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/*
* 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 <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <log/logger.h>
#include "LogBuffer.h"
#include "LogReader.h"
#define LOG_BUFFER_SIZE (256 * 1024) // Tuned on a per-platform basis here?
LogBuffer::LogBuffer(LastLogTimes *times)
: mTimes(*times) {
int i;
for (i = 0; i < LOG_ID_MAX; i++) {
mSizes[i] = 0;
mElements[i] = 0;
}
pthread_mutex_init(&mLogElementsLock, NULL);
}
void LogBuffer::log(log_id_t log_id, struct timespec realtime,
uid_t uid, pid_t pid, const char *msg,
unsigned short len) {
if ((log_id >= LOG_ID_MAX) || (log_id < 0)) {
return;
}
LogBufferElement *elem = new LogBufferElement(log_id, realtime,
uid, pid, msg, len);
pthread_mutex_lock(&mLogElementsLock);
// Insert elements in time sorted order if possible
// NB: if end is region locked, place element at end of list
LogBufferElementCollection::iterator it = mLogElements.end();
LogBufferElementCollection::iterator last = it;
while (--it != mLogElements.begin()) {
if ((*it)->getRealTime() <= realtime) {
break;
}
last = it;
}
if (last == mLogElements.end()) {
mLogElements.push_back(elem);
} else {
log_time end;
bool end_set = false;
bool end_always = false;
LogTimeEntry::lock();
LastLogTimes::iterator t = mTimes.begin();
while(t != mTimes.end()) {
LogTimeEntry *entry = (*t);
if (entry->owned_Locked()) {
if (!entry->mNonBlock) {
end_always = true;
break;
}
if (!end_set || (end <= entry->mEnd)) {
end = entry->mEnd;
end_set = true;
}
}
t++;
}
if (end_always
|| (end_set && (end >= (*last)->getMonotonicTime()))) {
mLogElements.push_back(elem);
} else {
mLogElements.insert(last,elem);
}
LogTimeEntry::unlock();
}
mSizes[log_id] += len;
mElements[log_id]++;
maybePrune(log_id);
pthread_mutex_unlock(&mLogElementsLock);
}
// If we're using more than 256K of memory for log entries, prune
// at least 10% of the log entries.
//
// mLogElementsLock must be held when this function is called.
void LogBuffer::maybePrune(log_id_t id) {
unsigned long sizes = mSizes[id];
if (sizes > LOG_BUFFER_SIZE) {
unsigned long sizeOver90Percent = sizes - ((LOG_BUFFER_SIZE * 9) / 10);
unsigned long elements = mElements[id];
unsigned long pruneRows = elements * sizeOver90Percent / sizes;
elements /= 10;
if (pruneRows <= elements) {
pruneRows = elements;
}
prune(id, pruneRows);
}
}
// prune "pruneRows" of type "id" from the buffer.
//
// mLogElementsLock must be held when this function is called.
void LogBuffer::prune(log_id_t id, unsigned long pruneRows) {
LogTimeEntry *oldest = NULL;
LogTimeEntry::lock();
// Region locked?
LastLogTimes::iterator t = mTimes.begin();
while(t != mTimes.end()) {
LogTimeEntry *entry = (*t);
if (entry->owned_Locked()
&& (!oldest || (oldest->mStart > entry->mStart))) {
oldest = entry;
}
t++;
}
LogBufferElementCollection::iterator it = mLogElements.begin();
while((pruneRows > 0) && (it != mLogElements.end())) {
LogBufferElement *e = *it;
if (e->getLogId() == id) {
if (oldest && (oldest->mStart <= e->getMonotonicTime())) {
if (mSizes[id] > (2 * LOG_BUFFER_SIZE)) {
// kick a misbehaving log reader client off the island
oldest->release_Locked();
} else {
oldest->triggerSkip_Locked(pruneRows);
}
break;
}
it = mLogElements.erase(it);
mSizes[id] -= e->getMsgLen();
mElements[id]--;
delete e;
pruneRows--;
} else {
it++;
}
}
LogTimeEntry::unlock();
}
// clear all rows of type "id" from the buffer.
void LogBuffer::clear(log_id_t id) {
pthread_mutex_lock(&mLogElementsLock);
prune(id, ULONG_MAX);
pthread_mutex_unlock(&mLogElementsLock);
}
// get the used space associated with "id".
unsigned long LogBuffer::getSizeUsed(log_id_t id) {
pthread_mutex_lock(&mLogElementsLock);
unsigned long retval = mSizes[id];
pthread_mutex_unlock(&mLogElementsLock);
return retval;
}
// get the total space allocated to "id"
unsigned long LogBuffer::getSize(log_id_t /*id*/) {
return LOG_BUFFER_SIZE;
}
struct timespec LogBuffer::flushTo(
SocketClient *reader, const struct timespec start, bool privileged,
bool (*filter)(const LogBufferElement *element, void *arg), void *arg) {
LogBufferElementCollection::iterator it;
log_time max = start;
uid_t uid = reader->getUid();
pthread_mutex_lock(&mLogElementsLock);
for (it = mLogElements.begin(); it != mLogElements.end(); ++it) {
LogBufferElement *element = *it;
if (!privileged && (element->getUid() != uid)) {
continue;
}
if (element->getMonotonicTime() <= start) {
continue;
}
// NB: calling out to another object with mLogElementsLock held (safe)
if (filter && !(*filter)(element, arg)) {
continue;
}
pthread_mutex_unlock(&mLogElementsLock);
// range locking in LastLogTimes looks after us
max = element->flushTo(reader);
if (max == element->FLUSH_ERROR) {
return max;
}
pthread_mutex_lock(&mLogElementsLock);
}
pthread_mutex_unlock(&mLogElementsLock);
return max;
}
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