Close retained connectors on worker shutdown

docs/setup.md

@@ -257,6 +257,9 @@ Important settings:
   4 KiB positional read. Cache-miss full-artifact reads use the same checks
   around 64 KiB positional chunks. A single in-progress regular-file syscall
   cannot be cooperatively interrupted; later reads and parsing cannot overrun the budget.
+  Wasmtime's serialized-module deserialization call is also synchronous and
+  cannot be interrupted; if it stalls, the timeout is reported after that call
+  returns rather than at the nominal wall-clock boundary.
   Initial/final descriptor identity, unique selected metadata sections, and
   strict 64-bit LEB high-bit validation reject changed or ambiguous artifacts.
 

docs/wasm-runtime-architecture.md

@@ -266,6 +266,10 @@ Cold module compilation and deserialization are host work, so `load_unit()`
 refreshes the epoch deadline before its first guest call. Otherwise a component
 whose compilation outlasted the guest CPU budget would immediately trap in the
 following allocator/relocation call even though no guest loop consumed it.
+Wasmtime's serialized-module deserialization API is synchronous and has no
+cooperative cancellation point. The absolute invocation timeout is checked
+immediately after it returns, so a stalled deserialization may overrun the
+nominal wall boundary before UCE reports the timeout.
 
 Unit artifacts live beneath an ABI-generation directory such as
 `BIN_DIRECTORY/units-c13-w7`: `c13` is the compiler/unit-metadata ABI and `w7`

scripts/test_mysql_persistent_pool_idle.sh

@@ -108,4 +108,15 @@ third=$(request /database.uce)
 IFS='|' read -r third_pid third_id third_source <<<"$third"
 [[ "$third_pid" == "$first_pid" && "$third_source" == "new" && "$third_id" != "$first_id" ]]
 
+sleep 3
+plain=$(request /plain.uce)
+[[ "$plain" == "$first_pid|plain" ]]
+deadline=$((SECONDS + 5))
+while (( SECONDS < deadline )); do
+	connections=$(mariadb --batch --skip-column-names -e "SELECT COUNT(*) FROM information_schema.PROCESSLIST WHERE USER='$test_user'")
+	[[ "$connections" == "0" ]] && break
+	sleep 0.05
+done
+[[ "$connections" == "0" ]] || { echo "final pooled fixture connection remained after idle eviction" >&2; exit 1; }
+
 echo "Persistent MySQL idle eviction preserved hot reuse and retired the expired connection"

src/wasm/backend.cpp

@@ -429,8 +429,8 @@ String wasm_backend_serve(Request& request, const String& entry_unit, const Stri
 	return("");
 }
 
-// Stop the ticker before the worker process exits (best-effort; forked workers
-// are usually killed, but a clean ager-out path should join the thread).
+// Stop the ticker before destroying the worker state it references. Deleting
+// the worker also closes retained connector resources on a clean process exit.
 void wasm_backend_shutdown()
 {
 	if(g_wasm_epoch_ticker)
@@ -441,4 +441,6 @@ void wasm_backend_shutdown()
 		delete g_wasm_epoch_ticker;
 		g_wasm_epoch_ticker = 0;
 	}
+	delete g_wasm_worker;
+	g_wasm_worker = 0;
 }