github.com/Serizao/go-winio@v0.0.0-20230906082528-f02f7f4ad6e8/pkg/etw/providerglobal.go (about)

     1  //go:build windows
     2  // +build windows
     3  
     4  package etw
     5  
     6  import (
     7  	"sync"
     8  )
     9  
    10  // Because the provider callback function needs to be able to access the
    11  // provider data when it is invoked by ETW, we need to keep provider data stored
    12  // in a global map based on an index. The index is passed as the callback
    13  // context to ETW.
    14  type providerMap struct {
    15  	m    map[uint]*Provider
    16  	i    uint
    17  	lock sync.Mutex
    18  }
    19  
    20  var providers = providerMap{
    21  	m: make(map[uint]*Provider),
    22  }
    23  
    24  func (p *providerMap) newProvider() *Provider {
    25  	p.lock.Lock()
    26  	defer p.lock.Unlock()
    27  
    28  	i := p.i
    29  	p.i++
    30  
    31  	provider := &Provider{
    32  		index: i,
    33  	}
    34  
    35  	p.m[i] = provider
    36  	return provider
    37  }
    38  
    39  func (p *providerMap) removeProvider(provider *Provider) {
    40  	p.lock.Lock()
    41  	defer p.lock.Unlock()
    42  
    43  	delete(p.m, provider.index)
    44  }
    45  
    46  func (p *providerMap) getProvider(index uint) *Provider {
    47  	p.lock.Lock()
    48  	defer p.lock.Unlock()
    49  
    50  	return p.m[index]
    51  }
    52  
    53  //todo: combine these into struct, so that "globalProviderCallback" is guaranteed to be initialized through method access
    54  
    55  var providerCallbackOnce sync.Once
    56  var globalProviderCallback uintptr