process_xxx_memory statistics for macOS (without cgo)

go.mod

@@ -17,6 +17,7 @@ require (
 )
 
 require (
+	github.com/ebitengine/purego v0.7.1 // indirect
 	github.com/jpillora/backoff v1.0.0 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect

go.sum

@@ -6,6 +6,8 @@ github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ3
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/ebitengine/purego v0.7.1 h1:6/55d26lG3o9VCZX8lping+bZcmShseiqlh2bnUDiPA=
+github.com/ebitengine/purego v0.7.1/go.mod h1:ah1In8AOtksoNK6yk5z1HTJeUkC1Ez4Wk2idgGslMwQ=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=

prometheus/process_collector_amd64_darwin.go

@@ -0,0 +1,54 @@
+// 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 amd64
+
+package prometheus
+
+// These are macros in xnu/osfmk/mach/shared_memory_server.h
+const (
+	globalSharedTextSegment uint64 = 0x90000000
+
+	sharedTextRegionSize uint64 = 0x10000000
+	sharedDataRegionSize uint64 = 0x10000000
+)
+
+const (
+	machTaskBasicInfoSizeOf   = 48 // sizeof(struct mach_task_basic_info)
+	vmRegionBasicInfo64SizeOf = 36 // sizeof(struct vm_region_basic_info_64)
+)
+
+// Fundamental mach types defined in xnu/osfmk/mach/i386/vm_types.h.  The integer_t and
+// __darwin_natural_t types are explicitly 32-bit here to help decoding into a structure,
+// where 'int' types are not supported.  The __darwin_natural_t type is defined in
+// xnu/bsd/i386/_types.h.
+type (
+	__darwin_natural_t = uint32             // typedef unsigned int __darwin_natural_t;
+	integer_t          = int32              // typedef int integer_t;
+	natural_t          = __darwin_natural_t // typedef __darwin_natural_t natural_t;
+
+	mach_vm_offset_t = uint64 // typedef uint64_t mach_vm_offset_t __kernel_ptr_semantics;
+	mach_vm_size_t   = uint64 // typedef uint64_t mach_vm_size_t;
+)
+
+// Defined in xnu/osfmk/mach/i386/boolean.h, and explicitly 32-bit here to help decoding
+// into a structure, where 'int' types are not supported.
+type (
+	boolean_t = uint32 // typedef unsigned int boolean_t;
+)
+
+// Defined in xnu/osfmk/mach/i386/kern_return.h; see xnu/osfmk/mach/kern_return.h for
+// possible values.
+type (
+	kern_return_t = int // typedef int kern_return_t;
+)

prometheus/process_collector_arm64_darwin.go

@@ -0,0 +1,55 @@
+// 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 arm64
+
+package prometheus
+
+// These are macros in xnu/osfmk/mach/shared_memory_server.h.  Note that __arm__
+// is not defined for 64-bit arm.
+const (
+	globalSharedTextSegment uint64 = 0x90000000
+
+	sharedTextRegionSize uint64 = 0x10000000
+	sharedDataRegionSize uint64 = 0x10000000
+)
+
+const (
+	machTaskBasicInfoSizeOf   = 48 // sizeof(struct mach_task_basic_info)
+	vmRegionBasicInfo64SizeOf = 36 // sizeof(struct vm_region_basic_info_64)
+)
+
+// Fundamental mach types defined in xnu/osfmk/mach/arm/vm_types.h.  The integer_t and
+// __darwin_natural_t types are explicitly 32-bit here to help decoding into a structure,
+// where 'int' types are not supported.  The __darwin_natural_t type is defined in
+// xnu/bsd/arm/_types.h.
+type (
+	__darwin_natural_t = uint32             // typedef unsigned int __darwin_natural_t;
+	integer_t          = int32              // typedef int integer_t;
+	natural_t          = __darwin_natural_t // typedef __darwin_natural_t natural_t;
+
+	mach_vm_offset_t = uint64 // typedef uint64_t mach_vm_offset_t __kernel_ptr_semantics;
+	mach_vm_size_t   = uint64 // typedef uint64_t mach_vm_size_t;
+)
+
+// Defined in xnu/osfmk/mach/arm/boolean.h, and explicitly 32-bit here to help decoding
+// into a structure, where 'int' types are not supported.
+type (
+	boolean_t = int32 // typedef int boolean_t;
+)
+
+// Defined in xnu/osfmk/mach/arm/kern_return.h; see xnu/osfmk/mach/kern_return.h for
+// possible values.
+type (
+	kern_return_t = int // typedef int kern_return_t;
+)

prometheus/process_collector_darwin.go

@@ -85,7 +85,13 @@ func (c *processCollector) processCollect(ch chan<- Metric) {
 		c.reportError(ch, c.cpuTotal, err)
 	}
 
-	// TODO: publish c.vsize and c.rss values
+	if info, err := getMemoryUsage(); err == nil {
+		ch <- MustNewConstMetric(c.rss, GaugeValue, float64(info.ResidentSize))
+		ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(info.VirtualSize))
+	} else {
+		c.reportError(ch, c.rss, err)
+		c.reportError(ch, c.vsize, err)
+	}
 
 	if fds, err := getOpenFileCount(); err == nil {
 		ch <- MustNewConstMetric(c.openFDs, GaugeValue, fds)

prometheus/process_collector_purego_darwin.go

@@ -0,0 +1,219 @@
+// 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 (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"github.com/ebitengine/purego"
+)
+
+func init() {
+	if lib, err := purego.Dlopen("/usr/lib/system/libsystem_kernel.dylib",
+		purego.RTLD_NOW|purego.RTLD_GLOBAL); err == nil {
+
+		// purego.RegisterLibFunc() panics if the symbol is missing.  Ignore any error,
+		// and the metric will simply be unavailable when it is queried, instead of
+		// bringing down the whole process.
+		defer func() {
+			if err := recover(); err != nil {
+				// TODO: Log this somehow
+			}
+		}()
+
+		purego.RegisterLibFunc(&machTaskSelf, lib, "mach_task_self")
+		purego.RegisterLibFunc(&taskInfo, lib, "task_info")
+		purego.RegisterLibFunc(&machVmRegion, lib, "mach_vm_region")
+	}
+}
+
+const (
+	// The task_info() flavor MACH_TASK_BASIC_INFO for retrieving machTaskBasicInfo.
+	mach_task_basic_info task_flavor_t = 20 /* always 64-bit basic info */
+
+	// The MACH_TASK_BASIC_INFO_COUNT value, which is passed to the Mach API as the size
+	// of the payload for MACH_TASK_BASIC_INFO commands.
+	machTaskBasicInfoCount mach_msg_type_number_t = machTaskBasicInfoSizeOf / 4
+)
+
+// Defined in xnu/osfmk/mach/policy.h, xnu/iokit/IOKit/IORPC.h, and xnu/osfmk/mach/message.h
+// respectively.  policy_t is explicitly 32-bit here to help decoding into a structure,
+// where 'int' types are not supported.
+type (
+	policy_t               = int32     // typedef int policy_t;
+	mach_port_t            = natural_t // typedef natural_t mach_port_t;
+	mach_msg_type_number_t = natural_t // typedef natural_t mach_msg_type_number_t;
+)
+
+// Defined in xnu/osfmk/mach/task_info.h.  Note that task_info_t is actually defined as
+// integer_t* and cast from the address of the structure in C.  Define it as []byte to
+// keep the type system happy.
+type (
+	task_flavor_t = natural_t // typedef natural_t task_flavor_t
+	task_info_t   = []byte    // typedef integer_t *task_info_t /* varying array of int */
+)
+
+// time_value_t is the type for kernel time values, defined in xnu/osfmk/mach/time_value.h
+type time_value_t struct {
+	Seconds      integer_t
+	MicroSeconds integer_t
+}
+
+var machTaskSelf func() mach_port_t
+
+var taskInfo func(
+	mach_port_t,
+	task_flavor_t,
+	task_info_t,
+	*mach_msg_type_number_t,
+) kern_return_t
+
+// machTaskBasicInfo is the representation of `struct mach_task_basic_info` defined in
+// xnu/osfmk/mach/task_info.h, which is the architecture independent payload for fetching
+// certain task values.
+type machTaskBasicInfo struct {
+	VirtualSize     mach_vm_size_t // virtual memory size (bytes)
+	ResidentSize    mach_vm_size_t // resident memory size (bytes)
+	ResidentSizeMax mach_vm_size_t // maximum resident memory size (bytes)
+	UserTime        time_value_t   // total user run time for terminated threads
+	SystemTime      time_value_t   // total system run time for terminated threads
+	Policy          policy_t       // default policy for new threads
+	SuspendCount    integer_t      // suspend count for task
+}
+
+func getBasicTaskInfo() (*machTaskBasicInfo, error) {
+	var info machTaskBasicInfo
+
+	if taskInfo == nil {
+		return nil, fmt.Errorf("task_info() is not supported")
+	}
+
+	var count = machTaskBasicInfoCount
+	buf := make([]byte, machTaskBasicInfoSizeOf)
+
+	if ret := taskInfo(machTaskSelf(), mach_task_basic_info, buf, &count); ret != 0 {
+		return nil, fmt.Errorf("task_info() returned %d", ret)
+	}
+
+	if err := loadStruct(buf, &info); err != nil {
+		return nil, err
+	}
+
+	return &info, nil
+}
+
+// Defined in xnu/osfmk/mach/memory_object_types.h, xnu/osfmk/mach/vm_behavior.h,
+// defined in xnu/osfmk/mach/vm_inherit.h, and defined in xnu/osfmk/mach/vm_prot.h
+// respectively.  These types are not identical to the native definitions, because the
+// struct decoding requires primitives with a specific width.  The widths here are the
+// same as the native types.
+type (
+	memory_object_offset_t = uint64 // typedef unsigned long long memory_object_offset_t;
+	vm_behavior_t          = int32  // typedef int vm_behavior_t
+	vm_inherit_t           = uint32 // typedef unsigned int vm_inherit_t;
+	vm_prot_t              = int32  // typedef int vm_prot_t;
+)
+
+// These are defined in xnu/osfmk/mach/vm_types.h.
+type (
+	vm_map_t = mach_port_t // typedef mach_port_t vm_map_t;
+)
+
+// Defined in xnu/osfmk/mach/vm_region.h.  vm_region_flavor_t is explicitly 32-bit here to
+// help decoding into a structure, where 'int' types are not supported, and vm_region_info_t
+// is []byte to keep the type system happy.
+type (
+	vm_region_flavor_t = int32  // typedef int vm_region_flavor_t;
+	vm_region_info_t   = []byte // typedef int *vm_region_info_t;
+)
+
+const (
+	// The mach_vm_region() flavor VM_REGION_BASIC_INFO_64 for retrieving
+	// vmRegionBasicInfo64.
+	vm_region_basic_info_64 vm_region_flavor_t = 9
+
+	// The VM_REGION_BASIC_INFO_COUNT_64 value, which is passed to the Mach API as the
+	// size of the payload for VM_REGION_BASIC_INFO_64 commands.
+	vmRegionBasicInfoCount64 mach_msg_type_number_t = vmRegionBasicInfo64SizeOf / 4
+)
+
+// vmRegionBasicInfo64 is the representation of `struct vm_region_basic_info_64` defined
+// in xnu/osfmk/mach/vm_region.h.  This is enclosed in `#pragma pack(push, 4)` in C, so
+// unsafe.SizeOf() won't match the actual sizeof(vm_region_basic_info_64).
+type vmRegionBasicInfo64 struct {
+	Protection     vm_prot_t
+	MaxProtection  vm_prot_t
+	Inheritance    vm_inherit_t
+	Shared         boolean_t
+	Reserved       boolean_t
+	Offset         memory_object_offset_t
+	Behavior       vm_behavior_t
+	UserWiredCount uint16
+}
+
+var machVmRegion func(
+	vm_map_t,
+	*mach_vm_offset_t, /* IN/OUT */
+	*mach_vm_size_t, /* OUT */
+	vm_region_flavor_t, /* IN */
+	vm_region_info_t, /* OUT */
+	*mach_msg_type_number_t, /* IN/OUT */
+	*mach_port_t, /* OUT */
+) kern_return_t
+
+func getMemoryUsage() (*machTaskBasicInfo, error) {
+	// The logic in here follows how the ps(1) utility determines the memory values.  The
+	// basic_task_info command used here is a more modern, cross-architecture one that is
+	// suggested in the kernel header files.
+	//
+	// https://github.com/apple-oss-distributions/adv_cmds/blob/8744084ea0ff41ca4bb96b0f9c22407d0e48e9b7/ps/tasks.c#L132
+
+	info, err := getBasicTaskInfo()
+
+	if err != nil {
+		return nil, err
+	} else if machVmRegion != nil {
+
+		var textInfo vmRegionBasicInfo64
+
+		buf := make([]byte, vmRegionBasicInfo64SizeOf)
+		address := globalSharedTextSegment
+		var size mach_vm_size_t
+		var objectName mach_port_t
+
+		cmd := vm_region_basic_info_64
+		count := vmRegionBasicInfoCount64
+
+		ret := machVmRegion(machTaskSelf(), &address, &size, cmd, buf, &count, &objectName)
+
+		if ret == 0 {
+			if err := loadStruct(buf, &textInfo); err == nil {
+				adjustment := sharedTextRegionSize + sharedDataRegionSize
+				if textInfo.Reserved != 0 && size == sharedTextRegionSize && info.VirtualSize > adjustment {
+					info.VirtualSize -= adjustment
+				}
+			}
+		}
+	}
+
+	return info, nil
+}
+
+func loadStruct(buffer []byte, data any) error {
+	r := bytes.NewReader(buffer)
+
+	// TODO: NativeEndian was added in go 1.21
+	return binary.Read(r, binary.LittleEndian, data)
+}