Object synchronization method was called from an unsynchronized block of code

Despite the tremendous improvement in .NET compared to anything Microsoft released earlier, Microsoft still lags behind where Java was with ease of use of multithreading. .NET multithreading is great and easy to use - but only if you already know multithreading. There are hundreds of different ways to handle synchronization, and some work well, some work poorly, and in my opinion, some don't work at all. All this makes me wish they would just give me Dijkstra's semaphore (P and V methods) and let me build my own stuff on top of it.

Today, I tried to Google an error I got: "System.ApplicationException: Object synchronization method was called from an unsynchronized block of code." Immediately (based on the error message), I thought I either needed to mark the method, class or assembly as needing to use synchronization somehow (either attributes or compiler switches came to mind). This was odd, because I didn't remember ever needing to do this before (well, not since the COM apartment threading mess anyway).

You would think this would be easy to find. I went through every entry on the first 3 Google pages (60 entries). Lots of people had this problem, but most answers were:

• use Monitors instead of synchronization object X-with no explanation of why.
• Do you really need to do this? - I always hate this answer when someone posts a legitimate technical question. The question still has merit, regardless of whether the author really the answer or not.
• Use Google to find the answer - I hate this too. I am convinced it will eventually destroy Google (any search will eventually only yield thousands of pages telling you to search Google).

Anyhow, I gave up on Google and went back to my code, and the answer was really simple. All I did was release the Mutex before I acquired it (I left out the line of code Mutex.WaitOne).

I guess I am posting this for 2 reasons

• I don't want anyone else looking through 60 pages of worthless Googling (although I doubt this blog will get ranked in the top 60 anyway).
• This is a really bad error message. Every time you enter a synchronized block of code, you do so by calling an object synchronization method from an unsynchronized block of code. What it should say is "Invalid Object synchronization method called from an unsynchronized block of code" or simply "Invalid Object synchronization method call". This would make finding the answer easy.