gh-117440: Make `syslog` thread-safe in free-threaded builds (#117441)

Use critical sections to protect access to the syslog module.

1 files changed, 13 insertions, 2 deletions

diff --git a/Modules/clinic/syslogmodule.c.h b/Modules/clinic/syslogmodule.c.h
index 58b0ea5..77cf24e 100644
--- a/Modules/clinic/syslogmodule.c.h
+++ b/Modules/clinic/syslogmodule.c.h
@@ -6,6 +6,7 @@ preserve
 #  include "pycore_gc.h"          // PyGC_Head
 #  include "pycore_runtime.h"     // _Py_ID()
 #endif
+#include "pycore_critical_section.h"// Py_BEGIN_CRITICAL_SECTION()
 #include "pycore_modsupport.h"    // _PyArg_UnpackKeywords()
 
 PyDoc_STRVAR(syslog_openlog__doc__,
@@ -88,7 +89,9 @@ syslog_openlog(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
         goto exit;
     }
 skip_optional_pos:
+    Py_BEGIN_CRITICAL_SECTION(module);
     return_value = syslog_openlog_impl(module, ident, logopt, facility);
+    Py_END_CRITICAL_SECTION();
 
 exit:
     return return_value;
@@ -129,7 +132,9 @@ syslog_syslog(PyObject *module, PyObject *args)
             PyErr_SetString(PyExc_TypeError, "syslog.syslog requires 1 to 2 arguments");
             goto exit;
     }
+    Py_BEGIN_CRITICAL_SECTION(module);
     return_value = syslog_syslog_impl(module, group_left_1, priority, message);
+    Py_END_CRITICAL_SECTION();
 
 exit:
     return return_value;
@@ -150,7 +155,13 @@ syslog_closelog_impl(PyObject *module);
 static PyObject *
 syslog_closelog(PyObject *module, PyObject *Py_UNUSED(ignored))
 {
-    return syslog_closelog_impl(module);
+    PyObject *return_value = NULL;
+
+    Py_BEGIN_CRITICAL_SECTION(module);
+    return_value = syslog_closelog_impl(module);
+    Py_END_CRITICAL_SECTION();
+
+    return return_value;
 }
 
 PyDoc_STRVAR(syslog_setlogmask__doc__,
@@ -251,4 +262,4 @@ syslog_LOG_UPTO(PyObject *module, PyObject *arg)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=86ca2fd84b2da98e input=a9049054013a1b77]*/
+/*[clinic end generated code: output=8d25899bd31969d3 input=a9049054013a1b77]*/