[chore]: Bump github.com/prometheus/client_golang from 1.20.5 to 1.21.0 (#3860)

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.20.5 to 1.21.0.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/main/CHANGELOG.md)
- [Commits](https://github.com/prometheus/client_golang/compare/v1.20.5...v1.21.0)

---
updated-dependencies:
- dependency-name: github.com/prometheus/client_golang
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

vendor/github.com/prometheus/client_golang/prometheus/atomic_update.go

@@ -0,0 +1,50 @@
+// Copyright 2014 The Prometheus 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 prometheus
+
+import (
+	"math"
+	"sync/atomic"
+	"time"
+)
+
+// atomicUpdateFloat atomically updates the float64 value pointed to by bits
+// using the provided updateFunc, with an exponential backoff on contention.
+func atomicUpdateFloat(bits *uint64, updateFunc func(float64) float64) {
+	const (
+		// both numbers are derived from empirical observations
+		// documented in this PR: https://github.com/prometheus/client_golang/pull/1661
+		maxBackoff     = 320 * time.Millisecond
+		initialBackoff = 10 * time.Millisecond
+	)
+	backoff := initialBackoff
+
+	for {
+		loadedBits := atomic.LoadUint64(bits)
+		oldFloat := math.Float64frombits(loadedBits)
+		newFloat := updateFunc(oldFloat)
+		newBits := math.Float64bits(newFloat)
+
+		if atomic.CompareAndSwapUint64(bits, loadedBits, newBits) {
+			break
+		} else {
+			// Exponential backoff with sleep and cap to avoid infinite wait
+			time.Sleep(backoff)
+			backoff *= 2
+			if backoff > maxBackoff {
+				backoff = maxBackoff
+			}
+		}
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/counter.go

@@ -134,13 +134,9 @@ func (c *counter) Add(v float64) {
 		return
 	}
 
-	for {
-		oldBits := atomic.LoadUint64(&c.valBits)
-		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
-		if atomic.CompareAndSwapUint64(&c.valBits, oldBits, newBits) {
-			return
-		}
-	}
+	atomicUpdateFloat(&c.valBits, func(oldVal float64) float64 {
+		return oldVal + v
+	})
 }
 
 func (c *counter) AddWithExemplar(v float64, e Labels) {

vendor/github.com/prometheus/client_golang/prometheus/desc.go

@@ -189,12 +189,15 @@ func (d *Desc) String() string {
 			fmt.Sprintf("%s=%q", lp.GetName(), lp.GetValue()),
 		)
 	}
-	vlStrings := make([]string, 0, len(d.variableLabels.names))
-	for _, vl := range d.variableLabels.names {
-		if fn, ok := d.variableLabels.labelConstraints[vl]; ok && fn != nil {
-			vlStrings = append(vlStrings, fmt.Sprintf("c(%s)", vl))
-		} else {
-			vlStrings = append(vlStrings, vl)
+	vlStrings := []string{}
+	if d.variableLabels != nil {
+		vlStrings = make([]string, 0, len(d.variableLabels.names))
+		for _, vl := range d.variableLabels.names {
+			if fn, ok := d.variableLabels.labelConstraints[vl]; ok && fn != nil {
+				vlStrings = append(vlStrings, fmt.Sprintf("c(%s)", vl))
+			} else {
+				vlStrings = append(vlStrings, vl)
+			}
 		}
 	}
 	return fmt.Sprintf(

vendor/github.com/prometheus/client_golang/prometheus/gauge.go

@@ -120,13 +120,9 @@ func (g *gauge) Dec() {
 }
 
 func (g *gauge) Add(val float64) {
-	for {
-		oldBits := atomic.LoadUint64(&g.valBits)
-		newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
-		if atomic.CompareAndSwapUint64(&g.valBits, oldBits, newBits) {
-			return
-		}
-	}
+	atomicUpdateFloat(&g.valBits, func(oldVal float64) float64 {
+		return oldVal + val
+	})
 }
 
 func (g *gauge) Sub(val float64) {

vendor/github.com/prometheus/client_golang/prometheus/go_collector_latest.go

@@ -288,7 +288,7 @@ func NewGoCollector(opts ...func(o *internal.GoCollectorOptions)) Collector {
 }
 
 func attachOriginalName(desc, origName string) string {
-	return fmt.Sprintf("%s Sourced from %s", desc, origName)
+	return fmt.Sprintf("%s Sourced from %s.", desc, origName)
 }
 
 // Describe returns all descriptions of the collector.

vendor/github.com/prometheus/client_golang/prometheus/histogram.go

@@ -14,6 +14,7 @@
 package prometheus
 
 import (
+	"errors"
 	"fmt"
 	"math"
 	"runtime"
@@ -28,6 +29,11 @@ import (
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
 
+const (
+	nativeHistogramSchemaMaximum = 8
+	nativeHistogramSchemaMinimum = -4
+)
+
 // nativeHistogramBounds for the frac of observed values. Only relevant for
 // schema > 0. The position in the slice is the schema. (0 is never used, just
 // here for convenience of using the schema directly as the index.)
@@ -330,11 +336,11 @@ func ExponentialBuckets(start, factor float64, count int) []float64 {
 // used for the Buckets field of HistogramOpts.
 //
 // The function panics if 'count' is 0 or negative, if 'min' is 0 or negative.
-func ExponentialBucketsRange(min, max float64, count int) []float64 {
+func ExponentialBucketsRange(minBucket, maxBucket float64, count int) []float64 {
 	if count < 1 {
 		panic("ExponentialBucketsRange count needs a positive count")
 	}
-	if min <= 0 {
+	if minBucket <= 0 {
 		panic("ExponentialBucketsRange min needs to be greater than 0")
 	}
 
@@ -342,12 +348,12 @@ func ExponentialBucketsRange(min, max float64, count int) []float64 {
 	// max = min*growthFactor^(bucketCount-1)
 
 	// We know max/min and highest bucket. Solve for growthFactor.
-	growthFactor := math.Pow(max/min, 1.0/float64(count-1))
+	growthFactor := math.Pow(maxBucket/minBucket, 1.0/float64(count-1))
 
 	// Now that we know growthFactor, solve for each bucket.
 	buckets := make([]float64, count)
 	for i := 1; i <= count; i++ {
-		buckets[i-1] = min * math.Pow(growthFactor, float64(i-1))
+		buckets[i-1] = minBucket * math.Pow(growthFactor, float64(i-1))
 	}
 	return buckets
 }
@@ -858,15 +864,35 @@ func (h *histogram) Write(out *dto.Metric) error {
 // findBucket returns the index of the bucket for the provided value, or
 // len(h.upperBounds) for the +Inf bucket.
 func (h *histogram) findBucket(v float64) int {
-	// TODO(beorn7): For small numbers of buckets (<30), a linear search is
-	// slightly faster than the binary search. If we really care, we could
-	// switch from one search strategy to the other depending on the number
-	// of buckets.
-	//
-	// Microbenchmarks (BenchmarkHistogramNoLabels):
-	// 11 buckets: 38.3 ns/op linear - binary 48.7 ns/op
-	// 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op
-	// 300 buckets: 154 ns/op linear - binary 61.6 ns/op
+	n := len(h.upperBounds)
+	if n == 0 {
+		return 0
+	}
+
+	// Early exit: if v is less than or equal to the first upper bound, return 0
+	if v <= h.upperBounds[0] {
+		return 0
+	}
+
+	// Early exit: if v is greater than the last upper bound, return len(h.upperBounds)
+	if v > h.upperBounds[n-1] {
+		return n
+	}
+
+	// For small arrays, use simple linear search
+	// "magic number" 35 is result of tests on couple different (AWS and baremetal) servers
+	// see more details here: https://github.com/prometheus/client_golang/pull/1662
+	if n < 35 {
+		for i, bound := range h.upperBounds {
+			if v <= bound {
+				return i
+			}
+		}
+		// If v is greater than all upper bounds, return len(h.upperBounds)
+		return n
+	}
+
+	// For larger arrays, use stdlib's binary search
 	return sort.SearchFloat64s(h.upperBounds, v)
 }
 
@@ -1440,9 +1466,9 @@ func pickSchema(bucketFactor float64) int32 {
 	floor := math.Floor(math.Log2(math.Log2(bucketFactor)))
 	switch {
 	case floor <= -8:
-		return 8
+		return nativeHistogramSchemaMaximum
 	case floor >= 4:
-		return -4
+		return nativeHistogramSchemaMinimum
 	default:
 		return -int32(floor)
 	}
@@ -1621,13 +1647,9 @@ func waitForCooldown(count uint64, counts *histogramCounts) {
 // atomicAddFloat adds the provided float atomically to another float
 // represented by the bit pattern the bits pointer is pointing to.
 func atomicAddFloat(bits *uint64, v float64) {
-	for {
-		loadedBits := atomic.LoadUint64(bits)
-		newBits := math.Float64bits(math.Float64frombits(loadedBits) + v)
-		if atomic.CompareAndSwapUint64(bits, loadedBits, newBits) {
-			break
-		}
-	}
+	atomicUpdateFloat(bits, func(oldVal float64) float64 {
+		return oldVal + v
+	})
 }
 
 // atomicDecUint32 atomically decrements the uint32 p points to.  See
@@ -1835,3 +1857,196 @@ func (n *nativeExemplars) addExemplar(e *dto.Exemplar) {
 		n.exemplars = append(n.exemplars[:nIdx], append([]*dto.Exemplar{e}, append(n.exemplars[nIdx:rIdx], n.exemplars[rIdx+1:]...)...)...)
 	}
 }
+
+type constNativeHistogram struct {
+	desc *Desc
+	dto.Histogram
+	labelPairs []*dto.LabelPair
+}
+
+func validateCount(sum float64, count uint64, negativeBuckets, positiveBuckets map[int]int64, zeroBucket uint64) error {
+	var bucketPopulationSum int64
+	for _, v := range positiveBuckets {
+		bucketPopulationSum += v
+	}
+	for _, v := range negativeBuckets {
+		bucketPopulationSum += v
+	}
+	bucketPopulationSum += int64(zeroBucket)
+
+	// If the sum of observations is NaN, the number of observations must be greater or equal to the sum of all bucket counts.
+	// Otherwise, the number of observations must be equal to the sum of all bucket counts .
+
+	if math.IsNaN(sum) && bucketPopulationSum > int64(count) ||
+		!math.IsNaN(sum) && bucketPopulationSum != int64(count) {
+		return errors.New("the sum of all bucket populations exceeds the count of observations")
+	}
+	return nil
+}
+
+// NewConstNativeHistogram returns a metric representing a Prometheus native histogram with
+// fixed values for the count, sum, and positive/negative/zero bucket counts. As those parameters
+// cannot be changed, the returned value does not implement the Histogram
+// interface (but only the Metric interface). Users of this package will not
+// have much use for it in regular operations. However, when implementing custom
+// OpenTelemetry Collectors, it is useful as a throw-away metric that is generated on the fly
+// to send it to Prometheus in the Collect method.
+//
+// zeroBucket counts all (positive and negative)
+// observations in the zero bucket (with an absolute value less or equal
+// the current threshold).
+// positiveBuckets and negativeBuckets are separate maps for negative and positive
+// observations. The map's value is an int64, counting observations in
+// that bucket. The map's key is the
+// index of the bucket according to the used
+// Schema. Index 0 is for an upper bound of 1 in positive buckets and for a lower bound of -1 in negative buckets.
+// NewConstNativeHistogram returns an error if
+//   - the length of labelValues is not consistent with the variable labels in Desc or if Desc is invalid.
+//   - the schema passed is not between 8 and -4
+//   - the sum of counts in all buckets including the zero bucket does not equal the count if sum is not NaN (or exceeds the count if sum is NaN)
+//
+// See https://opentelemetry.io/docs/specs/otel/compatibility/prometheus_and_openmetrics/#exponential-histograms for more details about the conversion from OTel to Prometheus.
+func NewConstNativeHistogram(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	positiveBuckets, negativeBuckets map[int]int64,
+	zeroBucket uint64,
+	schema int32,
+	zeroThreshold float64,
+	createdTimestamp time.Time,
+	labelValues ...string,
+) (Metric, error) {
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
+		return nil, err
+	}
+	if schema > nativeHistogramSchemaMaximum || schema < nativeHistogramSchemaMinimum {
+		return nil, errors.New("invalid native histogram schema")
+	}
+	if err := validateCount(sum, count, negativeBuckets, positiveBuckets, zeroBucket); err != nil {
+		return nil, err
+	}
+
+	NegativeSpan, NegativeDelta := makeBucketsFromMap(negativeBuckets)
+	PositiveSpan, PositiveDelta := makeBucketsFromMap(positiveBuckets)
+	ret := &constNativeHistogram{
+		desc: desc,
+		Histogram: dto.Histogram{
+			CreatedTimestamp: timestamppb.New(createdTimestamp),
+			Schema:           &schema,
+			ZeroThreshold:    &zeroThreshold,
+			SampleCount:      &count,
+			SampleSum:        &sum,
+
+			NegativeSpan:  NegativeSpan,
+			NegativeDelta: NegativeDelta,
+
+			PositiveSpan:  PositiveSpan,
+			PositiveDelta: PositiveDelta,
+
+			ZeroCount: proto.Uint64(zeroBucket),
+		},
+		labelPairs: MakeLabelPairs(desc, labelValues),
+	}
+	if *ret.ZeroThreshold == 0 && *ret.ZeroCount == 0 && len(ret.PositiveSpan) == 0 && len(ret.NegativeSpan) == 0 {
+		ret.PositiveSpan = []*dto.BucketSpan{{
+			Offset: proto.Int32(0),
+			Length: proto.Uint32(0),
+		}}
+	}
+	return ret, nil
+}
+
+// MustNewConstNativeHistogram is a version of NewConstNativeHistogram that panics where
+// NewConstNativeHistogram would have returned an error.
+func MustNewConstNativeHistogram(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	positiveBuckets, negativeBuckets map[int]int64,
+	zeroBucket uint64,
+	nativeHistogramSchema int32,
+	nativeHistogramZeroThreshold float64,
+	createdTimestamp time.Time,
+	labelValues ...string,
+) Metric {
+	nativehistogram, err := NewConstNativeHistogram(desc,
+		count,
+		sum,
+		positiveBuckets,
+		negativeBuckets,
+		zeroBucket,
+		nativeHistogramSchema,
+		nativeHistogramZeroThreshold,
+		createdTimestamp,
+		labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return nativehistogram
+}
+
+func (h *constNativeHistogram) Desc() *Desc {
+	return h.desc
+}
+
+func (h *constNativeHistogram) Write(out *dto.Metric) error {
+	out.Histogram = &h.Histogram
+	out.Label = h.labelPairs
+	return nil
+}
+
+func makeBucketsFromMap(buckets map[int]int64) ([]*dto.BucketSpan, []int64) {
+	if len(buckets) == 0 {
+		return nil, nil
+	}
+	var ii []int
+	for k := range buckets {
+		ii = append(ii, k)
+	}
+	sort.Ints(ii)
+
+	var (
+		spans     []*dto.BucketSpan
+		deltas    []int64
+		prevCount int64
+		nextI     int
+	)
+
+	appendDelta := func(count int64) {
+		*spans[len(spans)-1].Length++
+		deltas = append(deltas, count-prevCount)
+		prevCount = count
+	}
+
+	for n, i := range ii {
+		count := buckets[i]
+		// Multiple spans with only small gaps in between are probably
+		// encoded more efficiently as one larger span with a few empty
+		// buckets. Needs some research to find the sweet spot. For now,
+		// we assume that gaps of one or two buckets should not create
+		// a new span.
+		iDelta := int32(i - nextI)
+		if n == 0 || iDelta > 2 {
+			// We have to create a new span, either because we are
+			// at the very beginning, or because we have found a gap
+			// of more than two buckets.
+			spans = append(spans, &dto.BucketSpan{
+				Offset: proto.Int32(iDelta),
+				Length: proto.Uint32(0),
+			})
+		} else {
+			// We have found a small gap (or no gap at all).
+			// Insert empty buckets as needed.
+			for j := int32(0); j < iDelta; j++ {
+				appendDelta(0)
+			}
+		}
+		appendDelta(count)
+		nextI = i + 1
+	}
+	return spans, deltas
+}

vendor/github.com/prometheus/client_golang/prometheus/internal/difflib.go

@@ -22,17 +22,18 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"strconv"
 	"strings"
 )
 
-func min(a, b int) int {
+func minInt(a, b int) int {
 	if a < b {
 		return a
 	}
 	return b
 }
 
-func max(a, b int) int {
+func maxInt(a, b int) int {
 	if a > b {
 		return a
 	}
@@ -427,12 +428,12 @@ func (m *SequenceMatcher) GetGroupedOpCodes(n int) [][]OpCode {
 	if codes[0].Tag == 'e' {
 		c := codes[0]
 		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
-		codes[0] = OpCode{c.Tag, max(i1, i2-n), i2, max(j1, j2-n), j2}
+		codes[0] = OpCode{c.Tag, maxInt(i1, i2-n), i2, maxInt(j1, j2-n), j2}
 	}
 	if codes[len(codes)-1].Tag == 'e' {
 		c := codes[len(codes)-1]
 		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
-		codes[len(codes)-1] = OpCode{c.Tag, i1, min(i2, i1+n), j1, min(j2, j1+n)}
+		codes[len(codes)-1] = OpCode{c.Tag, i1, minInt(i2, i1+n), j1, minInt(j2, j1+n)}
 	}
 	nn := n + n
 	groups := [][]OpCode{}
@@ -443,12 +444,12 @@ func (m *SequenceMatcher) GetGroupedOpCodes(n int) [][]OpCode {
 		// there is a large range with no changes.
 		if c.Tag == 'e' && i2-i1 > nn {
 			group = append(group, OpCode{
-				c.Tag, i1, min(i2, i1+n),
-				j1, min(j2, j1+n),
+				c.Tag, i1, minInt(i2, i1+n),
+				j1, minInt(j2, j1+n),
 			})
 			groups = append(groups, group)
 			group = []OpCode{}
-			i1, j1 = max(i1, i2-n), max(j1, j2-n)
+			i1, j1 = maxInt(i1, i2-n), maxInt(j1, j2-n)
 		}
 		group = append(group, OpCode{c.Tag, i1, i2, j1, j2})
 	}
@@ -515,7 +516,7 @@ func (m *SequenceMatcher) QuickRatio() float64 {
 // is faster to compute than either .Ratio() or .QuickRatio().
 func (m *SequenceMatcher) RealQuickRatio() float64 {
 	la, lb := len(m.a), len(m.b)
-	return calculateRatio(min(la, lb), la+lb)
+	return calculateRatio(minInt(la, lb), la+lb)
 }
 
 // Convert range to the "ed" format
@@ -524,7 +525,7 @@ func formatRangeUnified(start, stop int) string {
 	beginning := start + 1 // lines start numbering with one
 	length := stop - start
 	if length == 1 {
-		return fmt.Sprintf("%d", beginning)
+		return strconv.Itoa(beginning)
 	}
 	if length == 0 {
 		beginning-- // empty ranges begin at line just before the range

vendor/github.com/prometheus/client_golang/prometheus/internal/go_runtime_metrics.go

@@ -66,7 +66,8 @@ func RuntimeMetricsToProm(d *metrics.Description) (string, string, string, bool)
 		name += "_total"
 	}
 
-	valid := model.IsValidMetricName(model.LabelValue(namespace + "_" + subsystem + "_" + name))
+	// Our current conversion moves to legacy naming, so use legacy validation.
+	valid := model.IsValidLegacyMetricName(namespace + "_" + subsystem + "_" + name)
 	switch d.Kind {
 	case metrics.KindUint64:
 	case metrics.KindFloat64:

vendor/github.com/prometheus/client_golang/prometheus/metric.go

@@ -108,15 +108,23 @@ func BuildFQName(namespace, subsystem, name string) string {
 	if name == "" {
 		return ""
 	}
-	switch {
-	case namespace != "" && subsystem != "":
-		return strings.Join([]string{namespace, subsystem, name}, "_")
-	case namespace != "":
-		return strings.Join([]string{namespace, name}, "_")
-	case subsystem != "":
-		return strings.Join([]string{subsystem, name}, "_")
+
+	sb := strings.Builder{}
+	sb.Grow(len(namespace) + len(subsystem) + len(name) + 2)
+
+	if namespace != "" {
+		sb.WriteString(namespace)
+		sb.WriteString("_")
 	}
-	return name
+
+	if subsystem != "" {
+		sb.WriteString(subsystem)
+		sb.WriteString("_")
+	}
+
+	sb.WriteString(name)
+
+	return sb.String()
 }
 
 type invalidMetric struct {

vendor/github.com/prometheus/client_golang/prometheus/process_collector.go

@@ -23,6 +23,7 @@ import (
 
 type processCollector struct {
 	collectFn         func(chan<- Metric)
+	describeFn        func(chan<- *Desc)
 	pidFn             func() (int, error)
 	reportErrors      bool
 	cpuTotal          *Desc
@@ -122,26 +123,23 @@ func NewProcessCollector(opts ProcessCollectorOpts) Collector {
 	// Set up process metric collection if supported by the runtime.
 	if canCollectProcess() {
 		c.collectFn = c.processCollect
+		c.describeFn = c.describe
 	} else {
-		c.collectFn = func(ch chan<- Metric) {
-			c.reportError(ch, nil, errors.New("process metrics not supported on this platform"))
-		}
+		c.collectFn = c.errorCollectFn
+		c.describeFn = c.errorDescribeFn
 	}
 
 	return c
 }
 
-// Describe returns all descriptions of the collector.
-func (c *processCollector) Describe(ch chan<- *Desc) {
-	ch <- c.cpuTotal
-	ch <- c.openFDs
-	ch <- c.maxFDs
-	ch <- c.vsize
-	ch <- c.maxVsize
-	ch <- c.rss
-	ch <- c.startTime
-	ch <- c.inBytes
-	ch <- c.outBytes
+func (c *processCollector) errorCollectFn(ch chan<- Metric) {
+	c.reportError(ch, nil, errors.New("process metrics not supported on this platform"))
+}
+
+func (c *processCollector) errorDescribeFn(ch chan<- *Desc) {
+	if c.reportErrors {
+		ch <- NewInvalidDesc(errors.New("process metrics not supported on this platform"))
+	}
 }
 
 // Collect returns the current state of all metrics of the collector.
@@ -149,6 +147,11 @@ func (c *processCollector) Collect(ch chan<- Metric) {
 	c.collectFn(ch)
 }
 
+// Describe returns all descriptions of the collector.
+func (c *processCollector) Describe(ch chan<- *Desc) {
+	c.describeFn(ch)
+}
+
 func (c *processCollector) reportError(ch chan<- Metric, desc *Desc, err error) {
 	if !c.reportErrors {
 		return

vendor/github.com/prometheus/client_golang/prometheus/process_collector_cgo_darwin.c

@@ -0,0 +1,84 @@
+// Copyright 2024 The Prometheus 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 darwin && cgo
+
+#include <mach/mach_init.h>
+#include <mach/task.h>
+#include <mach/mach_vm.h>
+
+// The compiler warns that mach/shared_memory_server.h is deprecated, and to use
+// mach/shared_region.h instead.  But that doesn't define
+// SHARED_DATA_REGION_SIZE or SHARED_TEXT_REGION_SIZE, so redefine them here and
+// avoid a warning message when running tests.
+#define GLOBAL_SHARED_TEXT_SEGMENT      0x90000000U
+#define SHARED_DATA_REGION_SIZE         0x10000000
+#define SHARED_TEXT_REGION_SIZE         0x10000000
+
+
+int get_memory_info(unsigned long long *rss, unsigned long long *vsize)
+{
+    // This is lightly adapted from how ps(1) obtains its memory info.
+    // https://github.com/apple-oss-distributions/adv_cmds/blob/8744084ea0ff41ca4bb96b0f9c22407d0e48e9b7/ps/tasks.c#L109
+
+    kern_return_t               error;
+    task_t                      task = MACH_PORT_NULL;
+    mach_task_basic_info_data_t info;
+    mach_msg_type_number_t      info_count = MACH_TASK_BASIC_INFO_COUNT;
+
+    error = task_info(
+                mach_task_self(),
+                MACH_TASK_BASIC_INFO,
+                (task_info_t) &info,
+                &info_count );
+
+    if( error != KERN_SUCCESS )
+    {
+        return error;
+    }
+
+    *rss   = info.resident_size;
+    *vsize = info.virtual_size;
+
+    {
+        vm_region_basic_info_data_64_t    b_info;
+        mach_vm_address_t                 address = GLOBAL_SHARED_TEXT_SEGMENT;
+        mach_vm_size_t                    size;
+        mach_port_t                       object_name;
+
+        /*
+         * try to determine if this task has the split libraries
+         * mapped in... if so, adjust its virtual size down by
+         * the 2 segments that are used for split libraries
+         */
+        info_count = VM_REGION_BASIC_INFO_COUNT_64;
+
+        error = mach_vm_region(
+                    mach_task_self(),
+                    &address,
+                    &size,
+                    VM_REGION_BASIC_INFO_64,
+                    (vm_region_info_t) &b_info,
+                    &info_count,
+                    &object_name);
+
+        if (error == KERN_SUCCESS) {
+            if (b_info.reserved && size == (SHARED_TEXT_REGION_SIZE) &&
+                *vsize > (SHARED_TEXT_REGION_SIZE + SHARED_DATA_REGION_SIZE)) {
+                    *vsize -= (SHARED_TEXT_REGION_SIZE + SHARED_DATA_REGION_SIZE);
+            }
+        }
+    }
+
+    return 0;
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_cgo_darwin.go

@@ -0,0 +1,51 @@
+// Copyright 2024 The Prometheus 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 darwin && cgo
+
+package prometheus
+
+/*
+int get_memory_info(unsigned long long *rss, unsigned long long *vs);
+*/
+import "C"
+import "fmt"
+
+func getMemory() (*memoryInfo, error) {
+	var rss, vsize C.ulonglong
+
+	if err := C.get_memory_info(&rss, &vsize); err != 0 {
+		return nil, fmt.Errorf("task_info() failed with 0x%x", int(err))
+	}
+
+	return &memoryInfo{vsize: uint64(vsize), rss: uint64(rss)}, nil
+}
+
+// describe returns all descriptions of the collector for Darwin.
+// Ensure that this list of descriptors is kept in sync with the metrics collected
+// in the processCollect method. Any changes to the metrics in processCollect
+// (such as adding or removing metrics) should be reflected in this list of descriptors.
+func (c *processCollector) describe(ch chan<- *Desc) {
+	ch <- c.cpuTotal
+	ch <- c.openFDs
+	ch <- c.maxFDs
+	ch <- c.maxVsize
+	ch <- c.startTime
+	ch <- c.rss
+	ch <- c.vsize
+
+	/* the process could be collected but not implemented yet
+	ch <- c.inBytes
+	ch <- c.outBytes
+	*/
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_darwin.go

@@ -0,0 +1,128 @@
+// Copyright 2024 The Prometheus 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 prometheus
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+// notImplementedErr is returned by stub functions that replace cgo functions, when cgo
+// isn't available.
+var notImplementedErr = errors.New("not implemented")
+
+type memoryInfo struct {
+	vsize uint64 // Virtual memory size in bytes
+	rss   uint64 // Resident memory size in bytes
+}
+
+func canCollectProcess() bool {
+	return true
+}
+
+func getSoftLimit(which int) (uint64, error) {
+	rlimit := syscall.Rlimit{}
+
+	if err := syscall.Getrlimit(which, &rlimit); err != nil {
+		return 0, err
+	}
+
+	return rlimit.Cur, nil
+}
+
+func getOpenFileCount() (float64, error) {
+	// Alternately, the undocumented proc_pidinfo(PROC_PIDLISTFDS) can be used to
+	// return a list of open fds, but that requires a way to call C APIs.  The
+	// benefits, however, include fewer system calls and not failing when at the
+	// open file soft limit.
+
+	if dir, err := os.Open("/dev/fd"); err != nil {
+		return 0.0, err
+	} else {
+		defer dir.Close()
+
+		// Avoid ReadDir(), as it calls stat(2) on each descriptor.  Not only is
+		// that info not used, but KQUEUE descriptors fail stat(2), which causes
+		// the whole method to fail.
+		if names, err := dir.Readdirnames(0); err != nil {
+			return 0.0, err
+		} else {
+			// Subtract 1 to ignore the open /dev/fd descriptor above.
+			return float64(len(names) - 1), nil
+		}
+	}
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	if procs, err := unix.SysctlKinfoProcSlice("kern.proc.pid", os.Getpid()); err == nil {
+		if len(procs) == 1 {
+			startTime := float64(procs[0].Proc.P_starttime.Nano() / 1e9)
+			ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
+		} else {
+			err = fmt.Errorf("sysctl() returned %d proc structs (expected 1)", len(procs))
+			c.reportError(ch, c.startTime, err)
+		}
+	} else {
+		c.reportError(ch, c.startTime, err)
+	}
+
+	// The proc structure returned by kern.proc.pid above has an Rusage member,
+	// but it is not filled in, so it needs to be fetched by getrusage(2).  For
+	// that call, the UTime, STime, and Maxrss members are filled out, but not
+	// Ixrss, Idrss, or Isrss for the memory usage.  Memory stats will require
+	// access to the C API to call task_info(TASK_BASIC_INFO).
+	rusage := unix.Rusage{}
+
+	if err := unix.Getrusage(syscall.RUSAGE_SELF, &rusage); err == nil {
+		cpuTime := time.Duration(rusage.Stime.Nano() + rusage.Utime.Nano()).Seconds()
+		ch <- MustNewConstMetric(c.cpuTotal, CounterValue, cpuTime)
+	} else {
+		c.reportError(ch, c.cpuTotal, err)
+	}
+
+	if memInfo, err := getMemory(); err == nil {
+		ch <- MustNewConstMetric(c.rss, GaugeValue, float64(memInfo.rss))
+		ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(memInfo.vsize))
+	} else if !errors.Is(err, notImplementedErr) {
+		// Don't report an error when support is not compiled in.
+		c.reportError(ch, c.rss, err)
+		c.reportError(ch, c.vsize, err)
+	}
+
+	if fds, err := getOpenFileCount(); err == nil {
+		ch <- MustNewConstMetric(c.openFDs, GaugeValue, fds)
+	} else {
+		c.reportError(ch, c.openFDs, err)
+	}
+
+	if openFiles, err := getSoftLimit(syscall.RLIMIT_NOFILE); err == nil {
+		ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(openFiles))
+	} else {
+		c.reportError(ch, c.maxFDs, err)
+	}
+
+	if addressSpace, err := getSoftLimit(syscall.RLIMIT_AS); err == nil {
+		ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(addressSpace))
+	} else {
+		c.reportError(ch, c.maxVsize, err)
+	}
+
+	// TODO: socket(PF_SYSTEM) to fetch "com.apple.network.statistics" might
+	//  be able to get the per-process network send/receive counts.
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_nocgo_darwin.go

@@ -0,0 +1,39 @@
+// Copyright 2024 The Prometheus 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 darwin && !cgo
+
+package prometheus
+
+func getMemory() (*memoryInfo, error) {
+	return nil, notImplementedErr
+}
+
+// describe returns all descriptions of the collector for Darwin.
+// Ensure that this list of descriptors is kept in sync with the metrics collected
+// in the processCollect method. Any changes to the metrics in processCollect
+// (such as adding or removing metrics) should be reflected in this list of descriptors.
+func (c *processCollector) describe(ch chan<- *Desc) {
+	ch <- c.cpuTotal
+	ch <- c.openFDs
+	ch <- c.maxFDs
+	ch <- c.maxVsize
+	ch <- c.startTime
+
+	/* the process could be collected but not implemented yet
+	ch <- c.rss
+	ch <- c.vsize
+	ch <- c.inBytes
+	ch <- c.outBytes
+	*/
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_other.go

@@ -11,8 +11,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build !windows && !js && !wasip1
-// +build !windows,!js,!wasip1
+//go:build !windows && !js && !wasip1 && !darwin
+// +build !windows,!js,!wasip1,!darwin
 
 package prometheus
 
@@ -78,3 +78,19 @@ func (c *processCollector) processCollect(ch chan<- Metric) {
 		c.reportError(ch, nil, err)
 	}
 }
+
+// describe returns all descriptions of the collector for others than windows, js, wasip1 and darwin.
+// Ensure that this list of descriptors is kept in sync with the metrics collected
+// in the processCollect method. Any changes to the metrics in processCollect
+// (such as adding or removing metrics) should be reflected in this list of descriptors.
+func (c *processCollector) describe(ch chan<- *Desc) {
+	ch <- c.cpuTotal
+	ch <- c.openFDs
+	ch <- c.maxFDs
+	ch <- c.vsize
+	ch <- c.maxVsize
+	ch <- c.rss
+	ch <- c.startTime
+	ch <- c.inBytes
+	ch <- c.outBytes
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_wasip1.go

@@ -1,26 +0,0 @@
-// Copyright 2023 The Prometheus 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 wasip1
-// +build wasip1
-
-package prometheus
-
-func canCollectProcess() bool {
-	return false
-}
-
-func (*processCollector) processCollect(chan<- Metric) {
-	// noop on this platform
-	return
-}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_wasip1_js.go

@@ -1,4 +1,4 @@
-// Copyright 2019 The Prometheus Authors
+// Copyright 2023 The Prometheus 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
@@ -11,8 +11,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build js
-// +build js
+//go:build wasip1 || js
+// +build wasip1 js
 
 package prometheus
 
@@ -21,6 +21,13 @@ func canCollectProcess() bool {
 }
 
 func (c *processCollector) processCollect(ch chan<- Metric) {
-	// noop on this platform
-	return
+	c.errorCollectFn(ch)
+}
+
+// describe returns all descriptions of the collector for wasip1 and js.
+// Ensure that this list of descriptors is kept in sync with the metrics collected
+// in the processCollect method. Any changes to the metrics in processCollect
+// (such as adding or removing metrics) should be reflected in this list of descriptors.
+func (c *processCollector) describe(ch chan<- *Desc) {
+	c.errorDescribeFn(ch)
 }

vendor/github.com/prometheus/client_golang/prometheus/process_collector_windows.go

@@ -79,14 +79,10 @@ func getProcessHandleCount(handle windows.Handle) (uint32, error) {
 }
 
 func (c *processCollector) processCollect(ch chan<- Metric) {
-	h, err := windows.GetCurrentProcess()
-	if err != nil {
-		c.reportError(ch, nil, err)
-		return
-	}
+	h := windows.CurrentProcess()
 
 	var startTime, exitTime, kernelTime, userTime windows.Filetime
-	err = windows.GetProcessTimes(h, &startTime, &exitTime, &kernelTime, &userTime)
+	err := windows.GetProcessTimes(h, &startTime, &exitTime, &kernelTime, &userTime)
 	if err != nil {
 		c.reportError(ch, nil, err)
 		return
@@ -111,6 +107,19 @@ func (c *processCollector) processCollect(ch chan<- Metric) {
 	ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(16*1024*1024)) // Windows has a hard-coded max limit, not per-process.
 }
 
+// describe returns all descriptions of the collector for windows.
+// Ensure that this list of descriptors is kept in sync with the metrics collected
+// in the processCollect method. Any changes to the metrics in processCollect
+// (such as adding or removing metrics) should be reflected in this list of descriptors.
+func (c *processCollector) describe(ch chan<- *Desc) {
+	ch <- c.cpuTotal
+	ch <- c.openFDs
+	ch <- c.maxFDs
+	ch <- c.vsize
+	ch <- c.rss
+	ch <- c.startTime
+}
+
 func fileTimeToSeconds(ft windows.Filetime) float64 {
 	return float64(uint64(ft.HighDateTime)<<32+uint64(ft.LowDateTime)) / 1e7
 }

vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go

@@ -207,7 +207,13 @@ func HandlerForTransactional(reg prometheus.TransactionalGatherer, opts HandlerO
 		if encodingHeader != string(Identity) {
 			rsp.Header().Set(contentEncodingHeader, encodingHeader)
 		}
-		enc := expfmt.NewEncoder(w, contentType)
+
+		var enc expfmt.Encoder
+		if opts.EnableOpenMetricsTextCreatedSamples {
+			enc = expfmt.NewEncoder(w, contentType, expfmt.WithCreatedLines())
+		} else {
+			enc = expfmt.NewEncoder(w, contentType)
+		}
 
 		// handleError handles the error according to opts.ErrorHandling
 		// and returns true if we have to abort after the handling.
@@ -408,6 +414,21 @@ type HandlerOpts struct {
 	// (which changes the identity of the resulting series on the Prometheus
 	// server).
 	EnableOpenMetrics bool
+	// EnableOpenMetricsTextCreatedSamples specifies if this handler should add, extra, synthetic
+	// Created Timestamps for counters, histograms and summaries, which for the current
+	// version of OpenMetrics are defined as extra series with the same name and "_created"
+	// suffix. See also the OpenMetrics specification for more details
+	// https://github.com/prometheus/OpenMetrics/blob/v1.0.0/specification/OpenMetrics.md#counter-1
+	//
+	// Created timestamps are used to improve the accuracy of reset detection,
+	// but the way it's designed in OpenMetrics 1.0 it also dramatically increases cardinality
+	// if the scraper does not handle those metrics correctly (converting to created timestamp
+	// instead of leaving those series as-is). New OpenMetrics versions might improve
+	// this situation.
+	//
+	// Prometheus introduced the feature flag 'created-timestamp-zero-ingestion'
+	// in version 2.50.0 to handle this situation.
+	EnableOpenMetricsTextCreatedSamples bool
 	// ProcessStartTime allows setting process start timevalue that will be exposed
 	// with "Process-Start-Time-Unix" response header along with the metrics
 	// payload. This allow callers to have efficient transformations to cumulative

vendor/github.com/prometheus/client_golang/prometheus/summary.go

@@ -243,6 +243,7 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 
 	s := &summary{
 		desc: desc,
+		now:  opts.now,
 
 		objectives:       opts.Objectives,
 		sortedObjectives: make([]float64, 0, len(opts.Objectives)),
@@ -280,6 +281,8 @@ type summary struct {
 
 	desc *Desc
 
+	now func() time.Time
+
 	objectives       map[float64]float64
 	sortedObjectives []float64
 
@@ -307,7 +310,7 @@ func (s *summary) Observe(v float64) {
 	s.bufMtx.Lock()
 	defer s.bufMtx.Unlock()
 
-	now := time.Now()
+	now := s.now()
 	if now.After(s.hotBufExpTime) {
 		s.asyncFlush(now)
 	}
@@ -326,7 +329,7 @@ func (s *summary) Write(out *dto.Metric) error {
 	s.bufMtx.Lock()
 	s.mtx.Lock()
 	// Swap bufs even if hotBuf is empty to set new hotBufExpTime.
-	s.swapBufs(time.Now())
+	s.swapBufs(s.now())
 	s.bufMtx.Unlock()
 
 	s.flushColdBuf()
@@ -468,13 +471,9 @@ func (s *noObjectivesSummary) Observe(v float64) {
 	n := atomic.AddUint64(&s.countAndHotIdx, 1)
 	hotCounts := s.counts[n>>63]
 
-	for {
-		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
-		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
-		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
-			break
-		}
-	}
+	atomicUpdateFloat(&hotCounts.sumBits, func(oldVal float64) float64 {
+		return oldVal + v
+	})
 	// Increment count last as we take it as a signal that the observation
 	// is complete.
 	atomic.AddUint64(&hotCounts.count, 1)
@@ -516,14 +515,13 @@ func (s *noObjectivesSummary) Write(out *dto.Metric) error {
 	// Finally add all the cold counts to the new hot counts and reset the cold counts.
 	atomic.AddUint64(&hotCounts.count, count)
 	atomic.StoreUint64(&coldCounts.count, 0)
-	for {
-		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
-		newBits := math.Float64bits(math.Float64frombits(oldBits) + sum.GetSampleSum())
-		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
-			atomic.StoreUint64(&coldCounts.sumBits, 0)
-			break
-		}
-	}
+
+	// Use atomicUpdateFloat to update hotCounts.sumBits atomically.
+	atomicUpdateFloat(&hotCounts.sumBits, func(oldVal float64) float64 {
+		return oldVal + sum.GetSampleSum()
+	})
+	atomic.StoreUint64(&coldCounts.sumBits, 0)
+
 	return nil
 }