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introduce #[pg_guard(unsafe_entry_thread)]#2242

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eeeebbbbrrrr merged 3 commits into
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eebbrr/unsafe_entry_thread
Feb 9, 2026
Merged

introduce #[pg_guard(unsafe_entry_thread)]#2242
eeeebbbbrrrr merged 3 commits into
developfrom
eebbrr/unsafe_entry_thread

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@eeeebbbbrrrr eeeebbbbrrrr commented Feb 3, 2026

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initial commit of rejiggering how pgrx tracks the "ACTIVE_THREAD". This is to address issue #2228.

Functions annotated with #[pg_guard(unsafe_entry_thread)] do some trickery to reset pgrx' understanding of the "ACTIVE_THREAD" so that whatever thread happens to be calling that function then becomes our understanding of the "ACTIVE_THREAD", thereby allowing pgrx to do Postgres FFI on a thread that isn't the main thread.

The situation behind #2228 is that pg_duckdb, an extension written in C++, uses threads (presumably "safely") within Postgres and if one of those threads does something like SPI, which then causes planner/executor hooks to be called, and one of those hooks is implemented with pgrx, this new unsafe_entry_thread tag will let that callback run. It's basically making an assumption that the caller is properly managing the thread it's on.

There's very little code changes here -- the bulk of the PR is a new example crate/extension with its own little c-shim so that I could manually test Postgres itself kicking off a thread that does SPI that ends up calling into a planner hook setup by the rust/pgrx extension.

I have a need to push this through for $DayJob, so I'm probably going to do that later this week.

initial commit of rejiggering how pgrx tracks the "ACTIVE_THREAD".  Functions annotated with `#[pg_guard(unsafe_entry_thread)]` do some trickery to reset pgrx' understanding of the "ACTIVE_THREAD" so that whatever thread happens to be calling that function then become our understanding of the "ACTIVE_THREAD", thereby allowing pgrx to do Postgres FFI on a thread that isn't the main thread.
Comment thread pgrx-pg-sys/src/submodules/thread_check.rs
@eeeebbbbrrrr eeeebbbbrrrr marked this pull request as ready for review February 4, 2026 12:23
@eeeebbbbrrrr eeeebbbbrrrr merged commit f4ec0ce into develop Feb 9, 2026
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eeeebbbbrrrr added a commit that referenced this pull request Feb 9, 2026
Welcome to pgrx v0.17.0. This is a new minor release that brings a bunch
of internal code refactoring, cleanup, new Postgres headers, and
additional `cargo-pgrx regress` CLI options.

As always, please install the latest `cargo-pgrx` with `cargo install
cargo-pgrx --version 0.17.0 --locked` and also update your extension
crate dependencies with `cargo pgrx upgrade`.

## What's Changed


### New Headers/Symbols

* include `access/tsmapi.h` by @usamoi in
#2155
* Include access/subtrans.h & access/commit_ts.h by @isdaniel in
#2147
* include `utils/guc_tables.h` by @usamoi in
#2243
* Include `scanner.h` in Rust bindings by @piki in
#2163
* Add `commands/publicationcmds.h` to generated `pg_sys` bindings by
@Sinjo in #2221
* Add the ClientAuthentication_hook by @daamien in
#2231
* add storage/dsm_*.h headers by @eeeebbbbrrrr in
#2244
* pg-sys: add catalog/heap.h bindings for PG18 by @charmitro in
#2150
* Add back `peer_dn` field to `Port` on `pg17..` by @workingjubilee in
#2200
* Add `repr(C)` to `struct Port` on `pg13..=16` by @workingjubilee in
#2201

### `cargo-pgrx` improvements

* Add a psql_verbosity parameter for cargo pgrx regress by @daamien in
#2230


### Code Cleanup

* Replace with let-chains in pgrx-bindgen by @workingjubilee in
#2168
* Replace with let-chains in pgrx-sql-entity-graph by @workingjubilee in
#2169
* Restore so-called needless lifetimes by @workingjubilee in
#2167
* Drop stray Postgres 12 support in cargo-pgrx by @workingjubilee in
#2173
* Remove deprecated enum##member constants by @workingjubilee in
#2170
* Remove `variadic!` macro by @workingjubilee in
#2171
* Semi-automated code cleanup by @workingjubilee in
#2189
* Deref instead of borrowing `Option<&String>` by @workingjubilee in
#2185
* Refactor schema.rs using a cargo command builder by @workingjubilee in
#2187
* Replace `impl AsRef<T>` with `&T` by @workingjubilee in
#2182
* Make `PgRelation::heap_relation` unsafe by @workingjubilee in
#2176
* Move `cargo_pgrx::env` to `cargo_pgrx::cargo` by @workingjubilee in
#2186
* Move `CargoProfile` into `cargo_pgrx::cargo` by @workingjubilee in
#2188
* Add Scalar trait for generic handling of primitive arrays by
@workingjubilee in #2153
* Set BGWORKER_SHMEM_ACCESS when building background workers by @cbandy
in #2161
* Stop referencing `pg_config` in schema generation by @workingjubilee
in #2174
* Show line number of failed asserts by @piki in
#2175
* Ghostbust `used_type.rs` a bit by @workingjubilee in
#2190
* Manually bind `static MyProcPort` and `struct Port` by @workingjubilee
in #2162
* Make datetime types import each other via `use super` by
@workingjubilee in #2198
* Migrate datetime types into `pgrx::datetime` by @workingjubilee in
#2199
* Use diagnostic attrs for ABI/SQL-related traits by @workingjubilee in
#2203
* Make `Scalar` provide `pg_sys::Oid` constant by @workingjubilee in
#2209
* Hoist varlena encoding fn by @workingjubilee in
#2208
* Recurse through `T` while anonymizing `&T` by @workingjubilee in
#2212
* `impl BorrowDatum for TimeTz` by @workingjubilee in
#2213
* Change `MemCx::alloc_bytes` to return `NonNull` by @workingjubilee in
#2214
* Add `MemCx<'current, T>` arguments and `PBox<'current, T>` returns by
@workingjubilee in #2210
* Further improve diagnostics for signatures with no SQL form by
@workingjubilee in #2215
* Add `array::Element` and `callconv::DatumPass` by @workingjubilee in
#2218
* Remove unused line in `memcxt_tests.rs` by @workingjubilee in
#2220
* Add `FlatArray<'_, T>` by @workingjubilee in
#2207
* Allow explicit handling of allocation errors by @workingjubilee in
#2226
* Place lbound before updating array len product by @workingjubilee in
#2236
* introduce `#[pg_guard(unsafe_entry_thread)]` by @eeeebbbbrrrr in
#2242


### Project Administrativa 

* Use Rust Edition 2024 by @workingjubilee in
#2165
* Remove testing for deprecated Intel Macs by @workingjubilee in
#2156
* Remove unused Cargo.lock for version-updater by @workingjubilee in
#2180
* Add rust-analyzer.toml by @workingjubilee in
#2179
* Note pgrx requires an unknown minimum Xcode version by @workingjubilee
in #2164

## New Contributors

* @isdaniel made their first contribution in
#2147
* @cbandy made their first contribution in
#2161
* @piki made their first contribution in
#2163
* @Sinjo made their first contribution in
#2221

**Full Changelog**:
v0.16.1...v0.17.0
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