Clean up env_posix.cc.
General cleanup principles: * Use override when applicable. * Remove static when redundant (methods and globals in anonymous namespaces). * Use const on class members where possible. * Standardize on "status" for Status local variables. * Renames where clarity can be improved. * Qualify standard library names with std:: when possible, to distinguish from POSIX names. * Qualify POSIX names with the global namespace (::) when possible, to distinguish from standard library names. This also refactors the background thread synchronization logic so that it's statically analyzable. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=219212089
This commit is contained in:
costan
Victor Costan
parent
a7dc502e9f
commit
1cb3840881
@ -3,22 +3,21 @@
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include <dirent.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <pthread.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/mman.h>
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#include <sys/resource.h>
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#include <sys/stat.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <time.h>
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#include <unistd.h>
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#include <atomic>
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#include <cerrno>
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#include <cstddef>
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#include <cstdint>
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#include <cstdio>
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#include <cstdlib>
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#include <cstring>
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#include <limits>
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#include <queue>
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@ -26,6 +25,7 @@
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#include <string>
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#include <thread>
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#include <type_traits>
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#include <utility>
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#include "leveldb/env.h"
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#include "leveldb/slice.h"
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@ -45,16 +45,22 @@ namespace leveldb {
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namespace {
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static int open_read_only_file_limit = -1;
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static int mmap_limit = -1;
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// Set by EnvPosixTestHelper::SetReadOnlyMMapLimit() and MaxOpenFiles().
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int g_open_read_only_file_limit = -1;
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// Up to 1000 mmap regions for 64-bit binaries; none for 32-bit.
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constexpr const int kDefaultMmapLimit = (sizeof(void*) >= 8) ? 1000 : 0;
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// Can be set using EnvPosixTestHelper::SetReadOnlyMMapLimit.
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int g_mmap_limit = kDefaultMmapLimit;
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constexpr const size_t kWritableFileBufferSize = 65536;
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static Status PosixError(const std::string& context, int err_number) {
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if (err_number == ENOENT) {
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return Status::NotFound(context, strerror(err_number));
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Status PosixError(const std::string& context, int error_number) {
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if (error_number == ENOENT) {
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return Status::NotFound(context, std::strerror(error_number));
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} else {
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return Status::IOError(context, strerror(err_number));
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return Status::IOError(context, std::strerror(error_number));
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}
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}
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@ -97,124 +103,147 @@ class Limiter {
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std::atomic<int> acquires_allowed_;
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};
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class PosixSequentialFile: public SequentialFile {
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private:
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std::string filename_;
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int fd_;
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// Implements sequential read access in a file using read().
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//
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// Instances of this class are thread-friendly but not thread-safe, as required
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// by the SequentialFile API.
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class PosixSequentialFile final : public SequentialFile {
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public:
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PosixSequentialFile(const std::string& fname, int fd)
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: filename_(fname), fd_(fd) {}
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virtual ~PosixSequentialFile() { close(fd_); }
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PosixSequentialFile(std::string filename, int fd)
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: fd_(fd), filename_(filename) {}
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~PosixSequentialFile() override { close(fd_); }
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virtual Status Read(size_t n, Slice* result, char* scratch) {
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Status s;
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Status Read(size_t n, Slice* result, char* scratch) override {
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Status status;
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while (true) {
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ssize_t r = read(fd_, scratch, n);
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if (r < 0) {
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::ssize_t read_size = ::read(fd_, scratch, n);
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if (read_size < 0) { // Read error.
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if (errno == EINTR) {
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continue; // Retry
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}
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s = PosixError(filename_, errno);
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status = PosixError(filename_, errno);
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break;
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}
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*result = Slice(scratch, r);
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*result = Slice(scratch, read_size);
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break;
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}
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return s;
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return status;
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}
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virtual Status Skip(uint64_t n) {
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if (lseek(fd_, n, SEEK_CUR) == static_cast<off_t>(-1)) {
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Status Skip(uint64_t n) override {
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if (::lseek(fd_, n, SEEK_CUR) == static_cast<off_t>(-1)) {
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return PosixError(filename_, errno);
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}
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return Status::OK();
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}
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private:
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const int fd_;
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const std::string filename_;
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};
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// pread() based random-access
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class PosixRandomAccessFile: public RandomAccessFile {
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private:
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std::string filename_;
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bool temporary_fd_; // If true, fd_ is -1 and we open on every read.
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int fd_;
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Limiter* limiter_;
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// Implements random read access in a file using pread().
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//
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// Instances of this class are thread-safe, as required by the RandomAccessFile
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// API. Instances are immutable and Read() only calls thread-safe library
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// functions.
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class PosixRandomAccessFile final : public RandomAccessFile {
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public:
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PosixRandomAccessFile(const std::string& fname, int fd, Limiter* limiter)
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: filename_(fname), fd_(fd), limiter_(limiter) {
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temporary_fd_ = !limiter->Acquire();
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if (temporary_fd_) {
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// Open file on every access.
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close(fd_);
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fd_ = -1;
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// The new instance takes ownership of |fd|. |fd_limiter| must outlive this
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// instance, and will be used to determine if .
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PosixRandomAccessFile(std::string filename, int fd, Limiter* fd_limiter)
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: has_permanent_fd_(fd_limiter->Acquire()),
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fd_(has_permanent_fd_ ? fd : -1),
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fd_limiter_(fd_limiter),
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filename_(std::move(filename)) {
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if (!has_permanent_fd_) {
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assert(fd_ == -1);
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::close(fd); // The file will be opened on every read.
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}
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}
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virtual ~PosixRandomAccessFile() {
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if (!temporary_fd_) {
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close(fd_);
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limiter_->Release();
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~PosixRandomAccessFile() override {
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if (has_permanent_fd_) {
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assert(fd_ != -1);
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::close(fd_);
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fd_limiter_->Release();
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}
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}
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virtual Status Read(uint64_t offset, size_t n, Slice* result,
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char* scratch) const {
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Status Read(uint64_t offset, size_t n, Slice* result,
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char* scratch) const override {
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int fd = fd_;
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if (temporary_fd_) {
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fd = open(filename_.c_str(), O_RDONLY);
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if (!has_permanent_fd_) {
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fd = ::open(filename_.c_str(), O_RDONLY);
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if (fd < 0) {
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return PosixError(filename_, errno);
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}
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}
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Status s;
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ssize_t r = pread(fd, scratch, n, static_cast<off_t>(offset));
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*result = Slice(scratch, (r < 0) ? 0 : r);
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if (r < 0) {
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// An error: return a non-ok status
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s = PosixError(filename_, errno);
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assert(fd != -1);
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Status status;
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ssize_t read_size = ::pread(fd, scratch, n, static_cast<off_t>(offset));
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*result = Slice(scratch, (read_size < 0) ? 0 : read_size);
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if (read_size < 0) {
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// An error: return a non-ok status.
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status = PosixError(filename_, errno);
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}
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if (temporary_fd_) {
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if (!has_permanent_fd_) {
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// Close the temporary file descriptor opened earlier.
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close(fd);
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assert(fd != fd_);
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::close(fd);
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}
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return s;
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return status;
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}
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private:
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const bool has_permanent_fd_; // If false, the file is opened on every read.
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const int fd_; // -1 if has_permanent_fd_ is false.
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Limiter* const fd_limiter_;
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const std::string filename_;
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};
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// mmap() based random-access
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class PosixMmapReadableFile: public RandomAccessFile {
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private:
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std::string filename_;
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void* mmapped_region_;
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size_t length_;
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Limiter* limiter_;
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// Implements random read access in a file using mmap().
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//
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// Instances of this class are thread-safe, as required by the RandomAccessFile
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// API. Instances are immutable and Read() only calls thread-safe library
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// functions.
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class PosixMmapReadableFile final : public RandomAccessFile {
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public:
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// base[0,length-1] contains the mmapped contents of the file.
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PosixMmapReadableFile(const std::string& fname, void* base, size_t length,
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Limiter* limiter)
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: filename_(fname), mmapped_region_(base), length_(length),
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limiter_(limiter) {
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// mmap_base[0, length-1] points to the memory-mapped contents of the file. It
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// must be the result of a successful call to mmap(). This instances takes
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// over the ownership of the region.
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//
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// |mmap_limiter| must outlive this instance. The caller must have already
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// aquired the right to use one mmap region, which will be released when this
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// instance is destroyed.
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PosixMmapReadableFile(std::string filename, char* mmap_base, size_t length,
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Limiter* mmap_limiter)
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: mmap_base_(mmap_base), length_(length), mmap_limiter_(mmap_limiter),
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filename_(std::move(filename)) {}
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~PosixMmapReadableFile() override {
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::munmap(static_cast<void*>(mmap_base_), length_);
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mmap_limiter_->Release();
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}
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virtual ~PosixMmapReadableFile() {
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munmap(mmapped_region_, length_);
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limiter_->Release();
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}
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virtual Status Read(uint64_t offset, size_t n, Slice* result,
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char* scratch) const {
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Status s;
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Status Read(uint64_t offset, size_t n, Slice* result,
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char* scratch) const override {
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if (offset + n > length_) {
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*result = Slice();
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s = PosixError(filename_, EINVAL);
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} else {
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*result = Slice(reinterpret_cast<char*>(mmapped_region_) + offset, n);
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return PosixError(filename_, EINVAL);
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}
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return s;
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*result = Slice(mmap_base_ + offset, n);
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return Status::OK();
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}
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private:
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char* const mmap_base_;
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const size_t length_;
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Limiter* const mmap_limiter_;
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const std::string filename_;
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};
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class PosixWritableFile final : public WritableFile {
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@ -378,30 +407,39 @@ class PosixWritableFile final : public WritableFile {
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const std::string dirname_; // The directory of filename_.
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};
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static int LockOrUnlock(int fd, bool lock) {
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int LockOrUnlock(int fd, bool lock) {
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errno = 0;
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struct flock f;
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memset(&f, 0, sizeof(f));
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f.l_type = (lock ? F_WRLCK : F_UNLCK);
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f.l_whence = SEEK_SET;
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f.l_start = 0;
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f.l_len = 0; // Lock/unlock entire file
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return fcntl(fd, F_SETLK, &f);
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struct ::flock file_lock_info;
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std::memset(&file_lock_info, 0, sizeof(file_lock_info));
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file_lock_info.l_type = (lock ? F_WRLCK : F_UNLCK);
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file_lock_info.l_whence = SEEK_SET;
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file_lock_info.l_start = 0;
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file_lock_info.l_len = 0; // Lock/unlock entire file.
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return ::fcntl(fd, F_SETLK, &file_lock_info);
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}
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// Instances are thread-safe because they are immutable.
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class PosixFileLock : public FileLock {
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public:
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int fd_;
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std::string name_;
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PosixFileLock(int fd, std::string filename)
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: fd_(fd), filename_(std::move(filename)) {}
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int fd() const { return fd_; }
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const std::string& filename() const { return filename_; }
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private:
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const int fd_;
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const std::string filename_;
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};
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// Set of locked files. We keep a separate set instead of just
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// relying on fcntrl(F_SETLK) since fcntl(F_SETLK) does not provide
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// any protection against multiple uses from the same process.
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// Tracks the files locked by PosixEnv::LockFile().
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//
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// We maintain a separate set instead of relying on fcntrl(F_SETLK) because
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// fcntl(F_SETLK) does not provide any protection against multiple uses from the
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// same process.
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//
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// Instances are thread-safe because all member data is guarded by a mutex.
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class PosixLockTable {
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private:
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port::Mutex mu_;
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std::set<std::string> locked_files_ GUARDED_BY(mu_);
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public:
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bool Insert(const std::string& fname) LOCKS_EXCLUDED(mu_) {
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mu_.Lock();
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@ -414,217 +452,225 @@ class PosixLockTable {
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locked_files_.erase(fname);
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mu_.Unlock();
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}
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private:
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port::Mutex mu_;
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std::set<std::string> locked_files_ GUARDED_BY(mu_);
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};
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class PosixEnv : public Env {
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public:
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PosixEnv();
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virtual ~PosixEnv() {
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char msg[] = "Destroying Env::Default()\n";
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fwrite(msg, 1, sizeof(msg), stderr);
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abort();
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~PosixEnv() override {
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static char msg[] = "PosixEnv singleton destroyed. Unsupported behavior!\n";
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std::fwrite(msg, 1, sizeof(msg), stderr);
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std::abort();
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}
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virtual Status NewSequentialFile(const std::string& fname,
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SequentialFile** result) {
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int fd = open(fname.c_str(), O_RDONLY);
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Status NewSequentialFile(const std::string& filename,
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SequentialFile** result) override {
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int fd = ::open(filename.c_str(), O_RDONLY);
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if (fd < 0) {
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*result = nullptr;
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return PosixError(fname, errno);
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} else {
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*result = new PosixSequentialFile(fname, fd);
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return PosixError(filename, errno);
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}
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*result = new PosixSequentialFile(filename, fd);
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return Status::OK();
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}
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}
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virtual Status NewRandomAccessFile(const std::string& fname,
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RandomAccessFile** result) {
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Status NewRandomAccessFile(const std::string& filename,
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RandomAccessFile** result) override {
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*result = nullptr;
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Status s;
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int fd = open(fname.c_str(), O_RDONLY);
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int fd = ::open(filename.c_str(), O_RDONLY);
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if (fd < 0) {
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s = PosixError(fname, errno);
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} else if (mmap_limit_.Acquire()) {
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uint64_t size;
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s = GetFileSize(fname, &size);
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if (s.ok()) {
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void* base = mmap(nullptr, size, PROT_READ, MAP_SHARED, fd, 0);
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if (base != MAP_FAILED) {
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*result = new PosixMmapReadableFile(fname, base, size, &mmap_limit_);
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} else {
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s = PosixError(fname, errno);
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}
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}
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close(fd);
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if (!s.ok()) {
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mmap_limit_.Release();
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}
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} else {
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*result = new PosixRandomAccessFile(fname, fd, &fd_limit_);
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}
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return s;
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return PosixError(filename, errno);
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}
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virtual Status NewWritableFile(const std::string& fname,
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WritableFile** result) {
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Status s;
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int fd = open(fname.c_str(), O_TRUNC | O_WRONLY | O_CREAT, 0644);
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if (!mmap_limiter_.Acquire()) {
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*result = new PosixRandomAccessFile(filename, fd, &fd_limiter_);
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return Status::OK();
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}
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uint64_t file_size;
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Status status = GetFileSize(filename, &file_size);
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if (status.ok()) {
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void* mmap_base = ::mmap(/*addr=*/nullptr, file_size, PROT_READ,
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MAP_SHARED, fd, 0);
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if (mmap_base != MAP_FAILED) {
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*result = new PosixMmapReadableFile(
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filename, reinterpret_cast<char*>(mmap_base), file_size,
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&mmap_limiter_);
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} else {
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status = PosixError(filename, errno);
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}
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}
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::close(fd);
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if (!status.ok()) {
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mmap_limiter_.Release();
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}
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return status;
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}
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Status NewWritableFile(const std::string& filename,
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WritableFile** result) override {
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int fd = ::open(filename.c_str(), O_TRUNC | O_WRONLY | O_CREAT, 0644);
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if (fd < 0) {
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*result = nullptr;
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s = PosixError(fname, errno);
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} else {
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*result = new PosixWritableFile(fname, fd);
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}
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return s;
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return PosixError(filename, errno);
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}
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virtual Status NewAppendableFile(const std::string& fname,
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WritableFile** result) {
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||||
Status s;
|
||||
int fd = open(fname.c_str(), O_APPEND | O_WRONLY | O_CREAT, 0644);
|
||||
*result = new PosixWritableFile(filename, fd);
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
Status NewAppendableFile(const std::string& filename,
|
||||
WritableFile** result) override {
|
||||
int fd = ::open(filename.c_str(), O_APPEND | O_WRONLY | O_CREAT, 0644);
|
||||
if (fd < 0) {
|
||||
*result = nullptr;
|
||||
s = PosixError(fname, errno);
|
||||
} else {
|
||||
*result = new PosixWritableFile(fname, fd);
|
||||
}
|
||||
return s;
|
||||
return PosixError(filename, errno);
|
||||
}
|
||||
|
||||
virtual bool FileExists(const std::string& fname) {
|
||||
return access(fname.c_str(), F_OK) == 0;
|
||||
*result = new PosixWritableFile(filename, fd);
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
virtual Status GetChildren(const std::string& dir,
|
||||
std::vector<std::string>* result) {
|
||||
bool FileExists(const std::string& filename) override {
|
||||
return ::access(filename.c_str(), F_OK) == 0;
|
||||
}
|
||||
|
||||
Status GetChildren(const std::string& directory_path,
|
||||
std::vector<std::string>* result) override {
|
||||
result->clear();
|
||||
DIR* d = opendir(dir.c_str());
|
||||
if (d == nullptr) {
|
||||
return PosixError(dir, errno);
|
||||
::DIR* dir = ::opendir(directory_path.c_str());
|
||||
if (dir == nullptr) {
|
||||
return PosixError(directory_path, errno);
|
||||
}
|
||||
struct dirent* entry;
|
||||
while ((entry = readdir(d)) != nullptr) {
|
||||
result->push_back(entry->d_name);
|
||||
struct ::dirent* entry;
|
||||
while ((entry = ::readdir(dir)) != nullptr) {
|
||||
result->emplace_back(entry->d_name);
|
||||
}
|
||||
closedir(d);
|
||||
::closedir(dir);
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
virtual Status DeleteFile(const std::string& fname) {
|
||||
Status result;
|
||||
if (unlink(fname.c_str()) != 0) {
|
||||
result = PosixError(fname, errno);
|
||||
Status DeleteFile(const std::string& filename) override {
|
||||
if (::unlink(filename.c_str()) != 0) {
|
||||
return PosixError(filename, errno);
|
||||
}
|
||||
return result;
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
virtual Status CreateDir(const std::string& name) {
|
||||
Status result;
|
||||
if (mkdir(name.c_str(), 0755) != 0) {
|
||||
result = PosixError(name, errno);
|
||||
Status CreateDir(const std::string& dirname) override {
|
||||
if (::mkdir(dirname.c_str(), 0755) != 0) {
|
||||
return PosixError(dirname, errno);
|
||||
}
|
||||
return result;
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
virtual Status DeleteDir(const std::string& name) {
|
||||
Status result;
|
||||
if (rmdir(name.c_str()) != 0) {
|
||||
result = PosixError(name, errno);
|
||||
Status DeleteDir(const std::string& dirname) override {
|
||||
if (::rmdir(dirname.c_str()) != 0) {
|
||||
return PosixError(dirname, errno);
|
||||
}
|
||||
return result;
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
virtual Status GetFileSize(const std::string& fname, uint64_t* size) {
|
||||
Status s;
|
||||
struct stat sbuf;
|
||||
if (stat(fname.c_str(), &sbuf) != 0) {
|
||||
Status GetFileSize(const std::string& filename, uint64_t* size) override {
|
||||
struct ::stat file_stat;
|
||||
if (::stat(filename.c_str(), &file_stat) != 0) {
|
||||
*size = 0;
|
||||
s = PosixError(fname, errno);
|
||||
} else {
|
||||
*size = sbuf.st_size;
|
||||
return PosixError(filename, errno);
|
||||
}
|
||||
return s;
|
||||
*size = file_stat.st_size;
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
virtual Status RenameFile(const std::string& src, const std::string& target) {
|
||||
Status result;
|
||||
if (rename(src.c_str(), target.c_str()) != 0) {
|
||||
result = PosixError(src, errno);
|
||||
Status RenameFile(const std::string& from, const std::string& to) override {
|
||||
if (std::rename(from.c_str(), to.c_str()) != 0) {
|
||||
return PosixError(from, errno);
|
||||
}
|
||||
return result;
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
virtual Status LockFile(const std::string& fname, FileLock** lock) {
|
||||
Status LockFile(const std::string& filename, FileLock** lock) override {
|
||||
*lock = nullptr;
|
||||
Status result;
|
||||
int fd = open(fname.c_str(), O_RDWR | O_CREAT, 0644);
|
||||
|
||||
int fd = ::open(filename.c_str(), O_RDWR | O_CREAT, 0644);
|
||||
if (fd < 0) {
|
||||
result = PosixError(fname, errno);
|
||||
} else if (!locks_.Insert(fname)) {
|
||||
close(fd);
|
||||
result = Status::IOError("lock " + fname, "already held by process");
|
||||
} else if (LockOrUnlock(fd, true) == -1) {
|
||||
result = PosixError("lock " + fname, errno);
|
||||
close(fd);
|
||||
locks_.Remove(fname);
|
||||
} else {
|
||||
PosixFileLock* my_lock = new PosixFileLock;
|
||||
my_lock->fd_ = fd;
|
||||
my_lock->name_ = fname;
|
||||
*lock = my_lock;
|
||||
}
|
||||
return result;
|
||||
return PosixError(filename, errno);
|
||||
}
|
||||
|
||||
virtual Status UnlockFile(FileLock* lock) {
|
||||
PosixFileLock* my_lock = reinterpret_cast<PosixFileLock*>(lock);
|
||||
Status result;
|
||||
if (LockOrUnlock(my_lock->fd_, false) == -1) {
|
||||
result = PosixError("unlock", errno);
|
||||
}
|
||||
locks_.Remove(my_lock->name_);
|
||||
close(my_lock->fd_);
|
||||
delete my_lock;
|
||||
return result;
|
||||
if (!locks_.Insert(filename)) {
|
||||
::close(fd);
|
||||
return Status::IOError("lock " + filename, "already held by process");
|
||||
}
|
||||
|
||||
virtual void Schedule(void (*function)(void*), void* arg);
|
||||
if (LockOrUnlock(fd, true) == -1) {
|
||||
int lock_errno = errno;
|
||||
::close(fd);
|
||||
locks_.Remove(filename);
|
||||
return PosixError("lock " + filename, lock_errno);
|
||||
}
|
||||
|
||||
virtual void StartThread(void (*function)(void* arg), void* arg);
|
||||
*lock = new PosixFileLock(fd, filename);
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
virtual Status GetTestDirectory(std::string* result) {
|
||||
const char* env = getenv("TEST_TMPDIR");
|
||||
Status UnlockFile(FileLock* lock) override {
|
||||
PosixFileLock* posix_file_lock = static_cast<PosixFileLock*>(lock);
|
||||
if (LockOrUnlock(posix_file_lock->fd(), false) == -1) {
|
||||
return PosixError("unlock " + posix_file_lock->filename(), errno);
|
||||
}
|
||||
locks_.Remove(posix_file_lock->filename());
|
||||
::close(posix_file_lock->fd());
|
||||
delete posix_file_lock;
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
void Schedule(void (*background_work_function)(void* background_work_arg),
|
||||
void* background_work_arg) override;
|
||||
|
||||
void StartThread(void (*thread_main)(void* thread_main_arg),
|
||||
void* thread_main_arg) override;
|
||||
|
||||
Status GetTestDirectory(std::string* result) override {
|
||||
const char* env = std::getenv("TEST_TMPDIR");
|
||||
if (env && env[0] != '\0') {
|
||||
*result = env;
|
||||
} else {
|
||||
char buf[100];
|
||||
snprintf(buf, sizeof(buf), "/tmp/leveldbtest-%d", int(geteuid()));
|
||||
std::snprintf(buf, sizeof(buf), "/tmp/leveldbtest-%d",
|
||||
static_cast<int>(::geteuid()));
|
||||
*result = buf;
|
||||
}
|
||||
// Directory may already exist
|
||||
|
||||
// The CreateDir status is ignored because the directory may already exist.
|
||||
CreateDir(*result);
|
||||
|
||||
return Status::OK();
|
||||
}
|
||||
|
||||
virtual Status NewLogger(const std::string& fname, Logger** result) {
|
||||
FILE* f = fopen(fname.c_str(), "w");
|
||||
if (f == nullptr) {
|
||||
Status NewLogger(const std::string& filename, Logger** result) override {
|
||||
std::FILE* fp = std::fopen(filename.c_str(), "w");
|
||||
if (fp == nullptr) {
|
||||
*result = nullptr;
|
||||
return PosixError(fname, errno);
|
||||
return PosixError(filename, errno);
|
||||
} else {
|
||||
*result = new PosixLogger(f);
|
||||
*result = new PosixLogger(fp);
|
||||
return Status::OK();
|
||||
}
|
||||
}
|
||||
|
||||
virtual uint64_t NowMicros() {
|
||||
struct timeval tv;
|
||||
gettimeofday(&tv, nullptr);
|
||||
return static_cast<uint64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
|
||||
uint64_t NowMicros() override {
|
||||
static constexpr uint64_t kUsecondsPerSecond = 1000000;
|
||||
struct ::timeval tv;
|
||||
::gettimeofday(&tv, nullptr);
|
||||
return static_cast<uint64_t>(tv.tv_sec) * kUsecondsPerSecond + tv.tv_usec;
|
||||
}
|
||||
|
||||
virtual void SleepForMicroseconds(int micros) {
|
||||
usleep(micros);
|
||||
void SleepForMicroseconds(int micros) override {
|
||||
::usleep(micros);
|
||||
}
|
||||
|
||||
private:
|
||||
@ -656,44 +702,41 @@ class PosixEnv : public Env {
|
||||
std::queue<BackgroundWorkItem> background_work_queue_
|
||||
GUARDED_BY(background_work_mutex_);
|
||||
|
||||
PosixLockTable locks_;
|
||||
Limiter mmap_limit_;
|
||||
Limiter fd_limit_;
|
||||
PosixLockTable locks_; // Thread-safe.
|
||||
Limiter mmap_limiter_; // Thread-safe.
|
||||
Limiter fd_limiter_; // Thread-safe.
|
||||
};
|
||||
|
||||
// Return the maximum number of concurrent mmaps.
|
||||
static int MaxMmaps() {
|
||||
if (mmap_limit >= 0) {
|
||||
return mmap_limit;
|
||||
}
|
||||
// Up to 1000 mmaps for 64-bit binaries; none for smaller pointer sizes.
|
||||
mmap_limit = sizeof(void*) >= 8 ? 1000 : 0;
|
||||
return mmap_limit;
|
||||
int MaxMmaps() {
|
||||
return g_mmap_limit;
|
||||
}
|
||||
|
||||
// Return the maximum number of read-only files to keep open.
|
||||
static intptr_t MaxOpenFiles() {
|
||||
if (open_read_only_file_limit >= 0) {
|
||||
return open_read_only_file_limit;
|
||||
int MaxOpenFiles() {
|
||||
if (g_open_read_only_file_limit >= 0) {
|
||||
return g_open_read_only_file_limit;
|
||||
}
|
||||
struct rlimit rlim;
|
||||
if (getrlimit(RLIMIT_NOFILE, &rlim)) {
|
||||
struct ::rlimit rlim;
|
||||
if (::getrlimit(RLIMIT_NOFILE, &rlim)) {
|
||||
// getrlimit failed, fallback to hard-coded default.
|
||||
open_read_only_file_limit = 50;
|
||||
g_open_read_only_file_limit = 50;
|
||||
} else if (rlim.rlim_cur == RLIM_INFINITY) {
|
||||
open_read_only_file_limit = std::numeric_limits<int>::max();
|
||||
g_open_read_only_file_limit = std::numeric_limits<int>::max();
|
||||
} else {
|
||||
// Allow use of 20% of available file descriptors for read-only files.
|
||||
open_read_only_file_limit = rlim.rlim_cur / 5;
|
||||
g_open_read_only_file_limit = rlim.rlim_cur / 5;
|
||||
}
|
||||
return open_read_only_file_limit;
|
||||
return g_open_read_only_file_limit;
|
||||
}
|
||||
|
||||
} // namespace
|
||||
|
||||
PosixEnv::PosixEnv()
|
||||
: background_work_cv_(&background_work_mutex_),
|
||||
started_background_thread_(false),
|
||||
mmap_limit_(MaxMmaps()),
|
||||
fd_limit_(MaxOpenFiles()) {
|
||||
mmap_limiter_(MaxMmaps()),
|
||||
fd_limiter_(MaxOpenFiles()) {
|
||||
}
|
||||
|
||||
void PosixEnv::Schedule(
|
||||
@ -737,6 +780,8 @@ void PosixEnv::BackgroundThreadMain() {
|
||||
}
|
||||
}
|
||||
|
||||
namespace {
|
||||
|
||||
// Wraps an Env instance whose destructor is never created.
|
||||
//
|
||||
// Intended usage:
|
||||
@ -800,12 +845,12 @@ void PosixEnv::StartThread(void (*thread_main)(void* thread_main_arg),
|
||||
|
||||
void EnvPosixTestHelper::SetReadOnlyFDLimit(int limit) {
|
||||
PosixDefaultEnv::AssertEnvNotInitialized();
|
||||
open_read_only_file_limit = limit;
|
||||
g_open_read_only_file_limit = limit;
|
||||
}
|
||||
|
||||
void EnvPosixTestHelper::SetReadOnlyMMapLimit(int limit) {
|
||||
PosixDefaultEnv::AssertEnvNotInitialized();
|
||||
mmap_limit = limit;
|
||||
g_mmap_limit = limit;
|
||||
}
|
||||
|
||||
Env* Env::Default() {
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user