(POC V2) GODRIVER-3173 Complete pending reads on conn checkout

[prestonvasquez]

Summary

Background & Motivation

[mongodb-drivers-pr-bot]

API Change Report

./v2/event

compatible changes

ConnectionPendingReadFailed: added
ConnectionPendingReadStarted: added
ConnectionPendingReadSucceeded: added
PoolEvent.RemainingTime: added
PoolEvent.RequestID: added

./v2/x/mongo/driver/topology

incompatible changes

BGReadCallback: removed
BGReadTimeout: removed

compatible changes

PendingReadTimeout: added

[Copilot]

Pull Request Overview

This pull request implements changes to support completing pending reads on connection checkout. Key changes include:

• Adding new YAML tests for client‐side operation timeouts related to pending reads.
• Updating connection and pool logic to handle pending reads with context values (e.g. maxTimeMS and requestID) and synchronizing background reads.
• Introducing new monitoring events and updating event verification and test instrumentation to track pending read events.

Reviewed Changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
testdata/client-side-operations-timeout/pending-reads.yml	New YAML tests for handling operation timeouts and pending read scenarios.
internal/integration/client_test.go	Updated concurrent operation tests to account for pending reads.
internal/driverutil/context.go	Added context helper functions for maxTimeMS and requestID propagation.
x/mongo/driver/topology/pool.go	Updated pool checkout logic to await completion of pending reads and renamed timeout constants.
x/mongo/driver/topology/pool_test.go	Revised pool tests to verify new pending read behaviors.
internal/integration/unified/event_verification.go	Added fields and tests for verifying new pending read pool events.
event/monitoring.go	Extended pool event monitoring with pending read event support.
x/mongo/driver/operation.go	Propagated context values in operation execution for pending read handling.
internal/integration/csot_test.go	Updated CSOT tests to ensure connection closure conditions with pending reads.

Comments suppressed due to low confidence (2)

internal/integration/unified/event_verification.go:61

• Field name 'ConnectionPendingreadSucceeded' should be 'ConnectionPendingReadSucceeded' to maintain consistent capitalization with the other pending read event fields.

ConnectionPendingreadSucceeded *struct{} `bson:"connectionPendingReadSucceeded"`

x/mongo/driver/topology/pool.go:908

• Typo in comment: 'alawys' should be corrected to 'always'. Consider removing or clarifying this inline question to avoid confusion.

if size == 0 { // Question: Would this alawys equal to zero?