Initial QSfera import

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/freebsd.txt

@@ -0,0 +1,30 @@
+/*
+ * Compile and run this as a C program to get the kinfo_proc offsets
+ * for your architecture.
+ * While FreeBSD works hard at binary-compatibility within an ABI, various
+ * we can't say for sure that these are right for _all_ use on a hardware
+ * platform.  The LP64 ifdef affects the offsets considerably.
+ *
+ * We use these offsets in hardware-specific files for FreeBSD, to avoid a cgo
+ * compilation-time dependency, allowing us to cross-compile for FreeBSD from
+ * other hardware platforms, letting us distribute binaries for FreeBSD.
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/user.h>
+
+#define SHOW_OFFSET(FIELD) printf(" KIP_OFF_%s = %zu\n", #FIELD, offsetof(struct kinfo_proc, ki_ ## FIELD))
+
+int main(int argc, char *argv[]) {
+	/* Uncomment these if you want some extra debugging aids:
+	SHOW_OFFSET(pid);
+	SHOW_OFFSET(ppid);
+	SHOW_OFFSET(uid);
+	*/
+	SHOW_OFFSET(size);
+	SHOW_OFFSET(rssize);
+	SHOW_OFFSET(pctcpu);
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_darwin.go

@@ -0,0 +1,86 @@
+// Copyright 2015-2021 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pse
+
+// On macs after some studying it seems that typical tools like ps and activity monitor report MaxRss and not
+// current RSS. I wrote some C code to pull the real RSS and although it does not go down very often, when it does
+// that is not reflected in the typical tooling one might compare us to, so we can skip cgo and just use rusage imo.
+// We also do not use virtual memory in the upper layers at all, so ok to skip since rusage does not report vss.
+
+import (
+	"math"
+	"sync"
+	"syscall"
+	"time"
+)
+
+type lastUsage struct {
+	sync.Mutex
+	last time.Time
+	cpu  time.Duration
+	rss  int64
+	pcpu float64
+}
+
+// To hold the last usage and call time.
+var lu lastUsage
+
+func init() {
+	updateUsage()
+	periodic()
+}
+
+// Get our usage.
+func getUsage() (now time.Time, cpu time.Duration, rss int64) {
+	var ru syscall.Rusage
+	syscall.Getrusage(syscall.RUSAGE_SELF, &ru)
+	now = time.Now()
+	cpu = time.Duration(ru.Utime.Sec)*time.Second + time.Duration(ru.Utime.Usec)*time.Microsecond
+	cpu += time.Duration(ru.Stime.Sec)*time.Second + time.Duration(ru.Stime.Usec)*time.Microsecond
+	return now, cpu, ru.Maxrss
+}
+
+// Update last usage.
+// We need to have a prior sample to compute pcpu.
+func updateUsage() (pcpu float64, rss int64) {
+	lu.Lock()
+	defer lu.Unlock()
+
+	now, cpu, rss := getUsage()
+	// Don't skew pcpu by sampling too close to last sample.
+	if elapsed := now.Sub(lu.last); elapsed < 500*time.Millisecond {
+		// Always update rss.
+		lu.rss = rss
+	} else {
+		tcpu := float64(cpu - lu.cpu)
+		lu.last, lu.cpu, lu.rss = now, cpu, rss
+		// Want to make this one decimal place and not count on upper layers.
+		// Cores already taken into account via cpu time measurements.
+		lu.pcpu = math.Round(tcpu/float64(elapsed)*1000) / 10
+	}
+	return lu.pcpu, lu.rss
+}
+
+// Sampling function to keep pcpu relevant.
+func periodic() {
+	updateUsage()
+	time.AfterFunc(time.Second, periodic)
+}
+
+// ProcUsage returns CPU and memory usage.
+// Note upper layers do not use virtual memory size, so ok that it is not filled in here.
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	*pcpu, *rss = updateUsage()
+	return nil
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_dragonfly.go

@@ -0,0 +1,36 @@
+// Copyright 2015-2023 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Copied from pse_openbsd.go
+
+package pse
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+// ProcUsage returns CPU usage
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	pidStr := fmt.Sprintf("%d", os.Getpid())
+	out, err := exec.Command("ps", "o", "pcpu=,rss=,vsz=", "-p", pidStr).Output()
+	if err != nil {
+		*rss, *vss = -1, -1
+		return fmt.Errorf("ps call failed:%v", err)
+	}
+	fmt.Sscanf(string(out), "%f %d %d", pcpu, rss, vss)
+	*rss *= 1024 // 1k blocks, want bytes.
+	*vss *= 1024 // 1k blocks, want bytes.
+	return nil
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_freebsd_cgo.go

@@ -0,0 +1,85 @@
+// Copyright 2015-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build cgo && freebsd
+
+package pse
+
+/*
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#include <sys/user.h>
+#include <stddef.h>
+#include <unistd.h>
+
+long pagetok(long size)
+{
+    int pageshift, pagesize;
+
+    pagesize = getpagesize();
+    pageshift = 0;
+
+    while (pagesize > 1) {
+        pageshift++;
+        pagesize >>= 1;
+    }
+
+    return (size << pageshift);
+}
+
+int getusage(double *pcpu, unsigned int *rss, unsigned int *vss)
+{
+    int mib[4], ret;
+    size_t len;
+    struct kinfo_proc kp;
+
+    len = 4;
+    sysctlnametomib("kern.proc.pid", mib, &len);
+
+    mib[3] = getpid();
+    len = sizeof(kp);
+
+    ret = sysctl(mib, 4, &kp, &len, NULL, 0);
+    if (ret != 0) {
+        return (errno);
+    }
+
+    *rss = pagetok(kp.ki_rssize);
+    *vss = kp.ki_size;
+    *pcpu = (double)kp.ki_pctcpu / FSCALE;
+
+    return 0;
+}
+
+*/
+import "C"
+
+import (
+	"syscall"
+)
+
+// This is a placeholder for now.
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	var r, v C.uint
+	var c C.double
+
+	if ret := C.getusage(&c, &r, &v); ret != 0 {
+		return syscall.Errno(ret)
+	}
+
+	*pcpu = float64(c)
+	*rss = int64(r)
+	*vss = int64(v)
+
+	return nil
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_freebsd_sysctl.go

@@ -0,0 +1,125 @@
+// Copyright 2015-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// There are two FreeBSD implementations; one which uses cgo and should build
+// locally on any FreeBSD, and this one which uses sysctl but needs us to know
+// the offset constants for the fields we care about.
+//
+// The advantage of this one is that without cgo, it is much easier to
+// cross-compile to a target.  The official releases are all built with
+// cross-compilation.
+//
+// We've switched the other implementation to include '_cgo' in the filename,
+// to show that it's not the default.  This isn't an os or arch build tag,
+// so we have to use explicit build-tags within.
+// If lacking CGO support and targeting an unsupported arch, then before the
+// change you would have a compile failure for not being able to cross-compile.
+// After the change, you have a compile failure for not having the symbols
+// because no source file satisfies them.
+// Thus we are no worse off, and it's now much easier to extend support for
+// non-CGO to new architectures, just by editing this file.
+//
+// To generate for other architectures:
+//   1. Copy `freebsd.txt` to have a .c filename on a box running the target
+//      architecture, compile and run it.
+//   2. Update the init() function below to include a case for this architecture
+//   3. Update the build-tags in this file.
+
+//go:build !cgo && freebsd && (amd64 || arm64)
+
+package pse
+
+import (
+	"encoding/binary"
+	"runtime"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// On FreeBSD, to get proc information we read it out of the kernel using a
+// binary sysctl.  The endianness of integers is thus explicitly "host", rather
+// than little or big endian.
+var nativeEndian = binary.LittleEndian
+
+var pageshift int // derived from getpagesize(3) in init() below
+
+var (
+	// These are populated in the init function, based on the current architecture.
+	// (It's less file-count explosion than having one small file for each
+	// FreeBSD architecture).
+	KIP_OFF_size   int
+	KIP_OFF_rssize int
+	KIP_OFF_pctcpu int
+)
+
+func init() {
+	switch runtime.GOARCH {
+	// These are the values which come from compiling and running
+	// freebsd.txt as a C program.
+	// Most recently validated: 2025-04 with FreeBSD 14.2R in AWS.
+	case "amd64":
+		KIP_OFF_size = 256
+		KIP_OFF_rssize = 264
+		KIP_OFF_pctcpu = 308
+	case "arm64":
+		KIP_OFF_size = 256
+		KIP_OFF_rssize = 264
+		KIP_OFF_pctcpu = 308
+	default:
+		panic("code bug: server/pse FreeBSD support missing case for '" + runtime.GOARCH + "' but build-tags allowed us to build anyway?")
+	}
+
+	// To get the physical page size, the C library checks two places:
+	//   process ELF auxiliary info, AT_PAGESZ
+	//   as a fallback, the hw.pagesize sysctl
+	// In looking closely, I found that the Go runtime support is handling
+	// this for us, and exposing that as syscall.Getpagesize, having checked
+	// both in the same ways, at process start, so a call to that should return
+	// a memory value without even a syscall bounce.
+	pagesize := syscall.Getpagesize()
+	pageshift = 0
+	for pagesize > 1 {
+		pageshift += 1
+		pagesize >>= 1
+	}
+}
+
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	rawdata, err := unix.SysctlRaw("kern.proc.pid", unix.Getpid())
+	if err != nil {
+		return err
+	}
+
+	r_vss_bytes := nativeEndian.Uint32(rawdata[KIP_OFF_size:])
+	r_rss_pages := nativeEndian.Uint32(rawdata[KIP_OFF_rssize:])
+	rss_bytes := r_rss_pages << pageshift
+
+	// In C: fixpt_t ki_pctcpu
+	// Doc: %cpu for process during ki_swtime
+	// fixpt_t is __uint32_t
+	// usr.bin/top uses pctdouble to convert to a double (float64)
+	// define pctdouble(p) ((double)(p) / FIXED_PCTCPU)
+	// FIXED_PCTCPU is _usually_ FSCALE (some architectures are special)
+	// <sys/param.h> has:
+	//   #define FSHIFT  11              /* bits to right of fixed binary point */
+	//   #define FSCALE  (1<<FSHIFT)
+	r_pcpu := nativeEndian.Uint32(rawdata[KIP_OFF_pctcpu:])
+	f_pcpu := float64(r_pcpu) / float64(2048)
+
+	*rss = int64(rss_bytes)
+	*vss = int64(r_vss_bytes)
+	*pcpu = f_pcpu
+
+	return nil
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_linux.go

@@ -0,0 +1,128 @@
+// Copyright 2015-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pse
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"sync/atomic"
+	"syscall"
+	"time"
+)
+
+var (
+	procStatFile string
+	ticks        int64
+	lastTotal    int64
+	lastSeconds  int64
+	ipcpu        int64
+	pageSize     int64
+)
+
+const (
+	utimePos = 13
+	stimePos = 14
+	startPos = 21
+	vssPos   = 22
+	rssPos   = 23
+)
+
+func init() {
+	// Avoiding to generate docker image without CGO
+	ticks = 100 // int64(C.sysconf(C._SC_CLK_TCK))
+	procStatFile = fmt.Sprintf("/proc/%d/stat", os.Getpid())
+	pageSize = int64(os.Getpagesize())
+	periodic()
+}
+
+// Sampling function to keep pcpu relevant.
+func periodic() {
+	contents, err := os.ReadFile(procStatFile)
+	if err != nil {
+		return
+	}
+	fields := bytes.Fields(contents)
+
+	// PCPU
+	pstart := parseInt64(fields[startPos])
+	utime := parseInt64(fields[utimePos])
+	stime := parseInt64(fields[stimePos])
+	total := utime + stime
+
+	var sysinfo syscall.Sysinfo_t
+	if err := syscall.Sysinfo(&sysinfo); err != nil {
+		return
+	}
+
+	seconds := int64(sysinfo.Uptime) - (pstart / ticks)
+
+	// Save off temps
+	lt := lastTotal
+	ls := lastSeconds
+
+	// Update last sample
+	lastTotal = total
+	lastSeconds = seconds
+
+	// Adjust to current time window
+	total -= lt
+	seconds -= ls
+
+	if seconds > 0 {
+		atomic.StoreInt64(&ipcpu, (total*1000/ticks)/seconds)
+	}
+
+	time.AfterFunc(1*time.Second, periodic)
+}
+
+// ProcUsage returns CPU usage
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	contents, err := os.ReadFile(procStatFile)
+	if err != nil {
+		return err
+	}
+	fields := bytes.Fields(contents)
+
+	// Memory
+	*rss = (parseInt64(fields[rssPos])) * pageSize
+	*vss = parseInt64(fields[vssPos])
+
+	// PCPU
+	// We track this with periodic sampling, so just load and go.
+	*pcpu = float64(atomic.LoadInt64(&ipcpu)) / 10.0
+
+	return nil
+}
+
+// Ascii numbers 0-9
+const (
+	asciiZero = 48
+	asciiNine = 57
+)
+
+// parseInt64 expects decimal positive numbers. We
+// return -1 to signal error
+func parseInt64(d []byte) (n int64) {
+	if len(d) == 0 {
+		return -1
+	}
+	for _, dec := range d {
+		if dec < asciiZero || dec > asciiNine {
+			return -1
+		}
+		n = n*10 + (int64(dec) - asciiZero)
+	}
+	return n
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_netbsd.go

@@ -0,0 +1,36 @@
+// Copyright 2022 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Copied from pse_openbsd.go
+
+package pse
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+// ProcUsage returns CPU usage
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	pidStr := fmt.Sprintf("%d", os.Getpid())
+	out, err := exec.Command("ps", "o", "pcpu=,rss=,vsz=", "-p", pidStr).Output()
+	if err != nil {
+		*rss, *vss = -1, -1
+		return fmt.Errorf("ps call failed:%v", err)
+	}
+	fmt.Sscanf(string(out), "%f %d %d", pcpu, rss, vss)
+	*rss *= 1024 // 1k blocks, want bytes.
+	*vss *= 1024 // 1k blocks, want bytes.
+	return nil
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_openbsd.go

@@ -0,0 +1,36 @@
+// Copyright 2015-2018 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Copied from pse_darwin.go
+
+package pse
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+// ProcUsage returns CPU usage
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	pidStr := fmt.Sprintf("%d", os.Getpid())
+	out, err := exec.Command("ps", "o", "pcpu=,rss=,vsz=", "-p", pidStr).Output()
+	if err != nil {
+		*rss, *vss = -1, -1
+		return fmt.Errorf("ps call failed:%v", err)
+	}
+	fmt.Sscanf(string(out), "%f %d %d", pcpu, rss, vss)
+	*rss *= 1024 // 1k blocks, want bytes.
+	*vss *= 1024 // 1k blocks, want bytes.
+	return nil
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_rumprun.go

@@ -0,0 +1,25 @@
+// Copyright 2015-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build rumprun
+
+package pse
+
+// This is a placeholder for now.
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	*pcpu = 0.0
+	*rss = 0
+	*vss = 0
+
+	return nil
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_solaris.go

@@ -0,0 +1,45 @@
+// Copyright 2015-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Copied from pse_openbsd.go
+
+//go:build illumos || solaris
+
+package pse
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+// ProcUsage returns CPU usage
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	pidStr := fmt.Sprintf("%d", os.Getpid())
+	out, err := exec.Command("ps", "-o", "pcpu,rss,vsz", "-p", pidStr).Output()
+	if err != nil {
+		*rss, *vss = -1, -1
+		return fmt.Errorf("ps call failed:%v", err)
+	}
+	lines := strings.Split(string(out), "\n")
+	if len(lines) < 2 {
+		*rss, *vss = -1, -1
+		return fmt.Errorf("no ps output")
+	}
+	output := lines[1]
+	fmt.Sscanf(output, "%f %d %d", pcpu, rss, vss)
+	*rss *= 1024 // 1k blocks, want bytes.
+	*vss *= 1024 // 1k blocks, want bytes.
+	return nil
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_wasm.go

@@ -0,0 +1,25 @@
+// Copyright 2022-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build wasm
+
+package pse
+
+// This is a placeholder for now.
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	*pcpu = 0.0
+	*rss = 0
+	*vss = 0
+
+	return nil
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_windows.go

@@ -0,0 +1,296 @@
+// Copyright 2015-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build windows
+
+package pse
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var (
+	pdh                            = windows.NewLazySystemDLL("pdh.dll")
+	winPdhOpenQuery                = pdh.NewProc("PdhOpenQuery")
+	winPdhAddCounter               = pdh.NewProc("PdhAddCounterW")
+	winPdhCollectQueryData         = pdh.NewProc("PdhCollectQueryData")
+	winPdhGetFormattedCounterValue = pdh.NewProc("PdhGetFormattedCounterValue")
+	winPdhGetFormattedCounterArray = pdh.NewProc("PdhGetFormattedCounterArrayW")
+)
+
+func init() {
+	if err := pdh.Load(); err != nil {
+		panic(err)
+	}
+	for _, p := range []*windows.LazyProc{
+		winPdhOpenQuery, winPdhAddCounter, winPdhCollectQueryData,
+		winPdhGetFormattedCounterValue, winPdhGetFormattedCounterArray,
+	} {
+		if err := p.Find(); err != nil {
+			panic(err)
+		}
+	}
+}
+
+// global performance counter query handle and counters
+var (
+	pcHandle                                       PDH_HQUERY
+	pidCounter, cpuCounter, rssCounter, vssCounter PDH_HCOUNTER
+	prevCPU                                        float64
+	prevRss                                        int64
+	prevVss                                        int64
+	lastSampleTime                                 time.Time
+	processPid                                     int
+	pcQueryLock                                    sync.Mutex
+	initialSample                                  = true
+)
+
+// maxQuerySize is the number of values to return from a query.
+// It represents the maximum # of servers that can be queried
+// simultaneously running on a machine.
+const maxQuerySize = 512
+
+// Keep static memory around to reuse; this works best for passing
+// into the pdh API.
+var counterResults [maxQuerySize]PDH_FMT_COUNTERVALUE_ITEM_DOUBLE
+
+// PDH Types
+type (
+	PDH_HQUERY   syscall.Handle
+	PDH_HCOUNTER syscall.Handle
+)
+
+// PDH constants used here
+const (
+	PDH_FMT_DOUBLE   = 0x00000200
+	PDH_INVALID_DATA = 0xC0000BC6
+	PDH_MORE_DATA    = 0x800007D2
+)
+
+// PDH_FMT_COUNTERVALUE_DOUBLE - double value
+type PDH_FMT_COUNTERVALUE_DOUBLE struct {
+	CStatus     uint32
+	DoubleValue float64
+}
+
+// PDH_FMT_COUNTERVALUE_ITEM_DOUBLE is an array
+// element of a double value
+type PDH_FMT_COUNTERVALUE_ITEM_DOUBLE struct {
+	SzName   *uint16 // pointer to a string
+	FmtValue PDH_FMT_COUNTERVALUE_DOUBLE
+}
+
+func pdhAddCounter(hQuery PDH_HQUERY, szFullCounterPath string, dwUserData uintptr, phCounter *PDH_HCOUNTER) error {
+	ptxt, _ := syscall.UTF16PtrFromString(szFullCounterPath)
+	r0, _, _ := winPdhAddCounter.Call(
+		uintptr(hQuery),
+		uintptr(unsafe.Pointer(ptxt)),
+		dwUserData,
+		uintptr(unsafe.Pointer(phCounter)))
+
+	if r0 != 0 {
+		return fmt.Errorf("pdhAddCounter failed. %d", r0)
+	}
+	return nil
+}
+
+func pdhOpenQuery(datasrc *uint16, userdata uint32, query *PDH_HQUERY) error {
+	r0, _, _ := syscall.Syscall(winPdhOpenQuery.Addr(), 3, 0, uintptr(userdata), uintptr(unsafe.Pointer(query)))
+	if r0 != 0 {
+		return fmt.Errorf("pdhOpenQuery failed - %d", r0)
+	}
+	return nil
+}
+
+func pdhCollectQueryData(hQuery PDH_HQUERY) error {
+	r0, _, _ := winPdhCollectQueryData.Call(uintptr(hQuery))
+	if r0 != 0 {
+		return fmt.Errorf("pdhCollectQueryData failed - %d", r0)
+	}
+	return nil
+}
+
+// pdhGetFormattedCounterArrayDouble returns the value of return code
+// rather than error, to easily check return codes
+func pdhGetFormattedCounterArrayDouble(hCounter PDH_HCOUNTER, lpdwBufferSize *uint32, lpdwBufferCount *uint32, itemBuffer *PDH_FMT_COUNTERVALUE_ITEM_DOUBLE) uint32 {
+	ret, _, _ := winPdhGetFormattedCounterArray.Call(
+		uintptr(hCounter),
+		uintptr(PDH_FMT_DOUBLE),
+		uintptr(unsafe.Pointer(lpdwBufferSize)),
+		uintptr(unsafe.Pointer(lpdwBufferCount)),
+		uintptr(unsafe.Pointer(itemBuffer)))
+
+	return uint32(ret)
+}
+
+func getCounterArrayData(counter PDH_HCOUNTER) ([]float64, error) {
+	var bufSize uint32
+	var bufCount uint32
+
+	// Retrieving array data requires two calls, the first which
+	// requires an addressable empty buffer, and sets size fields.
+	// The second call returns the data.
+	initialBuf := make([]PDH_FMT_COUNTERVALUE_ITEM_DOUBLE, 1)
+	ret := pdhGetFormattedCounterArrayDouble(counter, &bufSize, &bufCount, &initialBuf[0])
+	if ret == PDH_MORE_DATA {
+		// we'll likely never get here, but be safe.
+		if bufCount > maxQuerySize {
+			bufCount = maxQuerySize
+		}
+		ret = pdhGetFormattedCounterArrayDouble(counter, &bufSize, &bufCount, &counterResults[0])
+		if ret == 0 {
+			rv := make([]float64, bufCount)
+			for i := 0; i < int(bufCount); i++ {
+				rv[i] = counterResults[i].FmtValue.DoubleValue
+			}
+			return rv, nil
+		}
+	}
+	if ret != 0 {
+		return nil, fmt.Errorf("getCounterArrayData failed - %d", ret)
+	}
+
+	return nil, nil
+}
+
+// getProcessImageName returns the name of the process image, as expected by
+// the performance counter API.
+func getProcessImageName() (name string) {
+	name = filepath.Base(os.Args[0])
+	name = strings.TrimSuffix(name, ".exe")
+	return
+}
+
+// initialize our counters
+func initCounters() (err error) {
+
+	processPid = os.Getpid()
+	// require an addressible nil pointer
+	var source uint16
+	if err := pdhOpenQuery(&source, 0, &pcHandle); err != nil {
+		return err
+	}
+
+	// setup the performance counters, search for all server instances
+	name := fmt.Sprintf("%s*", getProcessImageName())
+	pidQuery := fmt.Sprintf("\\Process(%s)\\ID Process", name)
+	cpuQuery := fmt.Sprintf("\\Process(%s)\\%% Processor Time", name)
+	rssQuery := fmt.Sprintf("\\Process(%s)\\Working Set - Private", name)
+	vssQuery := fmt.Sprintf("\\Process(%s)\\Virtual Bytes", name)
+
+	if err = pdhAddCounter(pcHandle, pidQuery, 0, &pidCounter); err != nil {
+		return err
+	}
+	if err = pdhAddCounter(pcHandle, cpuQuery, 0, &cpuCounter); err != nil {
+		return err
+	}
+	if err = pdhAddCounter(pcHandle, rssQuery, 0, &rssCounter); err != nil {
+		return err
+	}
+	if err = pdhAddCounter(pcHandle, vssQuery, 0, &vssCounter); err != nil {
+		return err
+	}
+
+	// prime the counters by collecting once, and sleep to get somewhat
+	// useful information the first request.  Counters for the CPU require
+	// at least two collect calls.
+	if err = pdhCollectQueryData(pcHandle); err != nil {
+		return err
+	}
+	time.Sleep(50)
+
+	return nil
+}
+
+// ProcUsage returns process CPU and memory statistics
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	var err error
+
+	// For simplicity, protect the entire call.
+	// Most simultaneous requests will immediately return
+	// with cached values.
+	pcQueryLock.Lock()
+	defer pcQueryLock.Unlock()
+
+	// First time through, initialize counters.
+	if initialSample {
+		if err = initCounters(); err != nil {
+			return err
+		}
+		initialSample = false
+	} else if time.Since(lastSampleTime) < (2 * time.Second) {
+		// only refresh every two seconds as to minimize impact
+		// on the server.
+		*pcpu = prevCPU
+		*rss = prevRss
+		*vss = prevVss
+		return nil
+	}
+
+	// always save the sample time, even on errors.
+	defer func() {
+		lastSampleTime = time.Now()
+	}()
+
+	// refresh the performance counter data
+	if err = pdhCollectQueryData(pcHandle); err != nil {
+		return err
+	}
+
+	// retrieve the data
+	var pidAry, cpuAry, rssAry, vssAry []float64
+	if pidAry, err = getCounterArrayData(pidCounter); err != nil {
+		return err
+	}
+	if cpuAry, err = getCounterArrayData(cpuCounter); err != nil {
+		return err
+	}
+	if rssAry, err = getCounterArrayData(rssCounter); err != nil {
+		return err
+	}
+	if vssAry, err = getCounterArrayData(vssCounter); err != nil {
+		return err
+	}
+	// find the index of the entry for this process
+	idx := int(-1)
+	for i := range pidAry {
+		if int(pidAry[i]) == processPid {
+			idx = i
+			break
+		}
+	}
+	// no pid found...
+	if idx < 0 {
+		return fmt.Errorf("could not find pid in performance counter results")
+	}
+	// assign values from the performance counters
+	*pcpu = cpuAry[idx]
+	*rss = int64(rssAry[idx])
+	*vss = int64(vssAry[idx])
+
+	// save off cache values
+	prevCPU = *pcpu
+	prevRss = *rss
+	prevVss = *vss
+
+	return nil
+}

Server/vendor/github.com/nats-io/nats-server/v2/server/pse/pse_zos.go

@@ -0,0 +1,25 @@
+// Copyright 2023-2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build zos
+
+package pse
+
+// This is a placeholder for now.
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	*pcpu = 0.0
+	*rss = 0
+	*vss = 0
+
+	return nil
+}