Update some Phabricator behaviors for changes to Futures

Summary:
Depends on D21053. Ref T11968. Three things have changed:

  - Overseers can no longer use FutureIterator to continue execution of an arbitrary list of futures from any state. Use FuturePool instead.
  - Same with repository daemons.
  - Probably (?) fix an API change in the Harbormaster exec future.

Test Plan:
  - Ran "bin/phd debug task" and "bin/phd debug pull", no longer saw Future-management related errors.
  - The Harbormaster future is easiest to test by just seeing if production works once this change is deployed there.

Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam

Maniphest Tasks: T11968

Differential Revision: https://secure.phabricator.com/D21054

src/applications/harbormaster/future/HarbormasterExecFuture.php

@@ -25,9 +25,13 @@ final class HarbormasterExecFuture
   }
 
   public function isReady() {
+    if ($this->hasResult()) {
+      return true;
+    }
+
     $future = $this->getFuture();
 
-    $result = $future->isReady();
+    $is_ready = $future->isReady();
 
     list($stdout, $stderr) = $future->read();
     $future->discardBuffers();
@@ -40,11 +44,14 @@ final class HarbormasterExecFuture
       $this->stderr->append($stderr);
     }
 
-    return $result;
-  }
+    if ($future->hasResult()) {
+      $this->setResult($future->getResult());
+    }
 
-  protected function getResult() {
-    return $this->getFuture()->getResult();
+    // TODO: This should probably be implemented as a FutureProxy; it will
+    // not currently propagate exceptions or sockets properly.
+
+    return $is_ready;
   }
 
 }

src/applications/repository/daemon/PhabricatorRepositoryPullLocalDaemon.php

@@ -73,6 +73,11 @@ final class PhabricatorRepositoryPullLocalDaemon
     $futures = array();
     $queue = array();
 
+    $future_pool = new FuturePool();
+
+    $future_pool->getIteratorTemplate()
+      ->setUpdateInterval($min_sleep);
+
     $sync_wait = phutil_units('2 minutes in seconds');
     $last_sync = array();
 
@@ -214,10 +219,14 @@ final class PhabricatorRepositoryPullLocalDaemon
               $display_name));
 
           unset($queue[$id]);
-          $futures[$id] = $this->buildUpdateFuture(
+
+          $future = $this->buildUpdateFuture(
             $repository,
             $no_discovery);
 
+          $futures[$id] = $future->getFutureKey();
+
+          $future_pool->addFuture($future);
           break;
         }
       }
@@ -230,16 +239,14 @@ final class PhabricatorRepositoryPullLocalDaemon
             phutil_count($queue)));
       }
 
-      if ($futures) {
-        $iterator = id(new FutureIterator($futures))
-          ->setUpdateInterval($min_sleep);
+      if ($future_pool->hasFutures()) {
+        while ($future_pool->hasFutures()) {
+          $future = $future_pool->resolve();
 
-        foreach ($iterator as $id => $future) {
           $this->stillWorking();
 
           if ($future === null) {
             $this->log(pht('Waiting for updates to complete...'));
-            $this->stillWorking();
 
             if ($this->loadRepositoryUpdateMessages()) {
               $this->log(pht('Interrupted by pending updates!'));
@@ -249,9 +256,18 @@ final class PhabricatorRepositoryPullLocalDaemon
             continue;
           }
 
-          unset($futures[$id]);
-          $retry_after[$id] = $this->resolveUpdateFuture(
-            $pullable[$id],
+          $future_key = $future->getFutureKey();
+          $repository_id = null;
+          foreach ($futures as $id => $key) {
+            if ($key === $future_key) {
+              $repository_id = $id;
+              unset($futures[$id]);
+              break;
+            }
+          }
+
+          $retry_after[$repository_id] = $this->resolveUpdateFuture(
+            $pullable[$repository_id],
             $future,
             $min_sleep);
 

src/infrastructure/daemon/PhutilDaemonOverseer.php

@@ -32,6 +32,8 @@ final class PhutilDaemonOverseer extends Phobject {
   private $inAbruptShutdown;
   private $inGracefulShutdown;
 
+  private $futurePool;
+
   public function __construct(array $argv) {
     PhutilServiceProfiler::getInstance()->enableDiscardMode();
 
@@ -160,13 +162,13 @@ EOHELP
   public function run() {
     $this->createDaemonPools();
 
+    $future_pool = $this->getFuturePool();
+
     while (true) {
       if ($this->shouldReloadDaemons()) {
         $this->didReceiveSignal(SIGHUP);
       }
 
-      $futures = array();
-
       $running_pools = false;
       foreach ($this->getDaemonPools() as $pool) {
         $pool->updatePool();
@@ -180,7 +182,7 @@ EOHELP
         }
 
         foreach ($pool->getFutures() as $future) {
-          $futures[] = $future;
+          $future_pool->addFuture($future);
         }
 
         if ($pool->getDaemons()) {
@@ -190,9 +192,15 @@ EOHELP
 
       $this->updateMemory();
 
-      $this->waitForDaemonFutures($futures);
+      if ($future_pool->hasFutures()) {
+        $future_pool->resolve();
+      } else {
+        if (!$this->shouldShutdown()) {
+          sleep(1);
+        }
+      }
 
-      if (!$futures && !$running_pools) {
+      if (!$future_pool->hasFutures() && !$running_pools) {
         if ($this->shouldShutdown()) {
           break;
         }
@@ -202,23 +210,20 @@ EOHELP
     exit($this->err);
   }
 
+  private function getFuturePool() {
+    if (!$this->futurePool) {
+      $pool = new FuturePool();
 
-  private function waitForDaemonFutures(array $futures) {
-    assert_instances_of($futures, 'ExecFuture');
+      // TODO: This only wakes if any daemons actually exit, or 1 second
+      // passes. It would be a bit cleaner to wait on any I/O, but Futures
+      // currently can't do that.
 
-    if ($futures) {
-      // TODO: This only wakes if any daemons actually exit. It would be a bit
-      // cleaner to wait on any I/O with Channels.
-      $iter = id(new FutureIterator($futures))
+      $pool->getIteratorTemplate()
         ->setUpdateInterval(1);
-      foreach ($iter as $future) {
-        break;
-      }
-    } else {
-      if (!$this->shouldShutdown()) {
-        sleep(1);
-      }
+
+      $this->futurePool = $pool;
     }
+    return $this->futurePool;
   }
 
   private function createDaemonPools() {