Function TestCounterInt64_TimestampCollision

data/shared_state_variable_test.go:1473–1517

TestCounterInt64_TimestampCollision tests that allocateUpdatedAtMs produces unique timestamps even when called rapidly within the same millisecond.

(t *testing.T)

// TestCounterInt64_TimestampCollision tests that allocateUpdatedAtMs produces unique timestamps
// even when called rapidly within the same millisecond.
func TestCounterInt64_TimestampCollision(t *testing.T) {
	t.Run("allocateUpdatedAtMs produces monotonically increasing timestamps", func(t *testing.T) {
		base := &baseSharedVariable{}

		// Rapidly allocate many timestamps
		timestamps := make([]int64, 1000)
		for i := 0; i < 1000; i++ {
			timestamps[i] = base.allocateUpdatedAtMs()
		}

		// All should be strictly increasing
		for i := 1; i < len(timestamps); i++ {
			assert.Greater(t, timestamps[i], timestamps[i-1],
				"timestamp %d should be > timestamp %d", i, i-1)
		}
	})

	t.Run("concurrent allocations produce unique timestamps", func(t *testing.T) {
		base := &baseSharedVariable{}

		var wg sync.WaitGroup
		results := make(chan int64, 100)

		// 10 goroutines each allocate 10 timestamps
		for g := 0; g < 10; g++ {
			wg.Add(1)
			go func() {
				defer wg.Done()
				for i := 0; i < 10; i++ {
					results <- base.allocateUpdatedAtMs()
				}
			}()
		}
		wg.Wait()
		close(results)

		// Collect all timestamps
		seen := make(map[int64]bool)
		for ts := range results {
			assert.False(t, seen[ts], "duplicate timestamp detected: %d", ts)
			seen[ts] = true
		}
		assert.Equal(t, 100, len(seen), "should have 100 unique timestamps")
	})
}

// TestCounterInt64_BackgroundPushCoalescing tests that multiple rapid TryUpdate calls
// are coalesced into fewer remote pushes.