add vtr::thread_pool

Author: duck2

vpr/src/route/RouterThreadPool.h renamed to libs/libvtrutil/src/vtr_thread_pool.h

@@ -2,9 +2,7 @@
 
 /** 
  * @file RouterThreadPool.h
- * @brief A generic thread pool for parallel task execution.
- * 
- * This class manages a pool of threads and allows tasks to be executed in parallel.
+ * @brief A generic thread pool for parallel task execution
  */
 
 #include <thread>
@@ -19,7 +17,9 @@
 #include "vtr_log.h"
 #include "vtr_time.h"
 
-class RouterThreadPool {
+namespace vtr {
+
+class thread_pool {
 private:
     struct ThreadData {
         std::thread thread;
@@ -42,16 +42,16 @@ class RouterThreadPool {
     std::condition_variable completion_cv;
 
 public:
-    RouterThreadPool(size_t thread_count) {
+    thread_pool(size_t thread_count) {
         // VTR_LOG("Creating thread pool with %zu threads\n", thread_count);
         threads.reserve(thread_count);
-        
+
         for (size_t i = 0; i < thread_count; i++) {
             auto thread_data = std::make_unique<ThreadData>(i);
-            
-            thread_data->thread = std::thread([this, td = thread_data.get()]() {
+
+            thread_data->thread = std::thread([td = thread_data.get()]() {
                 // VTR_LOG("Thread %zu started\n", td->thread_id);
-                
+
                 while (true) {
                     std::function<void()> task;
                     {
@@ -93,14 +93,14 @@ class RouterThreadPool {
     template<typename F>
     void schedule_work(F&& f) {
         active_tasks++;
-        
+
         // Round-robin thread assignment
         size_t thread_idx = (next_thread++) % threads.size();
         auto thread_data = threads[thread_idx].get();
         size_t task_id = ++total_tasks_queued;
-        
+
         // VTR_LOG("Scheduling task %zu to thread %zu\n", task_id, thread_data->thread_id);
-        
+
         // Wrap the work with task completion tracking
         auto task = [this, f = std::forward<F>(f), thread_id = thread_data->thread_id, task_id]() {
             vtr::Timer task_timer;
@@ -126,7 +126,7 @@ class RouterThreadPool {
                 completion_cv.notify_all();
             }
         };
-        
+
         // Queue the task
         {
             std::lock_guard<std::mutex> lock(thread_data->queue_mutex);
@@ -142,7 +142,7 @@ class RouterThreadPool {
         completion_cv.wait(lock, [this]() { return active_tasks == 0; });
     }
 
-    ~RouterThreadPool() {
+    ~thread_pool() {
         // VTR_LOG("Shutting down thread pool after %.3f seconds, processed %zu total tasks\n", 
         //        pool_timer.elapsed_sec(), total_tasks_queued.load());
 
@@ -156,7 +156,7 @@ class RouterThreadPool {
             }
             thread_data->cv.notify_one();
         }
-        
+
         // Join all threads
         for (auto& thread_data : threads) {
             if (thread_data->thread.joinable()) {
@@ -167,3 +167,5 @@ class RouterThreadPool {
         }
     }
 };
+
+}  // namespace vtr

vpr/src/route/ParallelNetlistRouter.h

@@ -11,10 +11,9 @@
  * [0]: "Parallel FPGA Routing with On-the-Fly Net Decomposition", FPT'24 */
 #include "netlist_routers.h"
 #include "vtr_optional.h"
-#include "RouterThreadPool.h"
+#include "vtr_thread_pool.h"
 
 #include <tbb/task_group.h>
-#include <future>
 
 /** Parallel impl for NetlistRouter.
  * Holds enough context members to glue together ConnectionRouter and net routing functions,
@@ -105,7 +104,7 @@ class ParallelNetlistRouter : public NetlistRouter {
     /** The partition tree. Holds the groups of nets for each partition */
     vtr::optional<PartitionTree> _tree;
 
-    RouterThreadPool _thread_pool;
+    vtr::thread_pool _thread_pool;
 };
 
 #include "ParallelNetlistRouter.tpp"

vpr/src/route/ParallelNetlistRouter.tpp

@@ -6,7 +6,6 @@
 #include "netlist_routers.h"
 #include "route_net.h"
 #include "vtr_time.h"
-#include "RouterThreadPool.h"
 
 template<typename HeapType>
 inline RouteIterResults ParallelNetlistRouter<HeapType>::route_netlist(int itry, float pres_fac, float worst_neg_slack) {
@@ -33,7 +32,7 @@ inline RouteIterResults ParallelNetlistRouter<HeapType>::route_netlist(int itry,
     _thread_pool.schedule_work([this]() {
         route_partition_tree_node(_tree->root());
     });
-    
+
     /* Wait for all tasks in the thread pool to complete */
     _thread_pool.wait_for_all();