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POboost::thread and destructor of contained classes
 

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    <p>I would like to understand the behaviour of this code.</p> <pre><code>class Foo { public: Foo(); ~Foo(); void run(); int* get(); private: int *a; }; Foo::Foo() { a=NULL; } void Foo::run() { if ( a==NULL) a = new int[30000]; } int* Foo::get() { return a; } Foo::~Foo() { cout &lt;&lt; "destructor called" &lt;&lt; endl; if ( a!=NULL) delete a; } int main() { Foo *a = new Foo(); boost::thread Foothread( &amp;Foo::run, a); // Some very long computation that sometimes access int *b = a-&gt;get(); cout &lt;&lt; *b &lt;&lt; endl; //Foothread.join(); //delete a; //Foothread.join(); return 0; } </code></pre> <p>This code causes a memory leak of 120000 bytes because variable a is not destructed, so when I explicitly delete it the leak disappers and everything should be ok.</p> <p>Now if I instead of dynamically allocate a, I use static allocation the destructor is called many times!!!</p> <pre><code>int main() { Foo a; boost::thread Foothread( &amp;Foo::run, a); // Some very long computation that sometimes access "a" Foothread.join(); int *b = a.get(); cout &lt;&lt; *b &lt;&lt; endl; return 0; } </code></pre> <p>and the ouput is destructor called, a was 0 Now a is 0 destructor called, a was 0 Now a is 0 destructor called, a was 0 Now a is 0 destructor called, a was 0 Now a is 0 destructor called, a was 0 Now a is 0 destructor called, a was 0 Now a is 0 destructor called, a was 0x75e300 Now a is 0 Segmentation fault</p> <p>The destructor is called N times!!</p> <p>Now I would like to know how to safe allocate and deallocate both class member variable and objects using boost::thread and why the thread destructor doesn't handle the class destructor explicitly.</p> <p>Could someone give me an hint? Should boost::smart_ptr help me? I have to allocate memory with malloc (because I need to use some old C API), how can I do it thread-safely?</p>
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