newprovider.go

Documentation: github.com/Microsoft/go-winio/pkg/etw

     1  //go:build windows && (amd64 || arm64 || 386)
     2  // +build windows
     3  // +build amd64 arm64 386
     4  
     5  package etw
     6  
     7  import (
     8  	"bytes"
     9  	"encoding/binary"
    10  	"unsafe"
    11  
    12  	"github.com/Microsoft/go-winio/pkg/guid"
    13  	"golang.org/x/sys/windows"
    14  )
    15  
    16  // NewProviderWithOptions creates and registers a new ETW provider, allowing
    17  // the provider ID and Group to be manually specified. This is most useful when
    18  // there is an existing provider ID that must be used to conform to existing
    19  // diagnostic infrastructure.
    20  func NewProviderWithOptions(name string, options ...ProviderOpt) (provider *Provider, err error) {
    21  	var opts providerOpts
    22  	for _, opt := range options {
    23  		opt(&opts)
    24  	}
    25  
    26  	if opts.id == (guid.GUID{}) {
    27  		opts.id = providerIDFromName(name)
    28  	}
    29  
    30  	providerCallbackOnce.Do(func() {
    31  		globalProviderCallback = windows.NewCallback(providerCallbackAdapter)
    32  	})
    33  
    34  	provider = providers.newProvider()
    35  	defer func(provider *Provider) {
    36  		if err != nil {
    37  			providers.removeProvider(provider)
    38  		}
    39  	}(provider)
    40  	provider.ID = opts.id
    41  	provider.callback = opts.callback
    42  
    43  	if err := eventRegister((*windows.GUID)(&provider.ID), globalProviderCallback, uintptr(provider.index), &provider.handle); err != nil {
    44  		return nil, err
    45  	}
    46  
    47  	trait := &bytes.Buffer{}
    48  	if opts.group != (guid.GUID{}) {
    49  		_ = binary.Write(trait, binary.LittleEndian, uint16(0)) // Write empty size for buffer (update later)
    50  		_ = binary.Write(trait, binary.LittleEndian, uint8(1))  // EtwProviderTraitTypeGroup
    51  		traitArray := opts.group.ToWindowsArray()               // Append group guid
    52  		trait.Write(traitArray[:])
    53  		binary.LittleEndian.PutUint16(trait.Bytes(), uint16(trait.Len())) // Update size
    54  	}
    55  
    56  	metadata := &bytes.Buffer{}
    57  	_ = binary.Write(metadata, binary.LittleEndian, uint16(0)) // Write empty size for buffer (to update later)
    58  	metadata.WriteString(name)
    59  	metadata.WriteByte(0)                                                   // Null terminator for name
    60  	_, _ = trait.WriteTo(metadata)                                          // Add traits if applicable
    61  	binary.LittleEndian.PutUint16(metadata.Bytes(), uint16(metadata.Len())) // Update the size at the beginning of the buffer
    62  	provider.metadata = metadata.Bytes()
    63  
    64  	if err := eventSetInformation(
    65  		provider.handle,
    66  		eventInfoClassProviderSetTraits,
    67  		uintptr(unsafe.Pointer(&provider.metadata[0])),
    68  		uint32(len(provider.metadata)),
    69  	); err != nil {
    70  		return nil, err
    71  	}
    72  
    73  	return provider, nil
    74  }
    75
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