/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
** File: switch.c
** Description: trying to time context switches
*/
#include "prinit.h"
#include "prcvar.h"
#include "prmem.h"
#include "prinrval.h"
#include "prlock.h"
#include "prlog.h"
#include "prthread.h"
#include "prprf.h"
#include "plerror.h"
#include "plgetopt.h"
#include "private/pprio.h"
#include <stdlib.h>
#define INNER_LOOPS 100
#define DEFAULT_LOOPS 100
#define DEFAULT_THREADS 10
static PRFileDesc* debug_out = NULL;
static PRBool debug_mode = PR_FALSE, verbosity = PR_FALSE, failed = PR_FALSE;
typedef struct Shared {
PRLock* ml;
PRCondVar* cv;
PRBool twiddle;
PRThread* thread;
struct Shared* next;
} Shared;
static void Help(
void) {
debug_out = PR_STDOUT;
PR_fprintf(debug_out,
"Usage: >./switch [-c n] [-t n] [-d] [-v] [-G] [-C n]\n");
PR_fprintf(debug_out,
"-c n\tloops at thread level (default: %d)\n",
DEFAULT_LOOPS);
PR_fprintf(debug_out,
"-t n\tnumber of threads (default: %d)\n",
DEFAULT_THREADS);
PR_fprintf(debug_out,
"-d\tturn on debugging output (default: FALSE)\n");
PR_fprintf(debug_out,
"-v\tturn on verbose output (default: FALSE)\n");
PR_fprintf(debug_out,
"-G\tglobal threads only (default: FALSE)\n");
PR_fprintf(debug_out,
"-C n\tconcurrency setting (default: 1)\n");
}
/* Help */
static void PR_CALLBACK Notified(
void* arg) {
Shared* shared = (Shared*)arg;
PRStatus status = PR_SUCCESS;
while (PR_SUCCESS == status) {
PR_Lock(shared->ml);
while (shared->twiddle && (PR_SUCCESS == status)) {
status = PR_WaitCondVar(shared->cv, PR_INTERVAL_NO_TIMEOUT);
}
if (verbosity) {
PR_fprintf(debug_out,
"+");
}
shared->twiddle = PR_TRUE;
shared->next->twiddle = PR_FALSE;
PR_NotifyCondVar(shared->next->cv);
PR_Unlock(shared->ml);
}
}
/* Notified */
static Shared home;
PRIntn PR_CALLBACK
Switch(PRIntn argc,
char** argv) {
PLOptStatus os;
PRStatus status;
PRBool help = PR_FALSE;
PRUintn concurrency = 1;
Shared *shared, *link;
PRIntervalTime timein, timeout;
PRThreadScope thread_scope = PR_LOCAL_THREAD;
PRUintn thread_count, inner_count, loop_count, average;
PRUintn thread_limit = DEFAULT_THREADS, loop_limit = DEFAULT_LOOPS;
PLOptState* opt = PL_CreateOptState(argc, argv,
"hdvc:t:C:G");
while (PL_OPT_EOL != (os = PL_GetNextOpt(opt))) {
if (PL_OPT_BAD == os) {
continue;
}
switch (opt->option) {
case 'v':
/* verbose mode */
verbosity = PR_TRUE;
case 'd':
/* debug mode */
debug_mode = PR_TRUE;
break;
case 'c':
/* loop counter */
loop_limit = atoi(opt->value);
break;
case 't':
/* thread limit */
thread_limit = atoi(opt->value);
break;
case 'C':
/* Concurrency limit */
concurrency = atoi(opt->value);
break;
case 'G':
/* global threads only */
thread_scope = PR_GLOBAL_THREAD;
break;
case 'h':
/* help message */
Help();
help = PR_TRUE;
break;
default:
break;
}
}
PL_DestroyOptState(opt);
if (help) {
return -1;
}
if (PR_TRUE == debug_mode) {
debug_out = PR_STDOUT;
PR_fprintf(debug_out,
"Test parameters\n");
PR_fprintf(debug_out,
"\tThreads involved: %d\n", thread_limit);
PR_fprintf(debug_out,
"\tIteration limit: %d\n", loop_limit);
PR_fprintf(debug_out,
"\tConcurrency: %d\n", concurrency);
PR_fprintf(debug_out,
"\tThread type: %s\n",
(PR_GLOBAL_THREAD == thread_scope) ?
"GLOBAL" :
"LOCAL");
}
PR_SetConcurrency(concurrency);
link = &home;
home.ml = PR_NewLock();
home.cv = PR_NewCondVar(home.ml);
home.twiddle = PR_FALSE;
home.next = NULL;
timeout = 0;
for (thread_count = 1; thread_count <= thread_limit; ++thread_count) {
shared = PR_NEWZAP(Shared);
shared->ml = home.ml;
shared->cv = PR_NewCondVar(home.ml);
shared->twiddle = PR_TRUE;
shared->next = link;
link = shared;
shared->thread =
PR_CreateThread(PR_USER_THREAD, Notified, shared, PR_PRIORITY_HIGH,
thread_scope, PR_JOINABLE_THREAD, 0);
PR_ASSERT(shared->thread != NULL);
if (NULL == shared->thread) {
failed = PR_TRUE;
}
}
for (loop_count = 1; loop_count <= loop_limit; ++loop_count) {
timein = PR_IntervalNow();
for (inner_count = 0; inner_count < INNER_LOOPS; ++inner_count) {
PR_Lock(home.ml);
home.twiddle = PR_TRUE;
shared->twiddle = PR_FALSE;
PR_NotifyCondVar(shared->cv);
while (home.twiddle) {
status = PR_WaitCondVar(home.cv, PR_INTERVAL_NO_TIMEOUT);
if (PR_FAILURE == status) {
failed = PR_TRUE;
}
}
PR_Unlock(home.ml);
}
timeout += (PR_IntervalNow() - timein);
}
if (debug_mode) {
average = PR_IntervalToMicroseconds(timeout) /
(INNER_LOOPS * loop_limit * thread_count);
PR_fprintf(debug_out,
"Average switch times %d usecs for %d threads\n",
average, thread_limit);
}
link = shared;
for (thread_count = 1; thread_count <= thread_limit; ++thread_count) {
if (&home == link) {
break;
}
status = PR_Interrupt(link->thread);
if (PR_SUCCESS != status) {
failed = PR_TRUE;
if (debug_mode) {
PL_FPrintError(debug_out,
"Failed to interrupt");
}
}
link = link->next;
}
for (thread_count = 1; thread_count <= thread_limit; ++thread_count) {
link = shared->next;
status = PR_JoinThread(shared->thread);
if (PR_SUCCESS != status) {
failed = PR_TRUE;
if (debug_mode) {
PL_FPrintError(debug_out,
"Failed to join");
}
}
PR_DestroyCondVar(shared->cv);
PR_DELETE(shared);
if (&home == link) {
break;
}
shared = link;
}
PR_DestroyCondVar(home.cv);
PR_DestroyLock(home.ml);
PR_fprintf(PR_STDOUT, ((failed) ?
"FAILED\n" :
"PASSED\n"));
return ((failed) ? 1 : 0);
}
/* Switch */
int main(
int argc,
char** argv) {
PRIntn result;
PR_STDIO_INIT();
result = PR_Initialize(
Switch, argc, argv, 0);
return result;
}
/* main */
/* switch.c */
