Einfaches mbed RPC Beispiel

Dependencies:   EthernetInterface HttpServer mbed-rtos mbed

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Remote Procedure Call (RPC - „Aufruf einer fernen Prozedur“) ist eine Technik zur Realisierung von Interprozesskommunikation. Sie ermöglicht den Aufruf von Funktionen in anderen Adressräumen. Im Normalfall werden die aufgerufenen Funktionen auf einem anderen Computer als das aufrufende Programm ausgeführt. Es existieren viele Implementierungen dieser Technik, in der Regel sind sie untereinander nicht kompatibel

Die mbed Plattform beinhaltet eine RPC Library, welche ausgesuchte mbed Objekte (DigitalPin, DigitalOut etc.) mittels Serieller Schnittstelle oder via HTTP Aufrufen, zur Verfügung stellt.

Die mbed RCP Klassen verwenden C++ Templates, siehe Zeilen mit <Argument> und den Namespace RPC, siehe Zeilen mit RPC::.

Client

mbed-rpc/rpc.h

Committer:
stefan1691
Date:
2015-04-08
Revision:
11:43e28c85fd75

File content as of revision 11:43e28c85fd75:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2013 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef RPC_H
#define RPC_H

#include "mbed.h"
#include "Arguments.h"

namespace mbed {

#define RPC_MAX_STRING      128

struct rpc_function {
    const char *name;
    void (*function_caller)(Arguments*, Reply*);
};

struct rpc_class {
    const char *name;
    const rpc_function *static_functions;
    struct rpc_class *next;
};

/* Class RPC
 *  The RPC class for most things
 */
class RPC {

public:

    RPC(const char *name = NULL);

    virtual ~RPC();

    /* Function get_rpc_methods
     *  Returns a pointer to an array describing the rpc methods
     *  supported by this object, terminated by either
     *  RPC_METHOD_END or RPC_METHOD_SUPER(Superclass).
     *
     * Example
     * > class Example : public RPC {
     * >   int foo(int a, int b) { return a + b; }
     * >   virtual const struct rpc_method *get_rpc_methods() {
     * >     static const rpc_method rpc_methods[] = {
     * >       { "foo", generic_caller<int, Example, int, int, &Example::foo> },
     * >       RPC_METHOD_SUPER(RPC)
     * >     };
     * >     return rpc_methods;
     * >   }
     * > };
     */
    virtual const struct rpc_method *get_rpc_methods();

    static bool call(const char *buf, char *result);

    /* Function lookup
     *  Lookup and return the object that has the given name.
     *
     * Variables
     *  name - the name to lookup.
     */
    static RPC *lookup(const char *name);

protected:
    static RPC *_head;
    RPC *_next;
    char *_name;
    bool _from_construct;

private:
    static rpc_class *_classes;

    static const rpc_function _RPC_funcs[];
    static rpc_class _RPC_class;

    void delete_self();
    static void list_objs(Arguments *args, Reply *result);
    static void clear(Arguments *args, Reply *result);

public:
    /* Function add_rpc_class
     *  Add the class to the list of classes which can have static
     *  methods called via rpc (the static methods which can be called
     *  are defined by that class' get_rpc_class() static method).
     */
    template<class C>
    static void add_rpc_class() {
        rpc_class *c = C::get_rpc_class();
        c->next = _classes;
        _classes = c;
    }

    template<class C>
    static const char *construct() {
        RPC *p = new C();
        p->_from_construct = true;
        return p->_name;
    }

    template<class C, typename A1>
    static const char *construct(A1 arg1) {
        RPC *p = new C(arg1);
        p->_from_construct = true;
        return p->_name;
    }

    template<class C, typename A1, typename A2>
    static const char *construct(A1 arg1, A2 arg2) {
        RPC *p = new C(arg1, arg2);
        p->_from_construct = true;
        return p->_name;
    }

    template<class C, typename A1, typename A2, typename A3>
    static const char *construct(A1 arg1, A2 arg2, A3 arg3) {
        RPC *p = new C(arg1, arg2, arg3);
        p->_from_construct = true;
        return p->_name;
    }

    template<class C, typename A1, typename A2, typename A3, typename A4>
    static const char *construct(A1 arg1, A2 arg2, A3 arg3, A4 arg4) {
        RPC *p = new C(arg1, arg2, arg3, arg4);
        p->_from_construct = true;
        return p->_name;
    }
};

/* Macro MBED_OBJECT_NAME_MAX
 *  The maximum size of object name (including terminating null byte)
 *  that will be recognised when using fopen to open a FileLike
 *  object, or when using the rpc function.
 */
#define MBED_OBJECT_NAME_MAX 32

/* Macro MBED_METHOD_NAME_MAX
 *  The maximum size of rpc method name (including terminating null
 *  byte) that will be recognised by the rpc function (in rpc.h).
 */
#define MBED_METHOD_NAME_MAX 32

/* Function rpc_method_caller
 */
template<class T, void(T::*member)(const char *, char *)>
void rpc_method_caller(RPC *this_ptr, Arguments *arguments, Reply *result) {
    (static_cast<T*>(this_ptr)->*member)(arguments, result);
}

/* Function rpc_method_caller
 */
template<class T, void(T::*member)()>
void rpc_method_caller(RPC *this_ptr, Arguments *arguments, Reply *result) {
    (static_cast<T*>(this_ptr)->*member)();
}

/* Function rpc_method_caller
 */
template<class T, typename A1, void(T::*member)(A1)>
void rpc_method_caller(RPC *this_ptr, Arguments *arguments, Reply *result) {
    A1 arg1 = arguments->getArg<A1>();

    (static_cast<T*>(this_ptr)->*member)(arg1);
}

/* Function rpc_method_caller
 */
template<class T, typename A1, typename A2, void(T::*member)(A1, A2)>
void rpc_method_caller(RPC *this_ptr, Arguments *arguments, Reply *result) {
    A1 arg1 = arguments->getArg<A1>();
    A2 arg2 = arguments->getArg<A2>();

    (static_cast<T*>(this_ptr)->*member)(arg1, arg2);
}

/* Function rpc_method_caller
 */
template<class T, typename A1, typename A2, typename A3, void(T::*member)(A1, A2, A3)>
void rpc_method_caller(RPC *this_ptr, Arguments *arguments, Reply *result) {
    A1 arg1 = arguments->getArg<A1>();
    A2 arg2 = arguments->getArg<A2>();
    A3 arg3 = arguments->getArg<A3>();

    (static_cast<T*>(this_ptr)->*member)(arg1, arg2, arg3);
}

/* Function rpc_method_caller
 */
template<typename R, class T, R(T::*member)()>
void rpc_method_caller(RPC *this_ptr, Arguments *arguments, Reply *result) {
    R res = (static_cast<T*>(this_ptr)->*member)();
    result->putData<R>(res);
}

/* Function rpc_method_caller
 */
template<typename R, class T, typename A1, R(T::*member)(A1)>
void rpc_method_caller(RPC *this_ptr, Arguments *arguments, Reply *result) {
    A1 arg1 = arguments->getArg<A1>();

    R res = (static_cast<T*>(this_ptr)->*member)(arg1);
    result->putData<R>(res);
}

/* Function rpc_method_caller
 */
template<typename R, class T, typename A1, typename A2, R(T::*member)(A1, A2)>
void rpc_method_caller(RPC *this_ptr, Arguments *arguments, Reply *result) {
    A1 arg1 = arguments->getArg<A1>();
    A2 arg2 = arguments->getArg<A2>();

    R res = (static_cast<T*>(this_ptr)->*member)(arg1, arg2);
    result->putData<R>(res);
}

/* Function rpc_method_caller
 */
template<typename R, class T, typename A1, typename A2, typename A3, R(T::*member)(A1, A2, A3)>
void rpc_method_caller(RPC *this_ptr, Arguments *arguments, Reply *result) {
    A1 arg1 = arguments->getArg<A1>();
    A2 arg2 = arguments->getArg<A2>();
    A3 arg3 = arguments->getArg<A3>();

    R res = (static_cast<T*>(this_ptr)->*member)(arg1, arg2, arg3);
    result->putData<R>(res);
}

/* Function rpc_function caller
 */
template<typename R, R(*func)()>
void rpc_function_caller(Arguments *arguments, Reply *result) {
    R res = (*func)();
    result->putData<R>(res);
}

/* Function rpc_function caller
 */
template<typename R, typename A1, R(*func)(A1)>
void rpc_function_caller(Arguments *arguments, Reply *result) {
    A1 arg1 = arguments->getArg<A1>();
    R res = (*func)(arg1);
    result->putData<R>(res);
}

/* Function rpc_function caller
 */
template<typename R, typename A1, typename A2, R(*func)(A1, A2)>
void rpc_function_caller(Arguments *arguments, Reply *result) {
    A1 arg1 = arguments->getArg<A1>();
    A2 arg2 = arguments->getArg<A2>();

    R res = (*func)(arg1, arg2);
    result->putData<R>(res);
}

/* Function rpc_function caller
 */
template<typename R, typename A1, typename A2, typename A3, R(*func)(A1, A2, A3)>
void rpc_function_caller(Arguments *arguments, Reply *result) {
    A1 arg1 = arguments->getArg<A1>();
    A2 arg2 = arguments->getArg<A2>();
    A3 arg3 = arguments->getArg<A3>();

    R res = (*func)(arg1, arg2, arg3);
    result->putData<R>(res);
}

/* Function rpc_function caller
 */
template<typename R, typename A1, typename A2, typename A3, typename A4, R(*func)(A1, A2, A3, A4)>
void rpc_function_caller(Arguments *arguments, Reply *result) {
    A1 arg1 = arguments->getArg<A1>();
    A2 arg2 = arguments->getArg<A2>();
    A3 arg3 = arguments->getArg<A3>();
    A4 arg4 = arguments->getArg<A4>();

    R res = (*func)(arg1, arg2, arg3, arg4);
    result->putData<R>(res);
}

struct rpc_method {
    const char *name;
    typedef void (*method_caller_t)(RPC*, Arguments*, Reply*);
    typedef const struct rpc_method *(*super_t)(RPC*);
    union {
        method_caller_t method_caller;
        super_t super;
    };
};

template<class C>
const struct rpc_method *rpc_super(RPC *this_ptr) {
    return static_cast<C*>(this_ptr)->C::get_rpc_methods();
}

#define RPC_METHOD_END      { NULL, NULL }
#define RPC_METHOD_SUPER(C) { NULL, (rpc_method::method_caller_t)rpc_super<C> }

} // namespace mbed

#endif