gh-131268: Implement thread names on OpenBSD (#131528)

Author: xavierog

Modules/_threadmodule.c

@@ -2392,8 +2392,16 @@ PyDoc_STRVAR(thread__get_main_thread_ident_doc,
 Internal only. Return a non-zero integer that uniquely identifies the main thread\n\
 of the main interpreter.");
 
+#if defined(__OpenBSD__)
+    /* pthread_*_np functions, especially pthread_{get,set}_name_np().
+       pthread_np.h exists on both OpenBSD and FreeBSD but the latter declares
+       pthread_getname_np() and pthread_setname_np() in pthread.h as long as
+       __BSD_VISIBLE remains set.
+     */
+#   include <pthread_np.h>
+#endif
 
-#if defined(HAVE_PTHREAD_GETNAME_NP) || defined(MS_WINDOWS)
+#if defined(HAVE_PTHREAD_GETNAME_NP) || defined(HAVE_PTHREAD_GET_NAME_NP) || defined(MS_WINDOWS)
 /*[clinic input]
 _thread._get_name
 
@@ -2408,7 +2416,12 @@ _thread__get_name_impl(PyObject *module)
     // Linux and macOS are limited to respectively 16 and 64 bytes
     char name[100];
     pthread_t thread = pthread_self();
+#ifdef HAVE_PTHREAD_GETNAME_NP
     int rc = pthread_getname_np(thread, name, Py_ARRAY_LENGTH(name));
+#else /* defined(HAVE_PTHREAD_GET_NAME_NP) */
+    int rc = 0; /* pthread_get_name_np() returns void */
+    pthread_get_name_np(thread, name, Py_ARRAY_LENGTH(name));
+#endif
     if (rc) {
         errno = rc;
         return PyErr_SetFromErrno(PyExc_OSError);
@@ -2435,10 +2448,10 @@ _thread__get_name_impl(PyObject *module)
     return name_obj;
 #endif
 }
-#endif  // HAVE_PTHREAD_GETNAME_NP
+#endif  // HAVE_PTHREAD_GETNAME_NP || HAVE_PTHREAD_GET_NAME_NP || MS_WINDOWS
 
 
-#if defined(HAVE_PTHREAD_SETNAME_NP) || defined(MS_WINDOWS)
+#if defined(HAVE_PTHREAD_SETNAME_NP) || defined(HAVE_PTHREAD_SET_NAME_NP) || defined(MS_WINDOWS)
 /*[clinic input]
 _thread.set_name
 
@@ -2487,9 +2500,13 @@ _thread_set_name_impl(PyObject *module, PyObject *name_obj)
 #elif defined(__NetBSD__)
     pthread_t thread = pthread_self();
     int rc = pthread_setname_np(thread, "%s", (void *)name);
-#else
+#elif defined(HAVE_PTHREAD_SETNAME_NP)
     pthread_t thread = pthread_self();
     int rc = pthread_setname_np(thread, name);
+#else /* defined(HAVE_PTHREAD_SET_NAME_NP) */
+    pthread_t thread = pthread_self();
+    int rc = 0; /* pthread_set_name_np() returns void */
+    pthread_set_name_np(thread, name);
 #endif
     Py_DECREF(name_encoded);
     if (rc) {
@@ -2527,7 +2544,7 @@ _thread_set_name_impl(PyObject *module, PyObject *name_obj)
     Py_RETURN_NONE;
 #endif
 }
-#endif  // HAVE_PTHREAD_SETNAME_NP
+#endif  // HAVE_PTHREAD_SETNAME_NP || HAVE_PTHREAD_SET_NAME_NP || MS_WINDOWS
 
 
 static PyMethodDef thread_methods[] = {

Modules/clinic/_threadmodule.c.h

@@ -5147,7 +5147,8 @@ AC_CHECK_FUNCS([ \
   posix_spawn_file_actions_addclosefrom_np \
   pread preadv preadv2 process_vm_readv \
   pthread_cond_timedwait_relative_np pthread_condattr_setclock pthread_init \
-  pthread_kill pthread_getname_np pthread_setname_np pthread_getattr_np \
+  pthread_kill pthread_get_name_np pthread_getname_np pthread_set_name_np
+  pthread_setname_np pthread_getattr_np \
   ptsname ptsname_r pwrite pwritev pwritev2 readlink readlinkat readv realpath renameat \
   rtpSpawn sched_get_priority_max sched_rr_get_interval sched_setaffinity \
   sched_setparam sched_setscheduler sem_clockwait sem_getvalue sem_open \
@@ -7563,6 +7564,7 @@ case "$ac_sys_system" in
   Darwin) _PYTHREAD_NAME_MAXLEN=63;;
   iOS) _PYTHREAD_NAME_MAXLEN=63;;
   FreeBSD*) _PYTHREAD_NAME_MAXLEN=19;; # gh-131268
+  OpenBSD*) _PYTHREAD_NAME_MAXLEN=23;; # gh-131268
   *) _PYTHREAD_NAME_MAXLEN=;;
 esac
 if test -n "$_PYTHREAD_NAME_MAXLEN"; then

configure

@@ -993,6 +993,9 @@
 /* Define to 1 if you have the 'pthread_getname_np' function. */
 #undef HAVE_PTHREAD_GETNAME_NP
 
+/* Define to 1 if you have the 'pthread_get_name_np' function. */
+#undef HAVE_PTHREAD_GET_NAME_NP
+
 /* Define to 1 if you have the <pthread.h> header file. */
 #undef HAVE_PTHREAD_H
 
@@ -1005,6 +1008,9 @@
 /* Define to 1 if you have the 'pthread_setname_np' function. */
 #undef HAVE_PTHREAD_SETNAME_NP
 
+/* Define to 1 if you have the 'pthread_set_name_np' function. */
+#undef HAVE_PTHREAD_SET_NAME_NP
+
 /* Define to 1 if you have the 'pthread_sigmask' function. */
 #undef HAVE_PTHREAD_SIGMASK