wsd: improved forkit logs

And avoid pid of 0 in getKitPids().

Change-Id: I68743a55aed080ed54d7d8576f269974c644e1b2
Signed-off-by: Ashod Nakashian <ashod.nakashian@collabora.co.uk>

kit/ForKit.cpp

@@ -278,6 +278,9 @@ static void cleanupChildren()
     int status = 0;
     int segFaultCount = 0;
 
+    LOG_TRC("cleanupChildren with " << childJails.size()
+                                    << (childJails.size() == 1 ? " child" : " children"));
+
     // Reap quickly without doing slow cleanup so WSD can spawn more rapidly.
     while ((exitedChildPid = waitpid(-1, &status, WUNTRACED | WNOHANG)) > 0)
     {
@@ -304,6 +307,16 @@ static void cleanupChildren()
         }
     }
 
+    if (Log::traceEnabled())
+    {
+        std::ostringstream oss;
+        for (const auto& pair : childJails)
+            oss << pair.first << ' ';
+
+        LOG_TRC("cleanupChildren reaped " << cleanupJailPaths.size() << " children to have "
+                                          << childJails.size() << " left: " << oss.str());
+    }
+
     if (segFaultCount)
     {
 #ifdef KIT_IN_PROCESS
@@ -414,6 +427,8 @@ void forkLibreOfficeKit(const std::string& childRoot,
                         const std::string& loSubPath,
                         int limit)
 {
+    LOG_TRC("forkLibreOfficeKit limit: " << limit);
+
     // Cleanup first, to reduce disk load.
     cleanupChildren();
 

wsd/COOLWSD.cpp

@@ -4923,7 +4923,8 @@ std::set<pid_t> COOLWSD::getKitPids()
         for (const auto &child : NewChildren)
         {
             pid = child->getPid();
-            pids.emplace(pid);
+            if (pid > 0)
+                pids.emplace(pid);
         }
     }
     {