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POC++ Vector, push_back from another thread crashing?
 

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  1. POC++ Vector, push_back from another thread crashing?
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    <p>I have unexpected assertions faillures in my code using a checked STL implentation. </p> <p>After some research, I narrowed down the problem to a push_back in a vector called from a different thread than the one in which the vector was created.</p> <p>The simplest code to reproduce this problem is : </p> <pre><code>class SomeClass { private: std::vector&lt;int&gt; theVector; public: SomeClass () { theVector.push_back(1); // Ok } void add() { theVector.push_back(1); // Crash } }; </code></pre> <p>The only difference is that SomeClass is instanciated from my main thread, and add is called from another thread. However, there is no concurency issue : in the simplest form of code I used for troubleshooting nobody is reading or writing from this vector except the cases I mentioned above. </p> <p>Tracing into the push_back code, I noticed that some methods from std::vector like count() or size() return garbage, when it's called from the other thred (method "add"), and correct values when called from the creating thread (in the constructor for example)</p> <p>Should I conclude that std::vector is not usable in a multithreaded environement ? Or is there a solution for this problem ? </p> <p>EDIT : removed volatile</p> <p>EDIT 2 : Do you think it's possible that the problem doesn't lie in multithread ? In my test run, add is called only once (verified using a break point). If I remove the push_back from the constructor, I still crashes. So in the end, even with only one call to a vector's method, in a function called once make the assertion fail. Therefore there can't be concurency, or ... ? </p>
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    1. COif there's indeed no concurrency vector should work. If there're 2 or more threads working with vector *in parallel*, this will not work.
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    2. COAre you in an environment where each thread has its own heap?
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    3. COTry calling `reserve`.
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