1 #ifdef HAVE_CONFIG_H 2 # include <config.h> 3 #endif 4 5 #ifdef MPE 6 /* 7 * MPE lacks adjtime(), so we define our own. But note that time slewing has 8 * a sub-second accuracy bug documented in SR 5003462838 which prevents ntpd 9 * from being able to maintain clock synch. Because of the bug, this adjtime() 10 * implementation as used by ntpd has a side-effect of screwing up the hardware 11 * PDC clock, which will need to be reset with a reboot. 12 * 13 * This problem affects all versions of MPE at the time of this writing (when 14 * MPE/iX 7.0 is the most current). It only causes bad things to happen when 15 * doing continuous clock synchronization with ntpd; note that you CAN run ntpd 16 * with "disable ntp" in ntp.conf if you wish to provide a time server. 17 * 18 * The one-time clock adjustment functionality of ntpdate and ntp_timeset can 19 * be used without screwing up the PDC clock. 20 * 21 */ 22 #include <time.h> 23 24 int adjtime(struct timeval *delta, struct timeval *olddelta); 25 26 int adjtime(struct timeval *delta, struct timeval *olddelta) 27 28 { 29 /* Documented, supported MPE system intrinsics. */ 30 31 extern void GETPRIVMODE(void); 32 extern void GETUSERMODE(void); 33 34 /* Undocumented, unsupported MPE internal functions. */ 35 36 extern long long current_correction_usecs(void); 37 extern long long get_time(void); 38 extern void get_time_change_info(long long *, char *, char *); 39 extern long long pdc_time(int *); 40 extern void set_time_correction(long long, int, int); 41 extern long long ticks_to_micro(long long); 42 43 long long big_sec, big_usec, new_correction = 0LL; 44 long long prev_correction; 45 46 if (delta != NULL) { 47 /* Adjustment required. Convert delta to 64-bit microseconds. */ 48 big_sec = (long)delta->tv_sec; 49 big_usec = delta->tv_usec; 50 new_correction = (big_sec * 1000000LL) + big_usec; 51 } 52 53 GETPRIVMODE(); 54 55 /* Determine how much of a previous correction (if any) we're interrupting. */ 56 prev_correction = current_correction_usecs(); 57 58 if (delta != NULL) { 59 /* Adjustment required. */ 60 61 #if 0 62 /* Speculative code disabled until bug SR 5003462838 is fixed. This bug 63 prevents accurate time slewing, and indeed renders ntpd inoperable. */ 64 65 if (prev_correction != 0LL) { 66 /* A previous adjustment did not complete. Since the PDC UTC clock was 67 immediately jumped at the start of the previous adjustment, we must 68 explicitly reset it to the value of the MPE local time clock minus the 69 time zone offset. */ 70 71 char pwf_since_boot, recover_pwf_time; 72 long long offset_ticks, offset_usecs, pdc_usecs_current, pdc_usecs_wanted; 73 int hpe_status; 74 75 get_time_change_info(&offset_ticks, &pwf_since_boot, &recover_pwf_time); 76 offset_usecs = ticks_to_micro(offset_ticks); 77 pdc_usecs_wanted = get_time() - offset_usecs; 78 pdc_usecs_current = pdc_time(&hpe_status); 79 if (hpe_status == 0) 80 /* Force new PDC time by starting an extra correction. */ 81 set_time_correction(pdc_usecs_wanted - pdc_usecs_current,0,1); 82 } 83 #endif /* 0 */ 84 85 /* Immediately jump the PDC time to the new value, and then initiate a 86 gradual MPE time correction slew. */ 87 set_time_correction(new_correction,0,1); 88 } 89 90 GETUSERMODE(); 91 92 if (olddelta != NULL) { 93 /* Caller wants to know remaining amount of previous correction. */ 94 (long)olddelta->tv_sec = prev_correction / 1000000LL; 95 olddelta->tv_usec = prev_correction % 1000000LL; 96 } 97 98 return 0; 99 } 100 #endif /* MPE */ 101 102 #ifdef NEED_HPUX_ADJTIME 103 /*************************************************************************/ 104 /* (c) Copyright Tai Jin, 1988. All Rights Reserved. */ 105 /* Hewlett-Packard Laboratories. */ 106 /* */ 107 /* Permission is hereby granted for unlimited modification, use, and */ 108 /* distribution. This software is made available with no warranty of */ 109 /* any kind, express or implied. This copyright notice must remain */ 110 /* intact in all versions of this software. */ 111 /* */ 112 /* The author would appreciate it if any bug fixes and enhancements were */ 113 /* to be sent back to him for incorporation into future versions of this */ 114 /* software. Please send changes to tai@iag.hp.com or ken@sdd.hp.com. */ 115 /*************************************************************************/ 116 117 /* 118 * Revision history 119 * 120 * 9 Jul 94 David L. Mills, Unibergity of Delabunch 121 * Implemented variable threshold to limit age of 122 * corrections; reformatted code for readability. 123 */ 124 125 #ifndef lint 126 static char RCSid[] = "adjtime.c,v 3.1 1993/07/06 01:04:42 jbj Exp"; 127 #endif 128 129 #include <sys/types.h> 130 #include <sys/ipc.h> 131 #include <sys/msg.h> 132 #include <time.h> 133 #include <signal.h> 134 #include "adjtime.h" 135 136 #define abs(x) ((x) < 0 ? -(x) : (x)) 137 138 /* 139 * The following paramters are appropriate for an NTP adjustment 140 * interval of one second. 141 */ 142 #define ADJ_THRESH 200 /* initial threshold */ 143 #define ADJ_DELTA 4 /* threshold decrement */ 144 145 static long adjthresh; /* adjustment threshold */ 146 static long saveup; /* corrections accumulator */ 147 148 /* 149 * clear_adjtime - reset accumulator and threshold variables 150 */ 151 void 152 _clear_adjtime(void) 153 { 154 saveup = 0; 155 adjthresh = ADJ_THRESH; 156 } 157 158 /* 159 * adjtime - hp-ux copout of the standard Unix adjtime() system call 160 */ 161 int 162 adjtime( 163 register struct timeval *delta, 164 register struct timeval *olddelta 165 ) 166 { 167 struct timeval newdelta; 168 169 /* 170 * Corrections greater than one second are done immediately. 171 */ 172 if (delta->tv_sec) { 173 adjthresh = ADJ_THRESH; 174 saveup = 0; 175 return(_adjtime(delta, olddelta)); 176 } 177 178 /* 179 * Corrections less than one second are accumulated until 180 * tripping a threshold, which is initially set at ADJ_THESH and 181 * reduced in ADJ_DELTA steps to zero. The idea here is to 182 * introduce large corrections quickly, while making sure that 183 * small corrections are introduced without excessive delay. The 184 * idea comes from the ARPAnet routing update algorithm. 185 */ 186 saveup += delta->tv_usec; 187 if (abs(saveup) >= adjthresh) { 188 adjthresh = ADJ_THRESH; 189 newdelta.tv_sec = 0; 190 newdelta.tv_usec = saveup; 191 saveup = 0; 192 return(_adjtime(&newdelta, olddelta)); 193 } else { 194 adjthresh -= ADJ_DELTA; 195 } 196 197 /* 198 * While nobody uses it, return the residual before correction, 199 * as per Unix convention. 200 */ 201 if (olddelta) 202 olddelta->tv_sec = olddelta->tv_usec = 0; 203 return(0); 204 } 205 206 /* 207 * _adjtime - does the actual work 208 */ 209 int 210 _adjtime( 211 register struct timeval *delta, 212 register struct timeval *olddelta 213 ) 214 { 215 register int mqid; 216 MsgBuf msg; 217 register MsgBuf *msgp = &msg; 218 219 /* 220 * Get the key to the adjtime message queue (note that we must 221 * get it every time because the queue might have been removed 222 * and recreated) 223 */ 224 if ((mqid = msgget(KEY, 0)) == -1) 225 return (-1); 226 msgp->msgb.mtype = CLIENT; 227 msgp->msgb.tv = *delta; 228 if (olddelta) 229 msgp->msgb.code = DELTA2; 230 else 231 msgp->msgb.code = DELTA1; 232 233 /* 234 * Tickle adjtimed and snatch residual, if indicated. Lots of 235 * fanatic error checking here. 236 */ 237 if (msgsnd(mqid, &msgp->msgp, MSGSIZE, 0) == -1) 238 return (-1); 239 if (olddelta) { 240 if (msgrcv(mqid, &msgp->msgp, MSGSIZE, SERVER, 0) == -1) 241 return (-1); 242 *olddelta = msgp->msgb.tv; 243 } 244 return (0); 245 } 246 247 #else 248 # if NEED_QNX_ADJTIME 249 /* 250 * Emulate adjtime() using QNX ClockAdjust(). 251 * Chris Burghart <burghart@atd.ucar.edu>, 11/2001 252 * Miroslaw Pabich <miroslaw_pabich@o2.pl>, 09/2005 253 * 254 * This is an implementation of adjtime() for QNX. 255 * ClockAdjust() is used to tweak the system clock for about 256 * 1 second period until the desired delta is achieved. 257 * Time correction slew is limited to reasonable value. 258 * Internal rounding and relative errors are reduced. 259 */ 260 # include <sys/neutrino.h> 261 # include <sys/time.h> 262 263 # include <ntp_stdlib.h> 264 265 /* 266 * Time correction slew limit. QNX is a hard real-time system, 267 * so don't adjust system clock too fast. 268 */ 269 #define CORR_SLEW_LIMIT 0.02 /* [s/s] */ 270 271 /* 272 * Period of system clock adjustment. It should be equal to adjtime 273 * execution period (1s). If slightly less than 1s (0.95-0.99), then olddelta 274 * residual error (introduced by execution period jitter) will be reduced. 275 */ 276 #define ADJUST_PERIOD 0.97 /* [s] */ 277 278 int 279 adjtime (struct timeval *delta, struct timeval *olddelta) 280 { 281 double delta_nsec; 282 double delta_nsec_old; 283 struct _clockadjust adj; 284 struct _clockadjust oldadj; 285 286 /* 287 * How many nanoseconds are we adjusting? 288 */ 289 if (delta != NULL) 290 delta_nsec = 1e9 * (long)delta->tv_sec + 1e3 * delta->tv_usec; 291 else 292 delta_nsec = 0; 293 294 /* 295 * Build the adjust structure and call ClockAdjust() 296 */ 297 if (delta_nsec != 0) 298 { 299 struct _clockperiod period; 300 long count; 301 long increment; 302 long increment_limit; 303 int isneg = 0; 304 305 /* 306 * Convert to absolute value for future processing 307 */ 308 if (delta_nsec < 0) 309 { 310 isneg = 1; 311 delta_nsec = -delta_nsec; 312 } 313 314 /* 315 * Get the current clock period (nanoseconds) 316 */ 317 if (ClockPeriod (CLOCK_REALTIME, 0, &period, 0) < 0) 318 return -1; 319 320 /* 321 * Compute count and nanoseconds increment 322 */ 323 count = 1e9 * ADJUST_PERIOD / period.nsec; 324 increment = delta_nsec / count + .5; 325 /* Reduce relative error */ 326 if (count > increment + 1) 327 { 328 increment = 1 + (long)((delta_nsec - 1) / count); 329 count = delta_nsec / increment + .5; 330 } 331 332 /* 333 * Limit the adjust increment to appropriate value 334 */ 335 increment_limit = CORR_SLEW_LIMIT * period.nsec; 336 if (increment > increment_limit) 337 { 338 increment = increment_limit; 339 count = delta_nsec / increment + .5; 340 /* Reduce relative error */ 341 if (increment > count + 1) 342 { 343 count = 1 + (long)((delta_nsec - 1) / increment); 344 increment = delta_nsec / count + .5; 345 } 346 } 347 348 adj.tick_nsec_inc = isneg ? -increment : increment; 349 adj.tick_count = count; 350 } 351 else 352 { 353 adj.tick_nsec_inc = 0; 354 adj.tick_count = 0; 355 } 356 357 if (ClockAdjust (CLOCK_REALTIME, &adj, &oldadj) < 0) 358 return -1; 359 360 /* 361 * Build olddelta 362 */ 363 delta_nsec_old = (double)oldadj.tick_count * oldadj.tick_nsec_inc; 364 if (olddelta != NULL) 365 { 366 if (delta_nsec_old != 0) 367 { 368 /* Reduce rounding error */ 369 delta_nsec_old += (delta_nsec_old < 0) ? -500 : 500; 370 olddelta->tv_sec = delta_nsec_old / 1e9; 371 olddelta->tv_usec = (long)(delta_nsec_old - 1e9 372 * (long)olddelta->tv_sec) / 1000; 373 } 374 else 375 { 376 olddelta->tv_sec = 0; 377 olddelta->tv_usec = 0; 378 } 379 } 380 381 return 0; 382 } 383 # else /* no special adjtime() needed */ 384 int adjtime_bs; 385 # endif 386 #endif 387