do {
IOSTATS_TIMER_GUARD(open_nanos);
fd = open(fname.c_str(), flags, GetDBFileMode(allow_non_owner_access_));
} while (fd < 0 && errno == EINTR);
if (fd < 0) {
return IOError("While open a file for random read", fname, errno);
}
SetFD_CLOEXEC(fd, &options);
if (options.use_mmap_reads && sizeof(void*) >= 8) {
// Use of mmap for random reads has been removed because it
// kills performance when storage is fast.
// Use mmap when virtual address-space is plentiful.
uint64_t size;
s = GetFileSize(fname, &size);
if (s.ok()) {
void* base = mmap(nullptr, size, PROT_READ, MAP_SHARED, fd, 0);
if (base != MAP_FAILED) {
result->reset(new PosixMmapReadableFile(fd, fname, base,
size, options));
} else {
s = IOError("while mmap file for read", fname, errno);
close(fd);
}
}
} else {
if (options.use_direct_reads && !options.use_mmap_reads) {
#ifdef OS_MACOSX
if (fcntl(fd, F_NOCACHE, 1) == -1) {
close(fd);
return IOError("while fcntl NoCache", fname, errno);
}
#endif
}
result->reset(new PosixRandomAccessFile(fname, fd, options));
}
return s;
}
virtual Status OpenWritableFile(const std::string& fname,
unique_ptr<WritableFile>* result,
const EnvOptions& options,
bool reopen = false) {
result->reset();
Status s;
int fd = -1;
int flags = (reopen) ? (O_CREAT | O_APPEND) : (O_CREAT | O_TRUNC);
// Direct IO mode with O_DIRECT flag or F_NOCAHCE (MAC OSX)
if (options.use_direct_writes && !options.use_mmap_writes) {
// Note: we should avoid O_APPEND here due to ta the following bug:
// POSIX requires that opening a file with the O_APPEND flag should
// have no affect on the location at which pwrite() writes data.
// However, on Linux, if a file is opened with O_APPEND, pwrite()
// appends data to the end of the file, regardless of the value of
// offset.
// More info here: https://linux.die.net/man/2/pwrite
#ifdef ROCKSDB_LITE
return Status::IOError(fname, "Direct I/O not supported in RocksDB lite");
#endif // ROCKSDB_LITE
flags |= O_WRONLY;
#if !defined(OS_MACOSX) && !defined(OS_OPENBSD) && !defined(OS_SOLARIS)
flags |= O_DIRECT;
#endif
TEST_SYNC_POINT_CALLBACK("NewWritableFile:O_DIRECT", &flags);
} else if (options.use_mmap_writes) {
// non-direct I/O
flags |= O_RDWR;
} else {
flags |= O_WRONLY;
}
do {
IOSTATS_TIMER_GUARD(open_nanos);
fd = open(fname.c_str(), flags, GetDBFileMode(allow_non_owner_access_));
} while (fd < 0 && errno == EINTR);
if (fd < 0) {
s = IOError("While open a file for appending", fname, errno);
return s;
}
SetFD_CLOEXEC(fd, &options);
if (options.use_mmap_writes) {
if (!checkedDiskForMmap_) {
// this will be executed once in the program's lifetime.
// do not use mmapWrite on non ext-3/xfs/tmpfs systems.
if (!SupportsFastAllocate(fname)) {
forceMmapOff_ = true;
}
checkedDiskForMmap_ = true;
}
}
if (options.use_mmap_writes && !forceMmapOff_) {
result->reset(new PosixMmapFile(fname, fd, page_size_, options));
} else if (options.use_direct_writes && !options.use_mmap_writes) {
#ifdef OS_MACOSX
if (fcntl(fd, F_NOCACHE, 1) == -1) {
close(fd);
s = IOError("While fcntl NoCache an opened file for appending", fname,
errno);
return s;
}
#elif defined(OS_SOLARIS)
if (directio(fd, DIRECTIO_ON) == -1) {
if (errno != ENOTTY) { // ZFS filesystems don't support DIRECTIO_ON
close(fd);
s = IOError("While calling directio()", fname, errno);
return s;
}
}
#endif
result->reset(new PosixWritableFile(fname, fd, options));
} else {
// disable mmap writes
EnvOptions no_mmap_writes_options = options;
no_mmap_writes_options.use_mmap_writes = false;
result->reset(new PosixWritableFile(fname, fd, no_mmap_writes_options));
}
return s;
}
virtual Status NewWritableFile(const std::string& fname,
unique_ptr<WritableFile>* result,
const EnvOptions& options) override {
return OpenWritableFile(fname, result, options, false);
}
virtual Status ReopenWritableFile(const std::string& fname,
unique_ptr<WritableFile>* result,
const EnvOptions& options) override {
return OpenWritableFile(fname, result, options, true);
}
virtual Status ReuseWritableFile(const std::string& fname,
const std::string& old_fname,
unique_ptr<WritableFile>* result,
const EnvOptions& options) override {
result->reset();
Status s;
int fd = -1;
int flags = 0;
// Direct IO mode with O_DIRECT flag or F_NOCAHCE (MAC OSX)
if (options.use_direct_writes && !options.use_mmap_writes) {
#ifdef ROCKSDB_LITE
return Status::IOError(fname, "Direct I/O not supported in RocksDB lite");
#endif // !ROCKSDB_LITE
flags |= O_WRONLY;
#if !defined(OS_MACOSX) && !defined(OS_OPENBSD) && !defined(OS_SOLARIS)
flags |= O_DIRECT;
#endif
TEST_SYNC_POINT_CALLBACK("NewWritableFile:O_DIRECT", &flags);
} else if (options.use_mmap_writes) {
// mmap needs O_RDWR mode
flags |= O_RDWR;
} else {
flags |= O_WRONLY;
}
do {
IOSTATS_TIMER_GUARD(open_nanos);
fd = open(old_fname.c_str(), flags,
GetDBFileMode(allow_non_owner_access_));
} while (fd < 0 && errno == EINTR);
if (fd < 0) {
s = IOError("while reopen file for write", fname, errno);
return s;
}
SetFD_CLOEXEC(fd, &options);
// rename into place
if (rename(old_fname.c_str(), fname.c_str()) != 0) {
s = IOError("while rename file to " + fname, old_fname, errno);
close(fd);
return s;
}
if (options.use_mmap_writes) {
if (!checkedDiskForMmap_) {
// this will be executed once in the program's lifetime.
// do not use mmapWrite on non ext-3/xfs/tmpfs systems.
if (!SupportsFastAllocate(fname)) {
forceMmapOff_ = true;
}
checkedDiskForMmap_ = true;
}
}
if (options.use_mmap_writes && !forceMmapOff_) {
result->reset(new PosixMmapFile(fname, fd, page_size_, options));
} else if (options.use_direct_writes && !options.use_mmap_writes) {
#ifdef OS_MACOSX
if (fcntl(fd, F_NOCACHE, 1) == -1) {
close(fd);
s = IOError("while fcntl NoCache for reopened file for append", fname,
errno);
return s;
}
#elif defined(OS_SOLARIS)
if (directio(fd, DIRECTIO_ON) == -1) {
if (errno != ENOTTY) { // ZFS filesystems don't support DIRECTIO_ON
close(fd);
s = IOError("while calling directio()", fname, errno);
return s;
}
}
#endif
result->reset(new PosixWritableFile(fname, fd, options));
} else {
// disable mmap writes
EnvOptions no_mmap_writes_options = options;
no_mmap_writes_options.use_mmap_writes = false;
result->reset(new PosixWritableFile(fname, fd, no_mmap_writes_options));
}
return s;
}
virtual Status NewRandomRWFile(const std::string& fname,
unique_ptr<RandomRWFile>* result,
const EnvOptions& options) override {
int fd = -1;
while (fd < 0) {
IOSTATS_TIMER_GUARD(open_nanos);
fd = open(fname.c_str(), O_RDWR, GetDBFileMode(allow_non_owner_access_));
if (fd < 0) {
// Error while opening the file
if (errno == EINTR) {
continue;
}
return IOError("While open file for random read/write", fname, errno);
}
}
SetFD_CLOEXEC(fd, &options);
result->reset(new PosixRandomRWFile(fname, fd, options));
return Status::OK();
}
virtual Status NewMemoryMappedFileBuffer(
const std::string& fname,
unique_ptr<MemoryMappedFileBuffer>* result) override {
int fd = -1;
Status status;
while (fd < 0) {
IOSTATS_TIMER_GUARD(open_nanos);
fd = open(fname.c_str(), O_RDWR, 0644);
if (fd < 0) {
// Error while opening the file
if (errno == EINTR) {
continue;
}
status =
IOError("While open file for raw mmap buffer access", fname, errno);
break;
}
}
uint64_t size;
if (status.ok()) {
status = GetFileSize(fname, &size);
}
void* base = nullptr;
if (status.ok()) {
base = mmap(nullptr, static_cast<size_t>(size), PROT_READ | PROT_WRITE,
MAP_SHARED, fd, 0);
if (base == MAP_FAILED) {
status = IOError("while mmap file for read", fname, errno);
}
}
if (status.ok()) {
result->reset(
new PosixMemoryMappedFileBuffer(base, static_cast<size_t>(size)));
}
if (fd >= 0) {
// don't need to keep it open after mmap has been called
close(fd);
}
return status;
}
virtual Status NewDirectory(const std::string& name,
unique_ptr<Directory>* result) override {
result->reset();
int fd;
{
IOSTATS_TIMER_GUARD(open_nanos);
fd = open(name.c_str(), 0);
}
if (fd < 0) {
return IOError("While open directory", name, errno);
} else {
result->reset(new PosixDirectory(fd));
}
return Status::OK();
}
virtual Status FileExists(const std::string& fname) override {
int result = access(fname.c_str(), F_OK);
if (result == 0) {
return Status::OK();
}
switch (errno) {
case EACCES:
case ELOOP:
case ENAMETOOLONG:
case ENOENT:
case ENOTDIR:
return Status::NotFound();
default:
assert(result == EIO || result == ENOMEM);
return Status::IOError("Unexpected error(" + ToString(result) +
") accessing file `" + fname + "' ");
}
}
virtual Status GetChildren(const std::string& dir,
std::vector<std::string>* result) override {
result->clear();
DIR* d = opendir(dir.c_str());
if (d == nullptr) {
switch (errno) {
case EACCES:
case ENOENT:
case ENOTDIR:
return Status::NotFound();
default:
return IOError("While opendir", dir, errno);
}
}
struct dirent* entry;
while ((entry = readdir(d)) != nullptr) {
result->push_back(entry->d_name);
}
closedir(d);
return Status::OK();
}
virtual Status DeleteFile(const std::string& fname) override {
Status result;
if (unlink(fname.c_str()) != 0) {
result = IOError("while unlink() file", fname, errno);
}
return result;
};
virtual Status CreateDir(const std::string& name) override {
Status result;
if (mkdir(name.c_str(), 0755) != 0) {
result = IOError("While mkdir", name, errno);
}
return result;
};
virtual Status CreateDirIfMissing(const std::string& name) override {
Status result;
if (mkdir(name.c_str(), 0755) != 0) {
if (errno != EEXIST) {
result = IOError("While mkdir if missing", name, errno);
} else if (!DirExists(name)) { // Check that name is actually a
// directory.
// Message is taken from mkdir
result = Status::IOError("`"+name+"' exists but is not a directory");
}
}
return result;
};
virtual Status DeleteDir(const std::string& name) override {
Status result;
if (rmdir(name.c_str()) != 0) {
result = IOError("file rmdir", name, errno);
}
return result;
};
virtual Status GetFileSize(const std::string& fname,
uint64_t* size) override {
Status s;
struct stat sbuf;
if (stat(fname.c_str(), &sbuf) != 0) {
*size = 0;
s = IOError("while stat a file for size", fname, errno);
} else {
*size = sbuf.st_size;
}
return s;
}
virtual Status GetFileModificationTime(const std::string& fname,
uint64_t* file_mtime) override {
struct stat s;
if (stat(fname.c_str(), &s) !=0) {
return IOError("while stat a file for modification time", fname, errno);
}
*file_mtime = static_cast<uint64_t>(s.st_mtime);
return Status::OK();
}
virtual Status RenameFile(const std::string& src,
const std::string& target) override {
Status result;
if (rename(src.c_str(), target.c_str()) != 0) {
result = IOError("While renaming a file to " + target, src, errno);
}
return result;
}
virtual Status LinkFile(const std::string& src,
const std::string& target) override {
Status result;
if (link(src.c_str(), target.c_str()) != 0) {
if (errno == EXDEV) {
return Status::NotSupported("No cross FS links allowed");
}
result = IOError("while link file to " + target, src, errno);
}
return result;
}
Status NumFileLinks(const std::string& fname, uint64_t* count) override {
struct stat s;
if (stat(fname.c_str(), &s) != 0) {
return IOError("while stat a file for num file links", fname, errno);
}
*count = static_cast<uint64_t>(s.st_nlink);
return Status::OK();
}
virtual Status AreFilesSame(const std::string& first,
const std::string& second, bool* res) override {
struct stat statbuf[2];
if (stat(first.c_str(), &statbuf[0]) != 0) {
return IOError("stat file", first, errno);
}
if (stat(second.c_str(), &statbuf[1]) != 0) {
return IOError("stat file", second, errno);
}
if (major(statbuf[0].st_dev) != major(statbuf[1].st_dev) ||
minor(statbuf[0].st_dev) != minor(statbuf[1].st_dev) ||
statbuf[0].st_ino != statbuf[1].st_ino) {
*res = false;
} else {
*res = true;
}
return Status::OK();
}
virtual Status LockFile(const std::string& fname, FileLock** lock) override {
*lock = nullptr;
Status result;
mutex_lockedFiles.Lock();
// If it already exists in the lockedFiles set, then it is already locked,
// and fail this lock attempt. Otherwise, insert it into lockedFiles.
// This check is needed because fcntl() does not detect lock conflict
// if the fcntl is issued by the same thread that earlier acquired
// this lock.
// We must do this check *before* opening the file:
// Otherwise, we will open a new file descriptor. Locks are associated with
// a process, not a file descriptor and when *any* file descriptor is closed,
// all locks the process holds for that *file* are released
if (lockedFiles.insert(fname).second == false) {
mutex_lockedFiles.Unlock();
errno = ENOLCK;
return IOError("lock ", fname, errno);
}
int fd;
{
IOSTATS_TIMER_GUARD(open_nanos);
fd = open(fname.c_str(), O_RDWR | O_CREAT, 0644);
}
if (fd < 0) {
result = IOError("while open a file for lock", fname, errno);
} else if (LockOrUnlock(fd, true) == -1) {
// if there is an error in locking, then remove the pathname from lockedfiles
lockedFiles.erase(fname);
result = IOError("While lock file", fname, errno);
close(fd);
} else {
SetFD_CLOEXEC(fd, nullptr);
PosixFileLock* my_lock = new PosixFileLock;
my_lock->fd_ = fd;
my_lock->filename = fname;
*lock = my_lock;
}
mutex_lockedFiles.Unlock();
return result;
}
virtual Status UnlockFile(FileLock* lock) override {
PosixFileLock* my_lock = reinterpret_cast<PosixFileLock*>(lock);
Status result;
mutex_lockedFiles.Lock();
// If we are unlocking, then verify that we had locked it earlier,
// it should already exist in lockedFiles. Remove it from lockedFiles.
if (lockedFiles.erase(my_lock->filename) != 1) {
errno = ENOLCK;
result = IOError("unlock", my_lock->filename, errno);
} else if (LockOrUnlock(my_lock->fd_, false) == -1) {
result = IOError("unlock", my_lock->filename, errno);
}
close(my_lock->fd_);
delete my_lock;
mutex_lockedFiles.Unlock();
return result;
}
virtual void Schedule(void (*function)(void* arg1), void* arg,
Priority pri = LOW, void* tag = nullptr,
void (*unschedFunction)(void* arg) = nullptr) override;
virtual int UnSchedule(void* arg, Priority pri) override;
virtual void StartThread(void (*function)(void* arg), void* arg) override;
virtual void WaitForJoin() override;
virtual unsigned int GetThreadPoolQueueLen(Priority pri = LOW) const override;
virtual Status GetTestDirectory(std::string* result) override {
const char* env = getenv("TEST_TMPDIR");
if (env && env[0] != '\0') {
*result = env;
} else {
char buf[100];
snprintf(buf, sizeof(buf), "/tmp/rocksdbtest-%d", int(geteuid()));
*result = buf;
}
// Directory may already exist
CreateDir(*result);
return Status::OK();
}
virtual Status GetThreadList(
std::vector<ThreadStatus>* thread_list) override {
assert(thread_status_updater_);
return thread_status_updater_->GetThreadList(thread_list);
}
static uint64_t gettid(pthread_t tid) {
uint64_t thread_id = 0;
memcpy(&thread_id, &tid, std::min(sizeof(thread_id), sizeof(tid)));
return thread_id;
}
static uint64_t gettid() {
pthread_t tid = pthread_self();
return gettid(tid);
}
virtual uint64_t GetThreadID() const override {
return gettid(pthread_self());
}
virtual Status NewLogger(const std::string& fname,
shared_ptr<Logger>* result) override {
FILE* f;
{
IOSTATS_TIMER_GUARD(open_nanos);
f = fopen(fname.c_str(), "w");
}
if (f == nullptr) {
result->reset();
return IOError("when fopen a file for new logger", fname, errno);
} else {
int fd = fileno(f);
#ifdef ROCKSDB_FALLOCATE_PRESENT
fallocate(fd, FALLOC_FL_KEEP_SIZE, 0, 4 * 1024);
#endif
SetFD_CLOEXEC(fd, nullptr);
result->reset(new PosixLogger(f, &PosixEnv::gettid, this));
return Status::OK();
}
}
virtual uint64_t NowMicros() override {
struct timeval tv;
gettimeofday(&tv, nullptr);
return static_cast<uint64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
}
virtual uint64_t NowNanos() override {
#if defined(OS_LINUX) || defined(OS_FREEBSD) || defined(OS_AIX)
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return static_cast<uint64_t>(ts.tv_sec) * 1000000000 + ts.tv_nsec;
#elif defined(OS_SOLARIS)
return gethrtime();
#elif defined(__MACH__)
clock_serv_t cclock;
mach_timespec_t ts;
host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &cclock);
clock_get_time(cclock, &ts);
mach_port_deallocate(mach_task_self(), cclock);
return static_cast<uint64_t>(ts.tv_sec) * 1000000000 + ts.tv_nsec;
#else
return std::chrono::duration_cast<std::chrono::nanoseconds>(
std::chrono::steady_clock::now().time_since_epoch()).count();
#endif
}
virtual void SleepForMicroseconds(int micros) override { usleep(micros); }
virtual Status GetHostName(char* name, uint64_t len) override {
int ret = gethostname(name, static_cast<size_t>(len));
if (ret < 0) {
if (errno == EFAULT || errno == EINVAL)
return Status::InvalidArgument(strerror(errno));
else
return IOError("GetHostName", name, errno);
}
return Status::OK();
}
virtual Status GetCurrentTime(int64_t* unix_time) override {
time_t ret = time(nullptr);
if (ret == (time_t) -1) {
return IOError("GetCurrentTime", "", errno);
}
*unix_time = (int64_t) ret;
return Status::OK();
}
virtual Status GetAbsolutePath(const std::string& db_path,
std::string* output_path) override {
if (!db_path.empty() && db_path[0] == '/') {
*output_path = db_path;
return Status::OK();
}
char the_path[256];
char* ret = getcwd(the_path, 256);
if (ret == nullptr) {
return Status::IOError(strerror(errno));
}
*output_path = ret;
return Status::OK();
}
// Allow increasing the number of worker threads.
virtual void SetBackgroundThreads(int num, Priority pri) override {
assert(pri >= Priority::BOTTOM && pri <= Priority::HIGH);
thread_pools_[pri].SetBackgroundThreads(num);
}
virtual int GetBackgroundThreads(Priority pri) override {
assert(pri >= Priority::BOTTOM && pri <= Priority::HIGH);
return thread_pools_[pri].GetBackgroundThreads();
}
virtual Status SetAllowNonOwnerAccess(bool allow_non_owner_access) override {
allow_non_owner_access_ = allow_non_owner_access;
return Status::OK();
}
// Allow increasing the number of worker threads.
virtual void IncBackgroundThreadsIfNeeded(int num, Priority pri) override {
assert(pri >= Priority::BOTTOM && pri <= Priority::HIGH);
thread_pools_[pri].IncBackgroundThreadsIfNeeded(num);
}
virtual void LowerThreadPoolIOPriority(Priority pool = LOW) override {
assert(pool >= Priority::BOTTOM && pool <= Priority::HIGH);
#ifdef OS_LINUX
thread_pools_[pool].LowerIOPriority();
#else
(void)pool;
#endif
}
virtual void LowerThreadPoolCPUPriority(Priority pool = LOW) override {
assert(pool >= Priority::BOTTOM && pool <= Priority::HIGH);
#ifdef OS_LINUX
thread_pools_[pool].LowerCPUPriority();
#else
(void)pool;
#endif
}
virtual std::string TimeToString(uint64_t secondsSince1970) override {
const time_t seconds = (time_t)secondsSince1970;
struct tm t;
int maxsize = 64;
std::string dummy;
dummy.reserve(maxsize);
dummy.resize(maxsize);
char* p = &dummy[0];
localtime_r(&seconds, &t);
snprintf(p, maxsize,
"%04d/%02d/%02d-%02d:%02d:%02d ",
t.tm_year + 1900,
t.tm_mon + 1,
t.tm_mday,
t.tm_hour,
t.tm_min,
t.tm_sec);
return dummy;
}
EnvOptions OptimizeForLogWrite(const EnvOptions& env_options,
const DBOptions& db_options) const override {
EnvOptions optimized = env_options;
optimized.use_mmap_writes = false;
optimized.use_direct_writes = false;
optimized.bytes_per_sync = db_options.wal_bytes_per_sync;
// TODO(icanadi) it's faster if fallocate_with_keep_size is false, but it
// breaks TransactionLogIteratorStallAtLastRecord unit test. Fix the unit
// test and make this false
optimized.fallocate_with_keep_size = true;
optimized.writable_file_max_buffer_size =
db_options.writable_file_max_buffer_size;
return optimized;
}
EnvOptions OptimizeForManifestWrite(
const EnvOptions& env_options) const override {
EnvOptions optimized = env_options;
optimized.use_mmap_writes = false;
optimized.use_direct_writes = false;
optimized.fallocate_with_keep_size = true;
return optimized;
}
private:
bool checkedDiskForMmap_;
bool forceMmapOff_; // do we override Env options?
// Returns true iff the named directory exists and is a directory.
virtual bool DirExists(const std::string& dname) {
struct stat statbuf;
if (stat(dname.c_str(), &statbuf) == 0) {
return S_ISDIR(statbuf.st_mode);
}
return false; // stat() failed return false
}
bool SupportsFastAllocate(const std::string& path) {
#ifdef ROCKSDB_FALLOCATE_PRESENT
struct statfs s;
if (statfs(path.c_str(), &s)){
return false;
}
switch (s.f_type) {
case EXT4_SUPER_MAGIC:
return true;
case XFS_SUPER_MAGIC:
return true;
case TMPFS_MAGIC:
return true;
default:
return false;
}
#else
(void)path;
return false;
#endif
}
size_t page_size_;
std::vector<ThreadPoolImpl> thread_pools_;
pthread_mutex_t mu_;
std::vector<pthread_t> threads_to_join_;
// If true, allow non owner read access for db files. Otherwise, non-owner
// has no access to db files.
bool allow_non_owner_access_;
};
PosixEnv::PosixEnv()
: checkedDiskForMmap_(false),
forceMmapOff_(false),
page_size_(getpagesize()),
thread_pools_(Priority::TOTAL),
allow_non_owner_access_(true) {
ThreadPoolImpl::PthreadCall("mutex_init", pthread_mutex_init(&mu_, nullptr));
for (int pool_id = 0; pool_id < Env::Priority::TOTAL; ++pool_id) {
thread_pools_[pool_id].SetThreadPriority(
static_cast<Env::Priority>(pool_id));
// This allows later initializing the thread-local-env of each thread.
thread_pools_[pool_id].SetHostEnv(this);
}
thread_status_updater_ = CreateThreadStatusUpdater();
}
void PosixEnv::Schedule(void (*function)(void* arg1), void* arg, Priority pri,
void* tag, void (*unschedFunction)(void* arg)) {
assert(pri >= Priority::BOTTOM && pri <= Priority::HIGH);
thread_pools_[pri].Schedule(function, arg, tag, unschedFunction);
}
int PosixEnv::UnSchedule(void* arg, Priority pri) {
return thread_pools_[pri].UnSchedule(arg);
}
unsigned int PosixEnv::GetThreadPoolQueueLen(Priority pri) const {
assert(pri >= Priority::BOTTOM && pri <= Priority::HIGH);
return thread_pools_[pri].GetQueueLen();
}
struct StartThreadState {
void (*user_function)(void*);
void* arg;
};
static void* StartThreadWrapper(void* arg) {
StartThreadState* state = reinterpret_cast<StartThreadState*>(arg);
state->user_function(state->arg);
delete state;
return nullptr;
}
void PosixEnv::StartThread(void (*function)(void* arg), void* arg) {
pthread_t t;
StartThreadState* state = new StartThreadState;
state->user_function = function;
state->arg = arg;
ThreadPoolImpl::PthreadCall(
"start thread", pthread_create(&t, nullptr, &StartThreadWrapper, state));
ThreadPoolImpl::PthreadCall("lock", pthread_mutex_lock(&mu_));
threads_to_join_.push_back(t);
ThreadPoolImpl::PthreadCall("unlock", pthread_mutex_unlock(&mu_));
}
void PosixEnv::WaitForJoin() {
for (const auto tid : threads_to_join_) {
pthread_join(tid, nullptr);
}
threads_to_join_.clear();
}
} // namespace
std::string Env::GenerateUniqueId() {
std::string uuid_file = "/proc/sys/kernel/random/uuid";
Status s = FileExists(uuid_file);
if (s.ok()) {
std::string uuid;
s = ReadFileToString(this, uuid_file, &uuid);
if (s.ok()) {
return uuid;
}
}
// Could not read uuid_file - generate uuid using "nanos-random"
Random64 r(time(nullptr));
uint64_t random_uuid_portion =
r.Uniform(std::numeric_limits<uint64_t>::max());
uint64_t nanos_uuid_portion = NowNanos();
char uuid2[200];
snprintf(uuid2,
200,
"%lx-%lx",
(unsigned long)nanos_uuid_portion,
(unsigned long)random_uuid_portion);
return uuid2;
}
//
// Default Posix Env
//
Env* Env::Default() {
// The following function call initializes the singletons of ThreadLocalPtr
// right before the static default_env. This guarantees default_env will
// always being destructed before the ThreadLocalPtr singletons get
// destructed as C++ guarantees that the destructions of static variables
// is in the reverse order of their constructions.
//
// Since static members are destructed in the reverse order
// of their construction, having this call here guarantees that
// the destructor of static PosixEnv will go first, then the
// the singletons of ThreadLocalPtr.
ThreadLocalPtr::InitSingletons();
CompressionContextCache::InitSingleton();
INIT_SYNC_POINT_SINGLETONS();
static PosixEnv default_env;
return &default_env;
}
} // namespace rocksdb