Merge remote-tracking branch 'origin/master' into binary-cache

Dependencies

• [2] 73YR46NJ hydra-queue-runner: Write directly to a binary cache
• [3] FITVNQ2S Keep track of the time we spend copying to/from build machines
• [4] LE4VZIY5 More stats
• [5] CNLNT3T4 Allow only 1 thread to send a closure to a given machine at the same time
• [6] DWFTK56E Keep track of how many threads are waiting
• [7] A2GL5FOZ Moar stats
• [*] 5AIYUMTB Basic remote building

Change contents

• edit in src/hydra-queue-runner/build-remote.cc at line 238
  [4.251]→[2.917:980](∅→∅)
  − copyClosureTo(destStore, from, to, inputs, bytesSent);
• resurrect zombie in src/hydra-queue-runner/build-remote.cc at line 238
  [4.251]→[3.0:56](∅→∅),[4.251]→[3.0:56](∅→∅),[4.157]→[3.57:216](∅→∅),[4.157]→[3.57:216](∅→∅)
  +

  + auto now1 = std::chrono::steady_clock::now();

  +

  +

  + auto now2 = std::chrono::steady_clock::now();

  +

  + result.overhead += std::chrono::duration_cast<std::chrono::milliseconds>(now2 - now1).count();
• edit in src/hydra-queue-runner/build-remote.cc at line 241
  [3.56]

  [3.57]
  + copyClosureTo(destStore, from, to, inputs, bytesSent);
• edit in src/hydra-queue-runner/build-remote.cc at line 299
  [4.336]→[2.1036:1106](∅→∅)
  − copyClosureFrom(destStore, from, to, outputs, bytesReceived);
• resurrect zombie in src/hydra-queue-runner/build-remote.cc at line 299
  [4.336]→[3.217:273](∅→∅),[4.336]→[3.217:273](∅→∅),[4.998]→[3.274:433](∅→∅),[4.998]→[3.274:433](∅→∅)
  +

  + auto now1 = std::chrono::steady_clock::now();

  +

  +

  + auto now2 = std::chrono::steady_clock::now();

  +

  + result.overhead += std::chrono::duration_cast<std::chrono::milliseconds>(now2 - now1).count();
• edit in src/hydra-queue-runner/build-remote.cc at line 302
  [3.273]

  [3.274]
  + copyClosureFrom(destStore, from, to, outputs, bytesReceived);