glibc/nptl/pthread_getattr_np.c

180 lines
4.7 KiB
C

/* Copyright (C) 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include "pthreadP.h"
#include <lowlevellock.h>
#include <ldsodefs.h>
int
pthread_getattr_np (thread_id, attr)
pthread_t thread_id;
pthread_attr_t *attr;
{
struct pthread *thread = (struct pthread *) thread_id;
struct pthread_attr *iattr = (struct pthread_attr *) attr;
int ret = 0;
lll_lock (thread->lock);
/* The thread library is responsible for keeping the values in the
thread desriptor up-to-date in case the user changes them. */
memcpy (&iattr->schedparam, &thread->schedparam,
sizeof (struct sched_param));
iattr->schedpolicy = thread->schedpolicy;
/* Clear the flags work. */
iattr->flags = thread->flags;
/* The thread might be detached by now. */
if (IS_DETACHED (thread))
iattr->flags |= ATTR_FLAG_DETACHSTATE;
/* This is the guardsize after adjusting it. */
iattr->guardsize = thread->reported_guardsize;
/* The sizes are subject to alignment. */
if (__builtin_expect (thread->stackblock != NULL, 1))
{
iattr->stacksize = thread->stackblock_size;
iattr->stackaddr = (char *) thread->stackblock + iattr->stacksize;
}
else
{
/* No stack information available. This must be for the initial
thread. Get the info in some magical way. */
assert (abs (thread->pid) == thread->tid);
/* Stack size limit. */
struct rlimit rl;
/* The safest way to get the top of the stack is to read
/proc/self/maps and locate the line into which
__libc_stack_end falls. */
FILE *fp = fopen ("/proc/self/maps", "rc");
if (fp == NULL)
ret = errno;
/* We need the limit of the stack in any case. */
else
{
if (getrlimit (RLIMIT_STACK, &rl) != 0)
ret = errno;
else
{
/* We need no locking. */
__fsetlocking (fp, FSETLOCKING_BYCALLER);
/* Until we found an entry (which should always be the case)
mark the result as a failure. */
ret = ENOENT;
char *line = NULL;
size_t linelen = 0;
uintptr_t last_to = 0;
while (! feof_unlocked (fp))
{
if (__getdelim (&line, &linelen, '\n', fp) <= 0)
break;
uintptr_t from;
uintptr_t to;
if (sscanf (line, "%" SCNxPTR "-%" SCNxPTR, &from, &to) != 2)
continue;
if (from <= (uintptr_t) __libc_stack_end
&& (uintptr_t) __libc_stack_end < to)
{
/* Found the entry. Now we have the info we need. */
iattr->stacksize = rl.rlim_cur;
iattr->stackaddr = (void *) to;
/* The limit might be too high. */
if ((size_t) iattr->stacksize
> (size_t) iattr->stackaddr - last_to)
iattr->stacksize = (size_t) iattr->stackaddr - last_to;
/* We succeed and no need to look further. */
ret = 0;
break;
}
last_to = to;
}
free (line);
}
fclose (fp);
}
}
iattr->flags |= ATTR_FLAG_STACKADDR;
if (ret == 0)
{
size_t size = 16;
cpu_set_t *cpuset = NULL;
do
{
size <<= 1;
void *newp = realloc (cpuset, size);
if (newp == NULL)
{
ret = ENOMEM;
break;
}
cpuset = (cpu_set_t *) newp;
ret = __pthread_getaffinity_np (thread_id, size, cpuset);
}
/* Pick some ridiculous upper limit. Is 8 million CPUs enough? */
while (ret == EINVAL && size < 1024 * 1024);
if (ret == 0)
{
iattr->cpuset = cpuset;
iattr->cpusetsize = size;
}
else
{
free (cpuset);
if (ret == ENOSYS)
{
/* There is no such functionality. */
ret = 0;
iattr->cpuset = NULL;
iattr->cpusetsize = 0;
}
}
}
lll_unlock (thread->lock);
return ret;
}