Expose pthread_gettid_np(3) under _GNU_SOURCE

Looks like Glibc also added this function (and with a compatible prototype even!) -- something that I didn't know about, and has seemingly only done **years** after I already added it to KOS

Author: GrieferAtWork

kos/include/pthread.h

@@ -1,4 +1,4 @@
-/* HASH CRC-32:0x5ecc7c65 */
+/* HASH CRC-32:0x825f2384 */
 /* Copyright (c) 2019-2025 Griefer@Work                                       *
  *                                                                            *
  * This software is provided 'as-is', without any express or implied          *
@@ -1258,28 +1258,32 @@ __CREDIRECT(__ATTR_IN(2),__errno_t,__NOTHROW_NCX,pthread_setname_np,(pthread_t _
 #endif /* !... */
 #endif /* !__pthread_setname_np_defined */
 #endif /* __USE_GNU */
-#ifdef __USE_KOS
+#if defined(__USE_KOS) || defined(__USE_GNU)
 #ifndef __pthread_gettid_np_defined
 #define __pthread_gettid_np_defined
 #ifdef __CRT_HAVE_pthread_gettid_np
 /* >> pthread_gettid_np(3)
  * Return the TID of the given `self'.
  * If `self' has already terminated, 0 is returned
  * @return: * : The TID of the given thread
- * @return: 0 : The given `self' has already terminated */
+ * @return: 0 : The given `self' has already terminated (KOS)
+ * @return: -1: The given `self' has already terminated (GLibc) */
 __CDECLARE(__ATTR_PURE __ATTR_WUNUSED,__pid_t,__NOTHROW_NCX,pthread_gettid_np,(pthread_t __self),(__self))
 #elif defined(__CRT_HAVE_pthread_getunique_np) || defined(__CRT_HAVE_pthread_threadid_np)
 #include <libc/local/pthread/pthread_gettid_np.h>
 /* >> pthread_gettid_np(3)
  * Return the TID of the given `self'.
  * If `self' has already terminated, 0 is returned
  * @return: * : The TID of the given thread
- * @return: 0 : The given `self' has already terminated */
+ * @return: 0 : The given `self' has already terminated (KOS)
+ * @return: -1: The given `self' has already terminated (GLibc) */
 __NAMESPACE_LOCAL_USING_OR_IMPL(pthread_gettid_np, __FORCELOCAL __ATTR_ARTIFICIAL __ATTR_PURE __ATTR_WUNUSED __pid_t __NOTHROW_NCX(__LIBCCALL pthread_gettid_np)(pthread_t __self) { return (__NAMESPACE_LOCAL_SYM __LIBC_LOCAL_NAME(pthread_gettid_np))(__self); })
 #else /* ... */
 #undef __pthread_gettid_np_defined
 #endif /* !... */
 #endif /* !__pthread_gettid_np_defined */
+#endif /* __USE_KOS || __USE_GNU */
+#ifdef __USE_KOS
 #if !defined(__pthread_getpidfd_np_defined) && defined(__CRT_HAVE_pthread_getpidfd_np)
 #define __pthread_getpidfd_np_defined
 /* >> pthread_getpidfd_np(3)

kos/src/libc/auto/pthread.h

@@ -1,4 +1,4 @@
-/* HASH CRC-32:0xdc0f4352 */
+/* HASH CRC-32:0xb6a8daab */
 /* Copyright (c) 2019-2025 Griefer@Work                                       *
  *                                                                            *
  * This software is provided 'as-is', without any express or implied          *
@@ -267,7 +267,8 @@ INTDEF ATTR_IN(2) errno_t NOTHROW_NCX(LIBDCALL libd_pthread_setname_np)(pthread_
  * Return the TID of the given `self'.
  * If `self' has already terminated, 0 is returned
  * @return: * : The TID of the given thread
- * @return: 0 : The given `self' has already terminated */
+ * @return: 0 : The given `self' has already terminated (KOS)
+ * @return: -1: The given `self' has already terminated (GLibc) */
 INTDEF ATTR_PURE WUNUSED pid_t NOTHROW_NCX(LIBDCALL libd_pthread_gettid_np)(pthread_t self);
 /* >> pthread_getpidfd_np(3)
  * Return a PIDfd for `self'. If not already allocated, allocate a PIDfd  lazily.

kos/src/libc/magic/pthread.c

@@ -1290,12 +1290,13 @@ int pthread_equal(pthread_t thr1, pthread_t thr2) {
 %#endif /* __USE_GNU */
 
 
-%#ifdef __USE_KOS
+%#if defined(__USE_KOS) || defined(__USE_GNU)
 @@>> pthread_gettid_np(3)
 @@Return the TID of the given `self'.
 @@If `self' has already terminated, 0 is returned
 @@@return: * : The TID of the given thread
-@@@return: 0 : The given `self' has already terminated
+@@@return: 0 : The given `self' has already terminated (KOS)
+@@@return: -1: The given `self' has already terminated (GLibc)
 [[userimpl, guard, pure, wunused]]
 [[section(".text.crt{|.dos}.sched.pthread.ext.kos.tid")]]
 [[decl_include("<bits/types.h>", "<bits/crt/pthreadtypes.h>")]]
@@ -1307,7 +1308,10 @@ int pthread_equal(pthread_t thr1, pthread_t thr2) {
 		result = 0;
 	return result;
 }
+%#endif /* __USE_KOS || __USE_GNU */
+
 
+%#ifdef __USE_KOS
 @@>> pthread_getpidfd_np(3)
 @@Return a PIDfd for `self'. If not already allocated, allocate a PIDfd  lazily.
 @@To  guaranty that a PIDfd is available for a given thread, you can make use of

kos/src/libc/user/pthread.c

@@ -977,18 +977,19 @@ NOTHROW(LIBCCALL libc_pthread_self)(void)
 }
 /*[[[end:libc_pthread_self]]]*/
 
-/*[[[head:libc_pthread_gettid_np,hash:CRC-32=0x8b5628fb]]]*/
+/*[[[head:libc_pthread_gettid_np,hash:CRC-32=0xa9aa40ae]]]*/
 /* >> pthread_gettid_np(3)
  * Return the TID of the given `self'.
  * If `self' has already terminated, 0 is returned
  * @return: * : The TID of the given thread
- * @return: 0 : The given `self' has already terminated */
+ * @return: 0 : The given `self' has already terminated (KOS)
+ * @return: -1: The given `self' has already terminated (GLibc) */
 INTERN ATTR_SECTION(".text.crt.sched.pthread.ext.kos.tid") ATTR_PURE WUNUSED pid_t
 NOTHROW_NCX(LIBCCALL libc_pthread_gettid_np)(pthread_t self)
 /*[[[body:libc_pthread_gettid_np]]]*/
 {
 	pid_t result;
-	result = self->pt_tid;
+	result = atomic_read(&self->pt_tid);
 	return result;
 }
 /*[[[end:libc_pthread_gettid_np]]]*/

kos/src/libc/user/pthread.h

@@ -1,4 +1,4 @@
-/* HASH CRC-32:0x71b0ae1e */
+/* HASH CRC-32:0x63719ace */
 /* Copyright (c) 2019-2025 Griefer@Work                                       *
  *                                                                            *
  * This software is provided 'as-is', without any express or implied          *
@@ -277,7 +277,8 @@ INTDEF ATTR_IN(2) errno_t NOTHROW_NCX(LIBCCALL libc_pthread_setname_np)(pthread_
  * Return the TID of the given `self'.
  * If `self' has already terminated, 0 is returned
  * @return: * : The TID of the given thread
- * @return: 0 : The given `self' has already terminated */
+ * @return: 0 : The given `self' has already terminated (KOS)
+ * @return: -1: The given `self' has already terminated (GLibc) */
 INTDEF ATTR_PURE WUNUSED pid_t NOTHROW_NCX(LIBCCALL libc_pthread_gettid_np)(pthread_t self);
 /* >> pthread_getpidfd_np(3)
  * Return a PIDfd for `self'. If not already allocated, allocate a PIDfd  lazily.