Switch to deque mixin in tbb_task.

lib/pls/include/pls/internal/scheduling/tbb_task.h

@@ -2,7 +2,9 @@
 #ifndef PLS_TBB_LIKE_TASK_H
 #define PLS_TBB_LIKE_TASK_H
 
-#include <pls/internal/base/aligned_stack.h>
+#include "pls/internal/base/aligned_stack.h"
+#include "pls/internal/base/deque.h"
+
 #include "abstract_task.h"
 #include "thread_state.h"
 
@@ -10,7 +12,7 @@ namespace pls {
     namespace internal {
         namespace scheduling {
             class tbb_task;
-            class tbb_sub_task {
+            class tbb_sub_task: public base::deque_item {
                 friend class tbb_task;
 
                 // Coordinate finishing of sub_tasks
@@ -20,10 +22,6 @@ namespace pls {
                 // Access to TBB scheduling environment
                 tbb_task* tbb_task_;
 
-                // Double-Ended Queue management
-                tbb_sub_task* below_;
-                tbb_sub_task* above_;
-
                 // Stack Management (reset stack pointer after wait_for_all() calls)
                 base::aligned_stack::state stack_state_;
             protected:
@@ -60,9 +58,7 @@ namespace pls {
                 base::aligned_stack* my_stack_;
 
                 // Double-Ended Queue management
-                base::spin_lock lock_;
-                tbb_sub_task* top_;
-                tbb_sub_task* bottom_;
+                base::deque<tbb_sub_task> deque_;
 
                 // Steal Management
                 tbb_sub_task* last_stolen_;
@@ -77,8 +73,7 @@ namespace pls {
                 explicit tbb_task(tbb_sub_task* root_task):
                         abstract_task{0, 0},
                         root_task_{root_task},
-                        top_{nullptr},
-                        bottom_{nullptr},
+                        deque_{},
                         last_stolen_{nullptr} {
                     my_stack_ = base::this_thread::state<thread_state>()->task_stack_;
                     root_task_->tbb_task_ = this;

lib/pls/src/internal/scheduling/tbb_task.cpp

@@ -5,13 +5,13 @@ namespace pls {
     namespace internal {
         namespace scheduling {
             tbb_sub_task::tbb_sub_task():
+                base::deque_item{},
                 ref_count_{0},
                 parent_{nullptr},
                 tbb_task_{nullptr},
-                below_{nullptr},
-                above_{nullptr} {}
+                stack_state_{nullptr} {}
 
-            tbb_sub_task::tbb_sub_task(const tbb_sub_task& /*other*/) {
+            tbb_sub_task::tbb_sub_task(const tbb_sub_task& other): base::deque_item(other) {
                 // Do Nothing, will be inited after this anyways
             }
 
@@ -33,18 +33,7 @@ namespace pls {
                 sub_task->tbb_task_ = tbb_task_;
                 sub_task->stack_state_ = tbb_task_->my_stack_->save_state();
 
-                // Put sub_task into stealing queue
-                {
-                    std::lock_guard<base::spin_lock> lock{tbb_task_->lock_};
-                    if (tbb_task_->bottom_ != nullptr) {
-                        tbb_task_->bottom_->below_ = sub_task;
-                    } else {
-                        tbb_task_->top_ = sub_task;
-                    }
-                    sub_task->above_ = tbb_task_->bottom_;
-                    sub_task->below_ = nullptr;
-                    tbb_task_->bottom_ = sub_task;
-                }
+                tbb_task_->deque_.push_tail(sub_task);
             }
 
             void tbb_sub_task::wait_for_all() {
@@ -64,41 +53,11 @@ namespace pls {
             }
 
             tbb_sub_task* tbb_task::get_local_sub_task() {
-                // Remove from bottom of queue
-                std::lock_guard<base::spin_lock> lock{lock_};
-
-                if (bottom_ == nullptr) {
-                    return nullptr;
-                }
-
-                tbb_sub_task *result = bottom_;
-                bottom_ = bottom_->above_;
-                if (bottom_ == nullptr) {
-                    top_ = nullptr;
-                } else {
-                    bottom_->below_ = nullptr;
-                }
-
-                return result;
+                return deque_.pop_tail();
             }
 
             tbb_sub_task* tbb_task::get_stolen_sub_task() {
-                // Remove from top of queue
-                std::lock_guard<base::spin_lock> lock{lock_};
-
-                if (top_ == nullptr) {
-                    return nullptr;
-                }
-
-                tbb_sub_task *result = top_;
-                top_ = top_->below_;
-                if (top_ == nullptr) {
-                    bottom_ = nullptr;
-                } else {
-                    top_->above_ = nullptr;
-                }
-
-                return result;
+                return deque_.pop_head();
             }
 
             bool tbb_task::internal_stealing(abstract_task* other_task) {