(pulsar-client-cpp) branch main updated: Fix wrong TimeUtils::currentTimeMillis() implementation (#387)

[xyz]

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xyz pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/pulsar-client-cpp.git


The following commit(s) were added to refs/heads/main by this push:
     new 6eb228e  Fix wrong TimeUtils::currentTimeMillis() implementation (#387)
6eb228e is described below

commit 6eb228e117b52a95c144c95d5694860ac98446b9
Author: Yunze Xu <xyzinfern...@163.com>
AuthorDate: Fri Jan 19 09:57:25 2024 +0800

    Fix wrong TimeUtils::currentTimeMillis() implementation (#387)
    
    ### Motivation
    
    `TimeUtils::currentTimeMillis()` is used to get the timestamp since
    1970 but `high_resolution_clock` does not necessarily represent the
    system clock. For example, given the following code:
    
    ```c++
    template <typename Clock>
    inline int64_t getTimestamp() {
        using namespace std::chrono;
        return 
duration_cast<milliseconds>(Clock::now().time_since_epoch()).count();
    }
    
    int main() {
        std::cout << time(nullptr) << std::endl;
        std::cout << getTimestamp<std::chrono::system_clock>() << std::endl;
        std::cout << getTimestamp<std::chrono::high_resolution_clock>() << 
std::endl;
    }
    ```
    
    The outputs could be:
    
    ```
    1705584279
    1705584279351
    38566832
    ```
    
    ### Modifications
    
    Use `std::system_clock` for `currentTimeMillis()`. Add
    `BackoffTest.testCurrentTimeMillis` to verify the result is similar to
    1000 times of `time(nullptr)` (the timestamp in seconds from the C API).
---
 lib/TimeUtils.h      | 3 ++-
 tests/BackoffTest.cc | 8 ++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/TimeUtils.h b/lib/TimeUtils.h
index 03f563c..53f537a 100644
--- a/lib/TimeUtils.h
+++ b/lib/TimeUtils.h
@@ -35,8 +35,9 @@ inline decltype(std::chrono::milliseconds(0).count()) 
toMillis(TimeDuration dura
 class PULSAR_PUBLIC TimeUtils {
    public:
     static ptime now() { return std::chrono::high_resolution_clock::now(); }
+
     static int64_t currentTimeMillis() {
-        return 
std::chrono::duration_cast<std::chrono::milliseconds>(now().time_since_epoch()).count();
+        return toMillis(std::chrono::system_clock::now().time_since_epoch());
     }
 };
 
diff --git a/tests/BackoffTest.cc b/tests/BackoffTest.cc
index 5fe4f71..9c30a63 100644
--- a/tests/BackoffTest.cc
+++ b/tests/BackoffTest.cc
@@ -17,12 +17,14 @@
  * under the License.
  */
 #include <gtest/gtest.h>
+#include <time.h>
 
 #include <thread>
 
 #include "PulsarFriend.h"
 #include "lib/Backoff.h"
 #include "lib/ClientConnection.h"
+#include "lib/TimeUtils.h"
 #include "lib/stats/ProducerStatsImpl.h"
 
 using namespace pulsar;
@@ -43,6 +45,12 @@ static bool withinTenPercentAndDecrementTimer(Backoff& 
backoff, const unsigned i
     return (t1 >= t2 * 0.9 && t1 <= t2);
 }
 
+TEST(BackoffTest, testCurrentTimeMillis) {
+    auto t1 = TimeUtils::currentTimeMillis();
+    auto t2 = 1000L * time(nullptr);
+    ASSERT_TRUE(t1 - t2 < 1000L) << "t1: " << t1 << ", t2: " << t2;
+}
+
 TEST(BackoffTest, mandatoryStopTestNegativeTest) {
     Backoff backoff(milliseconds(100), seconds(60), milliseconds(1900));
     ASSERT_EQ(toMillis(backoff.next()), 100);