Re: Best way of Allocating and Deallocating memory

From:
 Amit_Basnak <Amit.Basnak@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Mon, 17 Sep 2007 04:31:18 -0700
Message-ID:
<1190028678.881897.215680@r29g2000hsg.googlegroups.com>
On Sep 17, 4:13 pm, DaveJ <davej2...@gmail.com> wrote:

On 17 Sep, 11:48, Amit_Basnak <Amit.Bas...@gmail.com> wrote:

Dear Friends

I have two structures as below
typedef struct {
long_int length;
char data[1];

} CI_STRUCT_DATA;

typedef CI_STRUCT_DATA *ptr_CiStructData;

typedef struct {
char opener_ref_num_fmtd[26];
char our_ref_num[15];
char txn_ref_num[15];
char stop_tracer_date[27];
char tracer_trans_medium[3];
char tracer_frequency[2];
ptr_CiStructData MSG_DATA;

} CI_STRUCT_MSG;

I have allocated memory for it as below
CI_STRUCT_MSG msg_details;
msg_details.MSG_DATA = (CI_STRUCT_DATA *)
malloc( sizeof(CI_STRUCT_DATA) +(sizeof(unsigned
char)*(strlen(ptr_msg_details) + 1)) );
        msg_details.MSG_DATA->length = strlen(ptr_msg_details);
        strcpy((char *)msg_details.MSG_DATA->data,(char *)ptr_msg_details);

Im freeing up the memory as
        free(ptr_msg_details);

Please suggest me any improvements in memory allocations if any

Thanks
Amit


I tend to use classes over structs for most things. But anyway, I
think new and delete are the prefered methods for memory allocation in
C++. You don't need to provide the size parameter, and new returns a
pointer to the object your creating.

I would do something like:

class CIData
{
    public:
        CIData();
        ~CIData();

         const long_int getLength() const;
         const char* getData() const;

         void setLength(long_int len);
         void setData(const char*);

   private:
       long_int m_Length;
       char[1] m_Data;

};

class CIMsg
{
    public:
        CIMsg();
        ~CIMsg();

        // Setters
        void setMsgData(CIData *);
        // .....

        // Getters
        // ......

    private:
       char opener_ref_num_fmtd[26];
       char our_ref_num[15];
       char txn_ref_num[15];
       char stop_tracer_date[27];
       char tracer_trans_medium[3];
       char tracer_frequency[2];
       const CIData * m_msgData;

}

int main(int argc, char** argv)
{
 const CIMsg msgDetails;
 const CIData data = new CIData();

 msgDetails.setMsgData(CIData);

 if(msgDetails)
 {
    // do some stuff

    ...

    delete msgDetails;
    msgDetails = NULL;
 }

 return 0;

}- Hide quoted text -

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Thanks all

Since its mandator for us to use C style malloc
thats why I tried to allocate the memory like
CI_STRUCT_MSG msg_details;
msg_details.MSG_DATA = (CI_STRUCT_DATA *)
malloc( sizeof(CI_STRUCT_DATA) +(sizeof(unsigned
char)*(strlen(ptr_msg_details) + 1)) );
        msg_details.MSG_DATA->length = strlen(ptr_msg_details);
        strcpy((char *)msg_details.MSG_DATA->data,(char
*)ptr_msg_details);

Now for freeing it up
free(msg_details.MSG_DATA);
Is above sufficient ?

Please let me know
Thanks

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