ce89b915d3
Change perror() to VPLOG() to avoid spamming the console with these errors (they reliably occur on the login screen). BUG=463306 TEST=build, boot, & login to pixel Review URL: https://codereview.chromium.org/1096203003 Cr-Commit-Position: refs/heads/master@{#326621}
84 lines
2.2 KiB
C++
84 lines
2.2 KiB
C++
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "rlz/lib/recursive_cross_process_lock_posix.h"
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#include <errno.h>
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#include <fcntl.h>
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#include <sys/file.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include "base/files/file_path.h"
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#include "base/logging.h"
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#include "base/posix/eintr_wrapper.h"
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namespace rlz_lib {
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bool RecursiveCrossProcessLock::TryGetCrossProcessLock(
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const base::FilePath& lock_filename) {
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bool just_got_lock = false;
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// Emulate a recursive mutex with a non-recursive one.
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if (pthread_mutex_trylock(&recursive_lock_) == EBUSY) {
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if (pthread_equal(pthread_self(), locking_thread_) == 0) {
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// Some other thread has the lock, wait for it.
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pthread_mutex_lock(&recursive_lock_);
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CHECK(locking_thread_ == 0);
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just_got_lock = true;
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}
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} else {
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just_got_lock = true;
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}
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locking_thread_ = pthread_self();
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// Try to acquire file lock.
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if (just_got_lock) {
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const int kMaxTimeoutMS = 5000; // Matches Windows.
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const int kSleepPerTryMS = 200;
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CHECK(file_lock_ == -1);
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file_lock_ = open(lock_filename.value().c_str(), O_RDWR | O_CREAT, 0666);
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if (file_lock_ == -1) {
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VPLOG(1) << "Failed to open: " << lock_filename.value();
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return false;
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}
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int flock_result = -1;
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int elapsed_ms = 0;
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while ((flock_result =
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HANDLE_EINTR(flock(file_lock_, LOCK_EX | LOCK_NB))) == -1 &&
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errno == EWOULDBLOCK &&
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elapsed_ms < kMaxTimeoutMS) {
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usleep(kSleepPerTryMS * 1000);
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elapsed_ms += kSleepPerTryMS;
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}
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if (flock_result == -1) {
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VPLOG(1) << "Failed flock: " << lock_filename.value();
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close(file_lock_);
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file_lock_ = -1;
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return false;
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}
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return true;
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} else {
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return file_lock_ != -1;
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}
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}
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void RecursiveCrossProcessLock::ReleaseLock() {
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if (file_lock_ != -1) {
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ignore_result(HANDLE_EINTR(flock(file_lock_, LOCK_UN)));
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close(file_lock_);
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file_lock_ = -1;
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}
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locking_thread_ = 0;
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pthread_mutex_unlock(&recursive_lock_);
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}
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} // namespace rlz_lib
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