wsd: CheckFileInfo - avoid over-complicating things.

We don't need a mutex & a condition - we can just spin our own
TerminatingPoll to get what we need; saves launching an
un-necessary thread, and reducing threading complexity.

Signed-off-by: Michael Meeks <michael.meeks@collabora.com>
Change-Id: Ia65398aa8a59ca297cd0a0caf0fa607681960764

wsd/DocumentBroker.cpp

@@ -916,7 +916,7 @@ bool DocumentBroker::download(
         {
             std::chrono::steady_clock::time_point start = std::chrono::steady_clock::now();
             auto poller = std::make_shared<TerminatingPoll>("CFISynReqPoll");
-            poller->startThread();
+            poller->runOnClientThread();
             CheckFileInfo checkFileInfo(poller, session->getPublicUri(), [](CheckFileInfo&) {});
             checkFileInfo.checkFileInfoSync(RedirectionLimit);
             wopiFileInfo = checkFileInfo.wopiFileInfo(session->getPublicUri());

wsd/wopi/CheckFileInfo.cpp

@@ -137,9 +137,6 @@ bool CheckFileInfo::checkFileInfo(int redirectLimit)
         {
             _onFinishCallback(*this);
         }
-
-        std::lock_guard<std::mutex> lock(_mutex);
-        _cv.notify_all();
     };
 
     _httpSession->setFinishedHandler(std::move(finishedCallback));
@@ -165,10 +162,24 @@ bool CheckFileInfo::checkFileInfo(int redirectLimit)
 
 void CheckFileInfo::checkFileInfoSync(int redirectionLimit)
 {
-    std::unique_lock<std::mutex> lock(_mutex);
     if (checkFileInfo(redirectionLimit))
     {
-        _cv.wait_for(lock, std::chrono::seconds(30));
+        assert(_poll);
+
+        std::chrono::steady_clock::time_point deadline =
+            std::chrono::steady_clock::now() +
+            std::chrono::seconds(30); // hmm ?
+        while (!completed())
+        {
+            const auto now = std::chrono::steady_clock::now();
+            if (now > deadline)
+            {
+                LOG_WRN("timed out waiting for CheckFileInfo");
+                break;
+            }
+            _poll->poll(std::chrono::duration_cast<
+                        std::chrono::microseconds>(deadline - now));
+        }
     }
 }
 

wsd/wopi/CheckFileInfo.hpp

@@ -54,6 +54,8 @@ public:
     /// Returns the state of the request.
     State state() const { return _state; }
 
+    bool completed() const { return _state != State::None && _state != State::Active; }
+
     /// Returns the sanitized document URL.
     const Poco::URI& url() const { return _url; }
 
@@ -97,6 +99,4 @@ private:
     std::atomic<State> _state;
     Poco::JSON::Object::Ptr _wopiInfo;
     ProfileZone _profileZone;
-    std::mutex _mutex;
-    std::condition_variable _cv;
 };