From beb78b1499a2e7cdf7a07a53216a45e86ff9ee00 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20P=C3=A4tzel?= <david.paetzel@posteo.de>
Date: Wed, 23 Jul 2025 10:34:24 +0200
Subject: [PATCH 1/2] Use proper tempfiles in {de,}serialize

Serialization was broken/errored due to always using the same fixed file
name for the temporary pickle files. This is a problem in setups where
multiple instances of XCSF run in parallel (e.g. on Slurm clusters).
---
 xcsf/pybind_wrapper.cpp | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/xcsf/pybind_wrapper.cpp b/xcsf/pybind_wrapper.cpp
index aee42bc31..baa0f0b99 100644
--- a/xcsf/pybind_wrapper.cpp
+++ b/xcsf/pybind_wrapper.cpp
@@ -649,8 +649,15 @@ class XCS
     py::bytes
     serialize() const
     {
-        // Write XCSF to a temporary binary file
-        const char *filename = "_tmp_pickle.bin";
+        // Create a unique temporary file in /tmp. The file name is made unique
+        // in place by mkstemp.
+        char filename[] = "/tmp/xcsf_pickle_XXXXXX";
+        int fd = mkstemp(filename);
+        if (fd == -1) {
+            throw std::runtime_error("Failed to create temporary file in serialize");
+        }
+        close(fd);
+
         xcsf_save(&xcs, filename);
         // Read the binary file into bytes
         std::ifstream file(filename, std::ios::binary);
@@ -673,8 +680,16 @@ class XCS
     static XCS
     deserialize(const py::bytes &state)
     {
-        // Write the XCSF bytes to a temporary binary file
-        const char *filename = "_tmp_pickle.bin";
+        // Create a unique temporary file in /tmp. The file name is made unique
+        // in place by mkstemp.
+        char filename[] = "/tmp/xcsf_pickle_XXXXXX";
+        int fd = mkstemp(filename);
+        if (fd == -1) {
+            throw std::runtime_error("Failed to create temporary file in deserialize");
+        }
+        close(fd);
+
+        // Write the XCSF bytes to the temporary file.
         std::ofstream file(filename, std::ios::binary);
         file.write(state.cast<std::string>().c_str(),
                    state.cast<std::string>().size());

From c1948050d131562541135b7175348eec9202694d Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Fri, 8 Aug 2025 09:07:17 +0000
Subject: [PATCH 2/2] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 xcsf/pybind_wrapper.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/xcsf/pybind_wrapper.cpp b/xcsf/pybind_wrapper.cpp
index baa0f0b99..5e781b1f5 100644
--- a/xcsf/pybind_wrapper.cpp
+++ b/xcsf/pybind_wrapper.cpp
@@ -654,7 +654,8 @@ class XCS
         char filename[] = "/tmp/xcsf_pickle_XXXXXX";
         int fd = mkstemp(filename);
         if (fd == -1) {
-            throw std::runtime_error("Failed to create temporary file in serialize");
+            throw std::runtime_error(
+                "Failed to create temporary file in serialize");
         }
         close(fd);
 
@@ -685,7 +686,8 @@ class XCS
         char filename[] = "/tmp/xcsf_pickle_XXXXXX";
         int fd = mkstemp(filename);
         if (fd == -1) {
-            throw std::runtime_error("Failed to create temporary file in deserialize");
+            throw std::runtime_error(
+                "Failed to create temporary file in deserialize");
         }
         close(fd);