NAME [Toc] [Back]
profil - execution time profile
SYNOPSIS [Toc] [Back]
unsigned short int *buff,
unsigned int scale
DESCRIPTION [Toc] [Back]
profil() controls profiling, by which the system maintains estimates
of the amount of time the calling program spends executing at various
places in its address space.
The buff argument must point to an area of memory whose length (in
bytes) is given by bufsiz. When profiling is on, the process's
program counter (pc) is examined each clock tick (CLK_TCK times per
second), offset is subtracted from the pc value, and the result is
multiplied by scale. If the resulting number corresponds to an
element inside the array of unsigned short ints to which buff points,
that element is incremented.
The number of samples per second for a given implementation is given
by CLK_TCK, which is defined in <time.h>.
The scale is interpreted as an unsigned, sixteen bit, fixed-point
fraction with binary point at the left: 0177777 (octal) gives a oneto-one
mapping of pc's to words in buff; 077777 (octal) maps each pair
of instruction words together. 02(octal) maps all instructions onto
the beginning of buff (producing a non-interrupting core clock).
Profiling is turned off by giving a scale of 0 or 1. It is rendered
ineffective by giving a bufsiz of 0. Profiling is turned off when one
of the exec() functions is executed, but remains on in child and
parent both after a fork(). Profiling is turned off if an update in
buff would cause a memory fault.
RETURN VALUE [Toc] [Back]
No value is returned.
SEE ALSO [Toc] [Back]
STANDARDS CONFORMANCE [Toc] [Back]
profil(): SVID2, SVID3, XPG2
Hewlett-Packard Company - 1 - HP-UX 11i Version 2: August 2003 [ Back ]