[test] thread, mutex, condition variable

19 files changed, 382 insertions, 160 deletions

diff --git a/LICENSE b/LICENSE
index 07dde7d..8959d98 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,3 +1,5 @@
+Copyright (c) 2012 yohhoy
+Copyright (c) 2022 Yonggang Luo
 Copyright (c) 2022 Mitya Selivanov
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
diff --git a/README.md b/README.md
index 83935bf..0e59887 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,16 @@
 # kit
+
 - Unit-testing
-- Async function
 - Lower bound
 - Dynamic array
 - Input buffer
 - Random number generation
+- Async function
+- Atomic
+- Condition variable
+- Mutual exclusion
+- Thread
+
+Condition variables, mutual exclusions and threads implementation was forked from [Mesa][mesa_link] source code.
+
+[mesa_link]: https://gitlab.freedesktop.org/mesa/mesa
diff --git a/source/kit/CMakeLists.txt b/source/kit/CMakeLists.txt
index 397b404..86c39dc 100644
--- a/source/kit/CMakeLists.txt
+++ b/source/kit/CMakeLists.txt
@@ -1,18 +1,21 @@
 target_sources(
   ${KIT_LIBRARY}
     PRIVATE
-      atomic.c input_buffer.c input_stream.c lower_bound.c
-      string_ref.c async_function.c allocator.c array_ref.c dynamic_array.c
-      mersenne_twister_64.c
+      atomic.c input_buffer.c threads.win32.c time.c
+      threads.posix.c input_stream.c lower_bound.c string_ref.c
+      async_function.c allocator.c array_ref.c dynamic_array.c
+      mersenne_twister_64.c threads_tls_callback.win32.cpp
     PUBLIC
+      $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/time.h>
       $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/atomic.h>
       $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/allocator.h>
       $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/string_ref.h>
+      $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/threads.h>
       $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/dynamic_array.h>
       $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/async_function.h>
+      $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/threads.win32.h>
       $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/input_stream.h>
       $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/input_buffer.h>
       $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/lower_bound.h>
       $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/array_ref.h>
       $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/mersenne_twister_64.h>)
-add_subdirectory(c11)
diff --git a/source/kit/c11/CMakeLists.txt b/source/kit/c11/CMakeLists.txt
deleted file mode 100644
index 205b256..0000000
--- a/source/kit/c11/CMakeLists.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-target_sources(
-  ${KIT_LIBRARY}
-    PUBLIC
-      $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/time.h>
-      $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/threads.h>)
-add_subdirectory(impl)
diff --git a/source/kit/c11/impl/CMakeLists.txt b/source/kit/c11/impl/CMakeLists.txt
deleted file mode 100644
index c64b895..0000000
--- a/source/kit/c11/impl/CMakeLists.txt
+++ /dev/null
@@ -1,7 +0,0 @@
-target_sources(
-  ${KIT_LIBRARY}
-    PRIVATE
-      time.c threads_posix.c threads_win32.c
-      threads_win32_tls_callback.cpp
-    PUBLIC
-      $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/threads_win32.h>)
diff --git a/source/kit/c11/impl/threads_win32.h b/source/kit/c11/impl/threads_win32.h
deleted file mode 100644
index 6adf5d2..0000000
--- a/source/kit/c11/impl/threads_win32.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright 2022 Yonggang Luo
- * SPDX-License-Identifier: MIT
- */
-
-#ifndef KIT_C11_IMPL_THREADS_WIN32_H_
-#define KIT_C11_IMPL_THREADS_WIN32_H_
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#ifdef KIT_HAVE_WINDOWS
-void __threads_win32_tls_callback(void);
-#endif
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
diff --git a/source/kit/mersenne_twister_64.c b/source/kit/mersenne_twister_64.c
index 4be4313..9ab39d3 100644
--- a/source/kit/mersenne_twister_64.c
+++ b/source/kit/mersenne_twister_64.c
@@ -1,6 +1,6 @@
 #include "mersenne_twister_64.h"
 
-#include <time.h>
+#include "time.h"
 
 void kit_mt64_init(kit_mt64_state_t *state, uint64_t seed) {
   state->mt[0] = seed;
diff --git a/source/kit/c11/threads.h b/source/kit/threads.h
index 0b73183..d98978d 100644
--- a/source/kit/c11/threads.h
+++ b/source/kit/threads.h
@@ -31,71 +31,72 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
-#ifndef KIT_C11_THREADS_H_INCLUDED_
-#define KIT_C11_THREADS_H_INCLUDED_
+#ifndef KIT_THREADS_H
+#define KIT_THREADS_H
 
-#include "time.h"
+#ifndef KIT_DISABLE_SYSTEM_THREADS
+#  include "time.h"
 
-#include <errno.h>
-#include <limits.h>
-#include <stdlib.h>
+#  include <errno.h>
+#  include <limits.h>
+#  include <stdlib.h>
 
-#ifdef _MSC_VER
-#  define _Noreturn __declspec(noreturn)
-#endif
+#  ifdef _MSC_VER
+#    define _Noreturn __declspec(noreturn)
+#  endif
 
-#if defined(_WIN32) && !defined(__CYGWIN__)
-#  include <io.h>      /* close */
-#  include <process.h> /* _exit */
-#elif defined(KIT_HAVE_PTHREAD)
-#  include <pthread.h>
-#  include <unistd.h> /* close, _exit */
-#else
-#  error Not supported on this platform.
-#endif
+#  if defined(_WIN32) && !defined(__CYGWIN__)
+#    include <io.h>      /* close */
+#    include <process.h> /* _exit */
+#  elif defined(KIT_HAVE_PTHREAD)
+#    include <pthread.h>
+#    include <unistd.h> /* close, _exit */
+#  else
+#    error Not supported on this platform.
+#  endif
 
 /*---------------------------- macros ---------------------------*/
 
-#ifndef _Thread_local
-#  if defined(__cplusplus)
+#  ifndef _Thread_local
+#    if defined(__cplusplus)
 /* C++11 doesn't need `_Thread_local` keyword or macro */
-#  elif !defined(__STDC_NO_THREADS__)
+#    elif !defined(__STDC_NO_THREADS__)
 /* threads are optional in C11, _Thread_local present in this
  * condition */
-#  elif defined(_MSC_VER)
-#    define _Thread_local __declspec(thread)
-#  elif defined(__GNUC__)
-#    define _Thread_local __thread
-#  else
+#    elif defined(_MSC_VER)
+#      define _Thread_local __declspec(thread)
+#    elif defined(__GNUC__)
+#      define _Thread_local __thread
+#    else
 /* Leave _Thread_local undefined so that use of _Thread_local would
  * not promote to a non-thread-local global variable
  */
+#    endif
 #  endif
-#endif
 
-#if !defined(__cplusplus)
+#  if !defined(__cplusplus)
 /*
  * C11 thread_local() macro
  * C++11 and above already have thread_local keyword
  */
-#  ifndef thread_local
-#    if _MSC_VER
-#      define thread_local __declspec(thread)
-#    else
-#      define thread_local _Thread_local
+#    ifndef thread_local
+#      if _MSC_VER
+#        define thread_local __declspec(thread)
+#      else
+#        define thread_local _Thread_local
+#      endif
 #    endif
 #  endif
-#endif
 
-#ifdef __cplusplus
+#  ifdef __cplusplus
 extern "C" {
-#endif
+#  endif
 
 /*---------------------------- types ----------------------------*/
 typedef void (*tss_dtor_t)(void *);
 typedef int (*thrd_start_t)(void *);
 
-#if defined(_WIN32) && !defined(__CYGWIN__)
+#  if defined(_WIN32) && !defined(__CYGWIN__)
 typedef struct {
   void *Ptr;
 } cnd_t;
@@ -117,29 +118,29 @@ typedef struct {
   volatile uintptr_t status;
 } once_flag;
 // FIXME: temporary non-standard hack to ease transition
-#  define KIT_MTX_INITIALIZER_NP_ \
-    { (void *) -1, -1, 0, 0, 0, 0 }
-#  define ONCE_FLAG_INIT \
-    { 0 }
-#  define TSS_DTOR_ITERATIONS 1
-#elif defined(KIT_HAVE_PTHREAD)
+#    define KIT_MTX_INITIALIZER_NP_ \
+      { (void *) -1, -1, 0, 0, 0, 0 }
+#    define ONCE_FLAG_INIT \
+      { 0 }
+#    define TSS_DTOR_ITERATIONS 1
+#  elif defined(KIT_HAVE_PTHREAD)
 typedef pthread_cond_t  cnd_t;
 typedef pthread_t       thrd_t;
 typedef pthread_key_t   tss_t;
 typedef pthread_mutex_t mtx_t;
 typedef pthread_once_t  once_flag;
 // FIXME: temporary non-standard hack to ease transition
-#  define KIT_MTX_INITIALIZER_NP_ PTHREAD_MUTEX_INITIALIZER
-#  define ONCE_FLAG_INIT PTHREAD_ONCE_INIT
-#  ifdef PTHREAD_DESTRUCTOR_ITERATIONS
-#    define TSS_DTOR_ITERATIONS PTHREAD_DESTRUCTOR_ITERATIONS
+#    define KIT_MTX_INITIALIZER_NP_ PTHREAD_MUTEX_INITIALIZER
+#    define ONCE_FLAG_INIT PTHREAD_ONCE_INIT
+#    ifdef PTHREAD_DESTRUCTOR_ITERATIONS
+#      define TSS_DTOR_ITERATIONS PTHREAD_DESTRUCTOR_ITERATIONS
+#    else
+#      define TSS_DTOR_ITERATIONS \
+        1 // assume TSS dtor MAY be called at least once.
+#    endif
 #  else
-#    define TSS_DTOR_ITERATIONS \
-      1 // assume TSS dtor MAY be called at least once.
+#    error Not supported on this platform.
 #  endif
-#else
-#  error Not supported on this platform.
-#endif
 
 /*-------------------- enumeration constants --------------------*/
 enum {
@@ -177,11 +178,11 @@ int    thrd_create(thrd_t *, thrd_start_t, void *);
 thrd_t thrd_current(void);
 int    thrd_detach(thrd_t);
 int    thrd_equal(thrd_t, thrd_t);
-#if defined(__cplusplus)
+#  if defined(__cplusplus)
 [[ noreturn ]]
-#else
+#  else
 _Noreturn
-#endif
+#  endif
 void thrd_exit(int);
 int   thrd_join(thrd_t, int *);
 int   thrd_sleep(const struct timespec *, struct timespec *);
@@ -191,8 +192,10 @@ void  tss_delete(tss_t);
 void *tss_get(tss_t);
 int   tss_set(tss_t, void *);
 
-#ifdef __cplusplus
+#  ifdef __cplusplus
 }
-#endif
+#  endif
+
+#endif /* KIT_DISABLE_SYSTEM_THREADS */
 
-#endif /* KIT_C11_THREADS_H_INCLUDED_ */
+#endif /* KIT_THREADS_H */
diff --git a/source/kit/c11/impl/threads_posix.c b/source/kit/threads.posix.c
index ebf411c..20ef1ae 100644
--- a/source/kit/c11/impl/threads_posix.c
+++ b/source/kit/threads.posix.c
@@ -29,17 +29,18 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  */
-#ifndef KIT_HAVE_WINDOWS
+#ifndef KIT_DISABLE_SYSTEM_THREADS
+#  ifdef KIT_HAVE_PTHREAD
 
-#  include <assert.h>
-#  include <errno.h>
-#  include <limits.h>
-#  include <sched.h>
-#  include <stdint.h> /* for intptr_t */
-#  include <stdlib.h>
-#  include <unistd.h>
+#    include <assert.h>
+#    include <errno.h>
+#    include <limits.h>
+#    include <sched.h>
+#    include <stdint.h> /* for intptr_t */
+#    include <stdlib.h>
+#    include <unistd.h>
 
-#  include "../threads.h"
+#    include "threads.h"
 
 /*
 Configuration macro:
@@ -48,10 +49,10 @@ Configuration macro:
     Use pthread_mutex_timedlock() for `mtx_timedlock()'
     Otherwise use mtx_trylock() + *busy loop* emulation.
 */
-#  if !defined(__CYGWIN__) && !defined(__APPLE__) && \
-      !defined(__NetBSD__)
-#    define EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
-#  endif
+#    if !defined(__CYGWIN__) && !defined(__APPLE__) && \
+        !defined(__NetBSD__)
+#      define EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
+#    endif
 
 /*---------------------------- types ----------------------------*/
 
@@ -149,7 +150,7 @@ void mtx_destroy(mtx_t *mtx) {
  * Thus the linker will be happy and things don't clash when building
  * with -O1 or greater.
  */
-#  if defined(HAVE_FUNC_ATTRIBUTE_WEAK) && !defined(__CYGWIN__)
+#    if defined(HAVE_FUNC_ATTRIBUTE_WEAK) && !defined(__CYGWIN__)
 __attribute__((weak)) int pthread_mutexattr_init(
     pthread_mutexattr_t *attr);
 
@@ -158,7 +159,7 @@ __attribute__((weak)) int pthread_mutexattr_settype(
 
 __attribute__((weak)) int pthread_mutexattr_destroy(
     pthread_mutexattr_t *attr);
-#  endif
+#    endif
 
 // 7.25.4.2
 int mtx_init(mtx_t *mtx, int type) {
@@ -193,13 +194,13 @@ int mtx_timedlock(mtx_t *mtx, const struct timespec *ts) {
   assert(ts != NULL);
 
   {
-#  ifdef EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
+#    ifdef EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
     int rt;
     rt = pthread_mutex_timedlock(mtx, ts);
     if (rt == 0)
       return thrd_success;
     return (rt == ETIMEDOUT) ? thrd_timedout : thrd_error;
-#  else
+#    else
     time_t expire = time(NULL);
     expire += ts->tv_sec;
     while (mtx_trylock(mtx) != thrd_success) {
@@ -210,7 +211,7 @@ int mtx_timedlock(mtx_t *mtx, const struct timespec *ts) {
       thrd_yield();
     }
     return thrd_success;
-#  endif
+#    endif
   }
 }
 
@@ -310,4 +311,5 @@ int tss_set(tss_t key, void *val) {
                                               : thrd_error;
 }
 
+#  endif
 #endif
diff --git a/source/kit/c11/impl/threads_win32.c b/source/kit/threads.win32.c
index b94d20f..d425a27 100644
--- a/source/kit/c11/impl/threads_win32.c
+++ b/source/kit/threads.win32.c
@@ -29,23 +29,24 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  */
-#ifdef KIT_HAVE_WINDOWS
+#ifndef KIT_DISABLE_SYSTEM_THREADS
+#  if defined(_WIN32) && !defined(__CYGWIN__)
 
-#  include <assert.h>
-#  include <errno.h>
-#  include <limits.h>
-#  include <process.h> // MSVCRT
-#  include <stdbool.h>
-#  include <stdlib.h>
+#    include <assert.h>
+#    include <errno.h>
+#    include <limits.h>
+#    include <process.h> // MSVCRT
+#    include <stdbool.h>
+#    include <stdlib.h>
 
-#  include "../threads.h"
+#    include "threads.h"
 
-#  include "threads_win32.h"
+#    include "threads_win32.h"
 
-#  ifndef WIN32_LEAN_AND_MEAN
-#    define WIN32_LEAN_AND_MEAN 1
-#  endif
-#  include <windows.h>
+#    ifndef WIN32_LEAN_AND_MEAN
+#      define WIN32_LEAN_AND_MEAN 1
+#    endif
+#    include <windows.h>
 
 /*
 Configuration macro:
@@ -59,20 +60,20 @@ Configuration macro:
     Max registerable TSS dtor number.
 */
 
-#  if _WIN32_WINNT >= 0x0600
+#    if _WIN32_WINNT >= 0x0600
 // Prefer native WindowsAPI on newer environment.
-#    if !defined(__MINGW32__)
-#      define EMULATED_THREADS_USE_NATIVE_CALL_ONCE
+#      if !defined(__MINGW32__)
+#        define EMULATED_THREADS_USE_NATIVE_CALL_ONCE
+#      endif
 #    endif
-#  endif
-#  define EMULATED_THREADS_TSS_DTOR_SLOTNUM \
-    64 // see TLS_MINIMUM_AVAILABLE
+#    define EMULATED_THREADS_TSS_DTOR_SLOTNUM \
+      64 // see TLS_MINIMUM_AVAILABLE
 
 // check configuration
-#  if defined(EMULATED_THREADS_USE_NATIVE_CALL_ONCE) && \
-      (_WIN32_WINNT < 0x0600)
-#    error EMULATED_THREADS_USE_NATIVE_CALL_ONCE requires _WIN32_WINNT>=0x0600
-#  endif
+#    if defined(EMULATED_THREADS_USE_NATIVE_CALL_ONCE) && \
+        (_WIN32_WINNT < 0x0600)
+#      error EMULATED_THREADS_USE_NATIVE_CALL_ONCE requires _WIN32_WINNT>=0x0600
+#    endif
 
 static_assert(sizeof(cnd_t) == sizeof(CONDITION_VARIABLE),
               "The size of cnd_t must equal to CONDITION_VARIABLE");
@@ -131,7 +132,7 @@ static DWORD impl_abs2relmsec(const struct timespec *abs_time) {
   return rel_ms;
 }
 
-#  ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE
+#    ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE
 struct impl_call_once_param {
   void (*func)(void);
 };
@@ -145,7 +146,7 @@ static BOOL CALLBACK impl_call_once_callback(PINIT_ONCE InitOnce,
   ((void) Context); // suppress warning
   return TRUE;
 }
-#  endif // ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE
+#    endif // ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE
 
 static struct impl_tss_dtor_entry {
   tss_t      key;
@@ -180,14 +181,14 @@ static void impl_tss_dtor_invoke(void) {
 // 7.25.2.1
 void call_once(once_flag *flag, void (*func)(void)) {
   assert(flag && func);
-#  ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE
+#    ifdef EMULATED_THREADS_USE_NATIVE_CALL_ONCE
   {
     struct impl_call_once_param param;
     param.func = func;
     InitOnceExecuteOnce((PINIT_ONCE) flag, impl_call_once_callback,
                         (PVOID) &param, NULL);
   }
-#  else
+#    else
   if (InterlockedCompareExchangePointer(
           (PVOID volatile *) &flag->status, (PVOID) 1, (PVOID) 0) ==
       0) {
@@ -200,7 +201,7 @@ void call_once(once_flag *flag, void (*func)(void)) {
       thrd_yield();
     }
   }
-#  endif
+#    endif
 }
 
 /*------------- 7.25.3 Condition variable functions -------------*/
@@ -457,4 +458,5 @@ int tss_set(tss_t key, void *val) {
   return TlsSetValue(key, val) ? thrd_success : thrd_error;
 }
 
-#endif
+#  endif
+#endif /* KIT_DISABLE_SYSTEM_THREADS */
diff --git a/source/kit/threads.win32.h b/source/kit/threads.win32.h
new file mode 100644
index 0000000..e8e9abf
--- /dev/null
+++ b/source/kit/threads.win32.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2022 Yonggang Luo
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef KIT_THREADS_WIN32_H
+#define KIT_THREADS_WIN32_H
+
+#ifndef KIT_DISABLE_SYSTEM_THREADS
+
+#  ifdef __cplusplus
+extern "C" {
+#  endif
+
+#  if defined(_WIN32) && !defined(__CYGWIN__)
+void __threads_win32_tls_callback(void);
+#  endif
+
+#  ifdef __cplusplus
+}
+#  endif
+
+#endif
+
+#endif
diff --git a/source/kit/c11/impl/threads_win32_tls_callback.cpp b/source/kit/threads_tls_callback.win32.cpp
index 27874c0..3cc3cc6 100644
--- a/source/kit/c11/impl/threads_win32_tls_callback.cpp
+++ b/source/kit/threads_tls_callback.win32.cpp
@@ -3,9 +3,10 @@
  * SPDX-License-Identifier: MIT
  */
 
-#include "threads_win32.h"
+#ifndef KIT_DISABLE_SYSTEM_THREADS
+#  if defined(_WIN32) && !defined(__CYGWIN__)
 
-#ifdef KIT_HAVE_WINDOWS
+#    include "threads.win32.h"
 
 struct tls_callback {
   tls_callback() { }
@@ -13,6 +14,8 @@ struct tls_callback {
     __threads_win32_tls_callback();
   }
 };
+
 static thread_local tls_callback tls_callback_instance;
 
+#  endif
 #endif
diff --git a/source/kit/c11/impl/time.c b/source/kit/time.c
index 777b976..bcb3819 100644
--- a/source/kit/c11/impl/time.c
+++ b/source/kit/time.c
@@ -81,4 +81,4 @@ int timespec_get(struct timespec *ts, int base) {
 }
 #  endif
 
-#endif /* KIT_HAVE_TIMESPEC_GET */
+#endif
diff --git a/source/kit/c11/time.h b/source/kit/time.h
index 7467a33..dbf8883 100644
--- a/source/kit/c11/time.h
+++ b/source/kit/time.h
@@ -5,8 +5,8 @@
  * C11 <time.h> emulation library
  */
 
-#ifndef KIT_C11_TIME_H_INCLUDED_
-#define KIT_C11_TIME_H_INCLUDED_
+#ifndef KIT_TIME_H
+#define KIT_TIME_H
 
 #include <time.h>
 
@@ -59,4 +59,4 @@ int timespec_get(struct timespec *ts, int base);
 }
 #endif
 
-#endif /* KIT_C11_TIME_H_INCLUDED_ */
+#endif /* KIT_TIME_H */
diff --git a/source/test/unittests/CMakeLists.txt b/source/test/unittests/CMakeLists.txt
index 5ec950d..e64628d 100644
--- a/source/test/unittests/CMakeLists.txt
+++ b/source/test/unittests/CMakeLists.txt
@@ -1,7 +1,8 @@
 target_sources(
   ${KIT_TEST_SUITE}
     PRIVATE
-      async_function.test.c test_duration.test.c main.test.c
-      string_ref.test.c atomic.test.c array_ref.test.c input_stream.test.c
-      lower_bound.test.c mersenne_twister_64.test.c input_buffer.test.c
+      async_function.test.c mutex.test.c test_duration.test.c
+      main.test.c string_ref.test.c atomic.test.c thread.test.c
+      array_ref.test.c input_stream.test.c lower_bound.test.c
+      condition_variable.test.c mersenne_twister_64.test.c input_buffer.test.c
       dynamic_array.test.c)
diff --git a/source/test/unittests/c11_threads.c b/source/test/unittests/c11_threads.c
deleted file mode 100644
index cd50846..0000000
--- a/source/test/unittests/c11_threads.c
+++ /dev/null
@@ -1,6 +0,0 @@
-#include "../../kit/c11/threads.h"
-
-#define KIT_TEST_FILE atomic
-#include "../../kit_test/test.h"
-
-TEST("c11 threads") { }
diff --git a/source/test/unittests/condition_variable.test.c b/source/test/unittests/condition_variable.test.c
new file mode 100644
index 0000000..c9d818a
--- /dev/null
+++ b/source/test/unittests/condition_variable.test.c
@@ -0,0 +1,60 @@
+#include "../../kit/threads.h"
+
+#define KIT_TEST_FILE condition_variable
+#include "../../kit_test/test.h"
+
+typedef struct {
+  mtx_t m;
+  cnd_t send;
+  cnd_t receive;
+  int   value;
+} test_data_t;
+
+static int test_run(void *p) {
+  test_data_t *data = (test_data_t *) p;
+
+  mtx_lock(&data->m);
+
+  data->value = 20;
+  mtx_unlock(&data->m);
+  cnd_broadcast(&data->send);
+
+  cnd_wait(&data->receive, &data->m);
+
+  data->value = 22;
+  cnd_broadcast(&data->send);
+
+  mtx_unlock(&data->m);
+
+  return 0;
+}
+
+TEST("condition variable") {
+  test_data_t data;
+  REQUIRE(mtx_init(&data.m, mtx_plain) == thrd_success);
+  REQUIRE(cnd_init(&data.send) == thrd_success);
+  REQUIRE(cnd_init(&data.receive) == thrd_success);
+  data.value = 0;
+
+  thrd_t t;
+  REQUIRE(thrd_create(&t, test_run, &data) == thrd_success);
+
+  REQUIRE(mtx_lock(&data.m) == thrd_success);
+
+  REQUIRE(cnd_wait(&data.send, &data.m) == thrd_success);
+  int x = data.value;
+
+  REQUIRE(cnd_broadcast(&data.receive) == thrd_success);
+
+  REQUIRE(cnd_wait(&data.send, &data.m) == thrd_success);
+  x += data.value;
+
+  REQUIRE(mtx_unlock(&data.m) == thrd_success);
+  REQUIRE(thrd_join(t, NULL) == thrd_success);
+
+  mtx_destroy(&data.m);
+  cnd_destroy(&data.send);
+  cnd_destroy(&data.receive);
+
+  REQUIRE(x == 42);
+}
diff --git a/source/test/unittests/mutex.test.c b/source/test/unittests/mutex.test.c
new file mode 100644
index 0000000..c0153e7
--- /dev/null
+++ b/source/test/unittests/mutex.test.c
@@ -0,0 +1,74 @@
+#include "../../kit/threads.h"
+
+#define KIT_TEST_FILE mutex
+#include "../../kit_test/test.h"
+
+enum { THREAD_COUNT = 200 };
+
+typedef struct {
+  mtx_t lock;
+  int   value;
+} test_data_t;
+
+static int test_run(void *data) {
+  test_data_t *x = (test_data_t *) data;
+  for (int i = 0; i < 1000; i++) {
+    mtx_lock(&x->lock);
+
+    x->value += i;
+    thrd_yield();
+    x->value -= i + 42;
+    thrd_yield();
+    x->value += i + 20;
+    thrd_yield();
+    x->value += 22 - i;
+
+    mtx_unlock(&x->lock);
+  }
+  return 0;
+}
+
+int test_lock_for_2_sec(void *data) {
+  mtx_t *m = (mtx_t *) data;
+  mtx_lock(m);
+
+  struct timespec sec = { .tv_sec = 2, .tv_nsec = 0 };
+  thrd_sleep(&sec, NULL);
+
+  mtx_unlock(m);
+}
+
+TEST("mutex lock") {
+  test_data_t data;
+  thrd_t      pool[THREAD_COUNT];
+  data.value = 42;
+  REQUIRE(mtx_init(&data.lock, mtx_plain) == thrd_success);
+
+  for (ptrdiff_t i = 0; i < THREAD_COUNT; i++)
+    thrd_create(pool + i, test_run, &data);
+  for (ptrdiff_t i = 0; i < THREAD_COUNT; i++)
+    thrd_join(pool[i], NULL);
+
+  mtx_destroy(&data.lock);
+  REQUIRE(data.value == 42);
+}
+
+TEST("mutex try lock") {
+  mtx_t m;
+  REQUIRE(mtx_init(&m, mtx_plain) == thrd_success);
+
+  thrd_t t;
+  REQUIRE(thrd_create(&t, test_lock_for_2_sec, &m) == thrd_success);
+
+  struct timespec sec = { .tv_sec = 1, .tv_nsec = 0 };
+  REQUIRE(thrd_sleep(&sec, NULL) == thrd_success);
+
+  REQUIRE(mtx_trylock(&m) == thrd_busy);
+
+  REQUIRE(thrd_join(t, NULL) == thrd_success);
+
+  REQUIRE(mtx_trylock(&m) == thrd_success);
+  REQUIRE(mtx_unlock(&m) == thrd_success);
+
+  mtx_destroy(&m);
+}
diff --git a/source/test/unittests/thread.test.c b/source/test/unittests/thread.test.c
new file mode 100644
index 0000000..44e51b5
--- /dev/null
+++ b/source/test/unittests/thread.test.c
@@ -0,0 +1,78 @@
+#include "../../kit/threads.h"
+
+#define KIT_TEST_FILE thread
+#include "../../kit_test/test.h"
+
+static int test_nothing(void *) { }
+
+static int test_run(void *data) {
+  int *n = (int *) data;
+  return *n + 20;
+}
+
+static int test_exit(void *data) {
+  int *n = (int *) data;
+
+  *n = 1;
+  thrd_exit(3);
+  *n = 2;
+  return 4;
+}
+
+static int test_yield(void *data) {
+  thrd_yield();
+}
+
+static int test_sleep(void *data) {
+  struct timespec t = { .tv_sec = 0, .tv_nsec = 10000000 };
+  thrd_sleep(&t, NULL);
+}
+
+TEST("thread run") {
+  thrd_t t;
+  int    data = 22;
+  int    result;
+  REQUIRE(thrd_create(&t, test_run, &data) == thrd_success);
+  REQUIRE(thrd_join(t, &result) == thrd_success);
+  REQUIRE(result == 42);
+}
+
+TEST("thread equal") {
+  thrd_t foo, bar;
+  REQUIRE(thrd_create(&foo, test_nothing, NULL) == thrd_success);
+  REQUIRE(thrd_create(&bar, test_nothing, NULL) == thrd_success);
+  REQUIRE(thrd_equal(foo, foo));
+  REQUIRE(!thrd_equal(foo, bar));
+  REQUIRE(!thrd_equal(foo, thrd_current()));
+}
+
+TEST("thread exit") {
+  thrd_t foo;
+  int    data;
+  int    result;
+  REQUIRE(thrd_create(&foo, test_exit, &data) == thrd_success);
+  REQUIRE(thrd_join(foo, &result) == thrd_success);
+  REQUIRE(data == 1);
+  REQUIRE(result == 3);
+}
+
+TEST("thread yield") {
+  thrd_t foo;
+  REQUIRE(thrd_create(&foo, test_yield, NULL) == thrd_success);
+  REQUIRE(thrd_join(foo, NULL) == thrd_success);
+}
+
+TEST("thread sleep") {
+  thrd_t foo;
+  REQUIRE(thrd_create(&foo, test_sleep, NULL) == thrd_success);
+  REQUIRE(thrd_join(foo, NULL) == thrd_success);
+}
+
+TEST("thread detach") {
+  thrd_t foo;
+  REQUIRE(thrd_create(&foo, test_nothing, NULL) == thrd_success);
+  REQUIRE(thrd_detach(foo) == thrd_success);
+
+  struct timespec t = { .tv_sec = 0, .tv_nsec = 10000000 };
+  thrd_sleep(&t, NULL);
+}