gh-112532: Isolate abandoned segments by interpreter (#113717)

* gh-112532: Isolate abandoned segments by interpreter

Mimalloc segments are data structures that contain memory allocations along
with metadata. Each segment is "owned" by a thread. When a thread exits,
it abandons its segments to a global pool to be later reclaimed by other
threads. This changes the pool to be per-interpreter instead of process-wide.

This will be important for when we use mimalloc to find GC objects in the
`--disable-gil` builds. We want heaps to only store Python objects from a
single interpreter. Absent this change, the abandoning and reclaiming process
could break this isolation.

* Add missing '&_mi_abandoned_default' to 'tld_empty'

1 files changed, 5 insertions, 0 deletions

diff --git a/Include/internal/pycore_interp.h b/Include/internal/pycore_interp.h
index 04d7a6a..4512b1e 100644
--- a/Include/internal/pycore_interp.h
+++ b/Include/internal/pycore_interp.h
@@ -27,6 +27,7 @@ extern "C" {
 #include "pycore_import.h"        // struct _import_state
 #include "pycore_instruments.h"   // _PY_MONITORING_EVENTS
 #include "pycore_list.h"          // struct _Py_list_state
+#include "pycore_mimalloc.h"      // struct _mimalloc_interp_state
 #include "pycore_object_state.h"  // struct _py_object_state
 #include "pycore_obmalloc.h"      // struct _obmalloc_state
 #include "pycore_tstate.h"        // _PyThreadStateImpl
@@ -166,6 +167,10 @@ struct _is {
     struct _warnings_runtime_state warnings;
     struct atexit_state atexit;
 
+#if defined(Py_GIL_DISABLED)
+    struct _mimalloc_interp_state mimalloc;
+#endif
+
     struct _obmalloc_state obmalloc;
 
     PyObject *audit_hooks;