Objectpool in Java

Recently, in the collision detection module of the Editor (Java + jogl), the detection function requires a large number of temporary objects, such as vector3f and matrix4f. Java is inherently slow, if we use new without scruples, I am really sorry... Fortunately, I found the objectpool concept, which is simple but practical.

 

/** <Br/> * @ author Yong. xue <br/> */<br/> public class ipoolvec3 {<br/> Private Static arraylist <vector3f> objects = new arraylist <vector3f> (256 ); <br/> Private Static int n = 256; <br/> Public static vector3f alloc (float X, float y, float Z) {<br/> If (n> 0) {<br/> vector3f v = objects. remove (-- N); <br/> v. set (x, y, z); <br/> return V; <br/>}else {<br/> return New vector3f (); <br/>}< br/> Public static vector3f alloc () {<br/> If (n> 0) {<br/> vector3f v = objects. remove (-- N); <br/> v. zero (); </P> <p> return V; <br/>} else {<br/> return New vector3f (); <br/>}< br/> Public static void free (vector3f v) {<br/> If (V = NULL) {<br/> return; <br/>}< br/> objects. add (V); <br/> + + N; <br/>}< br/>}

 

 

The usage is as follows:

/** <Br/> * tests the triangle for intersection with a ray. <br/> * @ Param Ray <br/> * @ return the distance between the ray origin and the intersection point <br/> */<br/> public float intersect (iray ray) {<br/> // map TMP vectors to local names <br/> vector3f e1 = ipoolvec3.alloc (); <br/> vector3f e2 = ipoolvec3.alloc (); <br/> vector3f P = ipoolvec3.alloc (); <br/> vector3f q = ipoolvec3.alloc (); <br/> vector3f S = ipoolvec3.alloc (); <br/> try {<br/> // test raydirection <br/> e1.sub (m_pvpositions [1], m_pvpositions [0]); <br/> e2.sub (m_pvpositions [2], m_pvpositions [0]); <br/> P. cross (Ray. m_vdirection, E2); <br/> float a = e1.dot (p); <br/> // if the result is "zero ", the pick Ray is parallel to the triangle <br/> If (-imath. epsilon <A) & (A <imath. epsilon) {<br/> return (-1f); <br/>}< br/> float F = 1.0f/; <br/> // compute barycentric coordinates <br/> S. sub (Ray. m_vorigin, m_pvpositions [0]); <br/> final float u = f * s. DOT (p); <br/> If (0.0f> U) | (u> 1.0f) {<br/> return (-1f ); <br/>}< br/> q. cross (S, E1); <br/> final float v = f * Ray. m_vdirection.dot (Q); <br/> If (0.0f> U) | (U + V> 1.0f) {<br/> return (-1f ); <br/>}< br/> // compute the intersection point on the ray <br/> final float L = f * e2.dot (Q ); <br/> If (L <0.0f) {<br/> return (-1f); <br/>}< br/> return (L * l ); <br/>} finally {<br/> ipoolvec3.free (s); <br/> ipoolvec3.free (Q); <br/> ipoolvec3.free (P ); <br/> ipoolvec3.free (E2); <br/> ipoolvec3.free (E1); <br/>}< br/>}

 

Well, all the temporary objects are not new, but get a reference from the object pool; if the pool does not exist, the new operation is implemented;

The most important thing is that it must be returned after use. Otherwise, memory leakage similar to C/C ++ may occur, with fewer and fewer available elements in the pool ..