logd: separate LogStatistics from LogBuffer
LogStatistics is intertwined with LogBuffer, even relying on it for
thread safety. This needs to change to have a proper
LogBufferInterface, so this CL separates them. Specifically:
1) Adding a lock to LogStatistics and adding thread annotations to
ensure that data structures are protected appropriately.
2) Moving prune_rows calculation into LogStatistics so it is done
while holding this lock.
3) Using LogStatistics instead of LogBuffer where appropriate.
Note that there should not be a significant performance regression
with this lock, as it will almost always been uncontended. If
anything, it should alleviate pressure from LogBuffer's lock.
Test: logging unit tests
Change-Id: I9d6dde2c96c9f024fa0341711c7bc63379e8e406
diff --git a/logd/LogStatistics.cpp b/logd/LogStatistics.cpp
index 4c4c1db..14bcb63 100644
--- a/logd/LogStatistics.cpp
+++ b/logd/LogStatistics.cpp
@@ -14,6 +14,8 @@
* limitations under the License.
*/
+#include "LogStatistics.h"
+
#include <ctype.h>
#include <fcntl.h>
#include <inttypes.h>
@@ -27,14 +29,12 @@
#include <private/android_logger.h>
-#include "LogStatistics.h"
-
static const uint64_t hourSec = 60 * 60;
static const uint64_t monthSec = 31 * 24 * hourSec;
-size_t LogStatistics::SizesTotal;
+std::atomic<size_t> LogStatistics::SizesTotal;
-LogStatistics::LogStatistics() : enable(false) {
+LogStatistics::LogStatistics(bool enable_statistics) : enable(enable_statistics) {
log_time now(CLOCK_REALTIME);
log_id_for_each(id) {
mSizes[id] = 0;
@@ -79,7 +79,8 @@
}
}
-void LogStatistics::addTotal(LogBufferElement* element) {
+void LogStatistics::AddTotal(LogBufferElement* element) {
+ auto lock = std::lock_guard{lock_};
if (element->getDropped()) return;
log_id_t log_id = element->getLogId();
@@ -89,7 +90,8 @@
++mElementsTotal[log_id];
}
-void LogStatistics::add(LogBufferElement* element) {
+void LogStatistics::Add(LogBufferElement* element) {
+ auto lock = std::lock_guard{lock_};
log_id_t log_id = element->getLogId();
uint16_t size = element->getMsgLen();
mSizes[log_id] += size;
@@ -159,7 +161,8 @@
}
}
-void LogStatistics::subtract(LogBufferElement* element) {
+void LogStatistics::Subtract(LogBufferElement* element) {
+ auto lock = std::lock_guard{lock_};
log_id_t log_id = element->getLogId();
uint16_t size = element->getMsgLen();
mSizes[log_id] -= size;
@@ -204,7 +207,8 @@
// Atomically set an entry to drop
// entry->setDropped(1) must follow this call, caller should do this explicitly.
-void LogStatistics::drop(LogBufferElement* element) {
+void LogStatistics::Drop(LogBufferElement* element) {
+ auto lock = std::lock_guard{lock_};
log_id_t log_id = element->getLogId();
uint16_t size = element->getMsgLen();
mSizes[log_id] -= size;
@@ -238,9 +242,13 @@
tagNameTable.subtract(TagNameKey(element), element);
}
+const char* LogStatistics::UidToName(uid_t uid) const {
+ auto lock = std::lock_guard{lock_};
+ return UidToNameLocked(uid);
+}
+
// caller must own and free character string
-// Requires parent LogBuffer::wrlock() to be held
-const char* LogStatistics::uidToName(uid_t uid) const {
+const char* LogStatistics::UidToNameLocked(uid_t uid) const {
// Local hard coded favourites
if (uid == AID_LOGD) {
return strdup("auditd");
@@ -300,7 +308,7 @@
template <typename TKey, typename TEntry>
void LogStatistics::WorstTwoWithThreshold(const LogHashtable<TKey, TEntry>& table, size_t threshold,
int* worst, size_t* worst_sizes,
- size_t* second_worst_sizes) {
+ size_t* second_worst_sizes) const {
std::array<const TEntry*, 2> max_entries;
table.MaxEntries(AID_ROOT, 0, &max_entries);
if (max_entries[0] == nullptr || max_entries[1] == nullptr) {
@@ -319,17 +327,20 @@
}
void LogStatistics::WorstTwoUids(log_id id, size_t threshold, int* worst, size_t* worst_sizes,
- size_t* second_worst_sizes) {
+ size_t* second_worst_sizes) const {
+ auto lock = std::lock_guard{lock_};
WorstTwoWithThreshold(uidTable[id], threshold, worst, worst_sizes, second_worst_sizes);
}
void LogStatistics::WorstTwoTags(size_t threshold, int* worst, size_t* worst_sizes,
- size_t* second_worst_sizes) {
+ size_t* second_worst_sizes) const {
+ auto lock = std::lock_guard{lock_};
WorstTwoWithThreshold(tagTable, threshold, worst, worst_sizes, second_worst_sizes);
}
void LogStatistics::WorstTwoSystemPids(log_id id, size_t worst_uid_sizes, int* worst,
- size_t* second_worst_sizes) {
+ size_t* second_worst_sizes) const {
+ auto lock = std::lock_guard{lock_};
std::array<const PidEntry*, 2> max_entries;
pidSystemTable[id].MaxEntries(AID_SYSTEM, 0, &max_entries);
if (max_entries[0] == nullptr || max_entries[1] == nullptr) {
@@ -340,6 +351,34 @@
*second_worst_sizes = worst_uid_sizes - max_entries[0]->getSizes() + max_entries[1]->getSizes();
}
+// Prune at most 10% of the log entries or maxPrune, whichever is less.
+bool LogStatistics::ShouldPrune(log_id id, unsigned long max_size,
+ unsigned long* prune_rows) const {
+ static constexpr size_t kMinPrune = 4;
+ static constexpr size_t kMaxPrune = 256;
+
+ auto lock = std::lock_guard{lock_};
+ size_t sizes = mSizes[id];
+ if (sizes <= max_size) {
+ return false;
+ }
+ size_t size_over = sizes - ((max_size * 9) / 10);
+ size_t elements = mElements[id] - mDroppedElements[id];
+ size_t min_elements = elements / 100;
+ if (min_elements < kMinPrune) {
+ min_elements = kMinPrune;
+ }
+ *prune_rows = elements * size_over / sizes;
+ if (*prune_rows < min_elements) {
+ *prune_rows = min_elements;
+ }
+ if (*prune_rows > kMaxPrune) {
+ *prune_rows = kMaxPrune;
+ }
+
+ return true;
+}
+
std::string UidEntry::formatHeader(const std::string& name, log_id_t id) const {
bool isprune = worstUidEnabledForLogid(id);
return formatLine(android::base::StringPrintf(name.c_str(),
@@ -351,10 +390,10 @@
}
// Helper to truncate name, if too long, and add name dressings
-static void formatTmp(const LogStatistics& stat, const char* nameTmp, uid_t uid,
- std::string& name, std::string& size, size_t nameLen) {
+void LogStatistics::FormatTmp(const char* nameTmp, uid_t uid, std::string& name, std::string& size,
+ size_t nameLen) const {
const char* allocNameTmp = nullptr;
- if (!nameTmp) nameTmp = allocNameTmp = stat.uidToName(uid);
+ if (!nameTmp) nameTmp = allocNameTmp = UidToNameLocked(uid);
if (nameTmp) {
size_t lenSpace = std::max(nameLen - name.length(), (size_t)1);
size_t len = EntryBaseConstants::total_len -
@@ -375,12 +414,12 @@
}
}
-std::string UidEntry::format(const LogStatistics& stat, log_id_t id) const {
+std::string UidEntry::format(const LogStatistics& stat, log_id_t id) const REQUIRES(stat.lock_) {
uid_t uid = getUid();
std::string name = android::base::StringPrintf("%u", uid);
std::string size = android::base::StringPrintf("%zu", getSizes());
- formatTmp(stat, nullptr, uid, name, size, 6);
+ stat.FormatTmp(nullptr, uid, name, size, 6);
std::string pruned = "";
if (worstUidEnabledForLogid(id)) {
@@ -390,9 +429,9 @@
it != stat.uidTable[id].end(); ++it) {
totalDropped += it->second.getDropped();
}
- size_t sizes = stat.sizes(id);
- size_t totalSize = stat.sizesTotal(id);
- size_t totalElements = stat.elementsTotal(id);
+ size_t sizes = stat.mSizes[id];
+ size_t totalSize = stat.mSizesTotal[id];
+ size_t totalElements = stat.mElementsTotal[id];
float totalVirtualSize =
(float)sizes + (float)totalDropped * totalSize / totalElements;
size_t entrySize = getSizes();
@@ -480,14 +519,14 @@
std::string("BYTES"), std::string("NUM"));
}
-std::string PidEntry::format(const LogStatistics& stat,
- log_id_t /* id */) const {
+std::string PidEntry::format(const LogStatistics& stat, log_id_t /* id */) const
+ REQUIRES(stat.lock_) {
uid_t uid = getUid();
pid_t pid = getPid();
std::string name = android::base::StringPrintf("%5u/%u", pid, uid);
std::string size = android::base::StringPrintf("%zu", getSizes());
- formatTmp(stat, getName(), uid, name, size, 12);
+ stat.FormatTmp(getName(), uid, name, size, 12);
std::string pruned = "";
size_t dropped = getDropped();
@@ -505,13 +544,13 @@
std::string("NUM"));
}
-std::string TidEntry::format(const LogStatistics& stat,
- log_id_t /* id */) const {
+std::string TidEntry::format(const LogStatistics& stat, log_id_t /* id */) const
+ REQUIRES(stat.lock_) {
uid_t uid = getUid();
std::string name = android::base::StringPrintf("%5u/%u", getTid(), uid);
std::string size = android::base::StringPrintf("%zu", getSizes());
- formatTmp(stat, getName(), uid, name, size, 12);
+ stat.FormatTmp(getName(), uid, name, size, 12);
std::string pruned = "";
size_t dropped = getDropped();
@@ -651,8 +690,36 @@
return output;
}
-std::string LogStatistics::format(uid_t uid, pid_t pid,
- unsigned int logMask) const {
+template <typename TKey, typename TEntry>
+std::string LogStatistics::FormatTable(const LogHashtable<TKey, TEntry>& table, uid_t uid,
+ pid_t pid, const std::string& name, log_id_t id) const
+ REQUIRES(lock_) {
+ static const size_t maximum_sorted_entries = 32;
+ std::string output;
+ std::array<const TEntry*, maximum_sorted_entries> sorted;
+ table.MaxEntries(uid, pid, &sorted);
+ bool header_printed = false;
+ for (size_t index = 0; index < maximum_sorted_entries; ++index) {
+ const TEntry* entry = sorted[index];
+ if (!entry) {
+ break;
+ }
+ if (entry->getSizes() <= (sorted[0]->getSizes() / 100)) {
+ break;
+ }
+ if (!header_printed) {
+ output += "\n\n";
+ output += entry->formatHeader(name, id);
+ header_printed = true;
+ }
+ output += entry->format(*this, id);
+ }
+ return output;
+}
+
+std::string LogStatistics::Format(uid_t uid, pid_t pid, unsigned int logMask) const {
+ auto lock = std::lock_guard{lock_};
+
static const uint16_t spaces_total = 19;
// Report on total logging, current and for all time
@@ -682,9 +749,9 @@
if (!(logMask & (1 << id))) continue;
oldLength = output.length();
if (spaces < 0) spaces = 0;
- size_t szs = sizesTotal(id);
+ size_t szs = mSizesTotal[id];
totalSize += szs;
- size_t els = elementsTotal(id);
+ size_t els = mElementsTotal[id];
totalEls += els;
output +=
android::base::StringPrintf("%*s%zu/%zu", spaces, "", szs, els);
@@ -703,11 +770,11 @@
log_id_for_each(id) {
if (!(logMask & (1 << id))) continue;
- size_t els = elements(id);
+ size_t els = mElements[id];
if (els) {
oldLength = output.length();
if (spaces < 0) spaces = 0;
- size_t szs = sizes(id);
+ size_t szs = mSizes[id];
totalSize += szs;
totalEls += els;
output +=
@@ -789,7 +856,7 @@
log_id_for_each(id) {
if (!(logMask & (1 << id))) continue;
- size_t els = elements(id);
+ size_t els = mElements[id];
if (els) {
oldLength = output.length();
if (spaces < 0) spaces = 0;
@@ -798,7 +865,7 @@
((sizeof(LogBufferElement) + sizeof(uint64_t) - 1) &
-sizeof(uint64_t)) +
sizeof(std::list<LogBufferElement*>);
- size_t szs = sizes(id) + els * overhead;
+ size_t szs = mSizes[id] + els * overhead;
totalSize += szs;
output += android::base::StringPrintf("%*s%zu", spaces, "", szs);
spaces -= output.length() - oldLength;
@@ -819,39 +886,38 @@
name = (uid == AID_ROOT) ? "Chattiest UIDs in %s log buffer:"
: "Logging for your UID in %s log buffer:";
- output += uidTable[id].format(*this, uid, pid, name, id);
+ output += FormatTable(uidTable[id], uid, pid, name, id);
}
if (enable) {
name = ((uid == AID_ROOT) && !pid) ? "Chattiest PIDs:"
: "Logging for this PID:";
- output += pidTable.format(*this, uid, pid, name);
+ output += FormatTable(pidTable, uid, pid, name);
name = "Chattiest TIDs";
if (pid) name += android::base::StringPrintf(" for PID %d", pid);
name += ":";
- output += tidTable.format(*this, uid, pid, name);
+ output += FormatTable(tidTable, uid, pid, name);
}
if (enable && (logMask & (1 << LOG_ID_EVENTS))) {
name = "Chattiest events log buffer TAGs";
if (pid) name += android::base::StringPrintf(" for PID %d", pid);
name += ":";
- output += tagTable.format(*this, uid, pid, name, LOG_ID_EVENTS);
+ output += FormatTable(tagTable, uid, pid, name, LOG_ID_EVENTS);
}
if (enable && (logMask & (1 << LOG_ID_SECURITY))) {
name = "Chattiest security log buffer TAGs";
if (pid) name += android::base::StringPrintf(" for PID %d", pid);
name += ":";
- output +=
- securityTagTable.format(*this, uid, pid, name, LOG_ID_SECURITY);
+ output += FormatTable(securityTagTable, uid, pid, name, LOG_ID_SECURITY);
}
if (enable) {
name = "Chattiest TAGs";
if (pid) name += android::base::StringPrintf(" for PID %d", pid);
name += ":";
- output += tagNameTable.format(*this, uid, pid, name);
+ output += FormatTable(tagNameTable, uid, pid, name);
}
return output;
@@ -879,12 +945,14 @@
}
}
-uid_t LogStatistics::pidToUid(pid_t pid) {
+uid_t LogStatistics::PidToUid(pid_t pid) {
+ auto lock = std::lock_guard{lock_};
return pidTable.add(pid)->second.getUid();
}
// caller must free character string
-const char* LogStatistics::pidToName(pid_t pid) const {
+const char* LogStatistics::PidToName(pid_t pid) const {
+ auto lock = std::lock_guard{lock_};
// An inconvenient truth ... getName() can alter the object
pidTable_t& writablePidTable = const_cast<pidTable_t&>(pidTable);
const char* name = writablePidTable.add(pid)->second.getName();