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// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package runtime
import (
"unsafe"
)
// Don't split the stack as this function may be invoked without a valid G,
// which prevents us from allocating more stack.
//
//go:nosplit
func sysAllocOS(n uintptr) unsafe.Pointer {
v, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
if err != 0 {
return nil
}
return v
}
func sysUnusedOS(v unsafe.Pointer, n uintptr) {
// MADV_FREE_REUSABLE is like MADV_FREE except it also propagates
// accounting information about the process to task_info.
madvise(v, n, _MADV_FREE_REUSABLE)
}
func sysUsedOS(v unsafe.Pointer, n uintptr) {
// MADV_FREE_REUSE is necessary to keep the kernel's accounting
// accurate. If called on any memory region that hasn't been
// MADV_FREE_REUSABLE'd, it's a no-op.
madvise(v, n, _MADV_FREE_REUSE)
}
func sysHugePageOS(v unsafe.Pointer, n uintptr) {
}
// Don't split the stack as this function may be invoked without a valid G,
// which prevents us from allocating more stack.
//
//go:nosplit
func sysFreeOS(v unsafe.Pointer, n uintptr) {
munmap(v, n)
}
func sysFaultOS(v unsafe.Pointer, n uintptr) {
mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE|_MAP_FIXED, -1, 0)
}
func sysReserveOS(v unsafe.Pointer, n uintptr) unsafe.Pointer {
p, err := mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
if err != 0 {
return nil
}
return p
}
const _ENOMEM = 12
func sysMapOS(v unsafe.Pointer, n uintptr) {
p, err := mmap(v, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_FIXED|_MAP_PRIVATE, -1, 0)
if err == _ENOMEM {
throw("runtime: out of memory")
}
if p != v || err != 0 {
print("runtime: mmap(", v, ", ", n, ") returned ", p, ", ", err, "\n")
throw("runtime: cannot map pages in arena address space")
}
}
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