libspl: move thread implementation from libzpool

Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes #17861

lib/libspl/Makefile.am

@@ -25,6 +25,7 @@ libspl_la_SOURCES = \
 	%D%/rwlock.c \
 	%D%/strlcat.c \
 	%D%/strlcpy.c \
+	%D%/thread.c \
 	%D%/timestamp.c \
 	%D%/tunables.c \
 	%D%/include/sys/list.h \

lib/libspl/thread.c

@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: CDDL-1.0
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2016 Actifio, Inc. All rights reserved.
+ * Copyright (c) 2025, Klara, Inc.
+ */
+
+#include <assert.h>
+#include <pthread.h>
+#include <string.h>
+#include <sys/thread.h>
+
+/* this only exists to have its address taken */
+struct proc p0;
+
+/*
+ * =========================================================================
+ * threads
+ * =========================================================================
+ *
+ * TS_STACK_MIN is dictated by the minimum allowed pthread stack size.  While
+ * TS_STACK_MAX is somewhat arbitrary, it was selected to be large enough for
+ * the expected stack depth while small enough to avoid exhausting address
+ * space with high thread counts.
+ */
+#define	TS_STACK_MIN	MAX(PTHREAD_STACK_MIN, 32768)
+#define	TS_STACK_MAX	(256 * 1024)
+
+struct zk_thread_wrapper {
+	void (*func)(void *);
+	void *arg;
+};
+
+static void *
+zk_thread_wrapper(void *arg)
+{
+	struct zk_thread_wrapper ztw;
+	memcpy(&ztw, arg, sizeof (ztw));
+	free(arg);
+	ztw.func(ztw.arg);
+	return (NULL);
+}
+
+kthread_t *
+zk_thread_create(const char *name, void (*func)(void *), void *arg,
+    size_t stksize, int state)
+{
+	pthread_attr_t attr;
+	pthread_t tid;
+	char *stkstr;
+	struct zk_thread_wrapper *ztw;
+	int detachstate = PTHREAD_CREATE_DETACHED;
+
+	VERIFY0(pthread_attr_init(&attr));
+
+	if (state & TS_JOINABLE)
+		detachstate = PTHREAD_CREATE_JOINABLE;
+
+	VERIFY0(pthread_attr_setdetachstate(&attr, detachstate));
+
+	/*
+	 * We allow the default stack size in user space to be specified by
+	 * setting the ZFS_STACK_SIZE environment variable.  This allows us
+	 * the convenience of observing and debugging stack overruns in
+	 * user space.  Explicitly specified stack sizes will be honored.
+	 * The usage of ZFS_STACK_SIZE is discussed further in the
+	 * ENVIRONMENT VARIABLES sections of the ztest(1) man page.
+	 */
+	if (stksize == 0) {
+		stkstr = getenv("ZFS_STACK_SIZE");
+
+		if (stkstr == NULL)
+			stksize = TS_STACK_MAX;
+		else
+			stksize = MAX(atoi(stkstr), TS_STACK_MIN);
+	}
+
+	VERIFY3S(stksize, >, 0);
+	stksize = P2ROUNDUP(MAX(stksize, TS_STACK_MIN), PAGESIZE);
+
+	/*
+	 * If this ever fails, it may be because the stack size is not a
+	 * multiple of system page size.
+	 */
+	VERIFY0(pthread_attr_setstacksize(&attr, stksize));
+	VERIFY0(pthread_attr_setguardsize(&attr, PAGESIZE));
+
+	VERIFY(ztw = malloc(sizeof (*ztw)));
+	ztw->func = func;
+	ztw->arg = arg;
+	VERIFY0(pthread_create(&tid, &attr, zk_thread_wrapper, ztw));
+	VERIFY0(pthread_attr_destroy(&attr));
+
+	pthread_setname_np(tid, name);
+
+	return ((void *)(uintptr_t)tid);
+}

lib/libzpool/kernel.c

@@ -63,92 +63,6 @@ struct utsname hw_utsname;
 /* If set, all blocks read will be copied to the specified directory. */
 char *vn_dumpdir = NULL;
 
-/* this only exists to have its address taken */
-struct proc p0;
-
-/*
- * =========================================================================
- * threads
- * =========================================================================
- *
- * TS_STACK_MIN is dictated by the minimum allowed pthread stack size.  While
- * TS_STACK_MAX is somewhat arbitrary, it was selected to be large enough for
- * the expected stack depth while small enough to avoid exhausting address
- * space with high thread counts.
- */
-#define	TS_STACK_MIN	MAX(PTHREAD_STACK_MIN, 32768)
-#define	TS_STACK_MAX	(256 * 1024)
-
-struct zk_thread_wrapper {
-	void (*func)(void *);
-	void *arg;
-};
-
-static void *
-zk_thread_wrapper(void *arg)
-{
-	struct zk_thread_wrapper ztw;
-	memcpy(&ztw, arg, sizeof (ztw));
-	free(arg);
-	ztw.func(ztw.arg);
-	return (NULL);
-}
-
-kthread_t *
-zk_thread_create(const char *name, void (*func)(void *), void *arg,
-    size_t stksize, int state)
-{
-	pthread_attr_t attr;
-	pthread_t tid;
-	char *stkstr;
-	struct zk_thread_wrapper *ztw;
-	int detachstate = PTHREAD_CREATE_DETACHED;
-
-	VERIFY0(pthread_attr_init(&attr));
-
-	if (state & TS_JOINABLE)
-		detachstate = PTHREAD_CREATE_JOINABLE;
-
-	VERIFY0(pthread_attr_setdetachstate(&attr, detachstate));
-
-	/*
-	 * We allow the default stack size in user space to be specified by
-	 * setting the ZFS_STACK_SIZE environment variable.  This allows us
-	 * the convenience of observing and debugging stack overruns in
-	 * user space.  Explicitly specified stack sizes will be honored.
-	 * The usage of ZFS_STACK_SIZE is discussed further in the
-	 * ENVIRONMENT VARIABLES sections of the ztest(1) man page.
-	 */
-	if (stksize == 0) {
-		stkstr = getenv("ZFS_STACK_SIZE");
-
-		if (stkstr == NULL)
-			stksize = TS_STACK_MAX;
-		else
-			stksize = MAX(atoi(stkstr), TS_STACK_MIN);
-	}
-
-	VERIFY3S(stksize, >, 0);
-	stksize = P2ROUNDUP(MAX(stksize, TS_STACK_MIN), PAGESIZE);
-
-	/*
-	 * If this ever fails, it may be because the stack size is not a
-	 * multiple of system page size.
-	 */
-	VERIFY0(pthread_attr_setstacksize(&attr, stksize));
-	VERIFY0(pthread_attr_setguardsize(&attr, PAGESIZE));
-
-	VERIFY(ztw = malloc(sizeof (*ztw)));
-	ztw->func = func;
-	ztw->arg = arg;
-	VERIFY0(pthread_create(&tid, &attr, zk_thread_wrapper, ztw));
-	VERIFY0(pthread_attr_destroy(&attr));
-
-	pthread_setname_np(tid, name);
-
-	return ((void *)(uintptr_t)tid);
-}
-
 /*
  * =========================================================================
  * kstats