github.com/newrelic/go-agent@v3.26.0+incompatible/internal/sysinfo/memtotal_darwin.go (about)

     1  // Copyright 2020 New Relic Corporation. All rights reserved.
     2  // SPDX-License-Identifier: Apache-2.0
     3  
     4  package sysinfo
     5  
     6  import (
     7  	"syscall"
     8  	"unsafe"
     9  )
    10  
    11  // PhysicalMemoryBytes returns the total amount of host memory.
    12  func PhysicalMemoryBytes() (uint64, error) {
    13  	mib := []int32{6 /* CTL_HW */, 24 /* HW_MEMSIZE */}
    14  
    15  	buf := make([]byte, 8)
    16  	bufLen := uintptr(8)
    17  
    18  	_, _, e1 := syscall.Syscall6(syscall.SYS___SYSCTL,
    19  		uintptr(unsafe.Pointer(&mib[0])), uintptr(len(mib)),
    20  		uintptr(unsafe.Pointer(&buf[0])), uintptr(unsafe.Pointer(&bufLen)),
    21  		uintptr(0), uintptr(0))
    22  
    23  	if e1 != 0 {
    24  		return 0, e1
    25  	}
    26  
    27  	if bufLen != 8 {
    28  		return 0, syscall.EIO
    29  	}
    30  
    31  	return *(*uint64)(unsafe.Pointer(&buf[0])), nil
    32  }