gh-111916: Make hashlib related modules thread-safe without the GIL (#111981)

Always use an individual lock on hash objects when in free-threaded builds.

Fixes #111916

1 files changed, 14 insertions, 18 deletions

diff --git a/Modules/md5module.c b/Modules/md5module.c
index 7883a8c..7d2b327 100644
--- a/Modules/md5module.c
+++ b/Modules/md5module.c
@@ -16,13 +16,8 @@
 
 /* MD5 objects */
 
-#ifndef _MSC_VER
-#include "pyconfig.h"   // Py_NOGIL
-#endif
-
-#ifndef Py_NOGIL
-// Need limited C API version 3.12 for Py_MOD_PER_INTERPRETER_GIL_SUPPORTED
-#define Py_LIMITED_API 0x030c0000
+#ifndef Py_BUILD_CORE_BUILTIN
+#  define Py_BUILD_CORE_MODULE 1
 #endif
 
 #include "Python.h"
@@ -54,8 +49,8 @@ typedef long long MD5_INT64; /* 64-bit integer */
 typedef struct {
     PyObject_HEAD
     // Prevents undefined behavior via multiple threads entering the C API.
-    // The lock will be NULL before threaded access has been enabled.
-    PyThread_type_lock lock;
+    bool use_mutex;
+    PyMutex mutex;
     Hacl_Streaming_MD5_state *hash_state;
 } MD5object;
 
@@ -78,7 +73,11 @@ static MD5object *
 newMD5object(MD5State * st)
 {
     MD5object *md5 = (MD5object *)PyObject_GC_New(MD5object, st->md5_type);
-    md5->lock = NULL;
+    if (!md5) {
+        return NULL;
+    }
+    HASHLIB_INIT_MUTEX(md5);
+
     PyObject_GC_Track(md5);
     return md5;
 }
@@ -95,9 +94,6 @@ static void
 MD5_dealloc(MD5object *ptr)
 {
     Hacl_Streaming_MD5_legacy_free(ptr->hash_state);
-    if (ptr->lock != NULL) {
-        PyThread_free_lock(ptr->lock);
-    }
     PyTypeObject *tp = Py_TYPE((PyObject*)ptr);
     PyObject_GC_UnTrack(ptr);
     PyObject_GC_Del(ptr);
@@ -202,14 +198,14 @@ MD5Type_update(MD5object *self, PyObject *obj)
 
     GET_BUFFER_VIEW_OR_ERROUT(obj, &buf);
 
-    if (self->lock == NULL && buf.len >= HASHLIB_GIL_MINSIZE) {
-        self->lock = PyThread_allocate_lock();
+    if (!self->use_mutex && buf.len >= HASHLIB_GIL_MINSIZE) {
+        self->use_mutex = true;
     }
-    if (self->lock != NULL) {
+    if (self->use_mutex) {
         Py_BEGIN_ALLOW_THREADS
-        PyThread_acquire_lock(self->lock, 1);
+        PyMutex_Lock(&self->mutex);
         update(self->hash_state, buf.buf, buf.len);
-        PyThread_release_lock(self->lock);
+        PyMutex_Unlock(&self->mutex);
         Py_END_ALLOW_THREADS
     } else {
         update(self->hash_state, buf.buf, buf.len);