Fix jsonb iterator freeing

Nikita Glukhov · Nikita Glukhov · commit 35e6d572966c · 2022-07-27T01:39:15.000+03:00
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
@@ -42,7 +42,7 @@ create_detoast_iterator(struct varlena *attr)
 		iter = (DetoastIterator) palloc0(sizeof(DetoastIteratorData));
 		iter->done = false;
 		iter->nrefs = 1;
-		iter->gen.free = (void (*)(void *)) free_detoast_iterator;
+		iter->gen.free_callback.func = (void (*)(void *)) free_detoast_iterator;
 
 		/* This is an externally stored datum --- initialize fetch datum iterator */
 		iter->fetch_datum_iterator = fetch_iter = create_fetch_datum_iterator(attr);
@@ -87,7 +87,7 @@ create_detoast_iterator(struct varlena *attr)
 		iter = (DetoastIterator) palloc0(sizeof(DetoastIteratorData));
 		iter->done = false;
 		iter->nrefs = 1;
-		iter->gen.free = (void (*)(void *)) free_detoast_iterator;
+		iter->gen.free_callback.func = (void (*)(void *)) free_detoast_iterator;
 
 		iter->fetch_datum_iterator = palloc0(sizeof(*iter->fetch_datum_iterator));
 		iter->fetch_datum_iterator->buf = buf = create_toast_buffer(VARSIZE_ANY(attr), true);
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
@@ -2961,7 +2961,6 @@ jsonbzIteratorInit(JsonContainer *jc)
 	return jsonbIteratorInitExt(jc, jbc, cjb);
 }
 
-#define JSONB_FREE_ITERATORS
 #ifdef JSONB_FREE_ITERATORS
 static struct
 {
@@ -3003,20 +3002,20 @@ jsonbzInitFromDetoastIterator(JsonContainerData *jc, DetoastIterator iter)
 #endif
 }
 
+#ifdef JSONB_FREE_ITERATORS
 void
 jsonbInitIterators(void)
 {
-#ifdef JSONB_FREE_ITERATORS
 	jsonb_detoast_iterators = palloc(sizeof(*jsonb_detoast_iterators));
 	jsonb_detoast_iterators->mcxt = CurrentMemoryContext;
 	jsonb_detoast_iterators->iterators = NIL;
-#endif
 }
+#endif
 
+#ifdef JSONB_FREE_ITERATORS
 void
 jsonbFreeIterators(void)
 {
-#ifdef JSONB_FREE_ITERATORS
 	ListCell *lc;
 
 	if (jsonb_detoast_iterators)
@@ -3031,20 +3030,28 @@ jsonbFreeIterators(void)
 		pfree(jsonb_detoast_iterators);
 		jsonb_detoast_iterators = NULL;
 	}
-#endif
 }
+#endif
 
+#ifdef JSONB_FREE_ITERATORS
 MemoryContext
 jsonbGetIteratorContext(void)
 {
 	return jsonb_detoast_iterators ? jsonb_detoast_iterators->mcxt : NULL;
 }
+#endif
 
 void
 jsonbRegisterIterator(GenericDetoastIterator iter)
 {
+#ifndef JSONB_FREE_ITERATORS
+	//iter->free_callback.func = iter->free;
+	iter->free_callback.arg = iter;
+	MemoryContextRegisterResetCallback(CurrentMemoryContext, &iter->free_callback);
+#else
 	if (jsonb_detoast_iterators)
 		jsonb_detoast_iterators->iterators = lappend(jsonb_detoast_iterators->iterators, iter);
+#endif
 }
 
 static void
@@ -3079,6 +3086,8 @@ jsonbzInit(JsonContainerData *jc, Datum value)
 		jsonbRegisterIterator(&iter->gen);
 		MemoryContextSwitchTo(oldcxt);
 	}
+#else
+	jsonbRegisterIterator(&iter->gen);
 #endif
 
 	jsonbzInitFromDetoastIterator(jc, iter);
@@ -3172,6 +3181,8 @@ DatumGetJsonbPC(Datum datum, Json *tmp, bool copy)
 		jsonbRegisterIterator(&iter->gen);
 		MemoryContextSwitchTo(oldcxt);
 	}
+# else
+	jsonbRegisterIterator(&iter->gen);
 # endif
 #endif
 
diff --git a/src/include/access/detoast.h b/src/include/access/detoast.h
@@ -95,7 +95,7 @@ typedef struct FetchDatumIteratorData *FetchDatumIterator;
 
 typedef struct GenericDetoastIteratorData
 {
-	void (*free)(void *iter);
+	MemoryContextCallback free_callback;
 } GenericDetoastIteratorData, *GenericDetoastIterator;
 
 typedef struct DetoastIteratorData
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
@@ -255,9 +255,15 @@ extern bool jsonb_sort_field_values;		/* GUC */
 extern bool jsonb_partial_decompression;	/* GUC */
 extern bool jsonb_partial_detoast;			/* GUC */
 
+//#define JSONB_FREE_ITERATORS
+#ifdef JSONB_FREE_ITERATORS
 extern void jsonbInitIterators(void);
 extern void jsonbFreeIterators(void);
 extern MemoryContext jsonbGetIteratorContext(void);
+#else
+# define jsonbInitIterators() ((void) 0)
+# define jsonbFreeIterators() ((void) 0)
+#endif
 extern void jsonbRegisterIterator(GenericDetoastIterator iter);
 
 #endif							/* __JSONB_H__ */

Original file line number	Diff line number	Diff line change
`@@ -2961,7 +2961,6 @@ jsonbzIteratorInit(JsonContainer *jc)`
`2961`	`2961`	`return jsonbIteratorInitExt(jc, jbc, cjb);`
`2962`	`2962`	`}`
`2963`	`2963`
`2964`		`-#define JSONB_FREE_ITERATORS`
`2965`	`2964`	`#ifdef JSONB_FREE_ITERATORS`
`2966`	`2965`	`static struct`
`2967`	`2966`	`{`
`@@ -3003,20 +3002,20 @@ jsonbzInitFromDetoastIterator(JsonContainerData *jc, DetoastIterator iter)`
`3003`	`3002`	`#endif`
`3004`	`3003`	`}`
`3005`	`3004`
	`3005`	`+#ifdef JSONB_FREE_ITERATORS`
`3006`	`3006`	`void`
`3007`	`3007`	`jsonbInitIterators(void)`
`3008`	`3008`	`{`
`3009`		`-#ifdef JSONB_FREE_ITERATORS`
`3010`	`3009`	`jsonb_detoast_iterators = palloc(sizeof(*jsonb_detoast_iterators));`
`3011`	`3010`	`jsonb_detoast_iterators->mcxt = CurrentMemoryContext;`
`3012`	`3011`	`jsonb_detoast_iterators->iterators = NIL;`
`3013`		`-#endif`
`3014`	`3012`	`}`
	`3013`	`+#endif`
`3015`	`3014`
	`3015`	`+#ifdef JSONB_FREE_ITERATORS`
`3016`	`3016`	`void`
`3017`	`3017`	`jsonbFreeIterators(void)`
`3018`	`3018`	`{`
`3019`		`-#ifdef JSONB_FREE_ITERATORS`
`3020`	`3019`	`ListCell *lc;`
`3021`	`3020`
`3022`	`3021`	`if (jsonb_detoast_iterators)`
`@@ -3031,20 +3030,28 @@ jsonbFreeIterators(void)`
`3031`	`3030`	`pfree(jsonb_detoast_iterators);`
`3032`	`3031`	`jsonb_detoast_iterators = NULL;`
`3033`	`3032`	`}`
`3034`		`-#endif`
`3035`	`3033`	`}`
	`3034`	`+#endif`
`3036`	`3035`
	`3036`	`+#ifdef JSONB_FREE_ITERATORS`
`3037`	`3037`	`MemoryContext`
`3038`	`3038`	`jsonbGetIteratorContext(void)`
`3039`	`3039`	`{`
`3040`	`3040`	`return jsonb_detoast_iterators ? jsonb_detoast_iterators->mcxt : NULL;`
`3041`	`3041`	`}`
	`3042`	`+#endif`
`3042`	`3043`
`3043`	`3044`	`void`
`3044`	`3045`	`jsonbRegisterIterator(GenericDetoastIterator iter)`
`3045`	`3046`	`{`
	`3047`	`+#ifndef JSONB_FREE_ITERATORS`
	`3048`	`+ //iter->free_callback.func = iter->free;`
	`3049`	`+ iter->free_callback.arg = iter;`
	`3050`	`+ MemoryContextRegisterResetCallback(CurrentMemoryContext, &iter->free_callback);`
	`3051`	`+#else`
`3046`	`3052`	`if (jsonb_detoast_iterators)`
`3047`	`3053`	`jsonb_detoast_iterators->iterators = lappend(jsonb_detoast_iterators->iterators, iter);`
	`3054`	`+#endif`
`3048`	`3055`	`}`
`3049`	`3056`
`3050`	`3057`	`static void`
`@@ -3079,6 +3086,8 @@ jsonbzInit(JsonContainerData *jc, Datum value)`
`3079`	`3086`	`jsonbRegisterIterator(&iter->gen);`
`3080`	`3087`	`MemoryContextSwitchTo(oldcxt);`
`3081`	`3088`	`}`
	`3089`	`+#else`
	`3090`	`+ jsonbRegisterIterator(&iter->gen);`
`3082`	`3091`	`#endif`
`3083`	`3092`
`3084`	`3093`	`jsonbzInitFromDetoastIterator(jc, iter);`
`@@ -3172,6 +3181,8 @@ DatumGetJsonbPC(Datum datum, Json *tmp, bool copy)`
`3172`	`3181`	`jsonbRegisterIterator(&iter->gen);`
`3173`	`3182`	`MemoryContextSwitchTo(oldcxt);`
`3174`	`3183`	`}`
	`3184`	`+# else`
	`3185`	`+ jsonbRegisterIterator(&iter->gen);`
`3175`	`3186`	`# endif`
`3176`	`3187`	`#endif`
`3177`	`3188`
Original file line number	Diff line number	Diff line change
`@@ -95,7 +95,7 @@ typedef struct FetchDatumIteratorData *FetchDatumIterator;`
`95`	`95`
`96`	`96`	`typedef struct GenericDetoastIteratorData`
`97`	`97`	`{`
`98`		`- void (free)(void iter);`
	`98`	`+ MemoryContextCallback free_callback;`
`99`	`99`	`} GenericDetoastIteratorData, *GenericDetoastIterator;`
`100`	`100`
`101`	`101`	`typedef struct DetoastIteratorData`