aosp12/system/logging/logd/LogReaderThread.h

113 lines
4.7 KiB
C++

/*
* Copyright (C) 2012-2013 The Android Open Source Project
*
* 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
#include <pthread.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <time.h>
#include <chrono>
#include <condition_variable>
#include <list>
#include <memory>
#include <android-base/thread_annotations.h>
#include <log/log.h>
#include "LogBuffer.h"
#include "LogWriter.h"
#include "LogdLock.h"
class LogReaderList;
class LogReaderThread {
public:
LogReaderThread(LogBuffer* log_buffer, LogReaderList* reader_list,
std::unique_ptr<LogWriter> writer, bool non_block, unsigned long tail,
LogMask log_mask, pid_t pid, log_time start_time, uint64_t sequence,
std::chrono::steady_clock::time_point deadline);
void TriggerReader() REQUIRES(logd_lock) { thread_triggered_condition_.notify_all(); }
void TriggerSkip(log_id_t id, unsigned int skip) REQUIRES(logd_lock) { skip_ahead_[id] = skip; }
void CleanSkip() REQUIRES(logd_lock) { memset(skip_ahead_, 0, sizeof(skip_ahead_)); }
void Release() REQUIRES(logd_lock) {
// gracefully shut down the socket.
writer_->Shutdown();
release_ = true;
thread_triggered_condition_.notify_all();
}
bool IsWatching(log_id_t id) const REQUIRES(logd_lock) {
return flush_to_state_->log_mask() & (1 << id);
}
bool IsWatchingMultiple(LogMask log_mask) const REQUIRES(logd_lock) {
return flush_to_state_->log_mask() & log_mask;
}
std::string name() const REQUIRES(logd_lock) { return writer_->name(); }
uint64_t start() const REQUIRES(logd_lock) { return flush_to_state_->start(); }
std::chrono::steady_clock::time_point deadline() const REQUIRES(logd_lock) { return deadline_; }
FlushToState& flush_to_state() REQUIRES(logd_lock) { return *flush_to_state_; }
private:
void ThreadFunction();
// flushTo filter callbacks
FilterResult FilterFirstPass(log_id_t log_id, pid_t pid, uint64_t sequence, log_time realtime)
REQUIRES(logd_lock);
FilterResult FilterSecondPass(log_id_t log_id, pid_t pid, uint64_t sequence, log_time realtime)
REQUIRES(logd_lock);
std::condition_variable thread_triggered_condition_;
LogBuffer* log_buffer_;
LogReaderList* reader_list_;
std::unique_ptr<LogWriter> writer_ GUARDED_BY(logd_lock);
// Set to true to cause the thread to end and the LogReaderThread to delete itself.
bool release_ GUARDED_BY(logd_lock) = false;
// If set to non-zero, only pids equal to this are read by the reader.
const pid_t pid_;
// When a reader is referencing (via start_) old elements in the log buffer, and the log
// buffer's size grows past its memory limit, the log buffer may request the reader to skip
// ahead a specified number of logs.
unsigned int skip_ahead_[LOG_ID_MAX] GUARDED_BY(logd_lock);
// LogBuffer::FlushTo() needs to store state across subsequent calls.
std::unique_ptr<FlushToState> flush_to_state_ GUARDED_BY(logd_lock);
// These next three variables are used for reading only the most recent lines aka `adb logcat
// -t` / `adb logcat -T`.
// tail_ is the number of most recent lines to print.
unsigned long tail_;
// count_ is the result of a first pass through the log buffer to determine how many total
// messages there are.
unsigned long count_;
// index_ is used along with count_ to only start sending lines once index_ > (count_ - tail_)
// and to disconnect the reader (if it is dumpAndClose, `adb logcat -t`), when index_ >= count_.
unsigned long index_;
// When a reader requests logs starting from a given timestamp, its stored here for the first
// pass, such that logs before this time stamp that are accumulated in the buffer are ignored.
log_time start_time_;
// CLOCK_MONOTONIC based deadline used for log wrapping. If this deadline expires before logs
// wrap, then wake up and send the logs to the reader anyway.
std::chrono::steady_clock::time_point deadline_ GUARDED_BY(logd_lock);
// If this reader is 'dumpAndClose' and will disconnect once it has read its intended logs.
const bool non_block_;
};