unit test failed in all probability in CI environment when pull request

[YesterdayxD]

Ⅰ. Issue Description

unit test failed in all probability in CI environment when pull request

Ⅱ. Describe what happened

unit test printed the following error:
FAIL: TestSuite/TestReleaseBuffer

Ⅲ. Describe what you expected to happen

unit test passes

Ⅳ. How to reproduce it (as minimally and precisely as possible)

1. run unit test

Ⅴ. Anything else we need to know?

Chencheng Zhou refered to the following comment about the GET method of the Type Pool in Dragonfly DingDing DevGroup.

// Get selects an arbitrary item from the Pool, removes it from the
// Pool, and returns it to the caller.
// Get may choose to ignore the pool and treat it as empty.
// Callers should not assume any relation between values passed to Put and
// the values returned by Get.
//
// If Get would otherwise return nil and p.New is non-nil, Get returns
// the result of calling p.New.
func (p *Pool) Get() interface{}

Ⅵ. Environment:

• dragonfly version: master
• OS (e.g. from /etc/os-release): CI environment(I am not sure)
• Kernel (e.g. uname -a): CI environment ((I am not sure)
• Install tools:
• Others:

[jim3ma]

@lowzj PTAL

[SataQiu]

/assign