github.com/twelsh-aw/go/src@v0.0.0-20230516233729-a56fe86a7c81/runtime/pprof/proto_windows.go (about)

     1  // Copyright 2022 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 pprof
     6  
     7  import (
     8  	"errors"
     9  	"internal/syscall/windows"
    10  	"syscall"
    11  )
    12  
    13  // readMapping adds memory mapping information to the profile.
    14  func (b *profileBuilder) readMapping() {
    15  	snap, err := createModuleSnapshot()
    16  	if err != nil {
    17  		// pprof expects a map entry, so fake one, when we haven't added anything yet.
    18  		b.addMappingEntry(0, 0, 0, "", "", true)
    19  		return
    20  	}
    21  	defer func() { _ = syscall.CloseHandle(snap) }()
    22  
    23  	var module windows.ModuleEntry32
    24  	module.Size = uint32(windows.SizeofModuleEntry32)
    25  	err = windows.Module32First(snap, &module)
    26  	if err != nil {
    27  		// pprof expects a map entry, so fake one, when we haven't added anything yet.
    28  		b.addMappingEntry(0, 0, 0, "", "", true)
    29  		return
    30  	}
    31  	for err == nil {
    32  		exe := syscall.UTF16ToString(module.ExePath[:])
    33  		b.addMappingEntry(
    34  			uint64(module.ModBaseAddr),
    35  			uint64(module.ModBaseAddr)+uint64(module.ModBaseSize),
    36  			0,
    37  			exe,
    38  			peBuildID(exe),
    39  			false,
    40  		)
    41  		err = windows.Module32Next(snap, &module)
    42  	}
    43  }
    44  
    45  func readMainModuleMapping() (start, end uint64, err error) {
    46  	snap, err := createModuleSnapshot()
    47  	if err != nil {
    48  		return 0, 0, err
    49  	}
    50  	defer func() { _ = syscall.CloseHandle(snap) }()
    51  
    52  	var module windows.ModuleEntry32
    53  	module.Size = uint32(windows.SizeofModuleEntry32)
    54  	err = windows.Module32First(snap, &module)
    55  	if err != nil {
    56  		return 0, 0, err
    57  	}
    58  
    59  	return uint64(module.ModBaseAddr), uint64(module.ModBaseAddr) + uint64(module.ModBaseSize), nil
    60  }
    61  
    62  func createModuleSnapshot() (syscall.Handle, error) {
    63  	for {
    64  		snap, err := syscall.CreateToolhelp32Snapshot(windows.TH32CS_SNAPMODULE|windows.TH32CS_SNAPMODULE32, uint32(syscall.Getpid()))
    65  		var errno syscall.Errno
    66  		if err != nil && errors.As(err, &errno) && errno == windows.ERROR_BAD_LENGTH {
    67  			// When CreateToolhelp32Snapshot(SNAPMODULE|SNAPMODULE32, ...) fails
    68  			// with ERROR_BAD_LENGTH then it should be retried until it succeeds.
    69  			continue
    70  		}
    71  		return snap, err
    72  	}
    73  }