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POAsking about threading, arrays and cache memory
 

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  1. POAsking about threading, arrays and cache memory
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    <p>I hope in a good manner :-) I wrote this piece of code. What I wished to do, is to build something like "cache". I assumed that I had to watch for different threads, as might many calls get to that class, so I tried the ThreadLocal functionality. Base pattern is have "MANY SETS of VECTOR" The vector holds something like: VECTOR.FieldName = "X" VECTOR.FieldValue= "Y" So many Vector objects in a set. Different set for different calls from different machines, users, objects.</p> <pre><code> private static CacheVector instance = null; private static SortedSet&lt;SplittingVector&gt; s = null; private static TreeSet&lt;SplittingVector&gt; t = null; private static ThreadLocal&lt;SortedSet&lt;SplittingVector&gt;&gt; setOfVectors = new ThreadLocal&lt;SortedSet&lt;SplittingVector&gt;&gt;(); private static class MyComparator implements Comparator&lt;SplittingVector&gt; { public int compare(SplittingVector a, SplittingVector b) { return 1; } // No need to override equals. } private CacheVector() { } public static SortedSet&lt;SplittingVector&gt; getInstance(SplittingVector vector) { if (instance == null) { instance = new CacheVector(); //TreeSet&lt;SplittingVector&gt; t = new TreeSet&lt;SplittingVector&gt;(new MyComparator()); t.add(vector); s = Collections.synchronizedSortedSet(t);//Sort the set of vectors CacheVector.assign(s); } else { //TreeSet&lt;SplittingVector&gt; t = new TreeSet&lt;SplittingVector&gt;(); t.add(vector); s = Collections.synchronizedSortedSet(t);//Sort the set of vectors CacheVector.assign(s); } return CacheVector.setOfVectors.get(); } public SortedSet&lt;SplittingVector&gt; retrieve() throws Exception { SortedSet&lt;SplittingVector&gt; set = setOfVectors.get(); if (set == null) { throw new Exception("SET IS EMPTY"); } return set; } private static void assign(SortedSet&lt;SplittingVector&gt; nSet) { CacheVector.setOfVectors.set(nSet); } </code></pre> <p>So... I have it in the attach and I use it like this:</p> <pre><code>CachedVector cache = CachedVector.getInstance(bufferedline); </code></pre> <p>The nice part: Bufferedline is a splitted line based on some delimiter from data files. Files can be of any size.</p> <p>So how do you see this code? Should I be worry ? I apologise for the size of this message!</p>
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    1. USNick Bastin
    1. UShephestos
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    1. PO
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    1. This table or related slice is empty.
    1. COYour singleton is not thread-safe.
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      1. POAsking about threading, arrays and cache memory
      1. USb_erb
    2. COUse `101010` button to format code snippet
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      1. POAsking about threading, arrays and cache memory
      1. USkhachik
    3. COAnd the usage of `ThreadLocal` is discouraged (see Effective Java 2nd…).
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      1. POAsking about threading, arrays and cache memory
      1. USb_erb
 

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