-
-for ac_func in crypt erand48 getopt getrusage inet_aton random rint srandom strdup strerror strlcat strlcpy strtol strtoul
+for ac_func in crypt getopt getrusage inet_aton random rint srandom strdup strerror strlcat strlcpy strtol strtoul
do
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
{ $as_echo "$as_me:$LINENO: checking for $ac_func" >&5
fi
-# Cygwin's erand48() is broken (always returns zero) in some releases,
-# so force use of ours.
-if test "$PORTNAME" = "cygwin"; then
- case " $LIBOBJS " in
- *" erand48.$ac_objext "* ) ;;
- *) LIBOBJS="$LIBOBJS erand48.$ac_objext"
- ;;
-esac
-
-fi
-
# Win32 support
if test "$PORTNAME" = "win32"; then
pgac_save_LIBS="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
-AC_REPLACE_FUNCS([crypt erand48 getopt getrusage inet_aton random rint srandom strdup strerror strlcat strlcpy strtol strtoul])
+AC_REPLACE_FUNCS([crypt getopt getrusage inet_aton random rint srandom strdup strerror strlcat strlcpy strtol strtoul])
case $host_os in
AC_LIBOBJ(getopt_long)
fi
-# Cygwin's erand48() is broken (always returns zero) in some releases,
-# so force use of ours.
-if test "$PORTNAME" = "cygwin"; then
- AC_LIBOBJ(erand48)
-fi
-
# Win32 support
if test "$PORTNAME" = "win32"; then
AC_REPLACE_FUNCS(gettimeofday)
instr_time start_time; /* thread start time */
instr_time *exec_elapsed; /* time spent executing cmds (per Command) */
int *exec_count; /* number of cmd executions (per Command) */
+ unsigned short random_state[3]; /* separate randomness for each thread */
} TState;
#define INVALID_THREAD ((pthread_t) 0)
/* random number generator: uniform distribution from min to max inclusive */
static int
-getrand(int min, int max)
+getrand(TState *thread, int min, int max)
{
/*
* Odd coding is so that min and max have approximately the same chance of
* being selected as do numbers between them.
+ *
+ * pg_erand48() is thread-safe and concurrent, which is why we use it
+ * rather than random(), which in glibc is non-reentrant, and therefore
+ * protected by a mutex, and therefore a bottleneck on machines with many
+ * CPUs.
*/
- return min + (int) (((max - min + 1) * (double) random()) / (MAX_RANDOM_VALUE + 1.0));
+ return min + (int) ((max - min + 1) * pg_erand48(thread->random_state));
}
/* call PQexec() and exit() on failure */
if (commands[st->state] == NULL)
{
st->state = 0;
- st->use_file = getrand(0, num_files - 1);
+ st->use_file = getrand(thread, 0, num_files - 1);
commands = sql_files[st->use_file];
}
}
}
#ifdef DEBUG
- printf("min: %d max: %d random: %d\n", min, max, getrand(min, max));
+ printf("min: %d max: %d random: %d\n", min, max, getrand(thread, min, max));
#endif
- snprintf(res, sizeof(res), "%d", getrand(min, max));
+ snprintf(res, sizeof(res), "%d", getrand(thread, min, max));
if (!putVariable(st, argv[0], argv[1], res))
{
thread->tid = i;
thread->state = &state[nclients / nthreads * i];
thread->nstate = nclients / nthreads;
+ thread->random_state[0] = random();
+ thread->random_state[1] = random();
+ thread->random_state[2] = random();
if (is_latencies)
{
Command **commands = sql_files[st->use_file];
int prev_ecnt = st->ecnt;
- st->use_file = getrand(0, num_files - 1);
+ st->use_file = getrand(thread, 0, num_files - 1);
if (!doCustom(thread, st, &result->conn_time, logfile))
remains--; /* I've aborted */
if (duration > 0)
setalarm(duration);
- /*
- * Set a different random seed in each child process. Otherwise they all
- * inherit the parent's state and generate the same "random" sequence. (In
- * the threaded case, the different threads will obtain subsets of the
- * output of a single random() sequence, which should be okay for our
- * purposes.)
- */
- INSTR_TIME_SET_CURRENT(start_time);
- srandom(((unsigned int) INSTR_TIME_GET_MICROSEC(start_time)) +
- ((unsigned int) getpid()));
-
ret = start_routine(arg);
write(th->pipes[1], ret, sizeof(TResult));
close(th->pipes[1]);
{
GeqoPrivateData *private = (GeqoPrivateData *) root->join_search_private;
- return erand48(private->random_state);
+ return pg_erand48(private->random_state);
}
* Ensure we have selected different genes, except if pool size is only
* one, when we can't.
*
- * This code has been observed to hang up in an infinite loop when the
- * platform's implementation of erand48() is broken. We consider that a
- * feature: it lets you know you'd better fix the random-number generator.
+ * This code was observed to hang up in an infinite loop when the
+ * platform's implementation of erand48() was broken. We now always
+ * use our own version.
*/
if (pool->size > 1)
{
typedef struct
{
List *initial_rels; /* the base relations we are joining */
- unsigned short random_state[3]; /* state for erand48() */
+ unsigned short random_state[3]; /* state for pg_erand48() */
} GeqoPrivateData;
/* Define to 1 if you have the <editline/readline.h> header file. */
#undef HAVE_EDITLINE_READLINE_H
-/* Define to 1 if you have the `erand48' function. */
-#undef HAVE_ERAND48
-
/* Define to 1 if you have the `ERR_set_mark' function. */
#undef HAVE_ERR_SET_MARK
#endif
#endif
-#ifndef HAVE_ERAND48
-/* we assume all of these are present or missing together */
-extern double erand48(unsigned short xseed[3]);
-extern long lrand48(void);
-extern void srand48(long seed);
-#endif
+extern double pg_erand48(unsigned short xseed[3]);
+extern long pg_lrand48(void);
+extern void pg_srand48(long seed);
#ifndef HAVE_FSEEKO
#define fseeko(a, b, c) fseek(a, b, c)
override CPPFLAGS := -I$(top_builddir)/src/port -DFRONTEND $(CPPFLAGS)
LIBS += $(PTHREAD_LIBS)
-OBJS = $(LIBOBJS) chklocale.o dirmod.o exec.o inet_net_ntop.o noblock.o \
- path.o pgcheckdir.o pgmkdirp.o pgsleep.o pgstrcasecmp.o \
+OBJS = $(LIBOBJS) chklocale.o dirmod.o erand48.o exec.o inet_net_ntop.o \
+ noblock.o path.o pgcheckdir.o pgmkdirp.o pgsleep.o pgstrcasecmp.o \
qsort.o qsort_arg.o sprompt.o thread.o
# foo_srv.o and foo.o are both built from foo.c, but only foo.o has -DFRONTEND
*
* erand48.c
*
- * This file supplies versions of erand48(), lrand48(), and srand48()
- * for machines that lack them. (These are all the members of the drand48
- * family that Postgres currently requires. We name the file after erand48
- * because that is the one that configure tests for.)
+ * This file supplies pg_erand48(), pg_lrand48(), and pg_srand48(), which
+ * are just like erand48(), lrand48(), and srand48() except that we use
+ * our own implementation rather than the one provided by the operating
+ * system. We used to test for an operating system version rather than
+ * unconditionally using our own, but (1) some versions of Cygwin have a
+ * buggy erand48() that always returns zero and (2) as of 2011, glibc's
+ * erand48() is strangely coded to be almost-but-not-quite thread-safe,
+ * which doesn't matter for the backend but is important for pgbench.
*
*
* Copyright (c) 1993 Martin Birgmeier
double
-erand48(unsigned short xseed[3])
+pg_erand48(unsigned short xseed[3])
{
_dorand48(xseed);
return ldexp((double) xseed[0], -48) +
}
long
-lrand48(void)
+pg_lrand48(void)
{
_dorand48(_rand48_seed);
return ((long) _rand48_seed[2] << 15) + ((long) _rand48_seed[1] >> 1);
}
void
-srand48(long seed)
+pg_srand48(long seed)
{
_rand48_seed[0] = RAND48_SEED_0;
_rand48_seed[1] = (unsigned short) seed;
long
random()
{
- return lrand48();
+ return pg_lrand48();
}
void
srandom(unsigned int seed)
{
- srand48((long int) seed);
+ pg_srand48((long int) seed);
}
projects / postgresql / commitdiff