commit 64e9016351bf789bfb70b64753449507f5cfc684
author Tom Cherry <tomcherry@google.com> Thu May 07 14:44:43 2020 -0700
committer Tom Cherry <tomcherry@google.com> Mon May 11 07:55:52 2020 -0700
tree 238b8bd56c578cf311f8eba3cbf888d3a6a23b22
parent b6b78e9bb4fb3d9d4b06cefdc8cad01b2f15b741

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

logd/LogAudit.cpp

diff --git a/logd/LogAudit.cpp b/logd/LogAudit.cpp
index bcc187d..6c42a28 100644
--- a/logd/LogAudit.cpp
+++ b/logd/LogAudit.cpp
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include "LogAudit.h"
+
 #include <ctype.h>
 #include <endian.h>
 #include <errno.h>
@@ -34,8 +36,6 @@
 #include <private/android_filesystem_config.h>
 #include <private/android_logger.h>
 
-#include "LogAudit.h"
-#include "LogBuffer.h"
 #include "LogKlog.h"
 #include "LogReader.h"
 #include "LogUtils.h"
@@ -45,16 +45,15 @@
     '<', '0' + LOG_MAKEPRI(LOG_AUTH, LOG_PRI(PRI)) / 10, \
         '0' + LOG_MAKEPRI(LOG_AUTH, LOG_PRI(PRI)) % 10, '>'
 
-LogAudit::LogAudit(LogBuffer* buf, LogReader* reader, int fdDmesg)
+LogAudit::LogAudit(LogBuffer* buf, LogReader* reader, int fdDmesg, LogStatistics* stats)
     : SocketListener(getLogSocket(), false),
       logbuf(buf),
       reader(reader),
       fdDmesg(fdDmesg),
-      main(__android_logger_property_get_bool("ro.logd.auditd.main",
-                                              BOOL_DEFAULT_TRUE)),
-      events(__android_logger_property_get_bool("ro.logd.auditd.events",
-                                                BOOL_DEFAULT_TRUE)),
-      initialized(false) {
+      main(__android_logger_property_get_bool("ro.logd.auditd.main", BOOL_DEFAULT_TRUE)),
+      events(__android_logger_property_get_bool("ro.logd.auditd.events", BOOL_DEFAULT_TRUE)),
+      initialized(false),
+      stats_(stats) {
     static const char auditd_message[] = { KMSG_PRIORITY(LOG_INFO),
                                            'l',
                                            'o',
@@ -211,9 +210,7 @@
             ++cp;
         }
         tid = pid;
-        logbuf->wrlock();
-        uid = logbuf->pidToUid(pid);
-        logbuf->unlock();
+        uid = stats_->PidToUid(pid);
         memmove(pidptr, cp, strlen(cp) + 1);
     }
 
@@ -301,9 +298,7 @@
         pid = tid;
         comm = "auditd";
     } else {
-        logbuf->wrlock();
-        comm = commfree = logbuf->pidToName(pid);
-        logbuf->unlock();
+        comm = commfree = stats_->PidToName(pid);
         if (!comm) {
             comm = "unknown";
         }