Mixing
Implementing ConcurrentDictionary
0
I'm trying to create my own Cache implementation for an API. It is the first time I work with ConcurrentDictionary and I do not know if I am using it correctly. In a test, something has thrown error and so far I have not been able to reproduce it again. Maybe some concurrency professional / ConcurrentDictionary can look at the code and find what may be wrong. Thank you!
private static readonly ConcurrentDictionary<string, ThrottleInfo> CacheList = new ConcurrentDictionary<string, ThrottleInfo>();
public override void OnActionExecuting(HttpActionContext actionExecutingContext)
{
if (CacheList.TryGetValue(userIdentifier, out var throttleInfo))
{
if (DateTime.Now >= throttleInfo.ExpiresOn)
{
if (CacheList.TryRemove(userIdentifier, out _))
{
//TODO:
}
}
else
{
if (throttleInfo.RequestCount >= defaultMaxRequest)
{
actionExecutingContext.Response = ResponseMessageExtension.TooManyRequestHttpResponseMessage();
}
else
{
throttleInfo.Increment();
}
}
}
else
{
if (CacheList.TryAdd(userIdentifier, new ThrottleInfo(Seconds)))
{
//TODO:
}
}
}
public class ThrottleInfo
{
private int _requestCount;
public int RequestCount => _requestCount;
public ThrottleInfo(int addSeconds)
{
Interlocked.Increment(ref _requestCount);
ExpiresOn = ExpiresOn.AddSeconds(addSeconds);
}
public void Increment()
{
// this is about as thread safe as you can get.
// From MSDN: Increments a specified variable and stores the result, as an atomic operation.
Interlocked.Increment(ref _requestCount);
// you can return the result of Increment if you want the new value,
//but DO NOT set the counter to the result :[i.e. counter = Interlocked.Increment(ref counter);] This will break the atomicity.
}
public DateTime ExpiresOn { get; } = DateTime.Now;
}
c# multithreading thread-safety concurrentdictionary
asked Nov 21 '18 at 15:55
avechucheavechuche
405821
add a comment |
0
I'm trying to create my own Cache implementation for an API. It is the first time I work with ConcurrentDictionary and I do not know if I am using it correctly. In a test, something has thrown error and so far I have not been able to reproduce it again. Maybe some concurrency professional / ConcurrentDictionary can look at the code and find what may be wrong. Thank you!
private static readonly ConcurrentDictionary<string, ThrottleInfo> CacheList = new ConcurrentDictionary<string, ThrottleInfo>();
public override void OnActionExecuting(HttpActionContext actionExecutingContext)
{
if (CacheList.TryGetValue(userIdentifier, out var throttleInfo))
{
if (DateTime.Now >= throttleInfo.ExpiresOn)
{
if (CacheList.TryRemove(userIdentifier, out _))
{
//TODO:
}
}
else
{
if (throttleInfo.RequestCount >= defaultMaxRequest)
{
actionExecutingContext.Response = ResponseMessageExtension.TooManyRequestHttpResponseMessage();
}
else
{
throttleInfo.Increment();
}
}
}
else
{
if (CacheList.TryAdd(userIdentifier, new ThrottleInfo(Seconds)))
{
//TODO:
}
}
}
public class ThrottleInfo
{
private int _requestCount;
public int RequestCount => _requestCount;
public ThrottleInfo(int addSeconds)
{
Interlocked.Increment(ref _requestCount);
ExpiresOn = ExpiresOn.AddSeconds(addSeconds);
}
public void Increment()
{
// this is about as thread safe as you can get.
// From MSDN: Increments a specified variable and stores the result, as an atomic operation.
Interlocked.Increment(ref _requestCount);
// you can return the result of Increment if you want the new value,
//but DO NOT set the counter to the result :[i.e. counter = Interlocked.Increment(ref counter);] This will break the atomicity.
}
public DateTime ExpiresOn { get; } = DateTime.Now;
}
c# multithreading thread-safety concurrentdictionary
asked Nov 21 '18 at 15:55
avechucheavechuche
405821
Which error did you get?
– Klaus Gütter
Nov 21 '18 at 17:18
That's the problem, when it happened, I did not take notes and now I can not reproduce it. I'm tried, but I can not. I assume it's a concurrency problem. At some point 2 or more threads want to do something with the same object and break the code. Being few lines of code, perhaps some expert, can visualize and find some error. It's the first time I use ConcurrentDictionary
– avechuche
Nov 21 '18 at 17:28
add a comment |
0
0
0
I'm trying to create my own Cache implementation for an API. It is the first time I work with ConcurrentDictionary and I do not know if I am using it correctly. In a test, something has thrown error and so far I have not been able to reproduce it again. Maybe some concurrency professional / ConcurrentDictionary can look at the code and find what may be wrong. Thank you!
private static readonly ConcurrentDictionary<string, ThrottleInfo> CacheList = new ConcurrentDictionary<string, ThrottleInfo>();
public override void OnActionExecuting(HttpActionContext actionExecutingContext)
{
if (CacheList.TryGetValue(userIdentifier, out var throttleInfo))
{
if (DateTime.Now >= throttleInfo.ExpiresOn)
{
if (CacheList.TryRemove(userIdentifier, out _))
{
//TODO:
}
}
else
{
if (throttleInfo.RequestCount >= defaultMaxRequest)
{
actionExecutingContext.Response = ResponseMessageExtension.TooManyRequestHttpResponseMessage();
}
else
{
throttleInfo.Increment();
}
}
}
else
{
if (CacheList.TryAdd(userIdentifier, new ThrottleInfo(Seconds)))
{
//TODO:
}
}
}
public class ThrottleInfo
{
private int _requestCount;
public int RequestCount => _requestCount;
public ThrottleInfo(int addSeconds)
{
Interlocked.Increment(ref _requestCount);
ExpiresOn = ExpiresOn.AddSeconds(addSeconds);
}
public void Increment()
{
// this is about as thread safe as you can get.
// From MSDN: Increments a specified variable and stores the result, as an atomic operation.
Interlocked.Increment(ref _requestCount);
// you can return the result of Increment if you want the new value,
//but DO NOT set the counter to the result :[i.e. counter = Interlocked.Increment(ref counter);] This will break the atomicity.
}
public DateTime ExpiresOn { get; } = DateTime.Now;
}
c# multithreading thread-safety concurrentdictionary
asked Nov 21 '18 at 15:55
avechucheavechuche
405821
I'm trying to create my own Cache implementation for an API. It is the first time I work with ConcurrentDictionary and I do not know if I am using it correctly. In a test, something has thrown error and so far I have not been able to reproduce it again. Maybe some concurrency professional / ConcurrentDictionary can look at the code and find what may be wrong. Thank you!
private static readonly ConcurrentDictionary<string, ThrottleInfo> CacheList = new ConcurrentDictionary<string, ThrottleInfo>();
public override void OnActionExecuting(HttpActionContext actionExecutingContext)
{
if (CacheList.TryGetValue(userIdentifier, out var throttleInfo))
{
if (DateTime.Now >= throttleInfo.ExpiresOn)
{
if (CacheList.TryRemove(userIdentifier, out _))
{
//TODO:
}
}
else
{
if (throttleInfo.RequestCount >= defaultMaxRequest)
{
actionExecutingContext.Response = ResponseMessageExtension.TooManyRequestHttpResponseMessage();
}
else
{
throttleInfo.Increment();
}
}
}
else
{
if (CacheList.TryAdd(userIdentifier, new ThrottleInfo(Seconds)))
{
//TODO:
}
}
}
public class ThrottleInfo
{
private int _requestCount;
public int RequestCount => _requestCount;
public ThrottleInfo(int addSeconds)
{
Interlocked.Increment(ref _requestCount);
ExpiresOn = ExpiresOn.AddSeconds(addSeconds);
}
public void Increment()
{
// this is about as thread safe as you can get.
// From MSDN: Increments a specified variable and stores the result, as an atomic operation.
Interlocked.Increment(ref _requestCount);
// you can return the result of Increment if you want the new value,
//but DO NOT set the counter to the result :[i.e. counter = Interlocked.Increment(ref counter);] This will break the atomicity.
}
public DateTime ExpiresOn { get; } = DateTime.Now;
}
c# multithreading thread-safety concurrentdictionary
c# multithreading thread-safety concurrentdictionary
asked Nov 21 '18 at 15:55
avechucheavechuche
405821
asked Nov 21 '18 at 15:55
avechucheavechuche
405821
asked Nov 21 '18 at 15:55
avechucheavechuche
405821
asked Nov 21 '18 at 15:55
avechucheavechuche
405821
asked Nov 21 '18 at 15:55
avechucheavechuche
405821
405821
Which error did you get?
– Klaus Gütter
Nov 21 '18 at 17:18
That's the problem, when it happened, I did not take notes and now I can not reproduce it. I'm tried, but I can not. I assume it's a concurrency problem. At some point 2 or more threads want to do something with the same object and break the code. Being few lines of code, perhaps some expert, can visualize and find some error. It's the first time I use ConcurrentDictionary
– avechuche
Nov 21 '18 at 17:28
add a comment |
Which error did you get?
– Klaus Gütter
Nov 21 '18 at 17:18
That's the problem, when it happened, I did not take notes and now I can not reproduce it. I'm tried, but I can not. I assume it's a concurrency problem. At some point 2 or more threads want to do something with the same object and break the code. Being few lines of code, perhaps some expert, can visualize and find some error. It's the first time I use ConcurrentDictionary
– avechuche
Nov 21 '18 at 17:28
Which error did you get?
– Klaus Gütter
Nov 21 '18 at 17:18
Which error did you get?
– Klaus Gütter
Nov 21 '18 at 17:18
That's the problem, when it happened, I did not take notes and now I can not reproduce it. I'm tried, but I can not. I assume it's a concurrency problem. At some point 2 or more threads want to do something with the same object and break the code. Being few lines of code, perhaps some expert, can visualize and find some error. It's the first time I use ConcurrentDictionary
– avechuche
Nov 21 '18 at 17:28
That's the problem, when it happened, I did not take notes and now I can not reproduce it. I'm tried, but I can not. I assume it's a concurrency problem. At some point 2 or more threads want to do something with the same object and break the code. Being few lines of code, perhaps some expert, can visualize and find some error. It's the first time I use ConcurrentDictionary
– avechuche
Nov 21 '18 at 17:28
add a comment |
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Which error did you get?
– Klaus Gütter
Nov 21 '18 at 17:18
That's the problem, when it happened, I did not take notes and now I can not reproduce it. I'm tried, but I can not. I assume it's a concurrency problem. At some point 2 or more threads want to do something with the same object and break the code. Being few lines of code, perhaps some expert, can visualize and find some error. It's the first time I use ConcurrentDictionary
– avechuche
Nov 21 '18 at 17:28