github.com/xushiwei/go@v0.0.0-20130601165731-2b9d83f45bc9/src/pkg/runtime/mem_darwin.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  void*
    12  runtime·SysAlloc(uintptr n)
    13  {
    14  	void *v;
    15  
    16  	mstats.sys += n;
    17  	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
    18  	if(v < (void*)4096)
    19  		return nil;
    20  	return v;
    21  }
    22  
    23  void
    24  runtime·SysUnused(void *v, uintptr n)
    25  {
    26  	// Linux's MADV_DONTNEED is like BSD's MADV_FREE.
    27  	runtime·madvise(v, n, MADV_FREE);
    28  }
    29  
    30  void
    31  runtime·SysFree(void *v, uintptr n)
    32  {
    33  	mstats.sys -= n;
    34  	runtime·munmap(v, n);
    35  }
    36  
    37  void*
    38  runtime·SysReserve(void *v, uintptr n)
    39  {
    40  	void *p;
    41  
    42  	p = runtime·mmap(v, n, PROT_NONE, MAP_ANON|MAP_PRIVATE, -1, 0);
    43  	if(p < (void*)4096)
    44  		return nil;
    45  	return p;
    46  }
    47  
    48  enum
    49  {
    50  	ENOMEM = 12,
    51  };
    52  
    53  void
    54  runtime·SysMap(void *v, uintptr n)
    55  {
    56  	void *p;
    57  	
    58  	mstats.sys += n;
    59  	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
    60  	if(p == (void*)ENOMEM)
    61  		runtime·throw("runtime: out of memory");
    62  	if(p != v)
    63  		runtime·throw("runtime: cannot map pages in arena address space");
    64  }