diff options
Diffstat (limited to 'src/util')
| -rw-r--r-- | src/util/support/ChangeLog | 12 | ||||
| -rw-r--r-- | src/util/support/Makefile.in | 1 | ||||
| -rw-r--r-- | src/util/support/libkrb5support.exports | 3 | ||||
| -rw-r--r-- | src/util/support/threads.c | 109 |
4 files changed, 125 insertions, 0 deletions
diff --git a/src/util/support/ChangeLog b/src/util/support/ChangeLog index 2c2a3252d..a49aa78cb 100644 --- a/src/util/support/ChangeLog +++ b/src/util/support/ChangeLog @@ -1,3 +1,15 @@ +2004-12-06 Ken Raeburn <raeburn@mit.edu> + + * threads.c [DEBUG_THREADS_STATS]: Include stdio.h. + (stats_logfile) [DEBUG_THREADS_STATS]: New variable. + (krb5int_thread_support_init) [DEBUG_THREADS_STATS]: Set it to + point to a file on /dev/tty or stderr. + (krb5int_thread_support_fini) [DEBUG_THREADS_STATS]: Flush it. + (k5_mutex_lock_update_stats, krb5int_mutex_unlock_update_stats, + get_stddev, krb5int_mutex_report_stats) [DEBUG_THREADS_STATS]: New + functions. + * libkrb5support.exports: Add krb5int_mutex_*_stats. + 2004-11-19 Ken Raeburn <raeburn@mit.edu> * fake-addrinfo.c (HAVE_GETADDRINFO, HAVE_GETNAMEINFO)[_WIN32]: diff --git a/src/util/support/Makefile.in b/src/util/support/Makefile.in index e17b46a6e..61188db4e 100644 --- a/src/util/support/Makefile.in +++ b/src/util/support/Makefile.in @@ -43,6 +43,7 @@ SRCS=\ $(srcdir)/init-addrinfo.c \ $(srcdir)/fake-addrinfo.c SHLIB_EXPDEPS = +# Add -lm if dumping thread stats, for sqrt. SHLIB_EXPLIBS= $(LIBS) SHLIB_DIRS= SHLIB_RDIRS=$(KRB5_LIBDIR) diff --git a/src/util/support/libkrb5support.exports b/src/util/support/libkrb5support.exports index 5e8208306..9a415acf7 100644 --- a/src/util/support/libkrb5support.exports +++ b/src/util/support/libkrb5support.exports @@ -2,6 +2,9 @@ krb5int_key_register krb5int_key_delete krb5int_getspecific krb5int_setspecific +krb5int_mutex_lock_update_stats +krb5int_mutex_unlock_update_stats +krb5int_mutex_report_stats krb5int_getaddrinfo krb5int_freeaddrinfo krb5int_gai_strerror diff --git a/src/util/support/threads.c b/src/util/support/threads.c index 7b061fdd7..c78751bd0 100644 --- a/src/util/support/threads.c +++ b/src/util/support/threads.c @@ -324,10 +324,22 @@ int krb5int_call_thread_support_init (void) #include "cache-addrinfo.h" +#ifdef DEBUG_THREADS_STATS +#include <stdio.h> +static FILE *stats_logfile; +#endif + int krb5int_thread_support_init (void) { int err; +#ifdef DEBUG_THREADS_STATS + /* stats_logfile = stderr; */ + stats_logfile = fopen("/dev/tty", "w+"); + if (stats_logfile == NULL) + stats_logfile = stderr; +#endif + #ifndef ENABLE_THREADS /* Nothing to do for TLS initialization. */ @@ -384,6 +396,103 @@ void krb5int_thread_support_fini (void) #endif +#ifdef DEBUG_THREADS_STATS + fflush(stats_logfile); + /* XXX Should close if not stderr, in case unloading library but + not exiting. */ +#endif + krb5int_fini_fac(); } +#ifdef DEBUG_THREADS_STATS +void +k5_mutex_lock_update_stats(k5_debug_mutex_stats *m, + k5_mutex_stats_tmp startwait) +{ + k5_debug_time_t now; + k5_debug_timediff_t tdiff, tdiff2; + + now = get_current_time(); + (void) krb5int_call_thread_support_init(); + m->count++; + m->time_acquired = now; + tdiff = timediff(now, startwait); + tdiff2 = tdiff * tdiff; + if (m->count == 1 || m->lockwait.valmin > tdiff) + m->lockwait.valmin = tdiff; + if (m->count == 1 || m->lockwait.valmax < tdiff) + m->lockwait.valmax = tdiff; + m->lockwait.valsum += tdiff; + m->lockwait.valsqsum += tdiff2; +} + +void +krb5int_mutex_unlock_update_stats(k5_debug_mutex_stats *m) +{ + k5_debug_time_t now = get_current_time(); + k5_debug_timediff_t tdiff, tdiff2; + tdiff = timediff(now, m->time_acquired); + tdiff2 = tdiff * tdiff; + if (m->count == 1 || m->lockheld.valmin > tdiff) + m->lockheld.valmin = tdiff; + if (m->count == 1 || m->lockheld.valmax < tdiff) + m->lockheld.valmax = tdiff; + m->lockheld.valsum += tdiff; + m->lockheld.valsqsum += tdiff2; +} + +#include <math.h> +static inline double +get_stddev(struct k5_timediff_stats sp, int count) +{ + long double mu, mu_squared, rho_squared; + mu = (long double) sp.valsum / count; + mu_squared = mu * mu; + /* SUM((x_i - mu)^2) + = SUM(x_i^2 - 2*mu*x_i + mu^2) + = SUM(x_i^2) - 2*mu*SUM(x_i) + N*mu^2 + + Standard deviation rho^2 = SUM(...) / N. */ + rho_squared = (sp.valsqsum - 2 * mu * sp.valsum + count * mu_squared) / count; + return sqrt(rho_squared); +} + +void +krb5int_mutex_report_stats(k5_mutex_t *m) +{ + char *p; + + /* Tweak this to only record data on "interesting" locks. */ + if (m->stats.count < 10) + return; + if (m->stats.lockwait.valsum < 10 * m->stats.count) + return; + + p = strrchr(m->loc_created.filename, '/'); + if (p == NULL) + p = m->loc_created.filename; + else + p++; + fprintf(stats_logfile, "mutex @%p: created at line %d of %s\n", + (void *) m, m->loc_created.lineno, p); + if (m->stats.count == 0) + fprintf(stats_logfile, "\tnever locked\n"); + else { + double sd_wait, sd_hold; + sd_wait = get_stddev(m->stats.lockwait, m->stats.count); + sd_hold = get_stddev(m->stats.lockheld, m->stats.count); + fprintf(stats_logfile, + "\tlocked %d time%s; wait %lu/%f/%lu/%fus, hold %lu/%f/%lu/%fus\n", + m->stats.count, m->stats.count == 1 ? "" : "s", + (unsigned long) m->stats.lockwait.valmin, + (double) m->stats.lockwait.valsum / m->stats.count, + (unsigned long) m->stats.lockwait.valmax, + sd_wait, + (unsigned long) m->stats.lockheld.valmin, + (double) m->stats.lockheld.valsum / m->stats.count, + (unsigned long) m->stats.lockheld.valmax, + sd_hold); + } +} +#endif |