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cc65/include/time.h
Oliver Schmidt 842c151edd Replaced _systime with clock_gettime.
We want to add the capability to not only get the time but also set the time, but there's no "setter" for the "getter" time().

The first ones that come into mind are gettimeofday() and settimeofday(). However, they take a struct timezone argument that doesn't make sense - even the man pages says "The use of the timezone structure is obsolete; the tz argument should normally be specified as NULL." And POSIX says "Applications should use the clock_gettime() function instead of the obsolescent gettimeofday() function."

The ...timeofday() functions work with microseconds while the clock_...time() functions work with nanoseconds. Given that we expect our targets to support only 1/10 of seconds the microseconds look preferable at first sight. However, already microseconds require the cc65 data type 'long' so it's not such a relevant difference to nanoseconds. Additionally clock_getres() seems useful.

In order to avoid code duplication clock_gettime() takes over the role of the actual time getter from _systime(). So time() now calls clock_gettime() instead of _systime().

For some reason beyond my understanding _systime() was mentioned in time.h. _systime() worked exactly like e.g. _sysremove() and those _sys...() functions are all considered internal. The only reason I could see would be a performance gain of bypassing the time() wrapper. However, all known _systime() implementations internally called mktime(). And mktime() is implemented in C using an iterative algorithm so I really can't see what would be left to gain here. From that perspective I decided to just remove _systime().
2018-08-15 16:06:44 +02:00

155 lines
5.8 KiB
C

/*****************************************************************************/
/* */
/* time.h */
/* */
/* Date and time */
/* */
/* */
/* */
/* (C) 1998-2012 Ullrich von Bassewitz */
/* Roemerstrasse 52 */
/* D-70794 Filderstadt */
/* EMail: uz@cc65.org */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* warranty. In no event will the authors be held liable for any damages */
/* arising from the use of this software. */
/* */
/* Permission is granted to anyone to use this software for any purpose, */
/* including commercial applications, and to alter it and redistribute it */
/* freely, subject to the following restrictions: */
/* */
/* 1. The origin of this software must not be misrepresented; you must not */
/* claim that you wrote the original software. If you use this software */
/* in a product, an acknowledgment in the product documentation would be */
/* appreciated but is not required. */
/* 2. Altered source versions must be plainly marked as such, and must not */
/* be misrepresented as being the original software. */
/* 3. This notice may not be removed or altered from any source */
/* distribution. */
/* */
/*****************************************************************************/
#ifndef _TIME_H
#define _TIME_H
/* NULL pointer */
#ifndef _HAVE_NULL
#define NULL 0
#define _HAVE_NULL
#endif
/* size_t is needed */
#ifndef _HAVE_size_t
#define _HAVE_size_t
typedef unsigned size_t;
#endif
typedef unsigned long time_t;
typedef unsigned long clock_t;
typedef unsigned char clockid_t;
/* Structure for broken down time */
struct tm {
int tm_sec;
int tm_min;
int tm_hour;
int tm_mday;
int tm_mon;
int tm_year;
int tm_wday;
int tm_yday;
int tm_isdst;
};
/* Structure for seconds and nanoseconds */
struct timespec {
time_t tv_sec;
long tv_nsec;
};
/* Timezone representation, default is UTC */
extern struct _timezone {
char daylight; /* True if daylight savings time active */
long timezone; /* Number of seconds behind UTC */
char tzname[5]; /* Name of timezone, e.g. CET */
char dstname[5]; /* Name when daylight true, e.g. CEST */
} _tz;
#if defined(__ATARI__)
/* The clock depends on the video standard, so read it at runtime */
unsigned _clocks_per_sec (void);
# define CLK_TCK _clocks_per_sec()
# define CLOCKS_PER_SEC _clocks_per_sec()
#elif defined(__ATARI5200__)
# define CLK_TCK 60 /* POSIX */
# define CLOCKS_PER_SEC 60 /* ANSI */
#elif defined(__ATMOS__)
# define CLK_TCK 100 /* POSIX */
# define CLOCKS_PER_SEC 100 /* ANSI */
#elif defined(__CBM__)
# if defined(__CBM510__) || defined(__CBM610__)
/* The 510/610 gets its clock from the AC current */
# define CLK_TCK 50 /* POSIX */
# define CLOCKS_PER_SEC 50 /* ANSI */
# else
# define CLK_TCK 60 /* POSIX */
# define CLOCKS_PER_SEC 60 /* ANSI */
# endif
#elif defined(__NES__)
# define CLK_TCK 50 /* POSIX */
# define CLOCKS_PER_SEC 50 /* ANSI */
#elif defined(__PCE__)
# define CLK_TCK 60 /* POSIX */
# define CLOCKS_PER_SEC 60 /* ANSI */
#elif defined(__GAMATE__)
# define CLK_TCK 135 /* POSIX */ /* FIXME */
# define CLOCKS_PER_SEC 135 /* ANSI */ /* FIXME */
#elif defined(__GEOS__)
# define CLK_TCK 1 /* POSIX */
# define CLOCKS_PER_SEC 1 /* ANSI */
#elif defined(__LYNX__)
/* The clock-rate depends on the video scan-rate;
** so, read it at run-time.
*/
extern clock_t _clk_tck (void);
# define CLK_TCK _clk_tck()
# define CLOCKS_PER_SEC _clk_tck()
#endif
#define CLOCK_REALTIME 0
/* ISO C function prototypes */
char* __fastcall__ asctime (const struct tm* timep);
clock_t clock (void);
char* __fastcall__ ctime (const time_t* timep);
struct tm* __fastcall__ gmtime (const time_t* timep);
struct tm* __fastcall__ localtime (const time_t* timep);
time_t __fastcall__ mktime (struct tm* timep);
size_t __fastcall__ strftime (char* buf, size_t bufsize, const char* format, const struct tm* tm);
time_t __fastcall__ time (time_t* t);
/* POSIX function prototypes */
int __fastcall__ clock_getres (clockid_t clock_id, struct timespec *res);
int __fastcall__ clock_gettime (clockid_t clock_id, struct timespec *tp);
int __fastcall__ clock_settime (clockid_t clock_id, const struct timespec *tp);
/* End of time.h */
#endif