Index: src/daemon/PhutilDaemon.php
===================================================================
--- src/daemon/PhutilDaemon.php
+++ src/daemon/PhutilDaemon.php
@@ -12,6 +12,7 @@
   private $traceMode;
   private $traceMemory;
   private $verbose;
+  private $notifyReceived;
 
   final public function setVerbose($verbose) {
     $this->verbose = $verbose;
@@ -35,6 +36,8 @@
       pcntl_signal(SIGTERM, __CLASS__.'::exitOnSignal');
     }
 
+    pcntl_signal(SIGUSR2, array($this, 'onNotifySignal'));
+
     // Without discard mode, this consumes unbounded amounts of memory. Keep
     // memory bounded.
     PhutilServiceProfiler::getInstance()->enableDiscardMode();
@@ -52,9 +55,10 @@
   }
 
   final protected function sleep($duration) {
+    $this->notifyReceived = false;
     $this->willSleep($duration);
     $this->stillWorking();
-    while ($duration > 0) {
+    while ($duration > 0 && !$this->notifyReceived) {
       sleep(min($duration, 60));
       $duration -= 60;
       $this->stillWorking();
@@ -104,6 +108,15 @@
     return $this->traceMode;
   }
 
+  public final function onNotifySignal($signo) {
+    $this->notifyReceived = true;
+    $this->onNotify($signo);
+  }
+
+  protected function onNotify($signo) {
+    // This is a hook for subclasses.
+  }
+
   protected function willRun() {
     // This is a hook for subclasses.
   }
Index: src/daemon/PhutilDaemonOverseer.php
===================================================================
--- src/daemon/PhutilDaemonOverseer.php
+++ src/daemon/PhutilDaemonOverseer.php
@@ -165,6 +165,7 @@
 
     declare(ticks = 1);
     pcntl_signal(SIGUSR1, array($this, 'didReceiveKeepaliveSignal'));
+    pcntl_signal(SIGUSR2, array($this, 'didReceiveNotifySignal'));
 
     pcntl_signal(SIGINT,  array($this, 'didReceiveTerminalSignal'));
     pcntl_signal(SIGTERM, array($this, 'didReceiveTerminalSignal'));
@@ -272,6 +273,13 @@
     }
   }
 
+  public function didReceiveNotifySignal($signo) {
+    $pid = $this->childPID;
+    if ($pid) {
+      posix_kill($pid, $signo);
+    }
+  }
+
   public function didReceiveKeepaliveSignal($signo) {
     $this->deadline = time() + $this->deadlineTimeout;
   }