gcc/libgomp/env.c

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/* Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
Contributed by Richard Henderson <rth@redhat.com>.
This file is part of the GNU OpenMP Library (libgomp).
Libgomp is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* This file defines the OpenMP internal control variables, and arranges
for them to be initialized from environment variables at startup. */
#include "libgomp.h"
#include "libgomp_f.h"
#include <ctype.h>
#include <stdlib.h>
#ifdef STRING_WITH_STRINGS
# include <string.h>
# include <strings.h>
#else
# ifdef HAVE_STRING_H
# include <string.h>
# else
# ifdef HAVE_STRINGS_H
# include <strings.h>
# endif
# endif
#endif
#include <limits.h>
#include <errno.h>
#ifndef HAVE_STRTOULL
# define strtoull(ptr, eptr, base) strtoul (ptr, eptr, base)
#endif
struct gomp_task_icv gomp_global_icv = {
.nthreads_var = 1,
.run_sched_var = GFS_DYNAMIC,
.run_sched_modifier = 1,
.dyn_var = false,
.nest_var = false
};
unsigned short *gomp_cpu_affinity;
size_t gomp_cpu_affinity_len;
unsigned long gomp_max_active_levels_var = INT_MAX;
unsigned long gomp_thread_limit_var = ULONG_MAX;
unsigned long gomp_remaining_threads_count;
#ifndef HAVE_SYNC_BUILTINS
gomp_mutex_t gomp_remaining_threads_lock;
#endif
unsigned long gomp_available_cpus = 1, gomp_managed_threads = 1;
unsigned long long gomp_spin_count_var, gomp_throttled_spin_count_var;
unsigned long *gomp_nthreads_var_list, gomp_nthreads_var_list_len;
/* Parse the OMP_SCHEDULE environment variable. */
static void
parse_schedule (void)
{
char *env, *end;
unsigned long value;
env = getenv ("OMP_SCHEDULE");
if (env == NULL)
return;
while (isspace ((unsigned char) *env))
++env;
if (strncasecmp (env, "static", 6) == 0)
{
gomp_global_icv.run_sched_var = GFS_STATIC;
env += 6;
}
else if (strncasecmp (env, "dynamic", 7) == 0)
{
gomp_global_icv.run_sched_var = GFS_DYNAMIC;
env += 7;
}
else if (strncasecmp (env, "guided", 6) == 0)
{
gomp_global_icv.run_sched_var = GFS_GUIDED;
env += 6;
}
else if (strncasecmp (env, "auto", 4) == 0)
{
gomp_global_icv.run_sched_var = GFS_AUTO;
env += 4;
}
else
goto unknown;
while (isspace ((unsigned char) *env))
++env;
if (*env == '\0')
{
gomp_global_icv.run_sched_modifier
= gomp_global_icv.run_sched_var != GFS_STATIC;
return;
}
if (*env++ != ',')
goto unknown;
while (isspace ((unsigned char) *env))
++env;
if (*env == '\0')
goto invalid;
errno = 0;
value = strtoul (env, &end, 10);
if (errno)
goto invalid;
while (isspace ((unsigned char) *end))
++end;
if (*end != '\0')
goto invalid;
if ((int)value != value)
goto invalid;
if (value == 0 && gomp_global_icv.run_sched_var != GFS_STATIC)
value = 1;
gomp_global_icv.run_sched_modifier = value;
return;
unknown:
gomp_error ("Unknown value for environment variable OMP_SCHEDULE");
return;
invalid:
gomp_error ("Invalid value for chunk size in "
"environment variable OMP_SCHEDULE");
return;
}
/* Parse an unsigned long environment variable. Return true if one was
present and it was successfully parsed. */
static bool
parse_unsigned_long (const char *name, unsigned long *pvalue, bool allow_zero)
{
char *env, *end;
unsigned long value;
env = getenv (name);
if (env == NULL)
return false;
while (isspace ((unsigned char) *env))
++env;
if (*env == '\0')
goto invalid;
errno = 0;
value = strtoul (env, &end, 10);
if (errno || (long) value <= 0 - allow_zero)
goto invalid;
while (isspace ((unsigned char) *end))
++end;
if (*end != '\0')
goto invalid;
*pvalue = value;
return true;
invalid:
gomp_error ("Invalid value for environment variable %s", name);
return false;
}
/* Parse an unsigned long list environment variable. Return true if one was
present and it was successfully parsed. */
static bool
parse_unsigned_long_list (const char *name, unsigned long *p1stvalue,
unsigned long **pvalues,
unsigned long *pnvalues)
{
char *env, *end;
unsigned long value, *values = NULL;
env = getenv (name);
if (env == NULL)
return false;
while (isspace ((unsigned char) *env))
++env;
if (*env == '\0')
goto invalid;
errno = 0;
value = strtoul (env, &end, 10);
if (errno || (long) value <= 0)
goto invalid;
while (isspace ((unsigned char) *end))
++end;
if (*end != '\0')
{
if (*end == ',')
{
unsigned long nvalues = 0, nalloced = 0;
do
{
env = end + 1;
if (nvalues == nalloced)
{
unsigned long *n;
nalloced = nalloced ? nalloced * 2 : 16;
n = realloc (values, nalloced * sizeof (unsigned long));
if (n == NULL)
{
free (values);
gomp_error ("Out of memory while trying to parse"
" environment variable %s", name);
return false;
}
values = n;
if (nvalues == 0)
values[nvalues++] = value;
}
while (isspace ((unsigned char) *env))
++env;
if (*env == '\0')
goto invalid;
errno = 0;
value = strtoul (env, &end, 10);
if (errno || (long) value <= 0)
goto invalid;
values[nvalues++] = value;
while (isspace ((unsigned char) *end))
++end;
if (*end == '\0')
break;
if (*end != ',')
goto invalid;
}
while (1);
*p1stvalue = values[0];
*pvalues = values;
*pnvalues = nvalues;
return true;
}
goto invalid;
}
*p1stvalue = value;
return true;
invalid:
free (values);
gomp_error ("Invalid value for environment variable %s", name);
return false;
}
/* Parse the OMP_STACKSIZE environment varible. Return true if one was
present and it was successfully parsed. */
static bool
parse_stacksize (const char *name, unsigned long *pvalue)
{
char *env, *end;
unsigned long value, shift = 10;
env = getenv (name);
if (env == NULL)
return false;
while (isspace ((unsigned char) *env))
++env;
if (*env == '\0')
goto invalid;
errno = 0;
value = strtoul (env, &end, 10);
if (errno)
goto invalid;
while (isspace ((unsigned char) *end))
++end;
if (*end != '\0')
{
switch (tolower ((unsigned char) *end))
{
case 'b':
shift = 0;
break;
case 'k':
break;
case 'm':
shift = 20;
break;
case 'g':
shift = 30;
break;
default:
goto invalid;
}
++end;
while (isspace ((unsigned char) *end))
++end;
if (*end != '\0')
goto invalid;
}
if (((value << shift) >> shift) != value)
goto invalid;
*pvalue = value << shift;
return true;
invalid:
gomp_error ("Invalid value for environment variable %s", name);
return false;
}
/* Parse the GOMP_SPINCOUNT environment varible. Return true if one was
present and it was successfully parsed. */
static bool
parse_spincount (const char *name, unsigned long long *pvalue)
{
char *env, *end;
unsigned long long value, mult = 1;
env = getenv (name);
if (env == NULL)
return false;
while (isspace ((unsigned char) *env))
++env;
if (*env == '\0')
goto invalid;
if (strncasecmp (env, "infinite", 8) == 0
|| strncasecmp (env, "infinity", 8) == 0)
{
value = ~0ULL;
end = env + 8;
goto check_tail;
}
errno = 0;
value = strtoull (env, &end, 10);
if (errno)
goto invalid;
while (isspace ((unsigned char) *end))
++end;
if (*end != '\0')
{
switch (tolower ((unsigned char) *end))
{
case 'k':
mult = 1000LL;
break;
case 'm':
mult = 1000LL * 1000LL;
break;
case 'g':
mult = 1000LL * 1000LL * 1000LL;
break;
case 't':
mult = 1000LL * 1000LL * 1000LL * 1000LL;
break;
default:
goto invalid;
}
++end;
check_tail:
while (isspace ((unsigned char) *end))
++end;
if (*end != '\0')
goto invalid;
}
if (value > ~0ULL / mult)
value = ~0ULL;
else
value *= mult;
*pvalue = value;
return true;
invalid:
gomp_error ("Invalid value for environment variable %s", name);
return false;
}
/* Parse a boolean value for environment variable NAME and store the
result in VALUE. */
static void
parse_boolean (const char *name, bool *value)
{
const char *env;
env = getenv (name);
if (env == NULL)
return;
while (isspace ((unsigned char) *env))
++env;
if (strncasecmp (env, "true", 4) == 0)
{
*value = true;
env += 4;
}
else if (strncasecmp (env, "false", 5) == 0)
{
*value = false;
env += 5;
}
else
env = "X";
while (isspace ((unsigned char) *env))
++env;
if (*env != '\0')
gomp_error ("Invalid value for environment variable %s", name);
}
/* Parse the OMP_WAIT_POLICY environment variable and store the
result in gomp_active_wait_policy. */
static int
parse_wait_policy (void)
{
const char *env;
int ret = -1;
env = getenv ("OMP_WAIT_POLICY");
if (env == NULL)
return -1;
while (isspace ((unsigned char) *env))
++env;
if (strncasecmp (env, "active", 6) == 0)
{
ret = 1;
env += 6;
}
else if (strncasecmp (env, "passive", 7) == 0)
{
ret = 0;
env += 7;
}
else
env = "X";
while (isspace ((unsigned char) *env))
++env;
if (*env == '\0')
return ret;
gomp_error ("Invalid value for environment variable OMP_WAIT_POLICY");
return -1;
}
/* Parse the GOMP_CPU_AFFINITY environment varible. Return true if one was
present and it was successfully parsed. */
static bool
parse_affinity (void)
{
char *env, *end;
unsigned long cpu_beg, cpu_end, cpu_stride;
unsigned short *cpus = NULL;
size_t allocated = 0, used = 0, needed;
env = getenv ("GOMP_CPU_AFFINITY");
if (env == NULL)
return false;
do
{
while (*env == ' ' || *env == '\t')
env++;
cpu_beg = strtoul (env, &end, 0);
cpu_end = cpu_beg;
cpu_stride = 1;
if (env == end || cpu_beg >= 65536)
goto invalid;
env = end;
if (*env == '-')
{
cpu_end = strtoul (++env, &end, 0);
if (env == end || cpu_end >= 65536 || cpu_end < cpu_beg)
goto invalid;
env = end;
if (*env == ':')
{
cpu_stride = strtoul (++env, &end, 0);
if (env == end || cpu_stride == 0 || cpu_stride >= 65536)
goto invalid;
env = end;
}
}
needed = (cpu_end - cpu_beg) / cpu_stride + 1;
if (used + needed >= allocated)
{
unsigned short *new_cpus;
if (allocated < 64)
allocated = 64;
if (allocated > needed)
allocated <<= 1;
else
allocated += 2 * needed;
new_cpus = realloc (cpus, allocated * sizeof (unsigned short));
if (new_cpus == NULL)
{
free (cpus);
gomp_error ("not enough memory to store GOMP_CPU_AFFINITY list");
return false;
}
cpus = new_cpus;
}
while (needed--)
{
cpus[used++] = cpu_beg;
cpu_beg += cpu_stride;
}
while (*env == ' ' || *env == '\t')
env++;
if (*env == ',')
env++;
else if (*env == '\0')
break;
}
while (1);
gomp_cpu_affinity = cpus;
gomp_cpu_affinity_len = used;
return true;
invalid:
gomp_error ("Invalid value for enviroment variable GOMP_CPU_AFFINITY");
return false;
}
static void __attribute__((constructor))
initialize_env (void)
{
unsigned long stacksize;
int wait_policy;
bool bind_var = false;
/* Do a compile time check that mkomp_h.pl did good job. */
omp_check_defines ();
parse_schedule ();
parse_boolean ("OMP_DYNAMIC", &gomp_global_icv.dyn_var);
parse_boolean ("OMP_NESTED", &gomp_global_icv.nest_var);
parse_boolean ("OMP_PROC_BIND", &bind_var);
parse_unsigned_long ("OMP_MAX_ACTIVE_LEVELS", &gomp_max_active_levels_var,
true);
parse_unsigned_long ("OMP_THREAD_LIMIT", &gomp_thread_limit_var, false);
if (gomp_thread_limit_var != ULONG_MAX)
gomp_remaining_threads_count = gomp_thread_limit_var - 1;
#ifndef HAVE_SYNC_BUILTINS
gomp_mutex_init (&gomp_remaining_threads_lock);
#endif
gomp_init_num_threads ();
gomp_available_cpus = gomp_global_icv.nthreads_var;
if (!parse_unsigned_long_list ("OMP_NUM_THREADS",
&gomp_global_icv.nthreads_var,
&gomp_nthreads_var_list,
&gomp_nthreads_var_list_len))
gomp_global_icv.nthreads_var = gomp_available_cpus;
if (parse_affinity () || bind_var)
gomp_init_affinity ();
wait_policy = parse_wait_policy ();
if (!parse_spincount ("GOMP_SPINCOUNT", &gomp_spin_count_var))
{
/* Using a rough estimation of 100000 spins per msec,
use 5 min blocking for OMP_WAIT_POLICY=active,
3 msec blocking when OMP_WAIT_POLICY is not specificed
and 0 when OMP_WAIT_POLICY=passive.
Depending on the CPU speed, this can be e.g. 5 times longer
or 5 times shorter. */
if (wait_policy > 0)
gomp_spin_count_var = 30000000000LL;
else if (wait_policy < 0)
gomp_spin_count_var = 300000LL;
}
/* gomp_throttled_spin_count_var is used when there are more libgomp
managed threads than available CPUs. Use very short spinning. */
if (wait_policy > 0)
gomp_throttled_spin_count_var = 1000LL;
else if (wait_policy < 0)
gomp_throttled_spin_count_var = 100LL;
if (gomp_throttled_spin_count_var > gomp_spin_count_var)
gomp_throttled_spin_count_var = gomp_spin_count_var;
/* Not strictly environment related, but ordering constructors is tricky. */
pthread_attr_init (&gomp_thread_attr);
pthread_attr_setdetachstate (&gomp_thread_attr, PTHREAD_CREATE_DETACHED);
if (parse_stacksize ("OMP_STACKSIZE", &stacksize)
|| parse_stacksize ("GOMP_STACKSIZE", &stacksize))
{
int err;
err = pthread_attr_setstacksize (&gomp_thread_attr, stacksize);
#ifdef PTHREAD_STACK_MIN
if (err == EINVAL)
{
if (stacksize < PTHREAD_STACK_MIN)
gomp_error ("Stack size less than minimum of %luk",
PTHREAD_STACK_MIN / 1024ul
+ (PTHREAD_STACK_MIN % 1024 != 0));
else
gomp_error ("Stack size larger than system limit");
}
else
#endif
if (err != 0)
gomp_error ("Stack size change failed: %s", strerror (err));
}
}
/* The public OpenMP API routines that access these variables. */
void
omp_set_num_threads (int n)
{
struct gomp_task_icv *icv = gomp_icv (true);
icv->nthreads_var = (n > 0 ? n : 1);
}
void
omp_set_dynamic (int val)
{
struct gomp_task_icv *icv = gomp_icv (true);
icv->dyn_var = val;
}
int
omp_get_dynamic (void)
{
struct gomp_task_icv *icv = gomp_icv (false);
return icv->dyn_var;
}
void
omp_set_nested (int val)
{
struct gomp_task_icv *icv = gomp_icv (true);
icv->nest_var = val;
}
int
omp_get_nested (void)
{
struct gomp_task_icv *icv = gomp_icv (false);
return icv->nest_var;
}
void
omp_set_schedule (omp_sched_t kind, int modifier)
{
struct gomp_task_icv *icv = gomp_icv (true);
switch (kind)
{
case omp_sched_static:
if (modifier < 1)
modifier = 0;
icv->run_sched_modifier = modifier;
break;
case omp_sched_dynamic:
case omp_sched_guided:
if (modifier < 1)
modifier = 1;
icv->run_sched_modifier = modifier;
break;
case omp_sched_auto:
break;
default:
return;
}
icv->run_sched_var = kind;
}
void
omp_get_schedule (omp_sched_t *kind, int *modifier)
{
struct gomp_task_icv *icv = gomp_icv (false);
*kind = icv->run_sched_var;
*modifier = icv->run_sched_modifier;
}
int
omp_get_max_threads (void)
{
struct gomp_task_icv *icv = gomp_icv (false);
return icv->nthreads_var;
}
int
omp_get_thread_limit (void)
{
return gomp_thread_limit_var > INT_MAX ? INT_MAX : gomp_thread_limit_var;
}
void
omp_set_max_active_levels (int max_levels)
{
if (max_levels >= 0)
gomp_max_active_levels_var = max_levels;
}
int
omp_get_max_active_levels (void)
{
return gomp_max_active_levels_var;
}
ialias (omp_set_dynamic)
ialias (omp_set_nested)
ialias (omp_set_num_threads)
ialias (omp_get_dynamic)
ialias (omp_get_nested)
ialias (omp_set_schedule)
ialias (omp_get_schedule)
ialias (omp_get_max_threads)
ialias (omp_get_thread_limit)
ialias (omp_set_max_active_levels)
ialias (omp_get_max_active_levels)