commit 5dc263beae313092b0ab0716a176fbdea7e47c4e
author Yao Chen <yaochen@google.com> Tue Mar 26 13:51:53 2019 -0700
committer Yao Chen <yaochen@google.com> Tue Apr 02 14:26:01 2019 -0700
tree 004d90d6cf1884e3400b0555082c982afeb5d593
parent a0f0ab95872bcd48dad4719ff5e99fea763a8b93

Report last atom tag of the failed stats log.

Test: manually tested with statsd

Change-Id: I4de61a2eea393e8518cb76147598778293440a81
Merged-In: I4de61a2eea393e8518cb76147598778293440a81
(cherry picked from commit cf776d9b833952991294b2b898ea4a69b4c2731b)

libstats/include/stats_event_list.h

diff --git a/libstats/include/stats_event_list.h b/libstats/include/stats_event_list.h
index b5bc5af..9610797 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(int error);
+void note_log_drop(int error, int atom_tag);
 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 5b90361..eb6b0ff 100644
--- a/libstats/stats_event_list.c
+++ b/libstats/stats_event_list.c
@@ -120,8 +120,8 @@
     return retValue;
 }
 
-void note_log_drop(int error) {
-    statsdLoggerWrite.noteDrop(error);
+void note_log_drop(int error, int tag) {
+    statsdLoggerWrite.noteDrop(error, tag);
 }
 
 void stats_log_close() {

libstats/statsd_writer.c

diff --git a/libstats/statsd_writer.c b/libstats/statsd_writer.c
index f5be95c..b778f92 100644
--- a/libstats/statsd_writer.c
+++ b/libstats/statsd_writer.c
@@ -47,9 +47,18 @@
 #endif
 #endif
 
+#ifndef htole64
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define htole64(x) (x)
+#else
+#define htole64(x) __bswap_64(x)
+#endif
+#endif
+
 static pthread_mutex_t log_init_lock = PTHREAD_MUTEX_INITIALIZER;
 static atomic_int dropped = 0;
 static atomic_int log_error = 0;
+static atomic_int atom_tag = 0;
 
 void statsd_writer_init_lock() {
     /*
@@ -152,9 +161,10 @@
     return 1;
 }
 
-static void statsdNoteDrop(int error) {
+static void statsdNoteDrop(int error, int tag) {
     atomic_fetch_add_explicit(&dropped, 1, memory_order_relaxed);
     atomic_exchange_explicit(&log_error, error, memory_order_relaxed);
+    atomic_exchange_explicit(&atom_tag, tag, memory_order_relaxed);
 }
 
 static int statsdWrite(struct timespec* ts, struct iovec* vec, size_t nr) {
@@ -203,12 +213,17 @@
     if (sock >= 0) {
         int32_t snapshot = atomic_exchange_explicit(&dropped, 0, memory_order_relaxed);
         if (snapshot) {
-            android_log_event_int_t buffer;
+            android_log_event_long_t buffer;
             header.id = LOG_ID_STATS;
             // 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);
+            buffer.payload.type = EVENT_TYPE_LONG;
+            // format:
+            // |atom_tag|dropped_count|
+            int64_t composed_long = atomic_load(&atom_tag);
+            // Send 2 int32's via an int64.
+            composed_long = ((composed_long << 32) | ((int64_t)snapshot));
+            buffer.payload.data = htole64(composed_long);
 
             newVec[headerLength].iov_base = &buffer;
             newVec[headerLength].iov_len = sizeof(buffer);

libstats/statsd_writer.h

diff --git a/libstats/statsd_writer.h b/libstats/statsd_writer.h
index 4fc3f8b..fe2d37c 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)(int error);
+    void (*noteDrop)(int error, int tag);
 };
 
 #endif  // ANDROID_STATS_LOG_STATS_WRITER_H