Question

I cannot figure out why g++ is giving the following errors. I believe that all the function are declared properly and the braces match up.

(testHashT.cpp just has the header and an empty main)

USERNAME@SERVER 391> g++ -Wall -pthread testHashT.cpp -o testHashT
memHashT.h:22: error: invalid function declaration
memHashT.h: In function âvoid memAccessUpdate(void*, unsigned int, pthread_t, bool)â:
memHashT.h:78: error: âgetHTElementâ was not declared in this scope
memHashT.h:88: error: âgetHTIndexâ was not declared in this scope
memHashT.h:93: error: cannot convert âlinkedMlist*â to âmList*â in assignment
memHashT.h:102: error: âcountWSâ was not declared in this scope
memHashT.h:107: error: âcountRAâ was not declared in this scope
memHashT.h: In function âmList* getHTElement(void*)â:
memHashT.h:133: error: âgetHTIndexâ was not declared in this scope

USERNAME@SERVER 389> cat memHashT.h
    //Basic hash table for memory addresses, recommended size for program running is table indexed by a prime ~81281


/************************************************************
* Structure of table:
* Hash table indexed by memory address
* at each entry a vector made of arrays with size 2 of void pointers
* each vector entry will have the unique memory address and a pointer to a vector
* the vector it points to will contain a list of all threads that accessed that location
*
* Overall:(currently being changed to HT=>LL=>LL
* Hash Table => Vector => Vector Containing threads that accessed a given memory location 
*************************************************************/

#include <pthread.h>//same as bellow
#include <stdlib.h>//watch out in case actual function contains this
//using namespace std;

//Global var
unsigned int tableSize; //note this is best if it is a prime number
unsigned long long countWA;
unsigned long long countRA:
unsigned long long countWS;
unsigned long long countRS;
//Linked Lists (thread, then mem)
//added all information in T_list to the M list, can be deleted
/*struct linkedT_list {
    int threadID;
    struct linkedT_list * nextT;
};
typedef struct linkedT_list tList;
tList * currT, * headT;*/


//For memory addresses
struct linkedM_list {
    void * memAddr;

    //Details
    bool shared;
    pthread_t  prevThread;
    unsigned long long rCounter;
    unsigned long long wCounter;
    //End Details
    struct linkedMlist * nextM;
};
typedef struct linkedM_list mList;
//mList * currM, * headM;

mList ** hashTable;
//Create the hash table

int createHashTable(unsigned int num) {
    tableSize =  num;
    hashTable = (mList **) malloc(sizeof(mList) * tableSize);
   if (hashTable == NULL)
   {
    return 0;
    //printf("Error: Memory could not be allocated");
   }
   else {
    unsigned int i;

    for(i=0;i<tableSize;i++)
    {
        hashTable[i]=NULL;
    }
   }
    return 1;
}

void destroyHashTable(){
    free(hashTable);
}

//adds a element to the hash table
void memAccessUpdate(void * memArg, unsigned int thread, pthread_t thread_id,  bool writeAccess){
    mList * headM = getHTElement(memArg);
    mList * currM;
    if (headM == NULL)
    {//then create and new mList
    currM = (mList *)malloc(sizeof(mList));
    //initialize values
    currM->shared = false;
    currM->prevThread = thread_id;
    currM->rCounter = 0;
    currM->wCounter = 0;
    currM->nextM = hashTable[getHTIndex(memArg)];
    hashTable[getHTIndex(memArg)] = currM;
    }
    else {//change details in linked list and global var
    //headM->nextM = (mList *)malloc(sizeof(mList));
    currM = headM->nextM;
    if (thread_id != currM->prevThread){
        currM->shared = true;
        currM->prevThread = thread_id;
    }
    if(writeAccess)
    {
        countWA++;
        if(currM->shared){
        countWS++;
        }
        currM->wCounter++;
    }
    else{//mem read
        countRA++;
        if(currM->shared){
        countRS++;
        }
        currM->rCounter++;
    }
    }
    //if (stuff) //possibly don't need
    //else
   // head = hashTable[index]; //note may be null
   // curr = (mList *)malloc(sizeof(mList));
   // curr->
}

//remove a element

void removeHTElement(void * memArg){
    //note no garbage collection yet
    ;
}

//returns pointer to mList containing information
    //NOT CORRECTLY IMPLEMENTED YET, NEED TO FIND RIGHT MEM ADDRESS, NOT JUST TOP MEM
mList * getHTElement(void * arg){
    mList * tempM;
    //tList * tempT = NULL;
    unsigned int index = getHTIndex(arg);
    tempM = hashTable[index];
    //tempT = tempM->threadList;
    return tempM;
}

//returns the number of threads to access a memery location
int tLength(void * arg){
    return -1;
}

//computes the index of the hash table
    //made its own function in case future implementation need to change how indexing is set up
unsigned int getHTIndex (void * arg){
    return (unsigned int) ((unsigned long long)arg%tableSize);
}

Answer 1

You’re using functions before you declare them. For example getHTElement uses getHTIndex which is not declared until afterwards.

In general, defining functions in headers is almost always wrong. Declare them in headers and define them in source files.

(You also have numerous errors in your testcase which tells me that the code you posted is not the code you’re using, but it was enough to deduce the above.)