5 files changed, 64 insertions, 11 deletions
diff --git a/Include/cpython/unicodeobject.h b/Include/cpython/unicodeobject.h
index 136f5d5c5f8..3d0414f5291 100644
--- a/Include/cpython/unicodeobject.h
+++ b/Include/cpython/unicodeobject.h
@@ -478,6 +478,10 @@ PyAPI_FUNC(int) PyUnicodeWriter_WriteUTF8(
     PyUnicodeWriter *writer,
     const char *str,
     Py_ssize_t size);
+PyAPI_FUNC(int) PyUnicodeWriter_WriteASCII(
+    PyUnicodeWriter *writer,
+    const char *str,
+    Py_ssize_t size);
 PyAPI_FUNC(int) PyUnicodeWriter_WriteWideChar(
     PyUnicodeWriter *writer,
     const wchar_t *str,
diff --git a/Include/internal/mimalloc/mimalloc/internal.h b/Include/internal/mimalloc/mimalloc/internal.h
index 71b7ea702d6..a7daa3a40a4 100644
--- a/Include/internal/mimalloc/mimalloc/internal.h
+++ b/Include/internal/mimalloc/mimalloc/internal.h
@@ -634,10 +634,10 @@ static inline mi_block_t* mi_block_nextx( const void* null, const mi_block_t* bl
   mi_track_mem_defined(block,sizeof(mi_block_t));
   mi_block_t* next;
   #ifdef MI_ENCODE_FREELIST
-  next = (mi_block_t*)mi_ptr_decode(null, mi_atomic_load_relaxed(&block->next), keys);
+  next = (mi_block_t*)mi_ptr_decode(null, mi_atomic_load_relaxed((_Atomic(mi_encoded_t)*)&block->next), keys);
   #else
   MI_UNUSED(keys); MI_UNUSED(null);
-  next = (mi_block_t*)mi_atomic_load_relaxed(&block->next);
+  next = (mi_block_t*)mi_atomic_load_relaxed((_Atomic(mi_encoded_t)*)&block->next);
   #endif
   mi_track_mem_noaccess(block,sizeof(mi_block_t));
   return next;
diff --git a/Include/internal/mimalloc/mimalloc/types.h b/Include/internal/mimalloc/mimalloc/types.h
index 4f77bd7bc52..a04169f7fb8 100644
--- a/Include/internal/mimalloc/mimalloc/types.h
+++ b/Include/internal/mimalloc/mimalloc/types.h
@@ -50,6 +50,32 @@ terms of the MIT license. A copy of the license can be found in the file
 #define mi_decl_cache_align
 #endif
 
+#if (MI_DEBUG)
+#if defined(_MSC_VER)
+#define mi_decl_noreturn        __declspec(noreturn)
+#elif (defined(__GNUC__) && (__GNUC__ >= 3)) || defined(__clang__)
+#define mi_decl_noreturn        __attribute__((__noreturn__))
+#else
+#define mi_decl_noreturn
+#endif
+
+/*
+ * 'cold' attribute seems to have been fully supported since GCC 4.x.
+ * See https://github.com/gcc-mirror/gcc/commit/52bf96d2f299e9e6.
+ */
+#if (defined(__GNUC__) && (__GNUC__ >= 4)) || defined(__clang__)
+#define mi_decl_cold            __attribute__((cold))
+#else
+#define mi_decl_cold
+#endif
+
+#if (defined(__GNUC__) && defined(__THROW))
+#define mi_decl_throw           __THROW
+#else
+#define mi_decl_throw
+#endif
+#endif
+
 // ------------------------------------------------------
 // Variants
 // ------------------------------------------------------
@@ -582,7 +608,8 @@ struct mi_heap_s {
 
 #if (MI_DEBUG)
 // use our own assertion to print without memory allocation
-void _mi_assert_fail(const char* assertion, const char* fname, unsigned int line, const char* func );
+mi_decl_noreturn mi_decl_cold mi_decl_throw
+void _mi_assert_fail(const char* assertion, const char* fname, unsigned int line, const char* func);
 #define mi_assert(expr)     ((expr) ? (void)0 : _mi_assert_fail(#expr,__FILE__,__LINE__,__func__))
 #else
 #define mi_assert(x)
diff --git a/Include/internal/pycore_crossinterp.h b/Include/internal/pycore_crossinterp.h
index 12729274138..713ddc66ba7 100644
--- a/Include/internal/pycore_crossinterp.h
+++ b/Include/internal/pycore_crossinterp.h
@@ -317,7 +317,9 @@ typedef enum error_code {
     _PyXI_ERR_ALREADY_RUNNING = -4,
     _PyXI_ERR_MAIN_NS_FAILURE = -5,
     _PyXI_ERR_APPLY_NS_FAILURE = -6,
-    _PyXI_ERR_NOT_SHAREABLE = -7,
+    _PyXI_ERR_PRESERVE_FAILURE = -7,
+    _PyXI_ERR_EXC_PROPAGATION_FAILURE = -8,
+    _PyXI_ERR_NOT_SHAREABLE = -9,
 } _PyXI_errcode;
 
 
@@ -350,16 +352,33 @@ typedef struct xi_session _PyXI_session;
 PyAPI_FUNC(_PyXI_session *) _PyXI_NewSession(void);
 PyAPI_FUNC(void) _PyXI_FreeSession(_PyXI_session *);
 
+typedef struct {
+    PyObject *preserved;
+    PyObject *excinfo;
+    _PyXI_errcode errcode;
+} _PyXI_session_result;
+PyAPI_FUNC(void) _PyXI_ClearResult(_PyXI_session_result *);
+
 PyAPI_FUNC(int) _PyXI_Enter(
     _PyXI_session *session,
     PyInterpreterState *interp,
-    PyObject *nsupdates);
-PyAPI_FUNC(void) _PyXI_Exit(_PyXI_session *session);
-
-PyAPI_FUNC(PyObject *) _PyXI_GetMainNamespace(_PyXI_session *);
-
-PyAPI_FUNC(PyObject *) _PyXI_ApplyCapturedException(_PyXI_session *session);
-PyAPI_FUNC(int) _PyXI_HasCapturedException(_PyXI_session *session);
+    PyObject *nsupdates,
+    _PyXI_session_result *);
+PyAPI_FUNC(int) _PyXI_Exit(
+    _PyXI_session *,
+    _PyXI_errcode,
+    _PyXI_session_result *);
+
+PyAPI_FUNC(PyObject *) _PyXI_GetMainNamespace(
+    _PyXI_session *,
+    _PyXI_errcode *);
+
+PyAPI_FUNC(int) _PyXI_Preserve(
+    _PyXI_session *,
+    const char *,
+    PyObject *,
+    _PyXI_errcode *);
+PyAPI_FUNC(PyObject *) _PyXI_GetPreserved(_PyXI_session_result *, const char *);
 
 
 /*************/
diff --git a/Include/internal/pycore_lock.h b/Include/internal/pycore_lock.h
index 7484b05d7f2..32b60cc33a2 100644
--- a/Include/internal/pycore_lock.h
+++ b/Include/internal/pycore_lock.h
@@ -48,6 +48,9 @@ typedef enum _PyLockFlags {
 
     // Handle signals if interrupted while waiting on the lock.
     _PY_LOCK_HANDLE_SIGNALS = 2,
+
+    // Fail if interrupted by a signal while waiting on the lock.
+    _PY_FAIL_IF_INTERRUPTED = 4,
 } _PyLockFlags;
 
 // Lock a mutex with an optional timeout and additional options. See