A common memory leak __c++ in C + + extended Python

a common memory leak in C/A + + extended python

For example, code like this:

Pyobject *dic = Pydict_new ();
Iret = Pydict_setitem (dic, Py_buildvalue ("s", "xxxxxx"), Py_buildvalue ("s"), "Hello xxxx");

This will cause a memory leak.

The correct writing should be this:

Pyobject *dic = Pydict_new ();
Pyobject *obj1 = Py_buildvalue ("s", "xxxxxx");
Pyobject *obj2 = Py_buildvalue ("s", "Hello xxxx");
Iret = Pydict_setitem (dic, Obj1, obj2);
Py_xdecref (obj1);
Py_xdecref (OBJ2);

There is also a way of writing that will lead to Coredump

Pyobject *dic = Pydict_new ();
Pyobject *obj1 = Py_buildvalue ("s", "xxxxxx");
Pyobject *obj2 = Py_buildvalue ("s", "Hello xxxx");
Py_xdecref (obj1);
Py_xdecref (OBJ2);
Iret = Pydict_setitem (dic, Obj1, OBJ2);

In fact, think of the right behavior: Python obj controls the lifecycle through reference. Returns if some obj reference count of c/++ APIs is not 0 at a time. These objects will always be inside the Python virtual machine. Python virtual machines should not have recycled them.

The last situation is a better understanding, access to an already recycled address of course it will coredump slightly

By the way, test methods: 1. Test memory leak is to increase the return data, for multiple calls. Top See the memory is constantly increasing is the memory leak. Long run, overlay test can discover this problem.

Author: Zhihuihui <camel_flying@163.com>

date:2012-06-29 00:02:19 CST

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