Re: [Tarantool-patches] [PATCH v4 0/2] vinyl: fix uninitialized memory accesses

[Nikita Pettik <korablev@tarantool.org>]

On 10 May 21:49, Vladislav Shpilevoy wrote:
> Hi! Thanks for the patchset!
> 
> LGTM.

I found that test occasionally fails. For instance:
https://gitlab.com/tarantool/tarantool/-/jobs/548447188

So I have to push fix below to make it stable. In a nutshell we
can't rely on range/count correlation if we want to avoid any
possible races: ranges/runs are updated during compaction,
meanwhile in fact we should wait till compaction is completed
(since due to fails/error some results may turn out to be rollbacked).

It seems pretty straightforward, so hope you don't mind this fix.

diff --git a/test/vinyl/gh-4864-stmt-alloc-fail-compact.test.lua b/test/vinyl/gh-4864-stmt-alloc-fail-compact.test.lua
index 547ab628e..4b3c55505 100644
--- a/test/vinyl/gh-4864-stmt-alloc-fail-compact.test.lua
+++ b/test/vinyl/gh-4864-stmt-alloc-fail-compact.test.lua
@@ -14,12 +14,18 @@ function dump(big)
     box.snapshot()
 end;
 
-function compact()
+-- Tuple clean-up takes place after compaction is completed.
+-- Meanwhile range count is updated during compaction process.
+-- So instead of relying on range/run match, let's check explicitly
+-- number of completed tasks.
+--
+function compact(tasks_expected)
+    local scheduler = box.stat.vinyl().scheduler
+    local tasks_completed = scheduler.tasks_completed
     s.index.pk:compact()
     repeat
         fiber.sleep(0.001)
-        local info = s.index.pk:stat()
-    until info.range_count == info.run_count
+    until box.stat.vinyl().scheduler.tasks_completed >= tasks_completed + tasks_expected
 end;
 test_run:cmd("setopt delimiter ''");
 
@@ -32,7 +38,7 @@ dump()
 assert(s.index.pk:stat().range_count == 1)
 assert(s.index.pk:stat().run_count == 2)
 
-compact()
+compact(1)
 assert(s.index.pk:stat().range_count == 1)
 assert(s.index.pk:stat().run_count == 1)
 
@@ -46,7 +52,7 @@ errinj.set('ERRINJ_VY_STMT_ALLOC', 0)
 -- Still split_range() fails, as a result we get one range
 -- instead two.
 --
-compact()
+compact(1)
 assert(s.index.pk:stat().range_count == 1)
 assert(s.index.pk:stat().run_count == 1)
 assert(errinj.get('ERRINJ_VY_STMT_ALLOC') == -1)
@@ -63,7 +69,7 @@ _ = s:create_index('pk', {run_count_per_level = 100, page_size = 128, range_size
 dump(true)
 dump()
 
-compact()
+compact(1)
 
 dump()
 
@@ -72,7 +78,7 @@ errinj.set('ERRINJ_VY_STMT_ALLOC', 5)
 -- Compaction of first range fails, so it is re-scheduled and
 -- then successfully finishes at the second attempt.
 --
-compact()
+compact(2)
 assert(s.index.pk:stat().range_count == 2)
 assert(s.index.pk:stat().run_count == 2)
 assert(errinj.get('ERRINJ_VY_STMT_ALLOC') == -1)
@@ -92,13 +98,13 @@ _ = s:create_index('pk', {run_count_per_level = 100, page_size = 128, range_size
 dump(true)
 dump()
 
-compact()
+compact(1)
 
 dump()
 
 errinj = box.error.injection
 errinj.set('ERRINJ_VY_READ_VIEW_MERGE_FAIL', true)
-compact()
+compact(2)
 assert(s.index.pk:stat().range_count == 2)
 assert(s.index.pk:stat().run_count == 2)
 assert(errinj.get('ERRINJ_VY_READ_VIEW_MERGE_FAIL') == false)
@@ -117,7 +123,7 @@ _ = s:create_index('pk', {run_count_per_level = 100, page_size = 128, range_size
 dump(true)
 dump()
 
-compact()
+compact(1)
 
 dump()
 assert(s.index.pk:stat().range_count == 1)
@@ -125,14 +131,7 @@ assert(s.index.pk:stat().run_count == 2)
 
 errinj.set('ERRINJ_VY_WRITE_ITERATOR_START_FAIL', true)
 errinj.set("ERRINJ_VY_SCHED_TIMEOUT", 0.1)
-tasks_completed = box.stat.vinyl().scheduler.tasks_completed
-s.index.pk:compact()
--- Tuple clean-up takes place after compaction is completed.
--- Meanwhile range count is updated during compaction process.
--- So instead of relying on range/run match, let's check explicitly
--- number of completed tasks.
---
-repeat fiber.sleep(0.001) until box.stat.vinyl().scheduler.tasks_completed >= tasks_completed + 1
+compact(2)