diff --git a/Makefile b/Makefile
index 45d812d..eefbd1b 100644
--- a/Makefile
+++ b/Makefile
@@ -21,7 +21,7 @@ cubescript.o: $(CUBESCRIPT_PATH)/cubescript.cc
 clean:
 	rm -f $(FILES) obuild
 
-main.o: globs.hh tpool.hh
+main.o: globs.hh
 main.o: $(CUBESCRIPT_PATH)/cubescript.hh
 
 globs.o: globs.hh
diff --git a/main.cc b/main.cc
index 08af68a..fc2a1ee 100644
--- a/main.cc
+++ b/main.cc
@@ -1,17 +1,19 @@
 #include <unistd.h>
+#include <pthread.h>
 
 #include <ostd/types.hh>
+#include <ostd/functional.hh>
 #include <ostd/string.hh>
 #include <ostd/vector.hh>
 #include <ostd/map.hh>
 #include <ostd/atomic.hh>
 #include <ostd/filesystem.hh>
 #include <ostd/platform.hh>
+#include <ostd/utility.hh>
 
 #include <cubescript.hh>
 
 #include "globs.hh"
-#include "tpool.hh"
 
 using ostd::ConstCharRange;
 using ostd::Vector;
@@ -24,6 +26,138 @@ using cscript::CsState;
 using cscript::TvalRange;
 using cscript::StackedValue;
 
+/* thread pool */
+
+struct Mutex {
+    Mutex() {
+        pthread_mutex_init(&mtx, nullptr);
+        locked = false;
+    }
+
+    ~Mutex() {
+        while (locked) unlock();
+        pthread_mutex_destroy(&mtx);
+    }
+
+    void lock() {
+        pthread_mutex_lock(&mtx);
+        locked = true;
+    }
+
+    void unlock() {
+        locked = false;
+        pthread_mutex_unlock(&mtx);
+    }
+
+    pthread_mutex_t mtx;
+    volatile bool locked;
+};
+
+struct Cond {
+    Cond() {
+        pthread_cond_init(&cnd, nullptr);
+    }
+
+    ~Cond() {
+        pthread_cond_destroy(&cnd);
+    }
+
+    void signal() {
+        pthread_cond_signal(&cnd);
+    }
+
+    void broadcast() {
+        pthread_cond_broadcast(&cnd);
+    }
+
+    void wait(Mutex &m) {
+        pthread_cond_wait(&cnd, &m.mtx);
+    }
+
+    pthread_cond_t cnd;
+};
+
+struct Task {
+    ostd::Function<void()> cb;
+    Task *next = nullptr;
+    Task(ostd::Function<void()> &&cb): cb(ostd::move(cb)) {}
+};
+
+struct ThreadPool {
+    ThreadPool() {}
+
+    ~ThreadPool() {
+        if (running) destroy();
+    }
+
+    static void *thr_func(void *ptr) {
+        ((ThreadPool *)ptr)->run();
+        return nullptr;
+    }
+
+    bool init(ostd::Size size) {
+        running = true;
+        for (ostd::Size i = 0; i < size; ++i) {
+            pthread_t tid;
+            if (pthread_create(&tid, nullptr, thr_func, this))
+                return false;
+            thrs.push(tid);
+        }
+        return true;
+    }
+
+    void destroy() {
+        mtx.lock();
+        running = false;
+        mtx.unlock();
+        cond.broadcast();
+        for (pthread_t &tid: thrs.iter()) {
+            void *ret;
+            pthread_join(tid, &ret);
+            cond.broadcast();
+        }
+    }
+
+    void run() {
+        for (;;) {
+            mtx.lock();
+            while (running && (tasks == nullptr))
+                cond.wait(mtx);
+            if (!running) {
+                mtx.unlock();
+                pthread_exit(nullptr);
+            }
+            Task *t = tasks;
+            tasks = t->next;
+            if (last_task == t)
+                last_task = nullptr;
+            mtx.unlock();
+            t->cb();
+            delete t;
+        }
+    }
+
+    void push(ostd::Function<void()> func) {
+        mtx.lock();
+        Task *t = new Task(ostd::move(func));
+        if (last_task)
+            last_task->next = t;
+        last_task = t;
+        if (!tasks)
+            tasks = t;
+        cond.signal();
+        mtx.unlock();
+    }
+
+private:
+    Cond cond;
+    Mutex mtx;
+    Vector<pthread_t> thrs;
+    Task *tasks;
+    Task *last_task;
+    volatile bool running;
+};
+
 /* check funcs */
 
 static bool ob_check_ts(ConstCharRange tname, const Vector<String> &deps) {
diff --git a/obuild.cfg b/obuild.cfg
index d603aa6..7abe944 100644
--- a/obuild.cfg
+++ b/obuild.cfg
@@ -26,7 +26,7 @@ action clean [
     shell rm -f $FILES obuild_ob
 ]
 
-depend main_ob.o globs.hh tpool.hh [@CS_PATH/cubescript.hh]
+depend main_ob.o globs.hh [@CS_PATH/cubescript.hh]
 depend globs_ob.o globs.hh [@CS_PATH/cubescript.hh]
 depend cubescript_ob.o [@CS_PATH/cubescript.hh]
 
diff --git a/tpool.hh b/tpool.hh
deleted file mode 100644
index 8cc4274..0000000
--- a/tpool.hh
+++ /dev/null
@@ -1,141 +0,0 @@
-#ifndef OCTABUILD_TPOOL_HH
-#define OCTABUILD_TPOOL_HH
-
-#include <pthread.h>
-
-#include <ostd/types.hh>
-#include <ostd/functional.hh>
-#include <ostd/vector.hh>
-#include <ostd/utility.hh>
-
-struct Mutex {
-    Mutex() {
-        pthread_mutex_init(&mtx, nullptr);
-        locked = false;
-    }
-
-    ~Mutex() {
-        while (locked) unlock();
-        pthread_mutex_destroy(&mtx);
-    }
-
-    void lock() {
-        pthread_mutex_lock(&mtx);
-        locked = true;
-    }
-
-    void unlock() {
-        locked = false;
-        pthread_mutex_unlock(&mtx);
-    }
-
-    pthread_mutex_t mtx;
-    volatile bool locked;
-};
-
-struct Cond {
-    Cond() {
-        pthread_cond_init(&cnd, nullptr);
-    }
-
-    ~Cond() {
-        pthread_cond_destroy(&cnd);
-    }
-
-    void signal() {
-        pthread_cond_signal(&cnd);
-    }
-
-    void broadcast() {
-        pthread_cond_broadcast(&cnd);
-    }
-
-    void wait(Mutex &m) {
-        pthread_cond_wait(&cnd, &m.mtx);
-    }
-
-    pthread_cond_t cnd;
-};
-
-struct Task {
-    ostd::Function<void()> cb;
-    Task *next = nullptr;
-    Task(ostd::Function<void()> &&cb): cb(ostd::move(cb)) {}
-};
-
-struct ThreadPool {
-    ThreadPool() {}
-
-    ~ThreadPool() {
-        if (running) destroy();
-    }
-
-    static void *thr_func(void *ptr) {
-        ((ThreadPool *)ptr)->run();
-        return nullptr;
-    }
-
-    bool init(ostd::Size size) {
-        running = true;
-        for (ostd::Size i = 0; i < size; ++i) {
-            pthread_t tid;
-            if (pthread_create(&tid, nullptr, thr_func, this))
-                return false;
-            thrs.push(tid);
-        }
-        return true;
-    }
-
-    void destroy() {
-        mtx.lock();
-        running = false;
-        mtx.unlock();
-        cond.broadcast();
-        for (pthread_t &tid: thrs.iter()) {
-            void *ret;
-            pthread_join(tid, &ret);
-            cond.broadcast();
-        }
-    }
-
-    void run() {
-        for (;;) {
-            mtx.lock();
-            while (running && (tasks == nullptr))
-                cond.wait(mtx);
-            if (!running) {
-                mtx.unlock();
-                pthread_exit(nullptr);
-            }
-            Task *t = tasks;
-            tasks = t->next;
-            if (last_task == t)
-                last_task = nullptr;
-            mtx.unlock();
-            t->cb();
-            delete t;
-        }
-    }
-
-    void push(ostd::Function<void()> func) {
-        mtx.lock();
-        Task *t = new Task(ostd::move(func));
-        if (last_task)
-            last_task->next = t;
-        last_task = t;
-        if (!tasks)
-            tasks = t;
-        cond.signal();
-        mtx.unlock();
-    }
-
-private:
-    Cond cond;
-    Mutex mtx;
-    ostd::Vector<pthread_t> thrs;
-    Task *tasks;
-    Task *last_task;
-    volatile bool running;
-};
-
-#endif /* OCTABUILD_TPOOL_HH */
\ No newline at end of file