[Tarantool-patches] [PATCH luajit 1/3] test: unify helpers for a custom allocator setting

[Sergey Kaplun via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

This patch merges two Lua C libraries that contain custom Lua allocators
with the injection of returning `NULL` into 1 library
<utils/allocinject.c>. The new library contains 2 helpers:
* `enable_null_alloc()` -- returns `NULL` on every allocation (not
  reallocation).
* `enable_null_doubling_realloc()` -- returns `NULL` on every
  reallocation that doubles the size of the object. It can be useful for
  testing corner cases, like OOM during IR/snapshot buffer reallocation
  during trace recording.
The original allocator is returned via the `disable()` library function.

The unified library helps to avoid code duplication and can be reused
for future tests.

Needed for tarantool/tarantool#11055
---
 test/tarantool-tests/CMakeLists.txt           |  5 +-
 .../lj-1166-error-stitch-oom-ir-buff.test.lua |  2 +-
 ...j-1166-error-stitch-oom-snap-buff.test.lua |  2 +-
 ...j-1247-fin-tab-rehashing-on-trace.test.lua |  4 +-
 .../CMakeLists.txt                            |  2 -
 .../lj_1247_allocinject.c                     | 49 -------------------
 .../CMakeLists.txt                            |  1 +
 .../allocinject.c                             | 34 +++++++++++--
 8 files changed, 37 insertions(+), 62 deletions(-)
 delete mode 100644 test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace/CMakeLists.txt
 delete mode 100644 test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace/lj_1247_allocinject.c
 rename test/tarantool-tests/{lj-1166-error-stitch => utils}/CMakeLists.txt (77%)
 rename test/tarantool-tests/{lj-1166-error-stitch => utils}/allocinject.c (50%)

diff --git a/test/tarantool-tests/CMakeLists.txt b/test/tarantool-tests/CMakeLists.txt
index a6d09dc7..682a883a 100644
--- a/test/tarantool-tests/CMakeLists.txt
+++ b/test/tarantool-tests/CMakeLists.txt
@@ -60,13 +60,14 @@ add_subdirectory(lj-802-panic-at-mcode-protfail)
 add_subdirectory(lj-flush-on-trace)
 add_subdirectory(lj-1004-oom-error-frame)
 add_subdirectory(lj-1066-fix-cur_L-after-coroutine-resume)
-add_subdirectory(lj-1166-error-stitch)
-add_subdirectory(lj-1247-fin-tab-rehashing-on-trace)
 add_subdirectory(profilers/gh-5813-resolving-of-c-symbols/both)
 add_subdirectory(profilers/gh-5813-resolving-of-c-symbols/gnuhash)
 add_subdirectory(profilers/gh-5813-resolving-of-c-symbols/hash)
 add_subdirectory(profilers/gh-5813-resolving-of-c-symbols/stripped)
 
+# Module for alloc injections to return OOM for allocations.
+add_subdirectory(utils)
+
 if(BUILDMODE STREQUAL "dynamic")
   add_subdirectory(fix-argv-handling)
 endif()
diff --git a/test/tarantool-tests/lj-1166-error-stitch-oom-ir-buff.test.lua b/test/tarantool-tests/lj-1166-error-stitch-oom-ir-buff.test.lua
index 354f5975..dc21cfbf 100644
--- a/test/tarantool-tests/lj-1166-error-stitch-oom-ir-buff.test.lua
+++ b/test/tarantool-tests/lj-1166-error-stitch-oom-ir-buff.test.lua
@@ -57,7 +57,7 @@ jparse.start('t')
 jit.on()
 jit.opt.start('hotloop=1', '-loop', '-fold')
 
-allocinject.enable()
+allocinject.enable_null_doubling_realloc()
 
 tracef()
 
diff --git a/test/tarantool-tests/lj-1166-error-stitch-oom-snap-buff.test.lua b/test/tarantool-tests/lj-1166-error-stitch-oom-snap-buff.test.lua
index c8e13760..b2387f23 100644
--- a/test/tarantool-tests/lj-1166-error-stitch-oom-snap-buff.test.lua
+++ b/test/tarantool-tests/lj-1166-error-stitch-oom-snap-buff.test.lua
@@ -59,7 +59,7 @@ jparse.start('t')
 jit.opt.start('hotloop=1')
 jit.on()
 
-allocinject.enable()
+allocinject.enable_null_doubling_realloc()
 
 tracef()
 
diff --git a/test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace.test.lua b/test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace.test.lua
index 308043a2..b9a49700 100644
--- a/test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace.test.lua
+++ b/test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace.test.lua
@@ -24,7 +24,7 @@ local test = tap.test('lj-1247-fin-tab-rehashing-on-trace'):skipcond({
 -- omitted, we test only the first case.
 test:plan(2)
 
-local allocinject = require('lj_1247_allocinject')
+local allocinject = require('allocinject')
 
 local ffi = require('ffi')
 ffi.cdef[[
@@ -115,7 +115,7 @@ crash_on_trace_unwind_gc_setup()
 
 -- OOM on every allocation (i.e., on finalizer table rehashing
 -- too).
-allocinject.enable()
+allocinject.enable_null_alloc()
 
 local r, err = pcall(f, res_tab)
 
diff --git a/test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace/CMakeLists.txt b/test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace/CMakeLists.txt
deleted file mode 100644
index 8c6fe7e4..00000000
--- a/test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace/CMakeLists.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-get_filename_component(test_name ${CMAKE_CURRENT_SOURCE_DIR} NAME)
-BuildTestCLib(lj_1247_allocinject lj_1247_allocinject.c ${test_name}.test.lua)
diff --git a/test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace/lj_1247_allocinject.c b/test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace/lj_1247_allocinject.c
deleted file mode 100644
index 81aea60b..00000000
--- a/test/tarantool-tests/lj-1247-fin-tab-rehashing-on-trace/lj_1247_allocinject.c
+++ /dev/null
@@ -1,49 +0,0 @@
-#include "lua.h"
-#include "lauxlib.h"
-
-#undef NDEBUG
-#include <assert.h>
-
-static lua_Alloc old_allocf = NULL;
-static void *old_alloc_state = NULL;
-
-/* Function to be used instead of the default allocator. */
-static void *allocf_with_injection(void *ud, void *ptr, size_t osize,
-				   size_t nsize)
-{
-	/* Always OOM on allocation (not on realloc). */
-	if (ptr == NULL)
-		return NULL;
-	else
-		return old_allocf(ud, ptr, osize, nsize);
-}
-
-static int enable(lua_State *L)
-{
-	assert(old_allocf == NULL);
-	old_allocf = lua_getallocf(L, &old_alloc_state);
-	lua_setallocf(L, allocf_with_injection, old_alloc_state);
-	return 0;
-}
-
-static int disable(lua_State *L)
-{
-	assert(old_allocf != NULL);
-	assert(old_allocf != allocf_with_injection);
-	lua_setallocf(L, old_allocf, old_alloc_state);
-	old_allocf = NULL;
-	old_alloc_state = NULL;
-	return 0;
-}
-
-static const struct luaL_Reg allocinject[] = {
-	{"enable", enable},
-	{"disable", disable},
-	{NULL, NULL}
-};
-
-LUA_API int luaopen_lj_1247_allocinject(lua_State *L)
-{
-	luaL_register(L, "lj_1247_allocinject", allocinject);
-	return 1;
-}
diff --git a/test/tarantool-tests/lj-1166-error-stitch/CMakeLists.txt b/test/tarantool-tests/utils/CMakeLists.txt
similarity index 77%
rename from test/tarantool-tests/lj-1166-error-stitch/CMakeLists.txt
rename to test/tarantool-tests/utils/CMakeLists.txt
index 658b3b8c..624cc933 100644
--- a/test/tarantool-tests/lj-1166-error-stitch/CMakeLists.txt
+++ b/test/tarantool-tests/utils/CMakeLists.txt
@@ -1,5 +1,6 @@
 list(APPEND tests
   lj-1166-error-stitch-oom-ir-buff.test.lua
   lj-1166-error-stitch-oom-snap-buff.test.lua
+  lj-1247-fin-tab-rehashing-on-trace.test.lua
 )
 BuildTestCLib(allocinject allocinject.c "${tests}")
diff --git a/test/tarantool-tests/lj-1166-error-stitch/allocinject.c b/test/tarantool-tests/utils/allocinject.c
similarity index 50%
rename from test/tarantool-tests/lj-1166-error-stitch/allocinject.c
rename to test/tarantool-tests/utils/allocinject.c
index 88fc9138..21e1d611 100644
--- a/test/tarantool-tests/lj-1166-error-stitch/allocinject.c
+++ b/test/tarantool-tests/utils/allocinject.c
@@ -7,9 +7,22 @@
 static lua_Alloc old_allocf = NULL;
 static void *old_alloc_state = NULL;
 
-/* Function to be used instead of the default allocator. */
-static void *allocf_with_injection(void *ud, void *ptr, size_t osize,
+/* Functions to be used instead of the default allocator. */
+
+/* Always OOM on allocation (not on realloc). */
+static void *allocf_inj_null_alloc(void *ud, void *ptr, size_t osize,
 				   size_t nsize)
+{
+	assert(old_allocf != NULL);
+	if (ptr == NULL)
+		return NULL;
+	else
+		return old_allocf(ud, ptr, osize, nsize);
+}
+
+/* Returns `NULL` on reallocations doubling used memory. */
+static void *allocf_inj_null_doubling_realloc(void *ud, void *ptr, size_t osize,
+					      size_t nsize)
 {
 	assert(old_allocf != NULL);
 	/*
@@ -21,7 +34,7 @@ static void *allocf_with_injection(void *ud, void *ptr, size_t osize,
 	return old_allocf(ud, ptr, osize, nsize);
 }
 
-static int enable(lua_State *L)
+static int enable(lua_State *L, lua_Alloc allocf_with_injection)
 {
 	assert(old_allocf == NULL);
 	old_allocf = lua_getallocf(L, &old_alloc_state);
@@ -29,10 +42,20 @@ static int enable(lua_State *L)
 	return 0;
 }
 
+static int enable_null_alloc(lua_State *L)
+{
+	return enable(L, allocf_inj_null_alloc);
+}
+
+static int enable_null_doubling_realloc(lua_State *L)
+{
+	return enable(L, allocf_inj_null_doubling_realloc);
+}
+
+/* Restore the default allocator function. */
 static int disable(lua_State *L)
 {
 	assert(old_allocf != NULL);
-	assert(old_allocf != allocf_with_injection);
 	lua_setallocf(L, old_allocf, old_alloc_state);
 	old_allocf = NULL;
 	old_alloc_state = NULL;
@@ -40,7 +63,8 @@ static int disable(lua_State *L)
 }
 
 static const struct luaL_Reg allocinject[] = {
-	{"enable", enable},
+	{"enable_null_alloc", enable_null_alloc},
+	{"enable_null_doubling_realloc", enable_null_doubling_realloc},
 	{"disable", disable},
 	{NULL, NULL}
 };
-- 
2.48.1