From: Ondřej Surý <ondrej@isc.org>
Date: Wed, 17 Jun 2026 18:37:55 +0000 (+0200)
Subject: Allocate work threads from their owning loop's memory context
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=72ff42d2bfff1d6d780a86841a371798288661ba;p=thirdparty%2Fbind9.git

Allocate work threads from their owning loop's memory context

A per-loop work thread referenced the loop manager's memory context,
which is not the context that backs the loop the thread serves. Pass
the owning loop instead and allocate from loop->mctx, keeping a loop
reference for the thread's lifetime. This matches how isc_work_enqueue
and work_done already obtain the context from the loop, and the
teardown uses loop->mctx before dropping the reference.
---

diff --git a/lib/isc/include/isc/work.h b/lib/isc/include/isc/work.h
index a4567f13f0d..8cb0c3f6d2f 100644
--- a/lib/isc/include/isc/work.h
+++ b/lib/isc/include/isc/work.h
@@ -85,7 +85,7 @@ isc_work_cancel(isc_work_t *work);
 typedef struct isc__workthread isc__workthread_t;
 
 isc__workthread_t *
-isc__workthread_create(isc_mem_t *mctx, isc_worklane_t lane);
+isc__workthread_create(isc_loop_t *loop, isc_worklane_t lane);
 /*%<
  * Create one worker thread for 'lane' with its own dispatch queue (the loop
  * manager creates one per loop).  Used by the loop manager; not for general
diff --git a/lib/isc/loop.c b/lib/isc/loop.c
index 062bcfa599e..7828decb6ba 100644
--- a/lib/isc/loop.c
+++ b/lib/isc/loop.c
@@ -289,8 +289,7 @@ loop_thread(void *arg) {
 	UV_RUNTIME_CHECK(uv_prepare_start, r);
 
 	for (isc_worklane_t lane = 0; lane < ISC_WORKLANE_COUNT; lane++) {
-		loop->workthreads[lane] =
-			isc__workthread_create(isc__loopmgr->mctx, lane);
+		loop->workthreads[lane] = isc__workthread_create(loop, lane);
 	}
 
 	isc_barrier_wait(&loopmgr->starting);
diff --git a/lib/isc/work.c b/lib/isc/work.c
index c2af8cfe16a..c70d512b2ef 100644
--- a/lib/isc/work.c
+++ b/lib/isc/work.c
@@ -68,7 +68,7 @@ typedef struct isc__workthread {
 		struct {
 			unsigned int magic;
 			isc_worklane_t lane;
-			isc_mem_t *mctx;
+			isc_loop_t *loop;
 			isc_thread_t thread;
 			struct __cds_wfcq_head qhead;
 			int32_t state; /* enum waitstate */
@@ -339,14 +339,14 @@ isc_work_cancel(isc_work_t *work) {
 }
 
 isc__workthread_t *
-isc__workthread_create(isc_mem_t *mctx, isc_worklane_t lane) {
-	isc__workthread_t *thread = isc_mem_get(mctx, sizeof(*thread));
+isc__workthread_create(isc_loop_t *loop, isc_worklane_t lane) {
+	isc__workthread_t *thread = isc_mem_get(loop->mctx, sizeof(*thread));
 
 	*thread = (isc__workthread_t){
 		.lane = lane,
 		.magic = WORKTHREAD_MAGIC,
 		.state = THREAD_WAITING,
-		.mctx = isc_mem_ref(mctx),
+		.loop = loop,
 	};
 
 	__cds_wfcq_init(&thread->qhead, &thread->qtail);
@@ -394,7 +394,7 @@ isc__workthread_destroy(isc__workthread_t **threadp) {
 	INSIST(cds_wfcq_empty(&thread->qhead, &thread->qtail));
 
 	thread->magic = 0;
-	isc_mem_putanddetach(&thread->mctx, thread, sizeof(*thread));
+	isc_mem_put(thread->loop->mctx, thread, sizeof(*thread));
 }
 
 void