process_xxx_memory statistics for macOS (cgo)

prometheus/process_collector_cgo_darwin.c

@@ -0,0 +1,80 @@
+// 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>
+// Compiler warns that shared_memory_server.h is deprecated, use this instead.
+// But this doesn't define SHARED_DATA_REGION_SIZE or SHARED_TEXT_REGION_SIZE.
+//#include <mach/shared_region.h>
+#include <mach/shared_memory_server.h>
+#include <mach/mach_vm.h>
+
+
+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;
+}

prometheus/process_collector_cgo_darwin.go

@@ -0,0 +1,34 @@
+// 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
+}

prometheus/process_collector_darwin.go

@@ -14,13 +14,23 @@
 package prometheus
 
 import (
+	"errors"
 	"fmt"
 	"golang.org/x/sys/unix"
 	"os"
 	"syscall"
 	"time"
 )
 
+// notImplementedErr is returned by stub functions that replace cgo functions, when cgo
+// isn't available.
+var notImplementedErr = fmt.Errorf("not implemented")
+
+type memoryInfo struct {
+	vsize uint64 // Virtual memory size in bytes
+	rss   uint64 // Resident memory size in bytes
+}
+
 func canCollectProcess() bool {
 	return true
 }
@@ -85,7 +95,14 @@ func (c *processCollector) processCollect(ch chan<- Metric) {
 		c.reportError(ch, c.cpuTotal, err)
 	}
 
-	// TODO: publish c.vsize and c.rss values
+	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)

prometheus/process_collector_nocgo_darwin.go

@@ -0,0 +1,20 @@
+// 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
+}