Potential Memory Leak Due to Slice Expression

[Lslightly]

Describe the bug

Dear developers,

I used a self-written code linter to check the project and discovered a potential memory leak issue.

In the following code, before the slice expression iter.objects[1:], the elements of iter.objects[0] are not set to nil. This could potentially cause the objects pointed to by each element of iter.objects[0] to be continuously referenced by the underlying array pointed to by the iter.objects slice. As a result, these objects may not be garbage collected in a timely manner by the garbage collector.

aws-sdk-go/service/s3/s3manager/batch.go

Line 171 in 7112c0a

iter.objects = iter.objects[1:]

// Next will use the S3API client to iterate through a list of objects.
func (iter *DeleteListIterator) Next() bool {
	if len(iter.objects) > 0 {
		iter.objects = iter.objects[1:]
	}

	if len(iter.objects) == 0 && iter.Paginator.Next() {
		iter.objects = iter.Paginator.Page().(*s3.ListObjectsOutput).Contents
	}

	return len(iter.objects) > 0
}

In a high-load production environment, if this memory leak persists, it could lead to increased memory consumption and eventually slow down the application or even cause out-of-memory errors.

A possible solution is setting the elements of iter.objects[0] to nil before the slice expression. This way, the objects that are no longer needed after the slice expression can be properly garbage collected.

However, I am not sure if this is indeed a problem. I would greatly appreciate it if you can kindly confirm whether setting nil may cause wrong behaviors of the program.

Thank you for your time and efforts in reading this issue and maintaining the project.

Regression Issue

• Select this option if this issue appears to be a regression.

Expected Behavior

Setting nil does not affect the behavior.

Current Behavior

No nil setting exist.

Reproduction Steps

The code is detected statically.

Possible Solution

No response

Additional Information/Context

No response

SDK version used

none

Environment details (Version of Go (go version)? OS name and version, etc.)

none

[Madrigal]

Hi @Lslightly,

Thank you for taking the time to report this. We appreciate your diligence in identifying this possible memory leak concern.

First thing to note: This is the version 1 of the Go SDK, which is currently on maintenance mode (see pinned issue #5270). Because of this, we will unfortunately not be making any changes to this package unless they are critical or address a security issue.

Instead, we would kindly ask that you please try running your linter in the aws-sdk-go-v2 project, where active development is happening. We would be more than happy to investigate further any issues brought up and work towards a resolution.

Answering your question

However, I am not sure if this is indeed a problem. I would greatly appreciate it if you can kindly confirm whether setting nil may cause wrong behaviors of the program.

It does seem like a potential memory leak, specially under high pressure.

Thank you again for your contribution and for helping us improve the quality of our software.

[Lslightly]

Thanks for your patience and I will try aws-sdk-go-v2.

[github-actions]

Comments on closed issues are hard for our team to see.
If you need more assistance, please either tag a team member or open a new issue that references this one.
If you wish to keep having a conversation with other community members under this issue feel free to do so.