root/src/pkg/runtime/mem_nacl.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"

enum
{
        Debug = 0,
};

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) {
                if(Debug)
                        runtime·printf("SysAlloc(%p): %p\n", n, v);
                return nil;
        }
        runtime·xadd64(stat, n);
        if(Debug)
                runtime·printf("SysAlloc(%p) = %p\n", n, v);
        return v;
}

void
runtime·SysUnused(void *v, uintptr n)
{
        if(Debug)
                runtime·printf("SysUnused(%p, %p)\n", v, n);
}

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

void
runtime·SysFree(void *v, uintptr n, uint64 *stat)
{
        if(Debug)
                runtime·printf("SysFree(%p, %p)\n", v, n);
        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;

        // On 64-bit, people with ulimit -v set complain if we reserve too
        // much address space.  Instead, assume that the reservation is okay
        // and check the assumption in SysMap.
        if(NaCl || sizeof(void*) == 8) {
                *reserved = false;
                return v;
        }
        
        p = runtime·mmap(v, n, PROT_NONE, MAP_ANON|MAP_PRIVATE, -1, 0);
        if(p < (void*)4096)
                return nil;
        *reserved = true;
        return p;
}

void
runtime·SysMap(void *v, uintptr n, bool reserved, uint64 *stat)
{
        void *p;
        
        runtime·xadd64(stat, n);

        // On 64-bit, we don't actually have v reserved, so tread carefully.
        if(!reserved) {
                p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
                if(p == (void*)ENOMEM) {
                        runtime·printf("SysMap(%p, %p): %p\n", v, n, p);
                        runtime·throw("runtime: out of memory");
                }
                if(p != v) {
                        runtime·printf("SysMap(%p, %p): %p\n", v, n, p);
                        runtime·printf("runtime: address space conflict: map(%p) = %p\n", v, p);
                        runtime·throw("runtime: address space conflict");
                }
                if(Debug)
                        runtime·printf("SysMap(%p, %p) = %p\n", v, n, p);
                return;
        }

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