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  //
    14  //go:nosplit
    15  func sysAllocOS(n uintptr) unsafe.Pointer {
    16  	p, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
    17  	if err != 0 {
    18  		if err == _EACCES {
    19  			print("runtime: mmap: access denied\n")
    20  			exit(2)
    21  		}
    22  		if err == _EAGAIN {
    23  			print("runtime: mmap: too much locked memory (check 'ulimit -l').\n")
    24  			exit(2)
    25  		}
    26  		return nil
    27  	}
    28  	return p
    29  }
    30  
    31  func sysUnusedOS(v unsafe.Pointer, n uintptr) {
    32  	madvise(v, n, _MADV_DONTNEED)
    33  }
    34  
    35  func sysUsedOS(v unsafe.Pointer, n uintptr) {
    36  }
    37  
    38  func sysHugePageOS(v unsafe.Pointer, n uintptr) {
    39  }
    40  
    41  func sysNoHugePageOS(v unsafe.Pointer, n uintptr) {
    42  }
    43  
    44  func sysHugePageCollapseOS(v unsafe.Pointer, n uintptr) {
    45  }
    46  
    47  // Don't split the stack as this function may be invoked without a valid G,
    48  // which prevents us from allocating more stack.
    49  //
    50  //go:nosplit
    51  func sysFreeOS(v unsafe.Pointer, n uintptr) {
    52  	munmap(v, n)
    53  }
    54  
    55  func sysFaultOS(v unsafe.Pointer, n uintptr) {
    56  	mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE|_MAP_FIXED, -1, 0)
    57  }
    58  
    59  func sysReserveOS(v unsafe.Pointer, n uintptr) unsafe.Pointer {
    60  	p, err := mmap(v, n, _PROT_NONE, _MAP_ANON|_MAP_PRIVATE, -1, 0)
    61  	if err != 0 {
    62  		return nil
    63  	}
    64  	return p
    65  }
    66  
    67  func sysMapOS(v unsafe.Pointer, n uintptr) {
    68  	// AIX does not allow mapping a range that is already mapped.
    69  	// So, call mprotect to change permissions.
    70  	// Note that sysMap is always called with a non-nil pointer
    71  	// since it transitions a Reserved memory region to Prepared,
    72  	// so mprotect is always possible.
    73  	_, err := mprotect(v, n, _PROT_READ|_PROT_WRITE)
    74  	if err == _ENOMEM {
    75  		throw("runtime: out of memory")
    76  	}
    77  	if err != 0 {
    78  		print("runtime: mprotect(", v, ", ", n, ") returned ", err, "\n")
    79  		throw("runtime: cannot map pages in arena address space")
    80  	}
    81  }
    82
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