commit c9fa42c0b8cbab68dd6b6525fde435066f215fb1
author Tom Cherry <tomcherry@google.com> Wed Apr 08 10:37:09 2020 -0700
committer Tom Cherry <tomcherry@google.com> Wed Apr 08 12:20:06 2020 -0700
tree 34b2b9cdbfbcc50ce0008dcc1cd26a2516292de0
parent cda0ee3db017429875e5d61e5ab325501c8a48ce

logd: wait for timeout via CLOCK_MONOTONIC

There are well known issues with CLOCK_REALTIME jumping drastically.

Test: --wrap works successfully
Change-Id: I5676274783ac9aa9374d2b9254e0109d883cc5a8

logd/LogReader.cpp

diff --git a/logd/LogReader.cpp b/logd/LogReader.cpp
index 9db8c00..d52d459 100644
--- a/logd/LogReader.cpp
+++ b/logd/LogReader.cpp
@@ -89,8 +89,7 @@
     static const char _timeout[] = " timeout=";
     cp = strstr(buffer, _timeout);
     if (cp) {
-        timeout = atol(cp + sizeof(_timeout) - 1) * NS_PER_SEC +
-                  log_time(CLOCK_REALTIME).nsec();
+        timeout = atol(cp + sizeof(_timeout) - 1) * NS_PER_SEC + log_time(CLOCK_MONOTONIC).nsec();
     }
 
     unsigned int logMask = -1;

logd/LogTimes.cpp

diff --git a/logd/LogTimes.cpp b/logd/LogTimes.cpp
index 208d67f..1723139 100644
--- a/logd/LogTimes.cpp
+++ b/logd/LogTimes.cpp
@@ -27,9 +27,9 @@
 
 pthread_mutex_t LogTimeEntry::timesLock = PTHREAD_MUTEX_INITIALIZER;
 
-LogTimeEntry::LogTimeEntry(LogReader& reader, SocketClient* client,
-                           bool nonBlock, unsigned long tail, log_mask_t logMask,
-                           pid_t pid, log_time start, uint64_t timeout)
+LogTimeEntry::LogTimeEntry(LogReader& reader, SocketClient* client, bool nonBlock,
+                           unsigned long tail, log_mask_t logMask, pid_t pid, log_time start,
+                           uint64_t timeout)
     : leadingDropped(false),
       mReader(reader),
       mLogMask(logMask),
@@ -39,8 +39,7 @@
       mIndex(0),
       mClient(client),
       mStart(start),
-      mNonBlock(nonBlock),
-      mEnd(log_time(android_log_clockid())) {
+      mNonBlock(nonBlock) {
     mTimeout.tv_sec = timeout / NS_PER_SEC;
     mTimeout.tv_nsec = timeout % NS_PER_SEC;
     memset(mLastTid, 0, sizeof(mLastTid));
@@ -85,8 +84,8 @@
 
     while (!me->mRelease) {
         if (me->mTimeout.tv_sec || me->mTimeout.tv_nsec) {
-            if (pthread_cond_timedwait(&me->threadTriggeredCondition,
-                                       &timesLock, &me->mTimeout) == ETIMEDOUT) {
+            if (pthread_cond_clockwait(&me->threadTriggeredCondition, &timesLock, CLOCK_MONOTONIC,
+                                       &me->mTimeout) == ETIMEDOUT) {
                 me->mTimeout.tv_sec = 0;
                 me->mTimeout.tv_nsec = 0;
             }

logd/LogTimes.h

diff --git a/logd/LogTimes.h b/logd/LogTimes.h
index 9f6f203..49b2d9d 100644
--- a/logd/LogTimes.h
+++ b/logd/LogTimes.h
@@ -56,9 +56,8 @@
 
     SocketClient* mClient;
     log_time mStart;
-    struct timespec mTimeout;
+    struct timespec mTimeout;  // CLOCK_MONOTONIC based timeout used for log wrapping.
     const bool mNonBlock;
-    const log_time mEnd;  // only relevant if mNonBlock
 
     // Protect List manipulations
     static void wrlock(void) {