/* 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, see <http://www.gnu.org/licenses/>. */ #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 ( 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, LLL_PRIVATE); /* 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, LLL_PRIVATE); return ret; }