logd: getTag() functional for chatty entries
getTag() becomes invalid when entry is dropped because mMsg
disappears to save space; but the per-tag spam filter depends on it
still being valid. Conserve space in LogBufferElement by optimizing
the size of the fields, then add a new mTag field that is set in the
object constructor. Add an isBinary() method.
SideEffects: save 12 bytes/log message overhead on 64-bit.
Test: define DEBUG_CHECK_FOR_STALE_ENTRIES and look for stale entries
Bug: 32247044
Change-Id: Iaa5f416718a92c9e0e6ffd56bd5260d8b908d5c0
diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index 5cab7a8..a009433 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -13,6 +13,8 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
+// for manual checking of stale entries during LogBuffer::erase()
+//#define DEBUG_CHECK_FOR_STALE_ENTRIES
#include <ctype.h>
#include <errno.h>
@@ -256,6 +258,11 @@
log_id_for_each(i) {
doSetLast |= setLast[i] = mLastSet[i] && (it == mLast[i]);
}
+#ifdef DEBUG_CHECK_FOR_STALE_ENTRIES
+ LogBufferElementCollection::iterator bad = it;
+ int key = ((id == LOG_ID_EVENTS) || (id == LOG_ID_SECURITY)) ?
+ element->getTag() : element->getUid();
+#endif
it = mLogElements.erase(it);
if (doSetLast) {
log_id_for_each(i) {
@@ -269,6 +276,27 @@
}
}
}
+#ifdef DEBUG_CHECK_FOR_STALE_ENTRIES
+ log_id_for_each(i) {
+ for(auto b : mLastWorst[i]) {
+ if (bad == b.second) {
+ android::prdebug("stale mLastWorst[%d] key=%d mykey=%d\n",
+ i, b.first, key);
+ }
+ }
+ for(auto b : mLastWorstPidOfSystem[i]) {
+ if (bad == b.second) {
+ android::prdebug("stale mLastWorstPidOfSystem[%d] pid=%d\n",
+ i, b.first);
+ }
+ }
+ if (mLastSet[i] && (bad == mLast[i])) {
+ android::prdebug("stale mLast[%d]\n", i);
+ mLastSet[i] = false;
+ mLast[i] = mLogElements.begin();
+ }
+ }
+#endif
if (coalesce) {
stats.erase(element);
} else {
diff --git a/logd/LogBufferElement.cpp b/logd/LogBufferElement.cpp
index a939002..f5c60c7 100644
--- a/logd/LogBufferElement.cpp
+++ b/logd/LogBufferElement.cpp
@@ -36,29 +36,24 @@
LogBufferElement::LogBufferElement(log_id_t log_id, log_time realtime,
uid_t uid, pid_t pid, pid_t tid,
const char *msg, unsigned short len) :
- mLogId(log_id),
mUid(uid),
mPid(pid),
mTid(tid),
- mMsgLen(len),
mSequence(sequence.fetch_add(1, memory_order_relaxed)),
- mRealTime(realtime) {
+ mRealTime(realtime),
+ mMsgLen(len),
+ mLogId(log_id) {
mMsg = new char[len];
memcpy(mMsg, msg, len);
+ mTag = (isBinary() && (mMsgLen >= sizeof(uint32_t))) ?
+ le32toh(reinterpret_cast<android_event_header_t *>(mMsg)->tag) :
+ 0;
}
LogBufferElement::~LogBufferElement() {
delete [] mMsg;
}
-uint32_t LogBufferElement::getTag() const {
- if (((mLogId != LOG_ID_EVENTS) && (mLogId != LOG_ID_SECURITY)) ||
- !mMsg || (mMsgLen < sizeof(uint32_t))) {
- return 0;
- }
- return le32toh(reinterpret_cast<android_event_header_t *>(mMsg)->tag);
-}
-
// caller must own and free character string
char *android::tidToName(pid_t tid) {
char *retval = NULL;
@@ -164,7 +159,7 @@
size_t hdrLen;
// LOG_ID_SECURITY not strictly needed since spam filter not activated,
// but required for accuracy.
- if ((mLogId == LOG_ID_EVENTS) || (mLogId == LOG_ID_SECURITY)) {
+ if (isBinary()) {
hdrLen = sizeof(android_log_event_string_t);
} else {
hdrLen = 1 + sizeof(tag);
@@ -178,7 +173,7 @@
}
size_t retval = hdrLen + len;
- if ((mLogId == LOG_ID_EVENTS) || (mLogId == LOG_ID_SECURITY)) {
+ if (isBinary()) {
android_log_event_string_t *event =
reinterpret_cast<android_log_event_string_t *>(buffer);
diff --git a/logd/LogBufferElement.h b/logd/LogBufferElement.h
index 2c7fd44..fb7fbed 100644
--- a/logd/LogBufferElement.h
+++ b/logd/LogBufferElement.h
@@ -36,33 +36,40 @@
friend LogBuffer;
- const log_id_t mLogId;
- const uid_t mUid;
- const pid_t mPid;
- const pid_t mTid;
- char *mMsg;
- union {
- const unsigned short mMsgLen; // mMSg != NULL
- unsigned short mDropped; // mMsg == NULL
- };
+ // sized to match reality of incoming log packets
+ uint32_t mTag; // only valid for isBinary()
+ const uint32_t mUid;
+ const uint32_t mPid;
+ const uint32_t mTid;
const uint64_t mSequence;
log_time mRealTime;
+ char *mMsg;
+ union {
+ const uint16_t mMsgLen; // mMSg != NULL
+ uint16_t mDropped; // mMsg == NULL
+ };
+ const uint8_t mLogId;
+
static atomic_int_fast64_t sequence;
// assumption: mMsg == NULL
size_t populateDroppedMessage(char *&buffer,
LogBuffer *parent);
-
public:
LogBufferElement(log_id_t log_id, log_time realtime,
uid_t uid, pid_t pid, pid_t tid,
const char *msg, unsigned short len);
virtual ~LogBufferElement();
- log_id_t getLogId() const { return mLogId; }
+ bool isBinary(void) const {
+ return (mLogId == LOG_ID_EVENTS) || (mLogId == LOG_ID_SECURITY);
+ }
+
+ log_id_t getLogId() const { return static_cast<log_id_t>(mLogId); }
uid_t getUid(void) const { return mUid; }
pid_t getPid(void) const { return mPid; }
pid_t getTid(void) const { return mTid; }
+ uint32_t getTag() const { return mTag; }
unsigned short getDropped(void) const { return mMsg ? 0 : mDropped; }
unsigned short setDropped(unsigned short value) {
if (mMsg) {
@@ -76,8 +83,6 @@
static uint64_t getCurrentSequence(void) { return sequence.load(memory_order_relaxed); }
log_time getRealTime(void) const { return mRealTime; }
- uint32_t getTag(void) const;
-
static const uint64_t FLUSH_ERROR;
uint64_t flushTo(SocketClient *writer, LogBuffer *parent, bool privileged);
};