github.com/comwrg/go/src@v0.0.0-20220319063731-c238d0440370/runtime/mem_darwin.go (about) 1 // Copyright 2018 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package runtime 6 7 import ( 8 "unsafe" 9 ) 10 11 // Don't split the stack as this function may be invoked without a valid G, 12 // which prevents us from allocating more stack. 13 //go:nosplit 14 func sysAlloc(n uintptr, sysStat *sysMemStat) unsafe.Pointer { 15 v, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0) 16 if err != 0 { 17 return nil 18 } 19 sysStat.add(int64(n)) 20 return v 21 } 22 23 func sysUnused(v unsafe.Pointer, n uintptr) { 24 // MADV_FREE_REUSABLE is like MADV_FREE except it also propagates 25 // accounting information about the process to task_info. 26 madvise(v, n, _MADV_FREE_REUSABLE) 27 } 28 29 func sysUsed(v unsafe.Pointer, n uintptr) { 30 // MADV_FREE_REUSE is necessary to keep the kernel's accounting 31 // accurate. If called on any memory region that hasn't been 32 // MADV_FREE_REUSABLE'd, it's a no-op. 33 madvise(v, n, _MADV_FREE_REUSE) 34 } 35 36 func sysHugePage(v unsafe.Pointer, n uintptr) { 37 } 38 39 // Don't split the stack as this function may be invoked without a valid G, 40 // which prevents us from allocating more stack. 41 //go:nosplit 42 func sysFree(v unsafe.Pointer, n uintptr, sysStat *sysMemStat) { 43 sysStat.add(-int64(n)) 44 munmap(v, n) 45 } 46 47 func sysFault(v unsafe.Pointer, n uintptr) { 48 mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE|_MAP_FIXED, -1, 0) 49 } 50 51 func sysReserve(v unsafe.Pointer, n uintptr) unsafe.Pointer { 52 p, err := mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE, -1, 0) 53 if err != 0 { 54 return nil 55 } 56 return p 57 } 58 59 const _ENOMEM = 12 60 61 func sysMap(v unsafe.Pointer, n uintptr, sysStat *sysMemStat) { 62 sysStat.add(int64(n)) 63 64 p, err := mmap(v, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_FIXED|_MAP_PRIVATE, -1, 0) 65 if err == _ENOMEM { 66 throw("runtime: out of memory") 67 } 68 if p != v || err != 0 { 69 throw("runtime: cannot map pages in arena address space") 70 } 71 }