github.com/xushiwei/go@v0.0.0-20130601165731-2b9d83f45bc9/src/pkg/runtime/mem_netbsd.c (about)

     1  // Copyright 2010 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  #include "runtime.h"
     6  #include "arch_GOARCH.h"
     7  #include "defs_GOOS_GOARCH.h"
     8  #include "os_GOOS.h"
     9  #include "malloc.h"
    10  
    11  enum
    12  {
    13  	ENOMEM = 12,
    14  };
    15  
    16  void*
    17  runtime·SysAlloc(uintptr n)
    18  {
    19  	void *v;
    20  
    21  	mstats.sys += n;
    22  	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
    23  	if(v < (void*)4096)
    24  		return nil;
    25  	return v;
    26  }
    27  
    28  void
    29  runtime·SysUnused(void *v, uintptr n)
    30  {
    31  	runtime·madvise(v, n, MADV_FREE);
    32  }
    33  
    34  void
    35  runtime·SysFree(void *v, uintptr n)
    36  {
    37  	mstats.sys -= n;
    38  	runtime·munmap(v, n);
    39  }
    40  
    41  void*
    42  runtime·SysReserve(void *v, uintptr n)
    43  {
    44  	void *p;
    45  
    46  	// On 64-bit, people with ulimit -v set complain if we reserve too
    47  	// much address space.  Instead, assume that the reservation is okay
    48  	// and check the assumption in SysMap.
    49  	if(sizeof(void*) == 8)
    50  		return v;
    51  
    52  	p = runtime·mmap(v, n, PROT_NONE, MAP_ANON|MAP_PRIVATE, -1, 0);
    53  	if(p < (void*)4096)
    54  		return nil;
    55  	return p;
    56  }
    57  
    58  void
    59  runtime·SysMap(void *v, uintptr n)
    60  {
    61  	void *p;
    62  	
    63  	mstats.sys += n;
    64  
    65  	// On 64-bit, we don't actually have v reserved, so tread carefully.
    66  	if(sizeof(void*) == 8) {
    67  		p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
    68  		if(p == (void*)ENOMEM)
    69  			runtime·throw("runtime: out of memory");
    70  		if(p != v) {
    71  			runtime·printf("runtime: address space conflict: map(%p) = %p\n", v, p);
    72  			runtime·throw("runtime: address space conflict");
    73  		}
    74  		return;
    75  	}
    76  
    77  	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
    78  	if(p == (void*)ENOMEM)
    79  		runtime·throw("runtime: out of memory");
    80  	if(p != v)
    81  		runtime·throw("runtime: cannot map pages in arena address space");
    82  }