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rails--rails/activerecord/test/cases/transaction_callbacks_test.rb
Jeremy Daer 8fd123f7eb Fix corrupt transaction state caused by before_commit exceptions
When a `before_commit` callback raises, the database is rolled back but
AR's record of the current transaction is not, leaving the connection in
a perpetually broken state that affects all future users of the
connection: subsequent requests, jobs, etc. They'll think a transaction
is active when none is, so they won't BEGIN on their own. This manifests
as missing `after_commit` callbacks and broken ROLLBACKs.

This happens because `before_commit` callbacks fire before the current
transaction is popped from the stack, but the exception-handling path
they hit assumes that the current transaction was already popped. So the
database ROLLBACK is issued, but the transaction stack is left intact.

Common cause: deadlocked `#touch`, which is now implemented with
`before_commit` callbacks.

What's next:
* We shouldn't allow active transaction state when checking in or out
  from the connection pool. Verify that conns are clean.
* Closer review of txn manager sad paths. Are we missing other spots
  where we'd end up with incorrect txn state? What's the worst that can
  happen if txn state drifts? How can we guarantee it doesn't and
  contain the fallout if it does?

Thanks for @tomafro for expert diagnosis!
2016-02-01 14:12:49 -07:00

510 lines
15 KiB
Ruby

require "cases/helper"
require 'models/owner'
require 'models/pet'
require 'models/topic'
class TransactionCallbacksTest < ActiveRecord::TestCase
fixtures :topics, :owners, :pets
class ReplyWithCallbacks < ActiveRecord::Base
self.table_name = :topics
belongs_to :topic, foreign_key: "parent_id"
validates_presence_of :content
after_commit :do_after_commit, on: :create
attr_accessor :save_on_after_create
after_create do
self.save! if save_on_after_create
end
def history
@history ||= []
end
def do_after_commit
history << :commit_on_create
end
end
class TopicWithCallbacks < ActiveRecord::Base
self.table_name = :topics
has_many :replies, class_name: "ReplyWithCallbacks", foreign_key: "parent_id"
before_commit { |record| record.do_before_commit(nil) }
after_commit { |record| record.do_after_commit(nil) }
after_create_commit { |record| record.do_after_commit(:create) }
after_update_commit { |record| record.do_after_commit(:update) }
after_destroy_commit { |record| record.do_after_commit(:destroy) }
after_rollback { |record| record.do_after_rollback(nil) }
after_rollback(on: :create) { |record| record.do_after_rollback(:create) }
after_rollback(on: :update) { |record| record.do_after_rollback(:update) }
after_rollback(on: :destroy) { |record| record.do_after_rollback(:destroy) }
def history
@history ||= []
end
def before_commit_block(on = nil, &block)
@before_commit ||= {}
@before_commit[on] ||= []
@before_commit[on] << block
end
def after_commit_block(on = nil, &block)
@after_commit ||= {}
@after_commit[on] ||= []
@after_commit[on] << block
end
def after_rollback_block(on = nil, &block)
@after_rollback ||= {}
@after_rollback[on] ||= []
@after_rollback[on] << block
end
def do_before_commit(on)
blocks = @before_commit[on] if defined?(@before_commit)
blocks.each{|b| b.call(self)} if blocks
end
def do_after_commit(on)
blocks = @after_commit[on] if defined?(@after_commit)
blocks.each{|b| b.call(self)} if blocks
end
def do_after_rollback(on)
blocks = @after_rollback[on] if defined?(@after_rollback)
blocks.each{|b| b.call(self)} if blocks
end
end
def setup
@first = TopicWithCallbacks.find(1)
end
# FIXME: Test behavior, not implementation.
def test_before_commit_exception_should_pop_transaction_stack
@first.before_commit_block { raise 'better pop this txn from the stack!' }
original_txn = @first.class.connection.current_transaction
begin
@first.save!
fail
rescue
assert_equal original_txn, @first.class.connection.current_transaction
end
end
def test_call_after_commit_after_transaction_commits
@first.after_commit_block{|r| r.history << :after_commit}
@first.after_rollback_block{|r| r.history << :after_rollback}
@first.save!
assert_equal [:after_commit], @first.history
end
def test_only_call_after_commit_on_update_after_transaction_commits_for_existing_record
add_transaction_execution_blocks @first
@first.save!
assert_equal [:commit_on_update], @first.history
end
def test_only_call_after_commit_on_destroy_after_transaction_commits_for_destroyed_record
add_transaction_execution_blocks @first
@first.destroy
assert_equal [:commit_on_destroy], @first.history
end
def test_only_call_after_commit_on_create_after_transaction_commits_for_new_record
new_record = TopicWithCallbacks.new(:title => "New topic", :written_on => Date.today)
add_transaction_execution_blocks new_record
new_record.save!
assert_equal [:commit_on_create], new_record.history
end
def test_only_call_after_commit_on_create_after_transaction_commits_for_new_record_if_create_succeeds_creating_through_association
topic = TopicWithCallbacks.create!(:title => "New topic", :written_on => Date.today)
reply = topic.replies.create
assert_equal [], reply.history
end
def test_only_call_after_commit_on_create_and_doesnt_leaky
r = ReplyWithCallbacks.new(content: 'foo')
r.save_on_after_create = true
r.save!
r.content = 'bar'
r.save!
r.save!
assert_equal [:commit_on_create], r.history
end
def test_only_call_after_commit_on_update_after_transaction_commits_for_existing_record_on_touch
add_transaction_execution_blocks @first
@first.touch
assert_equal [:commit_on_update], @first.history
end
def test_only_call_after_commit_on_top_level_transactions
@first.after_commit_block{|r| r.history << :after_commit}
assert @first.history.empty?
@first.transaction do
@first.transaction(requires_new: true) do
@first.touch
end
assert @first.history.empty?
end
assert_equal [:after_commit], @first.history
end
def test_call_after_rollback_after_transaction_rollsback
@first.after_commit_block{|r| r.history << :after_commit}
@first.after_rollback_block{|r| r.history << :after_rollback}
Topic.transaction do
@first.save!
raise ActiveRecord::Rollback
end
assert_equal [:after_rollback], @first.history
end
def test_only_call_after_rollback_on_update_after_transaction_rollsback_for_existing_record
add_transaction_execution_blocks @first
Topic.transaction do
@first.save!
raise ActiveRecord::Rollback
end
assert_equal [:rollback_on_update], @first.history
end
def test_only_call_after_rollback_on_update_after_transaction_rollsback_for_existing_record_on_touch
add_transaction_execution_blocks @first
Topic.transaction do
@first.touch
raise ActiveRecord::Rollback
end
assert_equal [:rollback_on_update], @first.history
end
def test_only_call_after_rollback_on_destroy_after_transaction_rollsback_for_destroyed_record
add_transaction_execution_blocks @first
Topic.transaction do
@first.destroy
raise ActiveRecord::Rollback
end
assert_equal [:rollback_on_destroy], @first.history
end
def test_only_call_after_rollback_on_create_after_transaction_rollsback_for_new_record
new_record = TopicWithCallbacks.new(:title => "New topic", :written_on => Date.today)
add_transaction_execution_blocks new_record
Topic.transaction do
new_record.save!
raise ActiveRecord::Rollback
end
assert_equal [:rollback_on_create], new_record.history
end
def test_call_after_rollback_when_commit_fails
@first.after_commit_block { |r| r.history << :after_commit }
@first.after_rollback_block { |r| r.history << :after_rollback }
assert_raises RuntimeError do
@first.transaction do
tx = @first.class.connection.transaction_manager.current_transaction
def tx.commit
raise
end
@first.save
end
end
assert_equal [:after_rollback], @first.history
end
def test_only_call_after_rollback_on_records_rolled_back_to_a_savepoint
def @first.rollbacks(i=0); @rollbacks ||= 0; @rollbacks += i if i; end
def @first.commits(i=0); @commits ||= 0; @commits += i if i; end
@first.after_rollback_block{|r| r.rollbacks(1)}
@first.after_commit_block{|r| r.commits(1)}
second = TopicWithCallbacks.find(3)
def second.rollbacks(i=0); @rollbacks ||= 0; @rollbacks += i if i; end
def second.commits(i=0); @commits ||= 0; @commits += i if i; end
second.after_rollback_block{|r| r.rollbacks(1)}
second.after_commit_block{|r| r.commits(1)}
Topic.transaction do
@first.save!
Topic.transaction(:requires_new => true) do
second.save!
raise ActiveRecord::Rollback
end
end
assert_equal 1, @first.commits
assert_equal 0, @first.rollbacks
assert_equal 0, second.commits
assert_equal 1, second.rollbacks
end
def test_only_call_after_rollback_on_records_rolled_back_to_a_savepoint_when_release_savepoint_fails
def @first.rollbacks(i=0); @rollbacks ||= 0; @rollbacks += i if i; end
def @first.commits(i=0); @commits ||= 0; @commits += i if i; end
@first.after_rollback_block{|r| r.rollbacks(1)}
@first.after_commit_block{|r| r.commits(1)}
Topic.transaction do
@first.save
Topic.transaction(:requires_new => true) do
@first.save!
raise ActiveRecord::Rollback
end
Topic.transaction(:requires_new => true) do
@first.save!
raise ActiveRecord::Rollback
end
end
assert_equal 1, @first.commits
assert_equal 2, @first.rollbacks
end
def test_after_commit_callback_should_not_swallow_errors
@first.after_commit_block{ fail "boom" }
assert_raises(RuntimeError) do
Topic.transaction do
@first.save!
end
end
end
def test_after_commit_callback_when_raise_should_not_restore_state
first = TopicWithCallbacks.new
second = TopicWithCallbacks.new
first.after_commit_block{ fail "boom" }
second.after_commit_block{ fail "boom" }
begin
Topic.transaction do
first.save!
assert_not_nil first.id
second.save!
assert_not_nil second.id
end
rescue
end
assert_not_nil first.id
assert_not_nil second.id
assert first.reload
end
def test_after_rollback_callback_should_not_swallow_errors_when_set_to_raise
error_class = Class.new(StandardError)
@first.after_rollback_block{ raise error_class }
assert_raises(error_class) do
Topic.transaction do
@first.save!
raise ActiveRecord::Rollback
end
end
end
def test_after_rollback_callback_when_raise_should_restore_state
error_class = Class.new(StandardError)
first = TopicWithCallbacks.new
second = TopicWithCallbacks.new
first.after_rollback_block{ raise error_class }
second.after_rollback_block{ raise error_class }
begin
Topic.transaction do
first.save!
assert_not_nil first.id
second.save!
assert_not_nil second.id
raise ActiveRecord::Rollback
end
rescue error_class
end
assert_nil first.id
assert_nil second.id
end
def test_after_rollback_callbacks_should_validate_on_condition
assert_raise(ArgumentError) { Topic.after_rollback(on: :save) }
e = assert_raise(ArgumentError) { Topic.after_rollback(on: 'create') }
assert_match(/:on conditions for after_commit and after_rollback callbacks have to be one of \[:create, :destroy, :update\]/, e.message)
end
def test_after_commit_callbacks_should_validate_on_condition
assert_raise(ArgumentError) { Topic.after_commit(on: :save) }
e = assert_raise(ArgumentError) { Topic.after_commit(on: 'create') }
assert_match(/:on conditions for after_commit and after_rollback callbacks have to be one of \[:create, :destroy, :update\]/, e.message)
end
def test_saving_a_record_with_a_belongs_to_that_specifies_touching_the_parent_should_call_callbacks_on_the_parent_object
pet = Pet.first
owner = pet.owner
flag = false
owner.on_after_commit do
flag = true
end
pet.name = "Fluffy the Third"
pet.save
assert flag
end
private
def add_transaction_execution_blocks(record)
record.after_commit_block(:create) { |r| r.history << :commit_on_create }
record.after_commit_block(:update) { |r| r.history << :commit_on_update }
record.after_commit_block(:destroy) { |r| r.history << :commit_on_destroy }
record.after_rollback_block(:create) { |r| r.history << :rollback_on_create }
record.after_rollback_block(:update) { |r| r.history << :rollback_on_update }
record.after_rollback_block(:destroy) { |r| r.history << :rollback_on_destroy }
end
end
class CallbacksOnMultipleActionsTest < ActiveRecord::TestCase
self.use_transactional_tests = false
class TopicWithCallbacksOnMultipleActions < ActiveRecord::Base
self.table_name = :topics
after_commit(on: [:create, :destroy]) { |record| record.history << :create_and_destroy }
after_commit(on: [:create, :update]) { |record| record.history << :create_and_update }
after_commit(on: [:update, :destroy]) { |record| record.history << :update_and_destroy }
before_commit(if: :save_before_commit_history) { |record| record.history << :before_commit }
before_commit(if: :update_title) { |record| record.update(title: "before commit title") }
def clear_history
@history = []
end
def history
@history ||= []
end
attr_accessor :save_before_commit_history, :update_title
end
def test_after_commit_on_multiple_actions
topic = TopicWithCallbacksOnMultipleActions.new
topic.save
assert_equal [:create_and_update, :create_and_destroy], topic.history
topic.clear_history
topic.approved = true
topic.save
assert_equal [:update_and_destroy, :create_and_update], topic.history
topic.clear_history
topic.destroy
assert_equal [:update_and_destroy, :create_and_destroy], topic.history
end
def test_before_commit_actions
topic = TopicWithCallbacksOnMultipleActions.new
topic.save_before_commit_history = true
topic.save
assert_equal [:before_commit, :create_and_update, :create_and_destroy], topic.history
end
def test_before_commit_update_in_same_transaction
topic = TopicWithCallbacksOnMultipleActions.new
topic.update_title = true
topic.save
assert_equal "before commit title", topic.title
assert_equal "before commit title", topic.reload.title
end
end
class TransactionEnrollmentCallbacksTest < ActiveRecord::TestCase
class TopicWithoutTransactionalEnrollmentCallbacks < ActiveRecord::Base
self.table_name = :topics
before_commit_without_transaction_enrollment { |r| r.history << :before_commit }
after_commit_without_transaction_enrollment { |r| r.history << :after_commit }
after_rollback_without_transaction_enrollment { |r| r.history << :rollback }
def history
@history ||= []
end
end
def setup
@topic = TopicWithoutTransactionalEnrollmentCallbacks.create!
end
def test_commit_does_not_run_transactions_callbacks_without_enrollment
@topic.transaction do
@topic.content = 'foo'
@topic.save!
end
assert @topic.history.empty?
end
def test_commit_run_transactions_callbacks_with_explicit_enrollment
@topic.transaction do
2.times do
@topic.content = 'foo'
@topic.save!
end
@topic.class.connection.add_transaction_record(@topic)
end
assert_equal [:before_commit, :after_commit], @topic.history
end
def test_rollback_does_not_run_transactions_callbacks_without_enrollment
@topic.transaction do
@topic.content = 'foo'
@topic.save!
raise ActiveRecord::Rollback
end
assert @topic.history.empty?
end
def test_rollback_run_transactions_callbacks_with_explicit_enrollment
@topic.transaction do
2.times do
@topic.content = 'foo'
@topic.save!
end
@topic.class.connection.add_transaction_record(@topic)
raise ActiveRecord::Rollback
end
assert_equal [:rollback], @topic.history
end
end