Re-add BRIN isolation test

This time, instead of using a core isolation test, put it on its own
test module; this way it can require the pageinspect module to be
present before running.

The module's Makefile is loosely modeled after test_decoding's, so that
it's easy to add further tests for either pg_regress or isolationtester
later.

Backpatch to 9.5.

src/test/modules/Makefile

@@ -5,6 +5,7 @@ top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
 SUBDIRS = \
+		  brin \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \

src/test/modules/brin/.gitignore

+# Generated subdirectories
+/isolation_output/
+/tmp_check/

src/test/modules/brin/Makefile

+# src/test/modules/brin/Makefile
+
+EXTRA_CLEAN = ./isolation_output
+EXTRA_INSTALL=contrib/pageinspect
+
+ISOLATIONCHECKS=summarization-and-inprogress-insertion
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/brin
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
+
+check: isolation-check
+
+isolation-check: | submake-isolation
+	$(MKDIR_P) isolation_output
+	$(pg_isolation_regress_check) \
+	    --outputdir=./isolation_output \
+	    $(ISOLATIONCHECKS)
+
+PHONY: check isolation-check
+
+submake-isolation:
+	$(MAKE) -C $(top_builddir)/src/test/isolation all

src/test/modules/brin/expected/summarization-and-inprogress-insertion.out

+Parsed test spec with 2 sessions
+
+starting permutation: s2check s1b s2b s1i s2summ s1c s2c s2check
+step s2check: SELECT * FROM brin_page_items(get_raw_page('brinidx', 2), 'brinidx'::regclass);
+itemoffset     blknum         attnum         allnulls       hasnulls       placeholder    value          
+
+1              0              1              f              f              f              {1 .. 1}       
+step s1b: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s2b: BEGIN ISOLATION LEVEL REPEATABLE READ; SELECT 1;
+?column?       
+
+1              
+step s1i: INSERT INTO brin_iso VALUES (1000);
+step s2summ: SELECT brin_summarize_new_values('brinidx'::regclass);
+brin_summarize_new_values
+
+1              
+step s1c: COMMIT;
+step s2c: COMMIT;
+step s2check: SELECT * FROM brin_page_items(get_raw_page('brinidx', 2), 'brinidx'::regclass);
+itemoffset     blknum         attnum         allnulls       hasnulls       placeholder    value          
+
+1              0              1              f              f              f              {1 .. 1}       
+2              1              1              f              f              f              {1 .. 1000}    
+
+starting permutation: s2check s1b s1i s2vacuum s1c s2check
+step s2check: SELECT * FROM brin_page_items(get_raw_page('brinidx', 2), 'brinidx'::regclass);
+itemoffset     blknum         attnum         allnulls       hasnulls       placeholder    value          
+
+1              0              1              f              f              f              {1 .. 1}       
+step s1b: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s1i: INSERT INTO brin_iso VALUES (1000);
+step s2vacuum: VACUUM brin_iso;
+step s1c: COMMIT;
+step s2check: SELECT * FROM brin_page_items(get_raw_page('brinidx', 2), 'brinidx'::regclass);
+itemoffset     blknum         attnum         allnulls       hasnulls       placeholder    value          
+
+1              0              1              f              f              f              {1 .. 1}       
+2              1              1              f              f              f              {1 .. 1000}    

src/test/modules/brin/specs/summarization-and-inprogress-insertion.spec

+# This test verifies that values inserted in transactions still in progress
+# are considered during concurrent range summarization (either using the
+# brin_summarize_new_values function or regular VACUUM).
+
+setup
+{
+    CREATE TABLE brin_iso (
+        value int
+    ) WITH (fillfactor=10);
+    CREATE INDEX brinidx ON brin_iso USING brin (value) WITH (pages_per_range=1);
+    -- this fills the first page
+    DO $$
+    DECLARE curtid tid;
+    BEGIN
+      LOOP
+        INSERT INTO brin_iso VALUES (1) RETURNING ctid INTO curtid;
+        EXIT WHEN curtid > tid '(1, 0)';
+      END LOOP;
+    END;
+    $$;
+    CREATE EXTENSION IF NOT EXISTS pageinspect;
+}
+
+teardown
+{
+    DROP TABLE brin_iso;
+}
+
+session "s1"
+step "s1b"		{ BEGIN ISOLATION LEVEL REPEATABLE READ; }
+step "s1i"		{ INSERT INTO brin_iso VALUES (1000); }
+step "s1c"		{ COMMIT; }
+
+session "s2"
+step "s2b"		{ BEGIN ISOLATION LEVEL REPEATABLE READ; SELECT 1; }
+step "s2summ"	{ SELECT brin_summarize_new_values('brinidx'::regclass); }
+step "s2c"		{ COMMIT; }
+
+step "s2vacuum"	{ VACUUM brin_iso; }
+
+step "s2check"	{ SELECT * FROM brin_page_items(get_raw_page('brinidx', 2), 'brinidx'::regclass); }
+
+permutation "s2check" "s1b" "s2b" "s1i" "s2summ" "s1c" "s2c" "s2check"
+permutation "s2check" "s1b" "s1i" "s2vacuum" "s1c" "s2check"