FreeNOS
gettimeofday.cpp
Go to the documentation of this file.
1 /*
2  * Copyright (C) 2015 Niek Linnenbank
3  *
4  * This program is free software: you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation, either version 3 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program. If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include <FreeNOS/User.h>
19 #include <sys/time.h>
20 #include <errno.h>
21 
22 int gettimeofday(struct timeval *tv, struct timezone *tz)
23 {
24  Timer::Info timer;
25 
26  // Get current system timer info
27  ProcessCtl(SELF, InfoTimer, (Address) &timer);
28 
29  // Check for a valid frequency
30  if (timer.frequency == 0)
31  {
32  errno = ERANGE;
33  return -1;
34  }
35 
36  // Fill the output variables
37  tv->tv_sec = timer.ticks / timer.frequency;
38  tv->tv_usec = (1000000 / timer.frequency) * (timer.ticks % timer.frequency);
39  return 0;
40 }
timezone
Time zone information.
Definition: time.h:47
errno
C int errno
The lvalue errno is used by many functions to return error values.
timeval::tv_usec
uint tv_usec
Microseconds.
Definition: time.h:41
Address
unsigned long Address
A memory address.
Definition: Types.h:131
ProcessCtl
API::Result ProcessCtl(const ProcessID proc, const ProcessOperation op, const Address addr=0, const Address output=0)
Prototype for user applications.
Definition: ProcessCtl.h:93
Timer::Info
Timer information structure.
Definition: Timer.h:42
time.h
SELF
#define SELF
Definition: ProcessID.h:35
InfoTimer
@ InfoTimer
Definition: ProcessCtl.h:49
gettimeofday
int gettimeofday(struct timeval *tv, struct timezone *tz)
Get current time of day.
Definition: gettimeofday.cpp:22
timeval::tv_sec
time_t tv_sec
Seconds.
Definition: time.h:38
timeval
Time value information.
Definition: time.h:35
ERANGE
#define ERANGE
Result too large.
Definition: errno.h:259
errno.h