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/*
* Copyright (C) by Argonne National Laboratory
* See COPYRIGHT in top-level directory
*/
#include <stdio.h>
#include <stdlib.h>
#include "mpitest.h"
/* This file provides a portability layer for using threads. */
#if THREAD_PACKAGE_NAME == THREAD_PACKAGE_NONE
/* Only empty initialization and finalization functions are supported. */
void MTest_init_thread_pkg(void)
{
}
void MTest_finalize_thread_pkg(void)
{
}
#else /* THREAD_PACKAGE_NAME != THREAD_PACKAGE_NONE */
/*
Define macro to override gcc strict flags,
-D_POSIX_C_SOURCE=199506L, -std=c89 and -std=c99,
that disallow pthread_barrier_t and friends.
*/
#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE < 200112L
#undef _POSIX_C_SOURCE
#define _POSIX_C_SOURCE 200112L
#endif
/* We remember all of the threads we create; this similifies terminating
(joining) them. */
#ifndef MTEST_MAX_THREADS
#define MTEST_MAX_THREADS 16
#endif
static MTEST_THREAD_HANDLE threads[MTEST_MAX_THREADS];
/* access w/o a lock is broken, but "volatile" should help reduce the amount of
* speculative loading/storing */
static volatile int nthreads = 0;
/* to-be-defined in the thread package, or default routines will be used */
#undef HAVE_MTEST_THREAD_BARRIER
#undef HAVE_MTEST_INIT_THREAD_PKG
#if !defined(THREAD_PACKAGE_NAME)
#error "thread package (THREAD_PACKAGE_NAME) not defined"
#elif THREAD_PACKAGE_NAME == THREAD_PACKAGE_WIN
#include "mtest_thread_win.h"
#elif THREAD_PACKAGE_NAME == THREAD_PACKAGE_POSIX || THREAD_PACKAGE_NAME == THREAD_PACKAGE_SOLARIS
#include "mtest_thread_pthread.h"
#elif THREAD_PACKAGE_NAME == THREAD_PACKAGE_ARGOBOTS
#include "mtest_thread_abt.h"
#else
#error "thread package (THREAD_PACKAGE_NAME) unknown"
#endif
/* Default routines */
#if !defined(HAVE_MTEST_THREAD_BARRIER)
static MTEST_THREAD_LOCK_TYPE barrierLock;
static volatile int phase = 0;
static volatile int c[2] = { -1, -1 };
int MTest_thread_barrier_init(void)
{
return MTest_thread_lock_create(&barrierLock);
}
int MTest_thread_barrier_free(void)
{
return MTest_thread_lock_free(&barrierLock);
}
#define LOCK_ERR_CHECK(err_) \
if (err_) { \
fprintf(stderr, "Lock failed in barrier!\n"); \
return err_; \
}
/* This is a generic barrier implementation. To ensure that tests don't
silently fail, this both prints an error message and returns an error
result on any failure. */
int MTest_thread_barrier(int nt)
{
volatile int *cntP;
int err = 0;
int num_left;
if (nt < 0)
nt = nthreads;
/* Force a write barrier by using lock/unlock */
err = MTest_thread_lock(&barrierLock);
LOCK_ERR_CHECK(err);
cntP = &c[phase];
/* printf("[%d] cnt = %d, phase = %d\n", pthread_self(), *cntP, phase); */
/* The first thread to enter will reset the counter */
if (*cntP < 0)
*cntP = nt;
/* printf("phase = %d, cnt = %d\n", phase, *cntP); */
/* The last thread to enter will force the counter to be negative */
if (*cntP == 1) {
/* printf("[%d] changing phase from %d\n", pthread_self(), phase); */
phase = !phase;
c[phase] = -1;
*cntP = 0;
}
/* Really need a write barrier here */
*cntP = *cntP - 1;
num_left = *cntP;
err = MTest_thread_unlock(&barrierLock);
LOCK_ERR_CHECK(err);
/* wait for other threads */
while (num_left > 0) {
err = MTest_thread_lock(&barrierLock);
LOCK_ERR_CHECK(err);
/* TODO: This would be improved with atomic ops instead of using
* a mutex. Integrating MPL for portable atomics would be an
* improvement. */
num_left = *cntP;
err = MTest_thread_unlock(&barrierLock);
LOCK_ERR_CHECK(err);
}
return err;
}
#endif /* Default barrier routine */
#if !defined(HAVE_MTEST_INIT_THREAD_PKG)
void MTest_init_thread_pkg(void)
{
}
void MTest_finalize_thread_pkg(void)
{
}
#endif /* THREAD_PACKAGE_NAME != THREAD_PACKAGE_NONE */
#endif /* Default MTest_init_thread_pkg */
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