Subj : Problems with 'undeclared' variables during compilation
To   : comp.programming.threads
From : mckrs
Date : Mon Apr 11 2005 03:11 pm

Hello all,

I am attempting to get a multi-threaded C++ program off the ground in a
Sun Solarix environment.  In this particular situation, I am required
to use namespaces.  The problem is that I get this error when I attempt
to compile using:
'g++ <source.cpp> -lpthreads -o <output>

ERROR MESSAGE:
sourcefile.cpp:218: error: `fOut' undeclared (first use this function)

I can't seem to figure out why the compiler cannot find the 'fOut' file
handle.  Any help is truly appreciated!

- Garbunkel

Here is a sample of the code:
// For I/O capabilities
#include <fstream>
#include <iostream>

// For file handling capabilities & random character generation
#include <cstdlib>

#include <cmath>

#include <sys/types.h>
#include <pthread.h>
#include <sched.h>
#include <semaphore.h>

bool writelock;
int readers, readersqueued, writersqueued;

pthread_cond_t active_wr_cond;
pthread_cond_t active_rd_cond;

pthread_mutex_t mutex;

char *thetime;

int numofreadloops;
int numofwriteloops;

// *****************************/
// Constant exit handlers

int INCORRECT_EXECUTION_SYNTAX = -1;
int PTHREAD_MUTEX_INIT_ERROR = -2;
int PTHREAD_COND_INIT_ERROR = -3;
int PTHREAD_RD_CREATE_ERROR = -4;
int PTHREAD_WR_CREATE_ERROR = -5;
int PTHREAD_WR_COND_SIGNAL_ERROR = -6;
int PTHREAD_WR_COND_WAIT_ERROR = -7;
int PTHREAD_RD_COND_SIGNAL_ERROR = -8;
int PTHREAD_RD_COND_WAIT_ERROR = -9;
int PTHREAD_JOIN_ERROR = -10;
int OUTPUT_FILE_CREATE_ERROR = -11;

// *****************************/

// Function declarations

void* monitor_rd(void *arg);
void* monitor_wr(void *arg);
void beginreader(void *param);
void beginwriter(void *param);
void endreader();
void endwriter();
void updateDB();
char* GetDB();
bool randnumisodd();

int main (int argc, char* argv[])
{

using namespace std;

char outfilename[255];

int numofreaders, numofwriters, numofops;
    int jobind = 0;

if (argc < 6)
{
   printf("\nUsage:mon<# of rdrs><# of wrtrs><# of rdr loops><# of wrtr

loops><output file>\n");
   exit (INCORRECT_EXECUTION_SYNTAX);
}

numofreaders = atoi(argv[1]);  /* r */
numofwriters = atoi(argv[2]);  /* w */
    numofreadloops = atoi(argv[3]);  /* R */
numofwriteloops = atoi(argv[4]);  /* W */
strcpy (outfilename, argv[5]); /* Output file name */

ifstream fIn("test.dat",ios::in);

numofops = numofreaders + numofwriters;

/* Set initial DB value in main thread */

updateDB();

// Attempt opening output file

ofstream fOut(outfilename,ios::out);  // This is the problem line

.