Add TAP tests for pg_resize_shared_buffers() with concurrent checkpoints#10
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Adds two TAP tests that exercise pg_resize_shared_buffers() against the
checkpointer, using the ProcSignalBarrier injection points already
present in buf_resize.c and three new injection points added to
CreateCheckPoint():
006_resize_concurrent_checkpoint_crash.pl
- Walks the resize state machine through every consecutive pair of
injection points in buf_resize.c (4 shrink pairs + 4 expand pairs).
- At each pair, issues a synchronous CHECKPOINT, crashes the server
with 'immediate' stop, restarts, and verifies that crash recovery
restores the intended shared_buffers value with no checksum
validation errors and no PANIC.
007_resize_async_checkpoint_crash.pl
- Runs pg_resize_shared_buffers() concurrently with a CHECKPOINT
that is parked at successive stages of CreateCheckPoint(). Eight
scripted interleavings (S1-S4 shrink, E1-E4 expand) drive both
the resize and the checkpointer forward through their injection
points, then crash the server and verify crash recovery.
Supporting changes:
* src/backend/access/transam/xlog.c: adds three INJECTION_POINT_LOAD
calls outside the critical section for the new checkpoint stages
(checkpoint-before-redo, checkpoint-before-redo-wal,
checkpoint-after-redo-wal), plus the matching INJECTION_POINT_CACHED
calls inside CreateCheckPoint(). The 'wait' action needs shmem
allocation, which is why the LOADs are outside the critical section.
* src/test/modules/injection_points: adds
injection_points_has_waiter(text) RETURNS boolean, a non-destructive
lookup useful as a poll target in TAP tests. Unlike a wait_for_event
style poll against pg_stat_activity, this function only takes the
injection_points shmem spinlock, so it cannot deadlock against a
backend holding ProcArrayLock.
* src/test/buffermgr/meson.build: registers the two new tests.
* src/test/buffermgr/t/ResizeBuffer/Utils.pm: shared helpers used by
both 006 and 007 (wait_injection_point via
injection_points_has_waiter, detach-before-wake, %point_backend
mapping, wakeup_all_known_points for END-block cleanup).
All 6 buffermgr TAP tests pass together (599 subtests) with
enable_injection_points=yes and EXTRA_INSTALL='contrib/pg_buffercache
src/test/modules/injection_points'.
An earlier iteration of the pg_resize_shared_buffers() TAP tests added a custom C helper, injection_points_has_waiter(), so tests could poll for a backend parked at a named injection point. This has been replaced with upstream's $node->wait_for_event() (which polls pg_stat_activity.wait_event), the same helper used by src/test/buffermgr/t/004_client_join_buffer_resize.pl and other upstream tests. Drop the C helper and its SQL binding.
Add t/002_resize_smoke.pl, a minimal sanity test that exercises pg_resize_shared_buffers() with no injection points, no concurrent workload, and no crash injection. Failures here indicate the resize feature is fundamentally broken; failures in the checkpoint-race tests (006, 007) should not be trusted until this baseline is green. Covers shrink round-trip (4MB -> 1MB -> 4MB), extreme range (256kB -> 32MB), and persistence across a clean restart.
The 006 and 007 crash-recovery tests run bt_index_check() on pgbench_accounts_pkey after recovery to verify that mid-resize crashes have not corrupted heap or index pages. Without amcheck in EXTRA_INSTALL, 'make check' fails to load the extension. meson already installs amcheck as part of the standard build.
Follow-up review pass on 006 and 007 and their shared Utils module. No behavioral change apart from stronger post-recovery checks: * 006: promote pgbench sums invariant from a note to an is() assertion; drop dead 'page verification failed' unlike (this tree does not enable data_checksums, so the regex can never match); drop count(*) as it is subsumed by bt_index_check(). * 007: replace the copy-pasted per-scenario blocks with a data table driven by named injection-point constants; add bt_index_check() and the sums invariant so post-recovery integrity coverage matches 006; rewrite the 'ordering is approximate' comment now that the invariants are understood. * Utils.pm: move %point_backend above attach_injection_point() so both attach and wait validate point names against it (typos die at attach time, not later at wait); drop the pgbench_extended and cointoss dead branches; trim historical/tutorial comments down to actionable ones. Test count is stable at 33+33=66 after the cleanup, running in ~20s combined.
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Adds two TAP tests that exercise pg_resize_shared_buffers() against the checkpointer, using the ProcSignalBarrier injection points already present in buf_resize.c and three new injection points added to CreateCheckPoint():
006_resize_concurrent_checkpoint_crash.pl
- Walks the resize state machine through every consecutive pair of injection points in buf_resize.c (4 shrink pairs + 4 expand pairs).
- At each pair, issues a synchronous CHECKPOINT, crashes the server with 'immediate' stop, restarts, and verifies that crash recovery restores the intended shared_buffers value with no checksum validation errors and no PANIC.
007_resize_async_checkpoint_crash.pl
- Runs pg_resize_shared_buffers() concurrently with a CHECKPOINT that is parked at successive stages of CreateCheckPoint(). Eight scripted interleavings (S1-S4 shrink, E1-E4 expand) drive both the resize and the checkpointer forward through their injection points, then crash the server and verify crash recovery.
Supporting changes:
src/backend/access/transam/xlog.c: adds three INJECTION_POINT_LOAD calls outside the critical section for the new checkpoint stages (checkpoint-before-redo, checkpoint-before-redo-wal, checkpoint-after-redo-wal), plus the matching INJECTION_POINT_CACHED calls inside CreateCheckPoint(). The 'wait' action needs shmem allocation, which is why the LOADs are outside the critical section.
src/test/modules/injection_points: adds injection_points_has_waiter(text) RETURNS boolean, a non-destructive lookup useful as a poll target in TAP tests. Unlike a wait_for_event style poll against pg_stat_activity, this function only takes the injection_points shmem spinlock, so it cannot deadlock against a backend holding ProcArrayLock.
src/test/buffermgr/meson.build: registers the two new tests.
src/test/buffermgr/t/ResizeBuffer/Utils.pm: shared helpers used by both 006 and 007 (wait_injection_point via injection_points_has_waiter, detach-before-wake, %point_backend mapping, wakeup_all_known_points for END-block cleanup).
All 6 buffermgr TAP tests pass together (599 subtests) with enable_injection_points=yes and EXTRA_INSTALL='contrib/pg_buffercache src/test/modules/injection_points'.