mem_aix.go

Documentation: runtime

     1  // Copyright 2018 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  package runtime
     6  
     7  import (
     8  	"unsafe"
     9  )
    10  
    11  // Don't split the stack as this method may be invoked without a valid G, which
    12  // prevents us from allocating more stack.
    13  //go:nosplit
    14  func sysAlloc(n uintptr, sysStat *sysMemStat) unsafe.Pointer {
    15  	p, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
    16  	if err != 0 {
    17  		if err == _EACCES {
    18  			print("runtime: mmap: access denied\n")
    19  			exit(2)
    20  		}
    21  		if err == _EAGAIN {
    22  			print("runtime: mmap: too much locked memory (check 'ulimit -l').\n")
    23  			exit(2)
    24  		}
    25  		return nil
    26  	}
    27  	sysStat.add(int64(n))
    28  	return p
    29  }
    30  
    31  func sysUnused(v unsafe.Pointer, n uintptr) {
    32  	madvise(v, n, _MADV_DONTNEED)
    33  }
    34  
    35  func sysUsed(v unsafe.Pointer, n uintptr) {
    36  }
    37  
    38  func sysHugePage(v unsafe.Pointer, n uintptr) {
    39  }
    40  
    41  // Don't split the stack as this function may be invoked without a valid G,
    42  // which prevents us from allocating more stack.
    43  //go:nosplit
    44  func sysFree(v unsafe.Pointer, n uintptr, sysStat *sysMemStat) {
    45  	sysStat.add(-int64(n))
    46  	munmap(v, n)
    47  
    48  }
    49  
    50  func sysFault(v unsafe.Pointer, n uintptr) {
    51  	mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE|_MAP_FIXED, -1, 0)
    52  }
    53  
    54  func sysReserve(v unsafe.Pointer, n uintptr) unsafe.Pointer {
    55  	p, err := mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
    56  	if err != 0 {
    57  		return nil
    58  	}
    59  	return p
    60  }
    61  
    62  func sysMap(v unsafe.Pointer, n uintptr, sysStat *sysMemStat) {
    63  	sysStat.add(int64(n))
    64  
    65  	// AIX does not allow mapping a range that is already mapped.
    66  	// So, call mprotect to change permissions.
    67  	// Note that sysMap is always called with a non-nil pointer
    68  	// since it transitions a Reserved memory region to Prepared,
    69  	// so mprotect is always possible.
    70  	_, err := mprotect(v, n, _PROT_READ|_PROT_WRITE)
    71  	if err == _ENOMEM {
    72  		throw("runtime: out of memory")
    73  	}
    74  	if err != 0 {
    75  		throw("runtime: cannot map pages in arena address space")
    76  	}
    77  }
    78
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