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Changes for page Deadlock Prevention

Last modified by chrisby on 2023/11/28 19:17
From version 4.1
edited by chrisby
on 2023/11/26 19:35
Change comment: Rollback to version 3.5
To version 1.2
edited by chrisby
on 2023/11/26 19:25
Change comment: There is no comment for this version

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1 1  Deadlocks can only occur if all four specific conditions are met. Therefore, strategies to prevent deadlocks focus on negating one of these conditions.
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3 -| ------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
4 -| **Condition** | **Description** | **Solutions** | **Dangers** |
5 -| Mutual Exclusion / Mutex | When resources can't be used by mutual thread and there are less resources than threads. | 1) Use concurrently accessible resources like AtomicInteger. 2) Increase the number of resources until its greater or equal to the number of competing threads. 3 ) Check if every required resource is accessible before the task starts. | |
6 -| Lock & Wait | Once a thread acquires a resource, it will not release the resource until it has acquired all of the other resources it requires and has completed its work. | Before reservation of a resource, check its accessibility. If a resource is not accessible, release every resource and start from anew. | Starvation: A thread never achieves to reserve all required resources. Livelock: Thread gets tangled up. These two approach are always applicable but inefficient as it causes a bad performance. |
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3 +| ------------------------ | ------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------- |
4 +| Condition | Description | Solutions | Dangers/Problems |
5 +| Mutual Exclusion (Mutex) |
9 9  
7 +When resources can't be used by mutual thread and there are less resources than threads. |
8 +
9 +1) Use concurrently accessible resources like AtomicInteger. 2) Increase the number of resources until its greater or equal to the number of competing threads. 3) Check if every required resource is accessible before the task starts. | |
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12 +| | | | |
13 +
10 10  #### Lock & Wait
11 11  
12 12  * Description: