github.com/bytedance/mockey@v1.2.10/internal/monkey/common/page.go (about)

     1  /*
     2   * Copyright 2022 ByteDance Inc.
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  package common
    18  
    19  import (
    20  	"syscall"
    21  	"unsafe"
    22  )
    23  
    24  var pageSize = uintptr(syscall.Getpagesize())
    25  
    26  func PageOf(ptr uintptr) uintptr {
    27  	return ptr &^ (pageSize - 1)
    28  }
    29  
    30  func PageSize() int {
    31  	return int(pageSize)
    32  }
    33  
    34  func AllocatePage() []byte {
    35  	var memStats uint64 = 0
    36  	addr := sysAlloc(pageSize, &memStats)
    37  	return BytesOf(uintptr(addr), int(pageSize))
    38  }
    39  
    40  func ReleasePage(mem []byte) {
    41  	memStats := uint64(cap(mem))
    42  	sysFree(unsafe.Pointer(PtrOf(mem)), uintptr(cap(mem)), &memStats)
    43  }