diff --git a/build/ipc.pro b/build/ipc.pro
index a446988..652f270 100644
--- a/build/ipc.pro
+++ b/build/ipc.pro
@@ -24,6 +24,7 @@ HEADERS += \
     ../include/def.h \
     ../include/rw_lock.h \
     ../include/tls_pointer.h \
+    ../include/pool_alloc.h \
     ../src/channel.inc \
     ../src/route.inc \
     ../src/id_pool.inc \
@@ -33,7 +34,8 @@ HEADERS += \
 
 SOURCES += \
     ../src/shm.cpp \
-    ../src/ipc.cpp
+    ../src/ipc.cpp \
+    ../src/pool_alloc.cpp
 
 unix {
 
diff --git a/include/pool_alloc.h b/include/pool_alloc.h
new file mode 100644
index 0000000..8747e08
--- /dev/null
+++ b/include/pool_alloc.h
@@ -0,0 +1,17 @@
+#pragma once
+
+#include "export.h"
+#include "def.h"
+
+namespace ipc {
+namespace mem {
+
+class IPC_EXPORT pool_alloc {
+public:
+    static void  clear();
+    static void* alloc(std::size_t size);
+    static void  free(void* p, std::size_t size);
+};
+
+} // namespace mem
+} // namespace ipc
diff --git a/src/memory/resource.hpp b/src/memory/resource.hpp
index 3de049b..7469da0 100644
--- a/src/memory/resource.hpp
+++ b/src/memory/resource.hpp
@@ -26,46 +26,34 @@ constexpr decltype(auto) static_switch(std::size_t i, std::index_sequence<N, I..
                       static_switch(i, std::index_sequence<I...>{}, f, def);
 }
 
-} // namespace detail
+template <std::size_t Size>
+auto& fixed() {
+    static synchronized<fixed_pool<Size>> pool;
+    return pool;
+}
+
+template <typename F>
+decltype(auto) choose(std::size_t size, F&& f) {
+    enum : std::size_t { base_size = sizeof(void*) };
+    size = ((size - 1) & (~(base_size - 1))) + base_size;
+    return detail::static_switch(size, std::index_sequence<
+        base_size     , base_size * 2 ,
+        base_size * 3 , base_size * 4 ,
+        base_size * 5 , base_size * 6 ,
+        base_size * 7 , base_size * 8 ,
+        base_size * 9 , base_size * 10,
+        base_size * 11, base_size * 12,
+        base_size * 13, base_size * 14,
+        base_size * 15, base_size * 16
+    >{}, [&f](auto index) {
+        return f(fixed<decltype(index)::value>());
+    }, [&f] { return f(static_alloc{}); });
+}
 
 class pool_alloc {
-private:
-    template <std::size_t Size>
-    static auto& fixed() {
-        static synchronized<fixed_pool<Size>> pool;
-        return pool;
-    }
-
-    template <typename F>
-    static decltype(auto) choose(std::size_t size, F&& f) {
-        enum : std::size_t { base_size = sizeof(void*) };
-        size = ((size - 1) & (~(base_size - 1))) + base_size;
-        return detail::static_switch(size, std::index_sequence<
-            base_size     , base_size * 2 ,
-            base_size * 3 , base_size * 4 ,
-            base_size * 5 , base_size * 6 ,
-            base_size * 7 , base_size * 8 ,
-            base_size * 9 , base_size * 10,
-            base_size * 11, base_size * 12,
-            base_size * 13, base_size * 14,
-            base_size * 15, base_size * 16
-        >{}, [&f](auto index) {
-            return f(fixed<decltype(index)::value>());
-        }, [&f] { return f(static_alloc{}); });
-    }
-
 public:
-    pool_alloc() = default;
-    pool_alloc(const pool_alloc&) = default;
-    pool_alloc& operator=(const pool_alloc&) = default;
-    pool_alloc(pool_alloc&&) = default;
-    pool_alloc& operator=(pool_alloc&&) = default;
-
-    static constexpr std::size_t remain() {
-        return (std::numeric_limits<std::size_t>::max)();
-    }
-
     static constexpr void clear() {}
+    static constexpr void swap(pool_alloc&) {}
 
     static void* alloc(std::size_t size) {
         return choose(size, [size](auto&& fp) { return fp.alloc(size); });
@@ -76,8 +64,10 @@ public:
     }
 };
 
+} // namespace detail
+
 template <typename T>
-using allocator = allocator_wrapper<T, pool_alloc>;
+using allocator = allocator_wrapper<T, detail::pool_alloc>;
 
 template <typename Key, typename T>
 using unordered_map = std::unordered_map<
diff --git a/src/pool_alloc.cpp b/src/pool_alloc.cpp
new file mode 100644
index 0000000..64d7e73
--- /dev/null
+++ b/src/pool_alloc.cpp
@@ -0,0 +1,21 @@
+#include "pool_alloc.h"
+
+#include "memory/resource.hpp"
+
+namespace ipc {
+namespace mem {
+
+void pool_alloc::clear() {
+    detail::pool_alloc::clear();
+}
+
+void* pool_alloc::alloc(std::size_t size) {
+    return detail::pool_alloc::alloc(size);
+}
+
+void pool_alloc::free(void* p, std::size_t size) {
+    detail::pool_alloc::free(p, size);
+}
+
+} // namespace mem
+} // namespace ipc
diff --git a/test/test.h b/test/test.h
index ff71177..1b57330 100644
--- a/test/test.h
+++ b/test/test.h
@@ -115,7 +115,7 @@ void benchmark_prod_cons(T* cq) {
 //                std::cout << cid << "-consumer-disconnect" << std::endl;
 //            }
             tcq.disconnect(cn);
-            if (++fini_c != std::extent<decltype(consumers)>::value) {
+            if ((fini_c.fetch_add(1, std::memory_order_relaxed) + 1) != std::extent<decltype(consumers)>::value) {
 //                std::unique_lock<capo::spin_lock> guard { lc };
 //                std::cout << cid << "-consumer-end" << std::endl;
                 return;
@@ -141,7 +141,9 @@ void benchmark_prod_cons(T* cq) {
 //                }
                 tcq.send(cn, { pid, i });
             }
-            if (++fini_p != std::extent<decltype(producers)>::value) return;
+            if ((fini_p.fetch_add(1, std::memory_order_relaxed) + 1) != std::extent<decltype(producers)>::value) {
+                return;
+            }
             // quit
             tcq.send(cn, { -1, -1 });
         }};
diff --git a/test/test_ipc.cpp b/test/test_ipc.cpp
index 21c27c6..9c18e62 100644
--- a/test/test_ipc.cpp
+++ b/test/test_ipc.cpp
@@ -258,7 +258,7 @@ void benchmark_lc() {
                 }
                 std::this_thread::yield();
             }
-            if (++fini == std::extent<decltype(r_trd)>::value) {
+            if ((fini.fetch_add(1, std::memory_order_relaxed) + 1) == std::extent<decltype(r_trd)>::value) {
                 sw.print_elapsed(W, R, Loops);
             }
             std::uint64_t sum = 0;
diff --git a/test/test_mem.cpp b/test/test_mem.cpp
index 5625b34..e52dee2 100644
--- a/test/test_mem.cpp
+++ b/test/test_mem.cpp
@@ -6,6 +6,8 @@
 #include "random.hpp"
 
 #include "memory/resource.hpp"
+#include "pool_alloc.h"
+
 #include "test.h"
 
 namespace {
@@ -21,7 +23,8 @@ private slots:
     void initTestCase();
     void cleanupTestCase();
 
-    void test_alloc();
+    void test_alloc_free();
+    void test_linear();
 } unit__;
 
 #include "test_mem.moc"
@@ -91,6 +94,27 @@ void Unit::cleanupTestCase() {
     sizes__.clear();
 }
 
+template <typename AllocT>
+void benchmark_alloc() {
+    std::cout << std::endl << type_name<AllocT>() << std::endl;
+
+    test_stopwatch sw;
+    sw.start();
+
+    for (std::size_t x = 0; x < 10; ++x)
+    for (std::size_t n = 0; n < LoopCount; ++n) {
+        std::size_t s = sizes__[n];
+        AllocT::free(AllocT::alloc(s), s);
+    }
+
+    sw.print_elapsed<1>(DataMin, DataMax, LoopCount * 10);
+}
+
+void Unit::test_alloc_free() {
+    benchmark_alloc<ipc::mem::static_alloc>();
+    benchmark_alloc<ipc::mem::pool_alloc>();
+}
+
 template <typename AllocT, typename ModeT, int ThreadsN>
 void benchmark_alloc() {
     std::cout << std::endl
@@ -126,7 +150,7 @@ void benchmark_alloc() {
                     }
                 }
             }
-            if (++fini == ThreadsN) {
+            if ((fini.fetch_add(1, std::memory_order_relaxed) + 1) == ThreadsN) {
                 sw.print_elapsed<1>(DataMin, DataMax, LoopCount);
             }
         }};
@@ -152,7 +176,7 @@ struct test_performance<AllocT, ModeT, 1> {
     }
 };
 
-void Unit::test_alloc() {
+void Unit::test_linear() {
     // malloc
     test_performance<ipc::mem::static_alloc, alloc_random, 8>::start();
     test_performance<ipc::mem::static_alloc, alloc_LIFO  , 8>::start();