`IOError` during tracing when running `PG::Connection#exec` in a thread

Current behaviour

Hello,

We're getting the following IOError when using the parallel gem in the following way:

IOError: stream closed in another thread (IOError)
  from ddtrace (1.23.3) lib/datadog/tracing/contrib/pg/instrumentation.rb:27:in `exec'
  from ddtrace (1.23.3) lib/datadog/tracing/contrib/pg/instrumentation.rb:27:in `block in exec'
  from ddtrace (1.23.3) lib/datadog/tracing/contrib/pg/instrumentation.rb:142:in `block in trace'
  from ddtrace (1.23.3) lib/datadog/tracing/trace_operation.rb:198:in `block in measure'
  from ddtrace (1.23.3) lib/datadog/tracing/span_operation.rb:150:in `measure'
  from ddtrace (1.23.3) lib/datadog/tracing/trace_operation.rb:198:in `measure'
  from ddtrace (1.23.3) lib/datadog/tracing/tracer.rb:385:in `start_span'
  from ddtrace (1.23.3) lib/datadog/tracing/tracer.rb:159:in `block in trace'
  from ddtrace (1.23.3) lib/datadog/tracing/context.rb:45:in `activate!'
  from ddtrace (1.23.3) lib/datadog/tracing/tracer.rb:158:in `trace'
  from ddtrace (1.23.3) lib/datadog/tracing.rb:18:in `trace'
  from ddtrace (1.23.3) lib/datadog/tracing/contrib/pg/instrumentation.rb:105:in `trace'
  from ddtrace (1.23.3) lib/datadog/tracing/contrib/pg/instrumentation.rb:26:in `exec'
  from packs/devtools/db/app/services/devtools/fork_database_helper.rb:217:in `block in analyze'

My usage:

# packs/devtools/db/app/services/devtools/fork_database_helper.rb

def analyze(tables_to_analyze)
  Parallel.each(tables_to_analyze, in_threads: 4) do |table|
    conn = PG::Connection.new(connection_string)
    conn.exec("ANALYZE #{table}") # This is line 217
  ensure
    conn.finish if conn && !conn.finished?
  end
end

Expected behaviour

No error is thrown

Steps to reproduce

Running the code above

Environment

datadog version: ddtrace (1.23.3), libdatadog (7.0.0.1.0)

Configuration block (Datadog.configure ...):

Datadog.configure do |c|
c.diagnostics.debug if ENV['DD_DEBUG'].present?
c.tracing.partial_flush.enabled = %w[t true 1].include?(ENV['DD_PARTIAL_FLUSH'])

c.profiling.enabled = true
c.profiling.advanced.force_enable_gc_profiling = true

c.env = Rails.env.to_s
c.service = Rails.application.class.module_parent.name.downcase
c.version = ENV['SOURCE_VERSION']

c.tracing.instrument :rails, request_queuing: :exclude_request
c.tracing.instrument :sidekiq, tag_args: true, service_name: 'sidekiq'
if ENV['REDIS_URL'].present?
  c.tracing.instrument :redis, describes: { url: ENV['REDIS_URL'] }, service_name: 'redis'
end
if ENV['REDIS_CACHE_URL'].present?
  c.tracing.instrument :redis, describes: { url: ENV['REDIS_CACHE_URL'] }, service_name: 'redis-cache'
end
c.tracing.instrument :http, split_by_domain: true
c.tracing.instrument :httpclient, split_by_domain: true
c.tracing.instrument :stripe
c.tracing.instrument :aws
c.tracing.instrument :rake
c.tracing.instrument :pg, comment_propagation: 'full'

# Track read-replica separately from primary
c.tracing.instrument :active_record, describes: :primary_replica, service_name: 'jeancaisse-postgres-replica'

# Enable DataDog runtime metrics (currently in beta phase)
c.runtime_metrics.enabled = true

# Add tags to all traces (documentation: https://datadoghq.dev/dd-trace-rb/#environment-and-tags)
# The repository URL is hardcoded because it's not expected to change frequently.
# If it does change, it will break the source code integration for DataDog, which can be easily fixed.
c.tags = {
  'git.repository_url' => 'https://github.com/pennylane-hq/jeancaisse',
  'git.commit.sha' => ENV['SOURCE_VERSION'],
}
end

Ruby version: ruby 3.3.4 (2024-07-09 revision be1089c8ec) [aarch64-linux]
Operating system:: aarch64 GNU/Linux running in a Docker image originating from ruby:3.3.4-slim-bookworm
Relevant library versions: parallel (1.26.3)

DataDog / dd-trace-rb

`IOError` during tracing when running `PG::Connection#exec` in a thread #3891