Illumos and Solaris Thread Native ID

[yuce]

Feature or enhancement

Proposal:

Currently, Illumos and Solaris 11 ports of Python doesn't have threading.get_native_id:

$ uname -a
SunOS omnios 5.11 omnios-r151054-180b86b9dd i86pc i386 i86pc
$ python3 --version
Python 3.13.3
$ python3 -c "import threading; print(threading.get_native_id())"                  
Traceback (most recent call last):
  File "<string>", line 1, in <module>
    import threading; print(threading.get_native_id())
                            ^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'threading' has no attribute 'get_native_id'

If that's OK, I'll submit a PR that enables threading.get_native_id on Illumos distributions and Solaris 11.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-137884: Added threading.get_native_id on Illumos/Solaris #137927

[picnixz]

How large would that patch be? is it a simple question of using a specific function? (that should be detected at the configure step as well)

[yuce]

The actual change is quite small, this is the diff:

diff --git a/Include/pythread.h b/Include/pythread.h
index 82247daf8e..8307ac5512 100644
--- a/Include/pythread.h
+++ b/Include/pythread.h
@@ -42,7 +42,8 @@ PyAPI_FUNC(unsigned long) PyThread_get_thread_ident(void);
 #if (defined(__APPLE__) || defined(__linux__) || defined(_WIN32) \
      || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) \
      || defined(__OpenBSD__) || defined(__NetBSD__) \
-     || defined(__DragonFly__) || defined(_AIX))
+     || defined(__DragonFly__) || defined(_AIX)) \
+     || defined(__sun__)
 #define PY_HAVE_THREAD_NATIVE_ID
 PyAPI_FUNC(unsigned long) PyThread_get_thread_native_id(void);
 #endif
diff --git a/Python/thread_pthread.h b/Python/thread_pthread.h
index 13992f9572..c04a374af5 100644
--- a/Python/thread_pthread.h
+++ b/Python/thread_pthread.h
@@ -30,6 +30,9 @@
 #   include <lwp.h>             /* _lwp_self() */
 #elif defined(__DragonFly__)
 #   include <sys/lwp.h>         /* lwp_gettid() */
+#elif defined(__sun__)
+#   include <thread.h>
+
 #endif
 
 /* The POSIX spec requires that use of pthread_attr_setstacksize
@@ -399,6 +402,10 @@ PyThread_get_thread_native_id(void)
 #elif defined(__DragonFly__)
     lwpid_t native_id;
     native_id = lwp_gettid();
+#elif defined(__sun__)
+    unsigned long native_id = (unsigned long)getpid();
+    native_id <<= 32;
+    native_id |= thr_self();
 #endif
     return (unsigned long) native_id;
 }

Illumos/Solaris has the thr_self function which returns the thread ID, unique for the process:
https://docs.oracle.com/cd/E36784_01/html/E36874/thr-self-3c.html
On OmniOS and Solaris, it just returns the thread IDs from 1, incrementing it for each thread.
Since it is not unique in the system, it is not usable by itself per Python doc:

get_native_id() -> integer
Return a non-negative integer identifying the thread as reported
by the OS (kernel). This may be used to uniquely identify a
particular thread within a system.

In order to make it unique within the system, I combine it with getpid().

With the changes in the patch, test_native_id_after_fork in Lib/test/test_threading.py passes, which was skipped before, with no additional test failures in that module (test_set_name fails before/after the patch):

cpython/Lib/test/test_threading.py

Line 1406 in 25b9728

def test_native_id_after_fork(self):

[serhiy-storchaka]

Then there should not be any objections. Do you want to create a PR, @yuce?

[serhiy-storchaka]

See also previous attempt #84374.

Was the only issue with thr_self() is that the returned value is not within a system? What is the difference between thr_self() and pthread_self() on Solaris, do they return the same value?

cc @isidentical