update

Author: xiehuc

ext/include/opentelemetry/ext/http/client/curl/http_client_curl.h

@@ -357,7 +357,7 @@ class HttpClient : public opentelemetry::ext::http::client::HttpClient
   std::chrono::milliseconds scheduled_delay_milliseconds_;
 
   std::chrono::milliseconds background_thread_wait_for_;
-  std::atomic<bool> is_shutdown;
+  std::atomic<bool> is_shutdown_;
 
   nostd::shared_ptr<HttpCurlGlobalInitializer> curl_global_initializer_;
 };

ext/src/http/client/curl/http_client_curl.cc

@@ -192,12 +192,12 @@ HttpClient::HttpClient()
       background_thread_wait_for_{std::chrono::minutes{1}},
       curl_global_initializer_(HttpCurlGlobalInitializer::GetInstance())
 {
-  is_shutdown.store(false);
+  is_shutdown_.store(false);
 }
 
 HttpClient::~HttpClient()
 {
-  is_shutdown.store(true, std::memory_order_release);
+  is_shutdown_.store(true, std::memory_order_release);
   while (true)
   {
     std::unique_ptr<std::thread> background_thread;
@@ -432,14 +432,16 @@ void HttpClient::MaybeSpawnBackgroundThread()
             continue;
           }
 
-          std::chrono::milliseconds wait_for;
+          std::chrono::milliseconds wait_for = std::chrono::milliseconds::zero();
+          ;
 #if LIBCURL_VERSION_NUM >= 0x074200
-          // only avaliable with curl_multi_poll
+          // only avaliable with curl_multi_poll, because curl_multi_wait would cause CPU busy,
+          // curl_multi_wait+sleep could not wakeup quickly
           wait_for = self->background_thread_wait_for_;
 #endif
-          if (self->is_shutdown.load(std::memory_order_acquire))
+          if (self->is_shutdown_.load(std::memory_order_acquire))
           {
-            wait_for = std::chrono::milliseconds{0};
+            wait_for = std::chrono::milliseconds::zero();
           }
 
           if (now - last_free_job_timepoint < wait_for)
@@ -541,7 +543,7 @@ void HttpClient::SetBackgroundWaitFor(std::chrono::milliseconds ms)
 
 void HttpClient::WaitBackgroundThreadExit()
 {
-  is_shutdown.store(true, std::memory_order_release);
+  is_shutdown_.store(true, std::memory_order_release);
   std::unique_ptr<std::thread> background_thread;
   {
     std::lock_guard<std::mutex> lock_guard{background_thread_m_};
@@ -552,7 +554,7 @@ void HttpClient::WaitBackgroundThreadExit()
   {
     background_thread->join();
   }
-  is_shutdown.store(false, std::memory_order_release);
+  is_shutdown_.store(false, std::memory_order_release);
 }
 
 void HttpClient::wakeupBackgroundThread()

ext/test/http/curl_http_test.cc

@@ -530,8 +530,9 @@ TEST_F(BasicCurlHttpTests, FinishInAsyncCallback)
 TEST_F(BasicCurlHttpTests, ElegantQuitQuick)
 {
   auto http_client = http_client::HttpClientFactory::Create();
-  std::dynamic_pointer_cast<curl::HttpClient>(http_client)->MaybeSpawnBackgroundThread();
-  auto beg     = std::chrono::system_clock::now();
+  std::static_pointer_cast<curl::HttpClient>(http_client)->MaybeSpawnBackgroundThread();
+  auto beg = std::chrono::system_clock::now();
+  // start background first, then test it could wakeup
   auto session = http_client->CreateSession("http://127.0.0.1:19000/get/");
   auto request = session->CreateRequest();
   request->SetUri("get/");
@@ -540,7 +541,9 @@ TEST_F(BasicCurlHttpTests, ElegantQuitQuick)
   http_client->FinishAllSessions();
   http_client.reset();
   // when use background_thread_wait_for_ should have no side effort on elegant quit
-  ASSERT_TRUE(std::chrono::system_clock::now() - beg < std::chrono::milliseconds{5});
+  // because ci machine may slow, so we assert it cost should less than
+  // scheduled_delay_milliseconds_
+  ASSERT_TRUE(std::chrono::system_clock::now() - beg < std::chrono::milliseconds{20});
   ASSERT_TRUE(handler->is_called_);
   ASSERT_TRUE(handler->got_response_);
 }