add C11 thread, mutex and condition API

CMakeLists.txt

@@ -33,6 +33,7 @@ endif()
 #
 include(GNUInstallDirs)
 include(CheckIncludeFile)
+include(CheckFunctionExists)
 find_package(Backtrace)
 find_package(Threads)
 find_package(OpenSSL)
@@ -86,6 +87,11 @@ else()
   set(Backtrace_LIBRARIES)
 endif()
 
+check_function_exists(thrd_create HAVE_THREADS)
+if(HAVE_THREADS)
+  add_definitions(-DHAVE_THREADS)
+endif()
+
 if(CMAKE_USE_PTHREADS_INIT)
   add_definitions(-DHAVE_PTHREAD)
   set(HAVE_PTHREAD ON)
@@ -543,6 +549,21 @@ elseif(HAVE_PTHREAD)
   )
 endif()
 
+if(HAVE_THREADS)
+  list(APPEND SRCS
+    src/thread/thread.c
+  )
+elseif(HAVE_PTHREAD)
+  list(APPEND SRCS
+    src/thread/thread.c
+    src/thread/posix.c
+  )
+elseif(CMAKE_USE_WIN32_THREADS_INIT)
+  list(APPEND SRCS
+    src/thread/thread.c
+    src/thread/win32.c
+  )
+endif()
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   list(APPEND SRCS

Makefile

@@ -43,7 +43,7 @@ MODULES += dns
 MODULES += md5 crc32 sha hmac base64
 MODULES += udp sa net tcp tls
 MODULES += list mbuf hash
-MODULES += fmt tmr trace btrace main mem dbg sys lock mqueue
+MODULES += fmt tmr trace btrace main mem dbg sys thread lock mqueue
 MODULES += mod conf
 MODULES += bfcp
 MODULES += aes srtp

include/re.h

@@ -56,6 +56,7 @@ extern "C" {
 #include "re_sys.h"
 #include "re_tcp.h"
 #include "re_telev.h"
+#include "re_thread.h"
 #include "re_tmr.h"
 #include "re_trace.h"
 #include "re_tls.h"

include/re_thread.h

@@ -0,0 +1,236 @@
+/**
+ * @file re_thread.h  Thread support
+ *
+ * Inspired by C11 thread support this provides a cross platform interfaces to
+ * thread, mutex and condition handling (C11, POSIX and Windows Threads).
+ *
+ * Preferred order:
+ *
+ * - C11 threads (glibc>=2.28, musl, FreeBSD>=10)
+ * - POSIX PTHREAD (Linux/UNIX, winpthreads)
+ * - Windows Thread API
+ *
+ * Copyright (C) 2022 Sebastian Reimers
+ */
+
+#if defined(HAVE_THREADS)
+#include <threads.h>
+
+#else
+
+#if defined(HAVE_PTHREAD)
+
+#include <pthread.h>
+#include <time.h>
+#define THREAD_ONCE_FLAG_INIT PTHREAD_ONCE_INIT
+typedef pthread_once_t thrd_once_flag;
+typedef pthread_t thrd_t;
+typedef pthread_cond_t cnd_t;
+typedef pthread_mutex_t mtx_t;
+
+#elif defined(WIN32)
+
+#include <windows.h>
+#define THREAD_ONCE_FLAG_INIT INIT_ONCE_STATIC_INIT
+typedef INIT_ONCE thrd_once_flag;
+typedef HANDLE thrd_t;
+typedef CONDITION_VARIABLE cnd_t;
+typedef CRITICAL_SECTION mtx_t;
+
+#endif
+
+enum { mtx_plain = 0, mtx_try = 1, mtx_timed = 2, mtx_recursive = 4 };
+
+/* Exit and error codes.  */
+enum {
+	thrd_success  = 0,
+	thrd_busy     = 1,
+	thrd_error    = 2,
+	thrd_nomem    = 3,
+	thrd_timedout = 4
+};
+
+typedef int (*thrd_start_t)(void *);
+
+
+/******************************************************************************
+ * Thread functions
+ *****************************************************************************/
+
+/**
+ * Creates a new thread
+ *
+ * @param thr   Pointer to new thread
+ * @param func  Function to execute
+ * @param arg   Argument to pass to the function
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int thrd_create(thrd_t *thr, thrd_start_t func, void *arg);
+
+
+/**
+ * Checks whether `lhs` and `rhs` refer to the same thread.
+ *
+ * @return Non-zero value if lhs and rhs refer to the same value, 0 otherwise.
+ */
+int thrd_equal(thrd_t lhs, thrd_t rhs);
+
+
+/**
+ * Return the identifier of the calling thread.
+ */
+thrd_t thrd_current(void);
+
+
+/**
+ * Detaches the thread identified by `thr` from the current environment.
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int thrd_detach(thrd_t thr);
+
+
+/**
+ * Blocks the current thread until the thread identified by `thr` finishes
+ * execution
+ *
+ * @param thr  Thread
+ * @param res  Result code location
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int thrd_join(thrd_t thr, int *res);
+
+
+/**
+ * Calls a function exactly once
+ *
+ * @param flag  Pointer to object initialized by THREAD_ONCE_FLAG_INIT
+ * @param func  The function to execute only once
+ */
+void call_once(thrd_once_flag *flag, void (*func)(void));
+
+
+/**
+ * Terminates the calling thread
+ *
+ * @param res  The result value to return
+ */
+void thrd_exit(int res);
+
+
+/******************************************************************************
+ * Condition functions
+ *****************************************************************************/
+
+/**
+ * Initializes new condition variable
+ *
+ * @param cnd  Pointer to a variable to store condition variable
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int cnd_init(cnd_t *cnd);
+
+
+/**
+ * Unblocks one thread blocked on a condition variable
+ *
+ * @param cnd  Pointer to condition variable
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int cnd_signal(cnd_t *cnd);
+
+
+/**
+ * Unblocks all thrds blocked on a condition variable
+ *
+ * @param cnd  Pointer to condition variable
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int cnd_broadcast(cnd_t *cnd);
+
+
+/**
+ * Blocks on a condition variable
+ *
+ * @param cnd   Pointer to condition variable
+ * @param lock  Lock mutex pointer
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int cnd_wait(cnd_t *cnd, mtx_t *mtx);
+
+
+/**
+ * Destroys the condition variable pointed to by cnd.
+ * If there are thrds waiting on cnd, the behavior is undefined.
+ *
+ * @param cnd  pointer to the condition variable to destroy
+ */
+void cnd_destroy(cnd_t *cnd);
+
+
+/******************************************************************************
+ * Mutex functions
+ *****************************************************************************/
+
+/**
+ * Creates a new mutex object with type. The object pointed to by mutex is set
+ * to an identifier of the newly created mutex.
+ *
+ * @param mtx   Pointer to the mutex to initialize
+ * @param type  The type of the mutex
+ *
+ * @return thrd_success on success, otherwise thrd_error
+ */
+int mtx_init(mtx_t *mtx, int type);
+
+
+/**
+ * Blocks the current thread until the mutex pointed to by mutex is locked.
+ * The behavior is undefined if the current thread has already locked the
+ * mutex and the mutex is not recursive.
+ *
+ * @param mtx   Pointer to the mutex
+ *
+ * @return thrd_success on success, otherwise thrd_error
+ */
+int mtx_lock(mtx_t *mtx);
+
+
+/**
+ * Tries to lock the mutex pointed to by mutex without blocking.
+ * Returns immediately if the mutex is already locked.
+ *
+ * @param mtx   Pointer to the mutex
+ *
+ * @return thrd_success on success, thrd_busy if alread locked,
+ * otherwise thrd_error
+ */
+int mtx_trylock(mtx_t *mtx);
+
+
+/**
+ * Unlocks the mutex pointed to by mutex.
+ *
+ * @param mtx   Pointer to the mutex
+ *
+ * @return thrd_success on success, otherwise thrd_error
+ */
+int mtx_unlock(mtx_t *mtx);
+
+
+#endif /* C11 threads fallback */
+
+
+/******************************************************************************
+ * Extra
+ *****************************************************************************/
+/* int thrd_prio(enum thrd_prio prio) */
+/* void thrd_print(struct re_printf *pf, void *unused); */
+int thrd_create_name(thrd_t *thr, const char *name, thrd_start_t func,
+		     void *arg);

mk/re.mk

@@ -500,6 +500,10 @@ CFLAGS  += -DUSE_ZLIB
 LIBS    += -lz
 endif
 
+HAVE_THREADS := $(shell $(call CC_TEST,threads.h))
+ifneq ($(HAVE_THREADS),)
+CFLAGS  += -DHAVE_THREADS
+endif
 
 HAVE_PTHREAD := $(shell $(call CC_TEST,pthread.h))
 ifneq ($(HAVE_PTHREAD),)

src/thread/mod.mk

@@ -0,0 +1,9 @@
+ifdef HAVE_THREADS
+SRCS	+= thread/thread.c
+else ifdef HAVE_PTHREAD
+SRCS	+= thread/thread.c
+SRCS	+= thread/posix.c
+else ifeq ($(OS),win32)
+SRCS	+= thread/thread.c
+SRCS	+= thread/win32.c
+endif