From: Victor Stinner <vstinner@python.org>
Date: Wed, 6 May 2020 16:25:06 +0000 (+0200)
Subject: bpo-40533: Disable GC in subinterpreters (GH-19961)
X-Git-Tag: v3.9.0b1~153
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d8135e913ab7c694db247c86d0a84c450c32d86e;p=thirdparty%2FPython%2Fcpython.git

bpo-40533: Disable GC in subinterpreters (GH-19961)

When Python is built with experimental isolated interpreters, a
garbage collection now does nothing in an isolated interpreter.

Temporary workaround until subinterpreters stop sharing Python
objects.
---

diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index 56dcb101e000..a44752b1cc4d 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -1181,6 +1181,14 @@ collect(PyThreadState *tstate, int generation,
     _PyTime_t t1 = 0;   /* initialize to prevent a compiler warning */
     GCState *gcstate = &tstate->interp->gc;
 
+#ifdef EXPERIMENTAL_ISOLATED_SUBINTERPRETERS
+    if (tstate->interp->config._isolated_interpreter) {
+        // bpo-40533: The garbage collector must not be run on parallel on
+        // Python objects shared by multiple interpreters.
+        return 0;
+    }
+#endif
+
     if (gcstate->debug & DEBUG_STATS) {
         PySys_WriteStderr("gc: collecting generation %d...\n", generation);
         show_stats_each_generations(gcstate);