root/src/pkg/runtime/mem_darwin.c

DEFINITIONS

1. runtime·SysAlloc
2. runtime·SysUnused
3. runtime·SysUsed
4. runtime·SysFree
5. runtime·SysFault
6. runtime·SysReserve
7. runtime·SysMap

// Copyright 2010 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.

#include "runtime.h"
#include "arch_GOARCH.h"
#include "defs_GOOS_GOARCH.h"
#include "os_GOOS.h"
#include "malloc.h"

void*
runtime·SysAlloc(uintptr n, uint64 *stat)
{
        void *v;

        v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
        if(v < (void*)4096)
                return nil;
        runtime·xadd64(stat, n);
        return v;
}

void
runtime·SysUnused(void *v, uintptr n)
{
        // Linux's MADV_DONTNEED is like BSD's MADV_FREE.
        runtime·madvise(v, n, MADV_FREE);
}

void
runtime·SysUsed(void *v, uintptr n)
{
        USED(v);
        USED(n);
}

void
runtime·SysFree(void *v, uintptr n, uint64 *stat)
{
        runtime·xadd64(stat, -(uint64)n);
        runtime·munmap(v, n);
}

void
runtime·SysFault(void *v, uintptr n)
{
        runtime·mmap(v, n, PROT_NONE, MAP_ANON|MAP_PRIVATE|MAP_FIXED, -1, 0);
}

void*
runtime·SysReserve(void *v, uintptr n, bool *reserved)
{
        void *p;

        *reserved = true;
        p = runtime·mmap(v, n, PROT_NONE, MAP_ANON|MAP_PRIVATE, -1, 0);
        if(p < (void*)4096)
                return nil;
        return p;
}

enum
{
        ENOMEM = 12,
};

void
runtime·SysMap(void *v, uintptr n, bool reserved, uint64 *stat)
{
        void *p;
        
        USED(reserved);

        runtime·xadd64(stat, n);
        p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
        if(p == (void*)ENOMEM)
                runtime·throw("runtime: out of memory");
        if(p != v)
                runtime·throw("runtime: cannot map pages in arena address space");
}