libstore: make Worker::wakeUp private

Change-Id: Iffa55272fe6ef4adaf3e9d4d25e5339792c2e460

src/libstore/build/derivation-goal.cc

@@ -648,8 +648,7 @@ Goal::WorkResult DerivationGoal::inputsRealised()
        slot to become available, since we don't need one if there is a
        build hook. */
     state = &DerivationGoal::tryToBuild;
-    worker.wakeUp(shared_from_this());
+    return ContinueImmediately{};
-    return StillAlive{};
 }
 
 Goal::WorkResult DerivationGoal::started()
@@ -763,8 +762,7 @@ Goal::WorkResult DerivationGoal::tryToBuild()
     actLock.reset();
 
     state = &DerivationGoal::tryLocalBuild;
-    worker.wakeUp(shared_from_this());
+    return ContinueImmediately{};
-    return StillAlive{};
 }
 
 Goal::WorkResult DerivationGoal::tryLocalBuild() {

src/libstore/build/goal.hh

@@ -108,12 +108,14 @@ public:
     struct [[nodiscard]] StillAlive {};
     struct [[nodiscard]] WaitForSlot {};
     struct [[nodiscard]] WaitForAWhile {};
+    struct [[nodiscard]] ContinueImmediately {};
     struct [[nodiscard]] Finished {
         ExitCode result;
         std::unique_ptr<Error> ex;
     };
 
-    struct [[nodiscard]] WorkResult : std::variant<StillAlive, WaitForSlot, WaitForAWhile, Finished>
+    struct [[nodiscard]] WorkResult
+        : std::variant<StillAlive, WaitForSlot, WaitForAWhile, ContinueImmediately, Finished>
     {
         WorkResult() = delete;
         using variant::variant;

src/libstore/build/substitution-goal.cc

@@ -181,8 +181,7 @@ Goal::WorkResult PathSubstitutionGoal::referencesValid()
             assert(worker.store.isValidPath(i));
 
     state = &PathSubstitutionGoal::tryToRun;
-    worker.wakeUp(shared_from_this());
+    return ContinueImmediately{};
-    return StillAlive{};
 }
 
 
@@ -255,8 +254,7 @@ Goal::WorkResult PathSubstitutionGoal::finished()
 
         /* Try the next substitute. */
         state = &PathSubstitutionGoal::tryNext;
-        worker.wakeUp(shared_from_this());
+        return ContinueImmediately{};
-        return StillAlive{};
     }
 
     worker.markContentsGood(storePath);

src/libstore/build/worker.cc

@@ -189,6 +189,7 @@ void Worker::handleWorkResult(GoalPtr goal, Goal::WorkResult how)
             [&](Goal::StillAlive) {},
             [&](Goal::WaitForSlot) { waitForBuildSlot(goal); },
             [&](Goal::WaitForAWhile) { waitForAWhile(goal); },
+            [&](Goal::ContinueImmediately) { wakeUp(goal); },
             [&](Goal::Finished & f) { goalFinished(goal, f); },
         },
         how
@@ -523,7 +524,7 @@ void Worker::waitForInput()
                 if (rd == 0 || (rd == -1 && errno == EIO)) {
                     debug("%1%: got EOF", goal->getName());
                     goal->handleEOF(k);
-                    wakeUp(goal);
+                    handleWorkResult(goal, Goal::ContinueImmediately{});
                     j->fds.erase(k);
                 } else if (rd == -1) {
                     if (errno != EINTR)

src/libstore/build/worker.hh

@@ -122,6 +122,11 @@ private:
      */
     void waitForAWhile(GoalPtr goal);
 
+    /**
+     * Wake up a goal (i.e., there is something for it to do).
+     */
+    void wakeUp(GoalPtr goal);
+
 public:
 
     const Activity act;
@@ -219,11 +224,6 @@ public:
      */
     void removeGoal(GoalPtr goal);
 
-    /**
-     * Wake up a goal (i.e., there is something for it to do).
-     */
-    void wakeUp(GoalPtr goal);
-
     /**
      * Return the number of local build processes currently running (but not
      * remote builds via the build hook).