smaheshwar-pltr opened a new issue, #1089:
URL: https://github.com/apache/iceberg-cpp/issues/1089

   `HttpClient` sends every request through one `cpr::ConnectionPool` 
([http_client.cc#L201](https://github.com/apache/iceberg-cpp/blob/9c478f7571e89ef6388c4fa776d7a4e5f448cbac/src/iceberg/catalog/rest/http_client.cc#L201)).
 That pool wraps a libcurl share handle that shares the connection cache, and 
[libcurl doesn't support](https://curl.se/libcurl/c/CURLSHOPT_SHARE.html) using 
a shared connection cache from several threads at once. When two requests 
overlap, the process can crash.
   
   A `RestCatalog` sends all its requests through one `HttpClient`, so requests 
can overlap even when the application only calls the catalog from one thread:
   
   - Metrics reports are posted from the executor passed to `RestCatalog::Make` 
([rest_metrics_reporter.cc#L73-L74](https://github.com/apache/iceberg-cpp/blob/9c478f7571e89ef6388c4fa776d7a4e5f448cbac/src/iceberg/catalog/rest/rest_metrics_reporter.cc#L73-L74)).
   - OAuth2 tokens are refreshed on the `auth_executor` passed to 
`RestCatalog::Make` 
([auth_session_internal.h#L284](https://github.com/apache/iceberg-cpp/blob/9c478f7571e89ef6388c4fa776d7a4e5f448cbac/src/iceberg/catalog/rest/auth/auth_session_internal.h#L284)).
   - Vended S3 credentials are refreshed through LoadCredentials when the AWS 
SDK signs a request. The refresh runs on whichever thread is doing the S3 I/O 
([arrow_s3_file_io.cc#L701-L708](https://github.com/apache/iceberg-cpp/blob/9c478f7571e89ef6388c4fa776d7a4e5f448cbac/src/iceberg/arrow/s3/arrow_s3_file_io.cc#L701-L708),
 
[rest_catalog.cc#L91](https://github.com/apache/iceberg-cpp/blob/9c478f7571e89ef6388c4fa776d7a4e5f448cbac/src/iceberg/catalog/rest/rest_catalog.cc#L91)).
   
   Applications that share one catalog between threads run into it directly.
   
   The shared pool was introduced in apache/iceberg-cpp#530, which replaced a 
mutex-guarded `cpr::Session`.
   
   ### Reproduction
   
   Run this against the REST fixture that `rest_catalog_integration_test` uses:
   
   ```cpp
   HttpClient client;
   auto session = auth::AuthSession::MakeDefault({});
   std::vector<std::thread> threads;
   for (int i = 0; i < 32; ++i) {
     threads.emplace_back([&] {
       for (int j = 0; j < 200; ++j) {
         (void)client.Get("http://localhost:8181/v1/config";, {}, {},
                          *DefaultErrorHandler::Instance(), *session);
       }
     });
   }
   for (auto& thread : threads) thread.join();
   ```
   
   With libcurl 8.22.0, this aborted in 6 of 6 runs with heap corruption 
(`free(): corrupted unsorted chunks` or `double free or corruption`). Sharing 
one `RestCatalog` between 32 threads that each call `LoadTable` also crashes, 
with both 8.22.0 and 8.5.0. Neither reproduces with 8.18.0, the version CI 
uses, so CI doesn't catch it.
   
   


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