Use callback to initialize the histogram

Summary: X-link: facebook/fb303#56 Removing expensive unused temporary. Reviewed By: ot Differential Revision: D61207391 fbshipit-source-id: 6a3c83358b879be68956a9adf9f1a8abce598ddf
facebook · Aug 15, 2024 · d5e00ce · d5e00ce
1 parent 8f6e4d6
commit d5e00ce
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/fboss/agent/hw/bcm/BcmPort.cpp b/fboss/agent/hw/bcm/BcmPort.cpp
@@ -397,11 +397,13 @@ void BcmPort::reinitPortStatsLocked(
       statName("out_queue_length", portName), &expType);
   // (re) init histograms
   auto histMap = fb303::fbData->getHistogramMap();
-  fb303::ExportedHistogram pktLenHist(1, 0, kInPktLengthStats.size());
+  auto makeLenHist = [] {
+    return fb303::ExportedHistogram(1, 0, kInPktLengthStats.size());
+  };
   inPktLengths_ = histMap->getOrCreateLockableHistogram(
-      statName("in_pkt_lengths", portName), &pktLenHist);
+      statName("in_pkt_lengths", portName), makeLenHist);
   outPktLengths_ = histMap->getOrCreateLockableHistogram(
-      statName("out_pkt_lengths", portName), &pktLenHist);
+      statName("out_pkt_lengths", portName), makeLenHist);
 
   *lockedPortStatsPtr =
       BcmPortStats(queueManager_->getNumQueues(cfg::StreamType::UNICAST));