[Jobs API]: Cleanup migration of missing Jobs pieces.

- JobHandle::IsCompleted()
- JobDelegate::GetTaskId()
- worker_count passed as argument to GetMaxConcurrency().
  Jobs implementation must call the new GetMaxConcurrency(), but Jobs
  users aren't migrated yet.

Bug: chromium:1114823
Change-Id: Ie09a8847d1cb884b1e388903370e49f33fa25a64
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2374308Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69683}

include/v8-platform.h

@@ -175,9 +175,8 @@ class JobDelegate {
    * Returns a task_id unique among threads currently running this job, such
    * that GetTaskId() < worker count. To achieve this, the same task_id may be
    * reused by a different thread after a worker_task returns.
-   * TODO(etiennep): Make pure virtual once custom embedders implement it.
    */
-  virtual uint8_t GetTaskId() { return 0; }
+  virtual uint8_t GetTaskId() = 0;
 };
 
 /**
@@ -212,9 +211,8 @@ class JobHandle {
 
   /**
    * Returns true if there's no work pending and no worker running.
-   * TODO(etiennep): Make pure virtual once custom embedders implement it.
    */
-  virtual bool IsCompleted() { return true; }
+  virtual bool IsCompleted() = 0;
 
   /**
    * Returns true if associated with a Job and other methods may be called.
@@ -233,23 +231,17 @@ class JobTask {
   virtual void Run(JobDelegate* delegate) = 0;
 
   /**
-   * Controls the maximum number of threads calling Run() concurrently. Run() is
-   * only invoked if the number of threads previously running Run() was less
-   * than the value returned. Since GetMaxConcurrency() is a leaf function, it
-   * must not call back any JobHandle methods.
+   * Controls the maximum number of threads calling Run() concurrently, given
+   * the number of threads currently assigned to this job and executing Run().
+   * Run() is only invoked if the number of threads previously running Run() was
+   * less than the value returned. Since GetMaxConcurrency() is a leaf function,
+   * it must not call back any JobHandle methods.
    */
-  virtual size_t GetMaxConcurrency() const = 0;
+  virtual size_t GetMaxConcurrency(size_t worker_count) const = 0;
 
-  /*
-   * Meant to replace the version above, given the number of threads currently
-   * assigned to this job and executing Run(). This is useful when the result
-   * must include local work items not visible globaly by other workers.
-   * TODO(etiennep): Replace the version above by this once custom embedders are
-   * migrated.
-   */
-  virtual size_t GetMaxConcurrency(size_t worker_count) const {
-    return GetMaxConcurrency();
-  }
+  // TODO(1114823): Clean up once all overrides are removed.
+  V8_DEPRECATED("Use the version that takes |worker_count|.")
+  virtual size_t GetMaxConcurrency() const { return 0; }
 };
 
 /**

src/d8/d8-platforms.cc

@@ -276,10 +276,6 @@ class DelayedTasksPlatform final : public Platform {
       job_task_->Run(delegate);
     }
 
-    size_t GetMaxConcurrency() const override {
-      return job_task_->GetMaxConcurrency();
-    }
-
     size_t GetMaxConcurrency(size_t worker_count) const override {
       return job_task_->GetMaxConcurrency(worker_count);
     }

src/heap/cppgc/sweeper.cc

@@ -401,7 +401,7 @@ class ConcurrentSweepTask final : public v8::JobTask,
     is_completed_.store(true, std::memory_order_relaxed);
   }
 
-  size_t GetMaxConcurrency() const final {
+  size_t GetMaxConcurrency(size_t /* active_worker_count */) const final {
     return is_completed_.load(std::memory_order_relaxed) ? 0 : 1;
   }
 

src/wasm/module-compiler.cc

@@ -1641,7 +1641,7 @@ class BackgroundCompileJob : public JobTask {
     }
   }
 
-  size_t GetMaxConcurrency() const override {
+  size_t GetMaxConcurrency(size_t /* worker_count */) const override {
     return std::min(max_concurrency_, current_concurrency_->load());
   }
 
@@ -3291,7 +3291,7 @@ class CompileJSToWasmWrapperJob final : public JobTask {
     }
   }
 
-  size_t GetMaxConcurrency() const override {
+  size_t GetMaxConcurrency(size_t /* worker_count */) const override {
     return std::min(max_concurrency_,
                     outstanding_units_.load(std::memory_order_relaxed));
   }

test/unittests/libplatform/default-job-unittest.cc

@@ -36,7 +36,7 @@ TEST(DefaultJobTest, CancelJob) {
       }
     }
 
-    size_t GetMaxConcurrency() const override {
+    size_t GetMaxConcurrency(size_t /* worker_count */) const override {
       return max_concurrency.load(std::memory_order_relaxed);
     }
 
@@ -83,7 +83,7 @@ TEST(DefaultJobTest, JoinJobContributes) {
       --max_concurrency;
     }
 
-    size_t GetMaxConcurrency() const override {
+    size_t GetMaxConcurrency(size_t /* worker_count */) const override {
       return max_concurrency.load(std::memory_order_relaxed);
     }
 
@@ -121,11 +121,6 @@ TEST(DefaultJobTest, WorkerCount) {
       if (max_concurrency > 0) --max_concurrency;
     }
 
-    size_t GetMaxConcurrency() const override {
-      DCHECK(false);  // not called.
-      return 0;
-    }
-
     size_t GetMaxConcurrency(size_t worker_count) const override {
       return worker_count + max_concurrency.load(std::memory_order_relaxed);
     }
@@ -166,7 +161,7 @@ TEST(DefaultJobTest, JobNotifyConcurrencyIncrease) {
       --max_concurrency;
     }
 
-    size_t GetMaxConcurrency() const override {
+    size_t GetMaxConcurrency(size_t /* worker_count */) const override {
       return max_concurrency.load(std::memory_order_relaxed);
     }
 
@@ -217,7 +212,7 @@ TEST(DefaultJobTest, FinishBeforeJoin) {
       --max_concurrency;
     }
 
-    size_t GetMaxConcurrency() const override {
+    size_t GetMaxConcurrency(size_t /* worker_count */) const override {
       return max_concurrency.load(std::memory_order_relaxed);
     }
 
@@ -254,7 +249,9 @@ TEST(DefaultJobTest, LeakHandle) {
 
     void Run(JobDelegate* delegate) override {}
 
-    size_t GetMaxConcurrency() const override { return 0; }
+    size_t GetMaxConcurrency(size_t /* worker_count */) const override {
+      return 0;
+    }
   };
 
   DefaultPlatform platform(0);
@@ -275,7 +272,9 @@ TEST(DefaultJobTest, AcquireTaskId) {
 
     void Run(JobDelegate* delegate) override {}
 
-    size_t GetMaxConcurrency() const override { return 0; }
+    size_t GetMaxConcurrency(size_t /* worker_count */) const override {
+      return 0;
+    }
   };
 
   DefaultPlatform platform(0);