pythongh-151929: Get uptime on BSD/macOS in pythoninfo (python#152189)

* Check sysctlbyname() function and sys/sysctl.h header in
  configure.
* Add _testcapi.uptime_bsd() function.

Author: vstinner

Lib/test/pythoninfo.py

@@ -1083,6 +1083,18 @@ def uptime_linux():
         return
 
 
+def uptime_bsd():
+    # Get sysctlbyname("kern.boottime")
+    try:
+        import _testcapi
+    except ImportError:
+        return None
+    try:
+        return _testcapi.uptime_bsd()
+    except (AttributeError, OSError):
+        return None
+
+
 def uptime_windows():
     try:
         import _winapi
@@ -1093,7 +1105,7 @@ def uptime_windows():
 
 
 def get_uptime():
-    for func in (uptime_boottime, uptime_linux, uptime_windows):
+    for func in (uptime_boottime, uptime_linux, uptime_bsd, uptime_windows):
         uptime = func()
         if uptime is not None:
             return uptime
@@ -1107,9 +1119,15 @@ def get_machine_id():
         if machine_guid:
             return machine_guid
 
-    machine_id = read_first_line("/etc/machine-id")
-    if machine_id:
-        return machine_id
+    for filename in (
+        # https://www.freedesktop.org/software/systemd/man/latest/machine-id.html
+        "/etc/machine-id",
+        # BSD
+        "/etc/hostid",
+    ):
+        machine_id = read_first_line(filename)
+        if machine_id:
+            return machine_id
 
     return None
 
@@ -1119,7 +1137,6 @@ def collect_linux(info_add):
     if boot_id:
         info_add('system.boot_id', boot_id)
 
-    # https://www.freedesktop.org/software/systemd/man/latest/machine-id.html
     machine_id = get_machine_id()
     if machine_id:
         info_add('system.machine_id', machine_id)

Modules/_testcapimodule.c

@@ -22,6 +22,9 @@
 #ifdef HAVE_SYS_WAIT_H
 #  include <sys/wait.h>           // W_STOPCODE
 #endif
+#ifdef HAVE_SYS_SYSCTL_H
+#  include <sys/sysctl.h>         // sysctlbyname()
+#endif
 
 #ifdef bool
 #  error "The public headers should not include <stdbool.h>, see gh-48924"
@@ -2970,6 +2973,31 @@ test_soft_deprecated_macros(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(args)
     Py_RETURN_NONE;
 }
 
+
+#ifdef HAVE_SYSCTLBYNAME
+static PyObject*
+uptime_bsd(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(args))
+{
+    struct timeval tv;
+    size_t size = sizeof(tv);
+    int res = sysctlbyname("kern.boottime", &tv, &size, NULL, 0);
+    if (res != 0) {
+        return PyErr_SetFromErrno(PyExc_OSError);
+    }
+    double boottime = (double)tv.tv_sec + tv.tv_usec * 1e-6;
+
+    PyTime_t now_t;
+    if (PyTime_Time(&now_t) < 0) {
+        return NULL;
+    }
+    double now = PyTime_AsSecondsDouble(now_t);
+
+    double uptime = now - boottime;
+    return PyFloat_FromDouble(uptime);
+}
+#endif
+
+
 static PyMethodDef TestMethods[] = {
     {"set_errno",               set_errno,                       METH_VARARGS},
     {"test_config",             test_config,                     METH_NOARGS},
@@ -3076,6 +3104,9 @@ static PyMethodDef TestMethods[] = {
     {"test_thread_state_ensure_detachment", test_thread_state_ensure_detachment, METH_NOARGS},
     {"test_thread_state_ensure_detached_gilstate", test_thread_state_ensure_detached_gilstate, METH_NOARGS},
     {"test_thread_state_release_with_destructor", test_thread_state_release_with_destructor, METH_NOARGS},
+#ifdef HAVE_SYSCTLBYNAME
+    {"uptime_bsd", uptime_bsd, METH_NOARGS},
+#endif
     {NULL, NULL} /* sentinel */
 };
 

configure

@@ -3163,7 +3163,8 @@ AC_CHECK_HEADERS([ \
   sys/endian.h sys/epoll.h sys/event.h sys/eventfd.h sys/file.h sys/ioctl.h sys/kern_control.h \
   sys/loadavg.h sys/lock.h sys/memfd.h sys/mkdev.h sys/mman.h sys/modem.h sys/param.h sys/pidfd.h sys/poll.h \
   sys/random.h sys/resource.h sys/select.h sys/sendfile.h sys/socket.h sys/soundcard.h sys/stat.h \
-  sys/statvfs.h sys/sys_domain.h sys/syscall.h sys/sysmacros.h sys/termio.h sys/time.h sys/times.h sys/timerfd.h \
+  sys/statvfs.h sys/sys_domain.h sys/syscall.h sys/sysctl.h \
+  sys/sysmacros.h sys/termio.h sys/time.h sys/times.h sys/timerfd.h \
   sys/types.h sys/uio.h sys/un.h sys/utsname.h sys/wait.h sys/xattr.h sysexits.h syslog.h \
   termios.h util.h utime.h utmp.h \
 ])
@@ -5431,7 +5432,7 @@ AC_CHECK_FUNCS([ \
   setresuid setreuid setsid setuid setvbuf shutdown sigaction sigaltstack \
   sigfillset siginterrupt sigpending sigrelse sigtimedwait sigwait \
   sigwaitinfo snprintf splice strftime strlcpy strsignal symlinkat sync \
-  sysconf tcgetpgrp tcsetpgrp tempnam timegm times tmpfile \
+  sysconf sysctlbyname tcgetpgrp tcsetpgrp tempnam timegm times tmpfile \
   tmpnam tmpnam_r truncate ttyname_r umask uname unlinkat unlockpt utimensat utimes vfork \
   wait wait3 wait4 waitid waitpid wcscoll wcsftime wcsxfrm wmemcmp writev \
 ])

configure.ac

@@ -1417,6 +1417,9 @@
 /* Define to 1 if you have the 'sysconf' function. */
 #undef HAVE_SYSCONF
 
+/* Define to 1 if you have the 'sysctlbyname' function. */
+#undef HAVE_SYSCTLBYNAME
+
 /* Define to 1 if you have the <sysexits.h> header file. */
 #undef HAVE_SYSEXITS_H
 
@@ -1521,6 +1524,9 @@
 /* Define to 1 if you have the <sys/syscall.h> header file. */
 #undef HAVE_SYS_SYSCALL_H
 
+/* Define to 1 if you have the <sys/sysctl.h> header file. */
+#undef HAVE_SYS_SYSCTL_H
+
 /* Define to 1 if you have the <sys/sysmacros.h> header file. */
 #undef HAVE_SYS_SYSMACROS_H