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CLOCKS_PER_SEC

From cppreference.com
< c‎ | chrono
Defined in header <time.h>
#define CLOCKS_PER_SEC /*implementation defined*/

Expands to an expression (not necessarily a compile-time constant) of type clock_t equal to the number of clock ticks per second, as returned by clock().

[edit] Notes

POSIX defines CLOCKS_PER_SEC as one million, regardless of the actual precision of clock.

Until standardized as CLOCKS_PER_SEC in C89, this macro was sometimes known by its IEEE std 1003.1-1988 name CLK_TCK: that name was not included in C89 and was removed from POSIX itself in 1996 over ambiguity with _SC_CLK_TCK, which gives number of clocks per second for the function times()).

[edit] References

  • C23 standard (ISO/IEC 9899:2023):
  • 7.27.1/2 Components of time (p: TBD)
  • C17 standard (ISO/IEC 9899:2018):
  • 7.27.1/2 Components of time (p: 284)
  • C11 standard (ISO/IEC 9899:2011):
  • 7.27.1/2 Components of time (p: 388)
  • C99 standard (ISO/IEC 9899:1999):
  • 7.23.1/2 Components of time (p: 338)
  • C89/C90 standard (ISO/IEC 9899:1990):
  • 4.12.1 Components of time

[edit] See also

returns raw processor clock time since the program is started
(function) [edit]
processor time since era type
(typedef) [edit]
C++ documentation for CLOCKS_PER_SEC