Add session pool example. (#107)

* Add session pool example.

* Fix typo.

* Fix compile.

* Expose session pool symbols.

.github/workflows/pull_request.yml

@@ -161,6 +161,7 @@ jobs:
             rm /usr/lib/x86_64-linux-gnu/libstdc++.so.6
             ln -s /opt/vesoft/toolset/clang/10.0.0/lib64/libstdc++.so /usr/lib/x86_64-linux-gnu/libstdc++.so.6
             LD_LIBRARY_PATH=/usr/local/nebula/lib64:/usr/local/nebula/lib:$LD_LIBRARY_PATH ./build/session_example graphd:9669
+            LD_LIBRARY_PATH=/usr/local/nebula/lib64:/usr/local/nebula/lib:$LD_LIBRARY_PATH ./build/session_pool_example graphd:9669
             popd
             ;;
           esac

examples/CMakeLists.txt

@@ -35,6 +35,10 @@ add_executable(session_example
     SessionExample.cpp
 )
 
+add_executable(session_pool_example
+    SessionPoolExample.cpp
+)
+
 add_executable(storage_client_example
     StorageClientExample.cpp
 )
@@ -44,6 +48,11 @@ target_link_libraries(session_example
         nebula_graph_client
 )
 
+target_link_libraries(session_pool_example
+    PRIVATE
+        nebula_graph_client
+)
+
 target_link_libraries(storage_client_example
     PRIVATE
         nebula_storage_client

examples/SessionPoolExample.cpp

@@ -0,0 +1,49 @@
+// Copyright (c) 2022 vesoft inc. All rights reserved.
+//
+// This source code is licensed under Apache 2.0 License.
+
+#include <common/Init.h>
+#include <nebula/client/SessionPool.h>
+
+#include <atomic>
+#include <chrono>
+#include <thread>
+#include "nebula/client/Config.h"
+
+int main(int argc, char* argv[]) {
+  nebula::init(&argc, &argv);
+  {
+    // Create space
+    nebula::ConnectionPool pool;
+    auto config = nebula::Config{};
+    config.maxConnectionPoolSize_ = 1;
+    pool.init({"127.0.0.1:9669"}, config);
+    auto session = pool.getSession("root", "nebula");
+    assert(session.valid());
+
+    auto resp = session.execute(
+        "CREATE SPACE IF NOT EXISTS session_pool_test(vid_type = FIXED_STRING(16));");
+    assert(resp.errorCode == nebula::ErrorCode::SUCCEEDED);
+  }
+
+  nebula::SessionPoolConfig config;
+  config.username_ = "root";
+  config.password_ = "nebula";
+  config.addrs_ = {"127.0.0.1:9669"};
+  config.spaceName_ = "session_pool_test";
+  config.maxSize_ = 10;
+  nebula::SessionPool pool(config);
+  pool.init();
+
+  std::vector<std::thread> threads;
+  for (std::size_t i = 0; i < config.maxSize_; ++i) {
+    threads.emplace_back([&pool]() {
+      auto resp = pool.execute("YIELD 1");
+      assert(resp.errorCode == nebula::ErrorCode::SUCCEEDED);
+      std::cout << "Result: " << *resp.data << std::endl;
+    });
+  }
+  for (auto& t : threads) {
+    t.join();
+  }
+}

exported-symbols.map

@@ -11,6 +11,7 @@ global:
         nebula::ConnectionPool::*;
         "nebula::init(int*, char***)";
         nebula::Session::*;
+        nebula::SessionPool::*;
         nebula::Value::*;
         nebula::DataSet::*;
         nebula::Date::*;