nrnpy_utils.h

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#ifndef nrnpy_utils_h
#define nrnpy_utils_h
 
#include <nrnwrap_Python.h>
#include <cassert>
 
inline bool is_python_string(PyObject* python_string) {
    return PyUnicode_Check(python_string) || PyBytes_Check(python_string);
}
 
class Py2NRNString {
  public:
    Py2NRNString(PyObject* python_string, bool disable_release = false) {
        disable_release_ = disable_release;
        str_ = NULL;
        if (PyUnicode_Check(python_string)) {
            PyObject* py_bytes = PyUnicode_AsASCIIString(python_string);
            if (py_bytes) {
                str_ = strdup(PyBytes_AsString(py_bytes));
                if (!str_) {  // errno is ENOMEM
                    PyErr_SetString(PyExc_MemoryError, "strdup in Py2NRNString");
                }
            }
            Py_XDECREF(py_bytes);
        } else if (PyBytes_Check(python_string)) {
            str_ = strdup(PyBytes_AsString(python_string));
            // assert(strlen(str_) == PyBytes_Size(python_string))
            // not checking for embedded '\0'
            if (!str_) {  // errno is ENOMEM
                PyErr_SetString(PyExc_MemoryError, "strdup in Py2NRNString");
            }
        } else {  // Neither Unicode or PyBytes
            PyErr_SetString(PyExc_TypeError, "Neither Unicode or PyBytes");
        }
    }
 
    ~Py2NRNString() {
        if (!disable_release_ && str_) {
            free(str_);
        }
    }
    inline char* c_str() const {
        return str_;
    }
    inline bool err() const {
        return str_ == NULL;
    }
    inline void set_pyerr(PyObject* type, const char* message) {
        PyObject* ptype = NULL;
        PyObject* pvalue = NULL;
        PyObject* ptraceback = NULL;
        if (err()) {
            PyErr_Fetch(&ptype, &pvalue, &ptraceback);
        }
        if (pvalue && ptype) {
            PyObject* umes = PyUnicode_FromFormat("%s (Note: %S: %S)", message, ptype, pvalue);
            PyErr_SetObject(type, umes);  // umes is borrowed reference
            Py_XDECREF(umes);
        } else {
            PyErr_SetString(type, message);
        }
        Py_XDECREF(ptype);
        Py_XDECREF(pvalue);
        Py_XDECREF(ptraceback);
    }
    inline char* get_pyerr() {
        PyObject* ptype = NULL;
        PyObject* pvalue = NULL;
        PyObject* ptraceback = NULL;
        if (err()) {
            PyErr_Fetch(&ptype, &pvalue, &ptraceback);
            if (pvalue) {
                PyObject* pstr = PyObject_Str(pvalue);
                if (pstr) {
                    const char* err_msg = PyUnicode_AsUTF8(pstr);
                    if (err_msg) {
                        str_ = strdup(err_msg);
                    } else {
                        str_ = strdup("get_pyerr failed at PyUnicode_AsUTF8");
                    }
                    Py_XDECREF(pstr);
                } else {
                    str_ = strdup("get_pyerr failed at PyObject_Str");
                }
            } else {
                str_ = strdup("get_pyerr failed at PyErr_Fetch");
            }
        }
        PyErr_Clear();  // in case could not turn pvalue into c_str.
        Py_XDECREF(ptype);
        Py_XDECREF(pvalue);
        Py_XDECREF(ptraceback);
        return str_;
    }
 
  private:
    Py2NRNString();
    Py2NRNString(const Py2NRNString&);
    Py2NRNString& operator=(const Py2NRNString&);
 
    char* str_;
    bool disable_release_;
};
 
 
class PyLockGIL {
  public:
    PyLockGIL()
        : state_(PyGILState_Ensure())
        , locked_(true) {}
 
    /* This is mainly used to unlock manually prior to a hoc_execerror() call
     * since this uses longjmp()
     */
    void release() {
        assert(locked_);
        locked_ = false;
        PyGILState_Release(state_);
    }
 
    ~PyLockGIL() {
        release();
    }
 
  private:
    PyLockGIL(const PyLockGIL&);
    PyLockGIL& operator=(const PyLockGIL&);
 
    PyGILState_STATE state_;
    bool locked_; /* check if double unlocking */
};
 
extern void nrnpy_sec_referr();
#define CHECK_SEC_INVALID(sec)  \
    {                           \
        if (!sec->prop) {       \
            nrnpy_sec_referr(); \
            return NULL;        \
        }                       \
    }
 
#endif /* end of include guard: nrnpy_utils_h */