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/main.cpp

diff --git a/logd/main.cpp b/logd/main.cpp
index d9dd249..d1e05b9 100644
--- a/logd/main.cpp
+++ b/logd/main.cpp
@@ -52,6 +52,7 @@
 #include "LogBuffer.h"
 #include "LogKlog.h"
 #include "LogListener.h"
+#include "LogStatistics.h"
 #include "LogTags.h"
 #include "LogUtils.h"
 
@@ -272,6 +273,11 @@
     LogTags log_tags;
     // Pruning configuration.
     PruneList prune_list;
+    // Partial (required for chatty) or full logging statistics.
+    bool enable_full_log_statistics = __android_logger_property_get_bool(
+            "logd.statistics", BOOL_DEFAULT_TRUE | BOOL_DEFAULT_FLAG_PERSIST |
+                                       BOOL_DEFAULT_FLAG_ENG | BOOL_DEFAULT_FLAG_SVELTE);
+    LogStatistics log_statistics(enable_full_log_statistics);
 
     // Serves the purpose of managing the last logs times read on a
     // socket connection, and as a reader lock on a range of log
@@ -282,14 +288,7 @@
     // LogBuffer is the object which is responsible for holding all
     // log entries.
 
-    LogBuffer* logBuf = new LogBuffer(times, &log_tags, &prune_list);
-
-    if (__android_logger_property_get_bool(
-            "logd.statistics", BOOL_DEFAULT_TRUE | BOOL_DEFAULT_FLAG_PERSIST |
-                                   BOOL_DEFAULT_FLAG_ENG |
-                                   BOOL_DEFAULT_FLAG_SVELTE)) {
-        logBuf->enableStatistics();
-    }
+    LogBuffer* logBuf = new LogBuffer(times, &log_tags, &prune_list, &log_statistics);
 
     // LogReader listens on /dev/socket/logdr. When a client
     // connects, log entries in the LogBuffer are written to the client.
@@ -312,7 +311,7 @@
     // Command listener listens on /dev/socket/logd for incoming logd
     // administrative commands.
 
-    CommandListener* cl = new CommandListener(logBuf, &log_tags, &prune_list);
+    CommandListener* cl = new CommandListener(logBuf, &log_tags, &prune_list, &log_statistics);
     if (cl->startListener()) {
         return EXIT_FAILURE;
     }
@@ -323,16 +322,17 @@
 
     LogAudit* al = nullptr;
     if (auditd) {
-        al = new LogAudit(logBuf, reader,
-                          __android_logger_property_get_bool(
-                              "ro.logd.auditd.dmesg", BOOL_DEFAULT_TRUE)
-                              ? fdDmesg
-                              : -1);
+        al = new LogAudit(
+                logBuf, reader,
+                __android_logger_property_get_bool("ro.logd.auditd.dmesg", BOOL_DEFAULT_TRUE)
+                        ? fdDmesg
+                        : -1,
+                &log_statistics);
     }
 
     LogKlog* kl = nullptr;
     if (klogd) {
-        kl = new LogKlog(logBuf, reader, fdDmesg, fdPmesg, al != nullptr);
+        kl = new LogKlog(logBuf, reader, fdDmesg, fdPmesg, al != nullptr, &log_statistics);
     }
 
     readDmesg(al, kl);