Merge "logd: add locks around ~SerializedFlushToState" am: 1bacb2c389

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1449535

Change-Id: I54186d82ba2603a8076ff6714a8f2f59a330643a

logd/LogBuffer.h

@@ -19,6 +19,7 @@
 #include <sys/types.h>
 
 #include <functional>
+#include <memory>
 
 #include <log/log.h>
 #include <log/log_read.h>
@@ -62,6 +63,7 @@ class LogBuffer {
                     const char* msg, uint16_t len) = 0;
 
     virtual std::unique_ptr<FlushToState> CreateFlushToState(uint64_t start, LogMask log_mask) = 0;
+    virtual void DeleteFlushToState(std::unique_ptr<FlushToState>) {}
     virtual bool FlushTo(
             LogWriter* writer, FlushToState& state,
             const std::function<FilterResult(log_id_t log_id, pid_t pid, uint64_t sequence,

logd/LogReaderThread.cpp

@@ -72,6 +72,7 @@ void LogReaderThread::ThreadFunction() {
                     [this](log_id_t log_id, pid_t pid, uint64_t sequence, log_time realtime) {
                         return FilterFirstPass(log_id, pid, sequence, realtime);
                     });
+            log_buffer_->DeleteFlushToState(std::move(first_pass_state));
         }
         bool flush_success = log_buffer_->FlushTo(
                 writer_.get(), *flush_to_state_,
@@ -105,6 +106,10 @@ void LogReaderThread::ThreadFunction() {
         }
     }
 
+    lock.unlock();
+    log_buffer_->DeleteFlushToState(std::move(flush_to_state_));
+    lock.lock();
+
     writer_->Release();
 
     auto& log_reader_threads = reader_list_->reader_threads();

logd/LogReaderThread.h

@@ -53,7 +53,7 @@ class LogReaderThread {
 
     bool IsWatching(log_id_t id) const { return flush_to_state_->log_mask() & (1 << id); }
     bool IsWatchingMultiple(LogMask log_mask) const {
-        return flush_to_state_->log_mask() & log_mask;
+        return flush_to_state_ && flush_to_state_->log_mask() & log_mask;
     }
 
     std::string name() const { return writer_->name(); }

logd/SerializedLogBuffer.cpp

@@ -201,6 +201,11 @@ std::unique_ptr<FlushToState> SerializedLogBuffer::CreateFlushToState(uint64_t s
     return std::make_unique<SerializedFlushToState>(start, log_mask);
 }
 
+void SerializedLogBuffer::DeleteFlushToState(std::unique_ptr<FlushToState> state) {
+    auto lock = std::unique_lock{lock_};
+    state.reset();
+}
+
 bool SerializedLogBuffer::FlushTo(
         LogWriter* writer, FlushToState& abstract_state,
         const std::function<FilterResult(log_id_t log_id, pid_t pid, uint64_t sequence,

logd/SerializedLogBuffer.h

@@ -42,6 +42,7 @@ class SerializedLogBuffer final : public LogBuffer {
     int Log(log_id_t log_id, log_time realtime, uid_t uid, pid_t pid, pid_t tid, const char* msg,
             uint16_t len) override;
     std::unique_ptr<FlushToState> CreateFlushToState(uint64_t start, LogMask log_mask) override;
+    void DeleteFlushToState(std::unique_ptr<FlushToState> state) override;
     bool FlushTo(LogWriter* writer, FlushToState& state,
                  const std::function<FilterResult(log_id_t log_id, pid_t pid, uint64_t sequence,
                                                   log_time realtime)>& filter) override;