commit 28cec14fb01c1079d157495665dc7a1dfe6f210f
author Yao Chen <yaochen@google.com> Thu Nov 08 15:43:08 2018 -0800
committer Yao Chen <yaochen@google.com> Fri Dec 07 11:02:08 2018 -0800
tree 8046eb5da0d948272e1c9dc652055378e9fdc21f
parent 33a03dbd10910ed6f6c2e73e0d67c470381906c2

Log the last error code of StatsLog failures

Test: builds and manual test
Bug: 80538532

Change-Id: I7f9d0e22b7ad4295dd787f6cb409bfb3342a7b27
Merged-In: I7f9d0e22b7ad4295dd787f6cb409bfb3342a7b27
(cherry picked from commit cb3527794cadfb828589e338602a08f464e40f83)

libstats/include/stats_event_list.h

diff --git a/libstats/include/stats_event_list.h b/libstats/include/stats_event_list.h
index 41ca79b..162d1cf 100644
--- a/libstats/include/stats_event_list.h
+++ b/libstats/include/stats_event_list.h
@@ -24,7 +24,7 @@
 #endif
 void reset_log_context(android_log_context ctx);
 int write_to_logger(android_log_context context, log_id_t id);
-void note_log_drop();
+void note_log_drop(int error);
 void stats_log_close();
 int android_log_write_char_array(android_log_context ctx, const char* value, size_t len);
 #ifdef __cplusplus

libstats/stats_event_list.c

diff --git a/libstats/stats_event_list.c b/libstats/stats_event_list.c
index f4a7e94..5b90361 100644
--- a/libstats/stats_event_list.c
+++ b/libstats/stats_event_list.c
@@ -120,8 +120,8 @@
     return retValue;
 }
 
-void note_log_drop() {
-    statsdLoggerWrite.noteDrop();
+void note_log_drop(int error) {
+    statsdLoggerWrite.noteDrop(error);
 }
 
 void stats_log_close() {

libstats/statsd_writer.c

diff --git a/libstats/statsd_writer.c b/libstats/statsd_writer.c
index 88f7d44..f00fc2d 100644
--- a/libstats/statsd_writer.c
+++ b/libstats/statsd_writer.c
@@ -48,6 +48,7 @@
 
 static pthread_mutex_t log_init_lock = PTHREAD_MUTEX_INITIALIZER;
 static atomic_int dropped = 0;
+static atomic_int log_error = 0;
 
 void statsd_writer_init_lock() {
     /*
@@ -150,8 +151,9 @@
     return 1;
 }
 
-static void statsdNoteDrop() {
+static void statsdNoteDrop(int error) {
     atomic_fetch_add_explicit(&dropped, 1, memory_order_relaxed);
+    atomic_exchange_explicit(&log_error, error, memory_order_relaxed);
 }
 
 static int statsdWrite(struct timespec* ts, struct iovec* vec, size_t nr) {
@@ -202,7 +204,8 @@
         if (snapshot) {
             android_log_event_int_t buffer;
             header.id = LOG_ID_STATS;
-            buffer.header.tag = htole32(LIBLOG_LOG_TAG);
+            // store the last log error in the tag field. This tag field is not used by statsd.
+            buffer.header.tag = htole32(atomic_load(&log_error));
             buffer.payload.type = EVENT_TYPE_INT;
             buffer.payload.data = htole32(snapshot);
 

libstats/statsd_writer.h

diff --git a/libstats/statsd_writer.h b/libstats/statsd_writer.h
index 7289441..4fc3f8b 100644
--- a/libstats/statsd_writer.h
+++ b/libstats/statsd_writer.h
@@ -39,7 +39,7 @@
     /* write log to transport, returns number of bytes propagated, or -errno */
     int (*write)(struct timespec* ts, struct iovec* vec, size_t nr);
     /* note one log drop */
-    void (*noteDrop)();
+    void (*noteDrop)(int error);
 };
 
 #endif  // ANDROID_STATS_LOG_STATS_WRITER_H