From d0259cd3ba14b0ba3bb5107abf12480323e9e8c1 Mon Sep 17 00:00:00 2001
From: Pietro Cerutti <pcerutti2@bloomberg.net>
Date: Mon, 22 Sep 2025 19:14:05 +0000
Subject: [PATCH 1/2] AVRO-4185: [C++] Use a temp file in StreamTests

StreamTests uses the test_str.bin file. This is problematic in our setup because we build and test 32-bit and 64-bit versions in parallel. When the 32-bit and 64-bit StreamTest happen to run concurrently, one ends up deleting the file that the other is trying to read.

My solution here is to use a temporary file instead of the hard-coded test_str.bin.
---
 lang/c++/test/StreamTests.cc | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/lang/c++/test/StreamTests.cc b/lang/c++/test/StreamTests.cc
index d14558ecd28..f179e8dbed9 100644
--- a/lang/c++/test/StreamTests.cc
+++ b/lang/c++/test/StreamTests.cc
@@ -21,6 +21,7 @@
 #include <boost/test/included/unit_test.hpp>
 #include <boost/test/parameterized_test.hpp>
 
+#include <cstdio>
 #include <filesystem>
 
 namespace avro {
@@ -134,36 +135,34 @@ void testNonEmpty2(const TestData &td) {
     Verify1()(*is, td.dataSize);
 }
 
-static const char filename[] = "test_str.bin";
-
-struct FileRemover {
-    const std::filesystem::path file;
-    explicit FileRemover(const char *fn) : file(fn) {}
-    ~FileRemover() { std::filesystem::remove(file); }
+struct FileGuard {
+    const std::filesystem::path path{ std::tmpnam(nullptr) };
+    ~FileGuard() { std::filesystem::remove(path); }
+    const char* filename() const { return path.c_str(); };
 };
 
 template<typename V>
 void testEmpty_fileStream() {
-    FileRemover fr(filename);
+    FileGuard fg;
     {
-        std::unique_ptr<OutputStream> os = fileOutputStream(filename);
+        std::unique_ptr<OutputStream> os = fileOutputStream(fg.filename());
     }
-    std::unique_ptr<InputStream> is = fileInputStream(filename);
+    std::unique_ptr<InputStream> is = fileInputStream(fg.filename());
     V()
     (*is);
 }
 
 template<typename F, typename V>
 void testNonEmpty_fileStream(const TestData &td) {
-    FileRemover fr(filename);
+    FileGuard fg;
     {
-        std::unique_ptr<OutputStream> os = fileOutputStream(filename,
+        std::unique_ptr<OutputStream> os = fileOutputStream(fg.filename(),
                                                             td.chunkSize);
         F()
         (*os, td.dataSize);
     }
 
-    std::unique_ptr<InputStream> is = fileInputStream(filename, td.chunkSize);
+    std::unique_ptr<InputStream> is = fileInputStream(fg.filename(), td.chunkSize);
     V()
     (*is, td.dataSize);
 }

From af1c75bc6a308548c62abbfa5a4d9ae7d331e1b4 Mon Sep 17 00:00:00 2001
From: Pietro Cerutti <gahr@gahr.ch>
Date: Thu, 23 Oct 2025 09:34:46 +0200
Subject: [PATCH 2/2] Update lang/c++/test/StreamTests.cc

Co-authored-by: Martin Grigorov <martin-g@users.noreply.github.com>
---
 lang/c++/test/StreamTests.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lang/c++/test/StreamTests.cc b/lang/c++/test/StreamTests.cc
index f179e8dbed9..71f889469a1 100644
--- a/lang/c++/test/StreamTests.cc
+++ b/lang/c++/test/StreamTests.cc
@@ -138,7 +138,7 @@ void testNonEmpty2(const TestData &td) {
 struct FileGuard {
     const std::filesystem::path path{ std::tmpnam(nullptr) };
     ~FileGuard() { std::filesystem::remove(path); }
-    const char* filename() const { return path.c_str(); };
+    const char* filename() const { return path.c_str(); }
 };
 
 template<typename V>