/*
* The contents of this file are subject to the AOLserver Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://aolserver.lcs.mit.edu/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* The Original Code is AOLserver Code and related documentation
* distributed by AOL.
*
* The Initial Developer of the Original Code is America Online,
* Inc. Portions created by AOL are Copyright (C) 1999 America Online,
* Inc. All Rights Reserved.
*
* Alternatively, the contents of this file may be used under the terms
* of the GNU General Public License (the "GPL"), in which case the
* provisions of GPL are applicable instead of those above. If you wish
* to allow use of your version of this file only under the terms of the
* GPL and not to allow others to use your version of this file under the
* License, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the GPL.
* If you do not delete the provisions above, a recipient may use your
* version of this file under either the License or the GPL.
*/
/*
* random.c --
*
* This file implements the "ns_rand" command.
*/
#include "nsd.h"
#if defined(__APPLE__)
#define HAVE_BSD_RANDOM 1
#define HAVE_RAND48 0
#elif defined(WIN32)
#define HAVE_BSD_RANDOM 0
#define HAVE_RAND48 0
#else
#define HAVE_BSD_RANDOM 0
#define HAVE_RAND48 1
#endif
#ifdef NOTDEF
/*
* Local functions defined in this file
*/
static void CounterThread(void);
static unsigned long raw_truerand(void);
/*
* These static variables are used the GenerateSeed routine to generate
* an array of random seeds.
*/
static volatile unsigned long Counter; /* counter in counting thread */
static volatile char counterRun; /* flag that controls the outer loop
* in the counting thread */
static volatile char keepCounting; /* flag that controls the inner loop
* in the counting thread */
static Ns_Sema counterSema; /* semaphore that controls the
* counting thread */
#endif
/*
*==========================================================================
* Exported functions
*==========================================================================
*/
/*
*----------------------------------------------------------------------
*
* NsTclRandCmd --
*
* This procedure implements the AOLserver Tcl
*
* ns_rand ?maximum?
*
* command.
*
* Results:
* The Tcl result string contains a random number, either a
* double >= 0.0 and < 1.0 or a integer >= 0 and < max.
*
* Side effects:
* None external.
*
* Note:
* Interpreters share the static variables which randomizes the
* the random numbers even more.
*
*----------------------------------------------------------------------
*/
int
NsTclRandCmd(ClientData dummy, Tcl_Interp *interp, int argc, char **argv)
{
double d;
int max;
if (argc > 2) {
Tcl_AppendResult(interp, argv[0], ": wrong number args: should be \"",
argv[0], " ?maximum?\"", (char *) NULL);
return TCL_ERROR;
}
if (argc == 2) {
if (Tcl_GetInt(interp, argv[1], &max) != TCL_OK) {
return TCL_ERROR;
} else if (max <= 0) {
Tcl_AppendResult(interp, "invalid max \"", argv[1],
"\": must be > 0", NULL);
return TCL_ERROR;
}
}
d = drand48();
if (argc == 1) {
Tcl_PrintDouble(interp, d, interp->result);
} else {
sprintf(interp->result, "%d", (int) (d * max));
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Ns_DRand --
*
* Return a random double value between 0 and 1.0.
*
* Results:
* Random double.
*
* Side effects:
* Will generate random seed on first call.
*
*----------------------------------------------------------------------
*/
#ifdef NOTDEF
double
Ns_DRand(void)
{
static int initialized;
if (!initialized) {
Ns_MasterLock();
if (!initialized) {
unsigned long seed = 0xdeadbeef;
Ns_GenSeeds(&seed, 1);
#if HAVE_RAND48
srand48(seed);
#elif HAVE_BSD_RANDOM
srandom((unsigned int) seed);
#else
srand((unsigned int) seed);
#endif
initialized = 1;
}
Ns_MasterUnlock();
}
#if HAVE_RAND48
return drand48();
#elif HAVE_BSD_RANDOM
return ((double) random() / (LONG_MAX + 1.0));
#else
return ((double) rand() / (RAND_MAX + 1.0));
#endif
}
/*
*----------------------------------------------------------------------
*
* Ns_GenSeeds --
*
* Calculate an array of random seeds used by both Ns_DRand() and
* the old SSL module.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
Ns_GenSeeds(unsigned long *seedsPtr, int nseeds)
{
Ns_Thread thr;
unsigned long seed;
Ns_Log(Notice, "generating %d random seed%s...", nseeds,
nseeds > 1 ? "s" : "");
Ns_MasterLock();
Ns_SemaInit(&counterSema, 0);
counterRun = 1;
Ns_ThreadCreate((Ns_ThreadProc *) CounterThread, NULL, 0, &thr);
while (nseeds-- > 0) {
*seedsPtr++ = raw_truerand();
}
counterRun = 0;
Ns_SemaPost(&counterSema, 1);
Ns_MasterUnlock();
Ns_ThreadJoin(&thr, NULL);
Ns_SemaDestroy(&counterSema);
Ns_Log(Notice, "seed generation complete.");
}
/*
*----------------------------------------------------------------------
*
* CounterThread --
*
* Generate a random seed. This routine runs as a separate thread
* where it imcrements a counter some indeterminate number of times.
* The assumption is that this thread runs for a sufficiently long time
* to be preempted an arbitrary number of times by the kernel threads
* scheduler.
*
* Results:
*
* Side effects:
* None external.
*
*----------------------------------------------------------------------
*/
static void
CounterThread(void)
{
while (counterRun) {
Ns_SemaWait(&counterSema);
if (counterRun) {
while (keepCounting) {
Counter++;
}
}
}
}
/*
*==========================================================================
* AT&T Seed Generation Code
*==========================================================================
*/
/*
* The authors of this software are Don Mitchell and Matt Blaze.
* Copyright (c) 1995 by AT&T.
* Permission to use, copy, and modify this software without fee
* is hereby granted, provided that this entire notice is included in
* all copies of any software which is or includes a copy or
* modification of this software and in all copies of the supporting
* documentation for such software.
*
* This software may be subject to United States export controls.
*
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR AT&T MAKE ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
*/
#define MSEC_TO_COUNT 31 /* duration of thread counting in milliseconds */
#define ROULETTE_PRE_ITERS 10
static unsigned long roulette(void);
static unsigned long
raw_truerand(void)
{
int i;
for (i = 0; i < ROULETTE_PRE_ITERS; i++) {
roulette();
}
return roulette();
}
static unsigned long
roulette(void)
{
static unsigned long ocount, randbuf;
struct timeval tv;
Counter = 0;
keepCounting = 1;
Ns_SemaPost(&counterSema, 1);
tv.tv_sec = (time_t)0;
tv.tv_usec = MSEC_TO_COUNT * 1000;
select(0, NULL, NULL, NULL, &tv);
keepCounting = 0;
Counter ^= (Counter >> 3) ^ (Counter >> 6) ^ (ocount);
Counter &= 0x7;
ocount = Counter;
randbuf = (randbuf<<3) ^ Counter;
return randbuf;
}
#endif