feat(JobScheduler): improve dependency handling logic

Updated `JobScheduler` to enhance dependency tracking by counting valid dependencies upfront and dynamically adjusting counts using `Interlocked` operations. Improved job enqueueing logic to ensure jobs are only enqueued when all dependencies are met.

Replaced `Interlocked.Increment` with `Interlocked.Add` for batch updates to `_totalJobCount`, improving performance. Adjusted `VirtualStack` cleanup to use the correct size variable for memory deallocation.

Simplified `JobDispatchingJob` API by removing `ctx.ThreadIndex` parameter. Updated `TestJobSystem` to pass job handles as dependencies for proper execution order.

Incremented assembly version to 1.5.9 to reflect these changes.

Misaki.HighPerformance.Jobs/JobScheduler.cs

@@ -228,8 +228,6 @@ public sealed unsafe partial class JobScheduler : IJobScheduler, IDisposable
 
     private bool _disposed = false;
 
-    internal volatile int _totalJobCount;
-
     internal bool IsCancellationRequested => _cts.IsCancellationRequested;
 
     public int WorkerCount => _workerThreads.Length;
@@ -242,11 +240,11 @@ public sealed unsafe partial class JobScheduler : IJobScheduler, IDisposable
     {
         var workerCount = Math.Max(1, threadCount);
 
-        _jobInfoPool = new();
-        _jobQueue = new();
+        _jobInfoPool = new ConcurrentSlotMap<JobInfo>();
+        _jobQueue = new ConcurrentQueue<JobHandle>();
 
-        _workSignal = new(0);
-        _cts = new();
+        _workSignal = new SemaphoreSlim(0);
+        _cts = new CancellationTokenSource();
 
         _workerThreads = new WorkerThread[workerCount];
 
@@ -297,13 +295,24 @@ public sealed unsafe partial class JobScheduler : IJobScheduler, IDisposable
                 jobQueue.Enqueue(handle);
             }
 
-            Interlocked.Increment(ref _totalJobCount);
             _workSignal.Release(handleCount);
         }
     }
 
     private JobHandle CreateJobHandle(ref JobInfo jobInfo, params ReadOnlySpan<JobHandle> dependencies)
     {
+        var validDepCount = 0;
+        for (var i = 0; i < dependencies.Length; i++)
+        {
+            if (dependencies[i].IsValid)
+            {
+                validDepCount++;
+            }
+        }
+
+        // Advance count to account for all dependencies upfront + 1 guard lock
+        jobInfo.dependencyCount = validDepCount + 1;
+
         var id = _jobInfoPool.Add(jobInfo, out var generation);
         ref var infoInPool = ref _jobInfoPool.GetElementReferenceAt(id, generation, out _);
 
@@ -321,13 +330,13 @@ public sealed unsafe partial class JobScheduler : IJobScheduler, IDisposable
             if (!exist)
             {
                 // Dependency does not exist (likely completed already)
+                Interlocked.Decrement(ref infoInPool.dependencyCount);
                 continue;
             }
 
             // Lock-free registration: Try to acquire "Reader Lock" by incrementing RC in high bits.
             // If state is already Completed, we skip (dependency met).
             var registered = false;
-            var completed = false;
             var spin = new SpinWait();
 
             while (true)
@@ -337,7 +346,6 @@ public sealed unsafe partial class JobScheduler : IJobScheduler, IDisposable
 
                 if (state == JobState.Completed)
                 {
-                    completed = true;
                     break;
                 }
 
@@ -374,20 +382,18 @@ public sealed unsafe partial class JobScheduler : IJobScheduler, IDisposable
                 spin.SpinOnce(-1);
             }
 
-            if (!registered && !completed)
+            // If we didn't successfully register (completed fast), drop it from the advanced counter
+            if (!registered)
             {
-                // Should not happen if logic is correct, unless loop logic changed
-                Interlocked.Increment(ref infoInPool.dependencyCount);
+                Interlocked.Decrement(ref infoInPool.dependencyCount);
             }
-            else if (registered)
-            {
-                // Successfully added dependency
-                Interlocked.Increment(ref infoInPool.dependencyCount);
-            }
-            // else: completed is true, registered is false -> Dependency is already done, so we don't increment our dependencyCount.
         }
 
-        EnqueueJobIfReady(handle);
+        // Lower the initial 1 guard lock; Enqueue if met
+        if (Interlocked.Decrement(ref infoInPool.dependencyCount) == 0)
+        {
+            EnqueueJobIfReady(handle);
+        }
 
         return handle;
     }
@@ -509,7 +515,6 @@ public sealed unsafe partial class JobScheduler : IJobScheduler, IDisposable
 
         NativeMemory.Free(info.pJobData);
         _jobInfoPool.Remove(handle.ID, handle.Generation);
-        Interlocked.Decrement(ref _totalJobCount);
 
         for (var i = 0; i < dependentCount; i++)
         {

Misaki.HighPerformance.Jobs/Misaki.HighPerformance.Jobs.csproj

@@ -6,7 +6,7 @@
     <Nullable>enable</Nullable>
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
-    <AssemblyVersion>1.5.8</AssemblyVersion>
+    <AssemblyVersion>1.5.9</AssemblyVersion>
     <Version>$(AssemblyVersion)</Version>
     <Authors>Misaki</Authors>
     <PackageProjectUrl>https://git.personalnas.com/Misaki/Misaki.HighPerformance.git</PackageProjectUrl>

Misaki.HighPerformance.Jobs/WorkerThread.cs

@@ -33,12 +33,6 @@ internal class WorkerThread : IDisposable
 
     private bool TryFindJob(out JobHandle handle)
     {
-        if (Interlocked.CompareExchange(ref _scheduler._totalJobCount, 0, 0) == 0)
-        {
-            handle = JobHandle.Invalid;
-            return false;
-        }
-
         if (_localQueue.TryDequeue(out handle))
         {
             return true;
@@ -112,14 +106,12 @@ internal class WorkerThread : IDisposable
                 if (jobInfo.pExecutionFunc != null)
                 {
                     var ctx = new JobExecutionContext(_index, _scheduler);
-                    if (!jobInfo.pExecutionFunc(jobInfo.pJobData, ref jobInfo.jobRanges, ref jobInfo.remainingBatches, in ctx))
+                    if (jobInfo.pExecutionFunc(jobInfo.pJobData, ref jobInfo.jobRanges, ref jobInfo.remainingBatches, in ctx))
                     {
-                        // If the job returns false, it means it we are not the last worker to process this job, so we should not mark it as complete yet.
-                        continue;
+                        // If the job returns true, it means we are the last worker to process this job.
+                        _scheduler.MarkJobComplete(handle);
                     }
                 }
-
-                _scheduler.MarkJobComplete(handle);
             }
         }
     }

Misaki.HighPerformance.LowLevel/Buffer/VirtualStack.cs

@@ -216,12 +216,13 @@ public unsafe struct VirtualStack : IMemoryAllocator<VirtualStack, VirtualStack.
         }
 
         var ptr = _baseAddress;
+        var size = _reserveCapacity;
 
         _baseAddress = null;
         _allocatedOffset = 0;
         _committedSize = 0;
         _reserveCapacity = 0;
 
-        Munmap(ptr, _reserveCapacity);
+        Munmap(ptr, size);
     }
 }

Misaki.HighPerformance.Test/Jobs/JobDispatchingJob.cs

@@ -28,7 +28,7 @@ internal struct JobDispatchingJob : IJobParallelFor
                 data = data[loopIndex]
             };
 
-            var handle = ctx.JobScheduler.ScheduleParallelFor(in innerJob, data[loopIndex].Length, 64, ctx.ThreadIndex);
+            var handle = ctx.JobScheduler.ScheduleParallelFor(in innerJob, data[loopIndex].Length, 64);
             handles.AddNoResize(handle);
         }
     }

Misaki.HighPerformance.Test/UnitTest/Jobs/TestJobSystem.cs

@@ -199,7 +199,7 @@ public unsafe class TestJobSystem
         };
 
         var handle1 = s_jobScheduler.ScheduleParallel(ref addJob, arraySize, 64);
-        var handle2 = s_jobScheduler.ScheduleParallel(ref multiplyJob, arraySize, 64);
+        var handle2 = s_jobScheduler.ScheduleParallel(ref multiplyJob, arraySize, 64, handle1);
         var handle3 = s_jobScheduler.Schedule(ref sumJob, handle2);
 
         s_jobScheduler.Wait(handle3);