Regression test WIP.

This hits the retry loop sometimes, but needs to be more reliable.

Author: shaunrd0

test/src/unit-cppapi-metadata.cc

@@ -30,6 +30,8 @@
  * Tests the C++ API for array metadata.
  */
 
+#include <tiledb/api/c_api/array/array_api_internal.h>
+#include <latch>
 #include "test/support/src/helpers.h"
 #include "test/support/src/vfs_helpers.h"
 #include "tiledb/sm/c_api/tiledb.h"
@@ -180,6 +182,55 @@ TEST_CASE_METHOD(
   array.close();
 }
 
+TEST_CASE_METHOD(
+    CPPMetadataFx,
+    "C++ API: Metadata write / read at timestamp smr",
+    "[cppapi][metadata][timestamp][smr]") {
+  create_default_array_1d();
+  Context ctx;
+
+  std::vector<uint64_t> a(100);
+  std::iota(a.begin(), a.end(), 0);
+  std::vector<uint64_t> b(1000);
+  std::iota(b.begin(), b.end(), 0);
+
+  const auto tp = TemporalPolicy(TimestampStartEnd, 0, 1);
+  std::latch latch(2);
+  std::string meta[]{"a", "b", "c", "d", "e", "f"};
+  Array array1(ctx, std::string(array_name_), TILEDB_WRITE, tp);
+  array1.put_metadata("a", TILEDB_UINT64, 100, a.data());
+  array1.close();
+
+  Array array(ctx, std::string(array_name_), TILEDB_WRITE, tp);
+  std::thread t1([&]() {
+    for (const auto& x : meta) {
+      array.put_metadata(x, TILEDB_UINT64, 1000, b.data());
+    }
+    latch.count_down();
+    array.close();
+  });
+
+  std::thread t2([&]() {
+    latch.arrive_and_wait();
+    Array read_array(ctx, std::string(array_name_), TILEDB_READ, tp);
+
+    for (const auto& x : meta) {
+      tiledb_datatype_t type;
+      uint32_t value_num = 0;
+      const void* data;
+      read_array.get_metadata(x, &type, &value_num, &data);
+      std::cout << "'value_num':" << value_num << std::endl;
+      std::cout << "'" << x << "': ";
+      for (size_t i = 0; i < value_num; ++i) {
+        std::cout << ((const uint64_t*)data)[i] << ",";
+      }
+      std::cout << std::endl;
+    }
+    read_array.close();
+  });
+  t1.join(), t2.join();
+}
+
 TEST_CASE_METHOD(
     CPPMetadataFx,
     "C++ API: Metadata, write/read",

tiledb/sm/array/array_directory.cc

@@ -366,18 +366,17 @@ Status ArrayDirectory::load() {
 
       // Load (in parallel) the array metadata URIs
       tasks.emplace_back(resources_.get().compute_tp().execute([&]() {
-        float delay = 250;
-        constexpr int max_retries = 25;
+        int delay = 250, max_retries = 25;
         for (int retry = 0; retry <= max_retries; ++retry) {
           if (load_array_meta_uris()) {
             break;
           }
-          // Retry if some metadata files were still flushing to disk.
+          // Retry is triggered if metadata files were still flushing to disk.
           std::this_thread::sleep_for(std::chrono::milliseconds(delay));
           resources_.get().logger()->info(
               "Encountered partially written array metadata while opening the "
               "array. Waiting {}ms and retrying.", delay);
-          // Apply default REST backoff and retry up to 25 times.
+          // Apply (default REST) backoff and retry up to 25 times.
           delay *= 1.25;
         }
         return Status::Ok();