logd: simplify Clear() + Prune() logic
Clear() and Prune() return a boolean indicating whether or not their
operations failed because the log buffer was 'busy'. This means that
they return false upon success and true upon failure, which is not
intuitive.
This change inverts their return value to simply be true if they were
successful or false otherwise. It also simplifies the return value of
ChattyLogBuffer::Prune() to true if the requested number of rows have
been pruned or if all rows in the log buffer have been pruned, and
otherwise return false.
Test: logging unit tests
Test: clearing works even under logging pressure
Change-Id: I346bb945496ef62bf8e973298f81c5163f49bc57
diff --git a/logd/ChattyLogBuffer.cpp b/logd/ChattyLogBuffer.cpp
index f92fe65..c213448 100644
--- a/logd/ChattyLogBuffer.cpp
+++ b/logd/ChattyLogBuffer.cpp
@@ -327,7 +327,6 @@
//
bool ChattyLogBuffer::Prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) {
LogReaderThread* oldest = nullptr;
- bool busy = false;
bool clearAll = pruneRows == ULONG_MAX;
auto reader_threads_lock = std::lock_guard{reader_list()->reader_threads_lock()};
@@ -359,17 +358,16 @@
}
if (oldest && oldest->start() <= element.sequence()) {
- busy = true;
KickReader(oldest, id, pruneRows);
- break;
+ return false;
}
it = Erase(it);
if (--pruneRows == 0) {
- break;
+ return true;
}
}
- return busy;
+ return true;
}
// prune by worst offenders; by blacklist, UID, and by PID of system UID
@@ -440,7 +438,6 @@
LogBufferElement& element = *it;
if (oldest && oldest->start() <= element.sequence()) {
- busy = true;
// Do not let chatty eliding trigger any reader mitigation
break;
}
@@ -577,7 +574,6 @@
}
if (oldest && oldest->start() <= element.sequence()) {
- busy = true;
if (!whitelist) KickReader(oldest, id, pruneRows);
break;
}
@@ -605,7 +601,6 @@
}
if (oldest && oldest->start() <= element.sequence()) {
- busy = true;
KickReader(oldest, id, pruneRows);
break;
}
@@ -615,5 +610,5 @@
}
}
- return (pruneRows > 0) && busy;
+ return pruneRows == 0 || it == logs().end();
}