From ce7528f637f7b9cddb3c22081d7e09b2a26c89bf Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Tue, 27 Jun 2017 10:29:29 -0300 Subject: nptl: Add C11 threads thrd_* functions This patch adds the thrd_* definitions from C11 threads (ISO/IEC 9899:2011), more specifically thrd_create, thrd_curent, rhd_detach, thrd_equal, thrd_exit, thrd_join, thrd_sleep, thrd_yield, and required types. Mostly of the definitions are composed based on POSIX conterparts, such as thrd_t (using pthread_t). For thrd_* function internally direct POSIX pthread call are used with the exceptions: 1. thrd_start uses pthread_create internal implementation, but changes how to actually calls the start routine. This is due the difference in signature between POSIX and C11, where former return a 'void *' and latter 'int'. To avoid calling convention issues due 'void *' to int cast, routines from C11 threads are started slight different than default pthread one. Explicit cast to expected return are used internally on pthread_create and the result is stored back to void also with an explicit cast. 2. thrd_sleep uses nanosleep internal direct syscall to avoid clobbering errno and to handle expected standard return codes. It is a cancellation entrypoint to be consistent with both thrd_join and cnd_{timed}wait. 3. thrd_yield also uses internal direct syscall to avoid errno clobbering. Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu, powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu, and x86_64-linux-gnu). Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu, arm-linux-gnueabhf, and powerpc64le-linux-gnu. [BZ #14092] * conform/Makefile (conformtest-headers-ISO11): Add threads.h. (linknamespace-libs-ISO11): Add libpthread.a. * conform/data/threads.h-data: New file: add C11 thrd_* types and functions. * include/stdc-predef.h (__STDC_NO_THREADS__): Remove definition. * nptl/Makefile (headers): Add threads.h. (libpthread-routines): Add new C11 thread thrd_create, thrd_current, thrd_detach, thrd_equal, thrd_exit, thrd_join, thrd_sleep, and thrd_yield. * nptl/Versions (libpthread) [GLIBC_2.28]): Add new C11 thread thrd_create, thrd_current, thrd_detach, thrd_equal, thrd_exit, thrd_join, thrd_sleep, and thrd_yield symbols. * nptl/descr.h (struct pthread): Add c11 field. * nptl/pthreadP.h (ATTR_C11_THREAD): New define. * nptl/pthread_create.c (START_THREAD_DEFN): Call C11 thread start routine with expected function prototype. (__pthread_create_2_1): Add C11 threads check based on attribute value. * sysdeps/unix/sysdep.h (INTERNAL_SYSCALL_CANCEL): New macro. * nptl/thrd_create.c: New file. * nptl/thrd_current.c: Likewise. * nptl/thrd_detach.c: Likewise. * nptl/thrd_equal.c: Likewise. * nptl/thrd_exit.c: Likewise. * nptl/thrd_join.c: Likewise. * nptl/thrd_priv.h: Likewise. * nptl/thrd_sleep.c: Likewise. * nptl/thrd_yield.c: Likewise. * include/threads.h: Likewise. --- nptl/threads.h | 90 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 nptl/threads.h (limited to 'nptl/threads.h') diff --git a/nptl/threads.h b/nptl/threads.h new file mode 100644 index 0000000000..5258e23919 --- /dev/null +++ b/nptl/threads.h @@ -0,0 +1,90 @@ +/* ISO C11 Standard: 7.26 - Thread support library . + Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef _THREADS_H +#define _THREADS_H 1 + +#include +#include + +__BEGIN_DECLS + +#include + +typedef unsigned long int thrd_t; +typedef int (*thrd_start_t) (void*); + +/* Exit and error codes. */ +enum +{ + thrd_success = 0, + thrd_busy = 1, + thrd_error = 2, + thrd_nomem = 3, + thrd_timedout = 4 +}; + +/* Threads functions. */ + +/* Create a new thread executing the function __FUNC. Arguments for __FUNC + are passed through __ARG. If succesful, __THR is set to new thread + identifier. */ +extern int thrd_create (thrd_t *__thr, thrd_start_t __func, void *__arg); + +/* Check if __LHS and __RHS point to the same thread. */ +extern int thrd_equal (thrd_t __lhs, thrd_t __rhs); + +/* Return current thread identifier. */ +extern thrd_t thrd_current (void); + +/* Block current thread execution for at least the time pointed by + __TIME_POINT. The current thread may resume if receives a signal. In + that case, if __REMAINING is not NULL, the remaining time is stored in + the object pointed by it. */ +extern int thrd_sleep (const struct timespec *__time_point, + struct timespec *__remaining); + +/* Terminate current thread execution, cleaning up any thread local + storage and freeing resources. Returns the value specified in __RES. */ +extern void thrd_exit (int __res) __attribute__ ((__noreturn__)); + +/* Detach the thread identified by __THR from the current environment + (it does not allow join or wait for it). */ +extern int thrd_detach (thrd_t __thr); + +/* Block current thread until execution of __THR is complete. In case that + __RES is not NULL, will store the return value of __THR when exiting. */ +extern int thrd_join (thrd_t __thr, int *__res); + +/* Stop current thread execution and call the scheduler to decide which + thread should execute next. The current thread may be selected by the + scheduler to keep running. */ +extern void thrd_yield (void); + +#ifdef __USE_EXTERN_INLINES +/* Optimizations. */ +__extern_inline int +thrd_equal (thrd_t __thread1, thrd_t __thread2) +{ + return __thread1 == __thread2; +} +#endif + +__END_DECLS + +#endif /* _THREADS_H */ -- cgit 1.4.1