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/* File: "pthread.c", Time-stamp: <2007-11-13 17:49:37 feeley> */
/* Copyright (c) 2006-2007 by Marc Feeley, All Rights Reserved. */
#include <stdio.h>
#include <pthread.h>
/*
* ___VERSION must match the version number of the Gambit header file.
*/
#define ___VERSION 402008
#include "gambit.h"
/*
* Include declarations exported by mylib.scm.
*/
#include "mylib.h"
/*
* Define SCHEME_LIBRARY_LINKER as the name of the Scheme library
* prefixed with "____20_" and suffixed with "__". This is the
* function that initializes the Scheme library.
*/
#define SCHEME_LIBRARY_LINKER ____20_mylib__
___BEGIN_C_LINKAGE
extern ___mod_or_lnk SCHEME_LIBRARY_LINKER (___global_state_struct*);
___END_C_LINKAGE
#define N 5 /* number of threads */
___SCMOBJ counter; /* the Scheme counter record to increment */
pthread_mutex_t mut; /* to implement critical section for incrementation */
void increment (void)
{
int got_throw = 0;
/*
* At most one thread at a time can execute Scheme code.
* So call Scheme in a critical section.
*/
pthread_mutex_lock (&mut);
/* call Scheme to increment counter */
___ON_THROW(increment_counter (counter), got_throw=1);
pthread_mutex_unlock (&mut);
if (got_throw)
{
printf ("thread %p is terminating\n", pthread_self ());
pthread_exit (NULL); /* exit if Scheme threw an exception */
}
}
void increment_loop (void)
{
int i;
for (i = 0; i<20000; i++)
increment ();
}
void* thread_main (void* param)
{
increment_loop ();
return NULL;
}
int main (int argc, char **argv)
{
/*
* Setup the Scheme library by calling "___setup" with appropriate
* parameters. The call to "___setup_params_reset" sets all parameters
* to their default setting.
*/
___setup_params_struct setup_params;
___setup_params_reset (&setup_params);
setup_params.version = ___VERSION;
setup_params.linker = SCHEME_LIBRARY_LINKER;
___setup (&setup_params);
/* Main part of program: start N threads that increment a counter */
counter = new_counter (); /* create a new counter */
pthread_mutex_init (&mut, NULL); /* initialize mutex */
{
int i;
pthread_t tid[N];
void* results[N];
for (i = 0; i<N; i++)
pthread_create (&tid[i], NULL, thread_main, NULL);
for (i = 0; i<N; i++)
pthread_join (tid[i], &results[i]);
}
{
int got_throw = 0;
int count = 0;
___ON_THROW(count = get_counter (counter), got_throw=1);
if (got_throw)
printf ("Scheme threw an exception\n");
else
printf ("final count = %d\n", count);
}
/* we don't need the counter anymore */
___ON_THROW(release_counter (counter),);
/* Cleanup the Scheme library */
___cleanup ();
return 0;
}
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