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.

2 files changed, 29 insertions, 4 deletions

diff --git a/conform/Makefile b/conform/Makefile
index 74fbda0786..a0ab70e302 100644
--- a/conform/Makefile
+++ b/conform/Makefile
@@ -34,9 +34,9 @@ conformtest-headers-ISO := assert.h ctype.h errno.h float.h limits.h locale.h \
 conformtest-headers-ISO99 := $(conformtest-headers-ISO) complex.h fenv.h \
 			     inttypes.h iso646.h stdbool.h stdint.h tgmath.h \
 			     wchar.h wctype.h
-# Missing ISO11 expectations for: stdatomic.h threads.h.
+# Missing ISO11 expectations for: stdatomic.h
 conformtest-headers-ISO11 := $(conformtest-headers-ISO99) stdalign.h \
-			     stdnoreturn.h uchar.h
+			     stdnoreturn.h threads.h uchar.h
 conformtest-headers-POSIX := $(conformtest-headers-ISO) aio.h dirent.h \
 			     fcntl.h fnmatch.h glob.h grp.h mqueue.h \
 			     pthread.h pwd.h regex.h sched.h semaphore.h \
@@ -196,8 +196,10 @@ linknamespace-libs-posix = $(linknamespace-libs-thr) \
 linknamespace-libs-xsi = $(linknamespace-libs-posix)
 linknamespace-libs-ISO = $(linknamespace-libs-isoc)
 linknamespace-libs-ISO99 = $(linknamespace-libs-isoc)
-linknamespace-libs-ISO11 = $(linknamespace-libs-isoc)
-linknamespace-libs-XPG4 = $(linknamespace-libs-isoc)
+linknamespace-libs-ISO11 = $(linknamespace-libs-isoc) \
+			   $(common-objpfx)nptl/libpthread.a
+linknamespace-libs-XPG4 = $(linknamespace-libs-isoc) \
+			  $(common-objpfx)crypt/libcrypt.a
 linknamespace-libs-XPG42 = $(linknamespace-libs-XPG4)
 linknamespace-libs-POSIX = $(linknamespace-libs-thr)
 linknamespace-libs-UNIX98 = $(linknamespace-libs-xsi)
diff --git a/conform/data/threads.h-data b/conform/data/threads.h-data
new file mode 100644
index 0000000000..bc2d8578de
--- /dev/null
+++ b/conform/data/threads.h-data
@@ -0,0 +1,23 @@
+#if defined ISO11
+
+constant thrd_success
+constant thrd_busy
+constant thrd_error
+constant thrd_nomem
+constant thrd_timedout
+
+type thrd_t
+type thrd_start_t
+
+function int thrd_create (thrd_t*, thrd_start_t, void*)
+function int thrd_equal (thrd_t, thrd_t)
+function thrd_t thrd_current (void)
+function int thrd_sleep (const struct timespec*, struct timespec*)
+function void thrd_exit (int)
+function int thrd_detach (thrd_t)
+function int thrd_join (thrd_t, int*)
+function void thrd_yield (void)
+
+#include "time.h-data"
+
+#endif