Проект OpenNet: MAN td_ta_enable_stats (3) Библиотечные вызовы (FreeBSD и Linux)

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td_ta_enable_stats (3)

>> td_ta_enable_stats (3) ( Solaris man: Библиотечные вызовы )

NAME

td_ta_enable_stats, td_ta_reset_stats, td_ta_get_stats - collect target process statistics for libc_db

SYNOPSIS

cc [ flag... ] file... -lc_db [ library... ]
#include <proc_service.h>
#include <thread_db.h>

td_err_e td_ta_enable_stats(const td_thragent_t *ta_p, int on_off);

td_err_e_stats td_ta_reset(const td_thragent_t *ta_p);

td_err_e td_ta_get_stats(const td_thragent_t *ta_p, td_ta_stats_t *tstats);

DESCRIPTION

The controlling process can request the collection of certain statistics about a target process. Statistics gathering is disabled by default. Each target process has a td_ta_stats_t structure that contains current values when statistic gathering is enabled.

The td_ta_enable_stats() function turns statistics gathering on or off for the process identified by ta_p, depending on whether or not on_off is non-zero. When statistics gathering is turned on, all statistics are implicitly reset as though td_ta_reset_stats() had been called. Statistics are not reset when statistics gathering is turned off. Except for nthreads and r_concurrency, the values do not change further, but they remain available for inspection by way of td_ta_get_stats().

The td_ta_reset_stats() function resets all counters in the td_ta_stats_t structure to zero for the target process.

The td_ta_get_stats() function returns the structure for the process in tstats.

The td_ta_stats_t structure is defined in <thread_db.h> and contains the following members:

typedef struct { 
  int nthreads;            /* total number of threads in use */
  int r_concurrency;       /* requested concurrency level */
  int nrunnable_num;       /* numerator of avg runnable threads */
  int nrunnable_den;       /* denominator of avg runnable threads */
  int a_concurrency_num;   /* numerator, avg achieved concurrency */
  int a_concurrency_den;   /* denominator, avg achieved concurrency */
  int nlwps_num;           /* numerator, avg number of LWPs in use */
  int nlwps_den;           /* denominator, avg number of LWPs in use */
  int nidle_num;           /* numerator, avg number of idling LWPs */
  int nidle_den;           /* denominator, avg number of idling LWPs */
} td_ta_stats_t;

The nthreads member is the number of threads that are currently part of the target process. The r_concurrency member is the current requested concurrency level, such as would be returned by thr_setconcurrency(3C). The remaining members are averages over time, each expressed as a fraction with an integral numerator and denominator. The nrunnable_num and nrunnable_den members represent the average number of runnable threads. The a_concurrency_num and a_concurrency_den members represent the average achieved concurrency, the number of actually running threads. The a_concurrency_num and a_concurrency_den members are less than or equal to nrunnable_num and nrunnable_den, respectively. The nlwps_num and nlwps_den members represent the average number of lightweight processes (LWPs) participating in this process. They must be greater than or equal to a_concurrency_num and a_concurrency_den, respectively, since every running thread is assigned to an LWP, but there can at times be additional idling LWPs with no thread assigned to them. The nidle_num and nidle_den members represent the average number of idle LWPs.