platform_system_core/logd/FlushCommand.cpp

113 lines
3.7 KiB
C++

/*
* Copyright (C) 2012-2014 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.
*/
#include <stdlib.h>
#include <private/android_filesystem_config.h>
#include "FlushCommand.h"
#include "LogBuffer.h"
#include "LogBufferElement.h"
#include "LogCommand.h"
#include "LogReader.h"
#include "LogTimes.h"
#include "LogUtils.h"
FlushCommand::FlushCommand(LogReader& reader, bool nonBlock, unsigned long tail,
unsigned int logMask, pid_t pid, log_time start,
uint64_t timeout)
: mReader(reader),
mNonBlock(nonBlock),
mTail(tail),
mLogMask(logMask),
mPid(pid),
mStart(start),
mTimeout((start != log_time::EPOCH) ? timeout : 0) {
}
// runSocketCommand is called once for every open client on the
// log reader socket. Here we manage and associated the reader
// client tracking and log region locks LastLogTimes list of
// LogTimeEntrys, and spawn a transitory per-client thread to
// work at filing data to the socket.
//
// global LogTimeEntry::wrlock() is used to protect access,
// reference counts are used to ensure that individual
// LogTimeEntry lifetime is managed when not protected.
void FlushCommand::runSocketCommand(SocketClient* client) {
LogTimeEntry* entry = NULL;
LastLogTimes& times = mReader.logbuf().mTimes;
LogTimeEntry::wrlock();
LastLogTimes::iterator it = times.begin();
while (it != times.end()) {
entry = (*it);
if (entry->mClient == client) {
if (entry->mTimeout.tv_sec || entry->mTimeout.tv_nsec) {
if (mReader.logbuf().isMonotonic()) {
LogTimeEntry::unlock();
return;
}
// If the user changes the time in a gross manner that
// invalidates the timeout, fall through and trigger.
log_time now(CLOCK_REALTIME);
if (((entry->mEnd + entry->mTimeout) > now) &&
(now > entry->mEnd)) {
LogTimeEntry::unlock();
return;
}
}
entry->triggerReader_Locked();
if (entry->runningReader_Locked()) {
LogTimeEntry::unlock();
return;
}
entry->incRef_Locked();
break;
}
it++;
}
if (it == times.end()) {
// Create LogTimeEntry in notifyNewLog() ?
if (mTail == (unsigned long)-1) {
LogTimeEntry::unlock();
return;
}
entry = new LogTimeEntry(mReader, client, mNonBlock, mTail, mLogMask,
mPid, mStart, mTimeout);
times.push_front(entry);
}
client->incRef();
// release client and entry reference counts once done
entry->startReader_Locked();
LogTimeEntry::unlock();
}
bool FlushCommand::hasReadLogs(SocketClient* client) {
return clientHasLogCredentials(client);
}
static bool clientHasSecurityCredentials(SocketClient* client) {
return (client->getUid() == AID_SYSTEM) || (client->getGid() == AID_SYSTEM);
}
bool FlushCommand::hasSecurityLogs(SocketClient* client) {
return clientHasSecurityCredentials(client);
}