C++ rlimit函数代码示例

int test(char *URL)
{
  CURLcode res;
  CURL *curl;

  if(!strcmp(URL, "check")) {
    /* used by the test script to ask if we can run this test or not */
    if(rlimit(FALSE)) {
      fprintf(stdout, "rlimit problem: %s\n", msgbuff);
      return 1;
    }
    return 0; /* sure, run this! */
  }

  if(rlimit(TRUE)) {
    /* failure */
    return TEST_ERR_MAJOR_BAD;
  }

  /* run the test with the bunch of open file descriptors
     and close them all once the test is over */

  if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
    fprintf(stderr, "curl_global_init() failed\n");
    close_file_descriptors();
    return TEST_ERR_MAJOR_BAD;
  }

  curl = curl_easy_init();
  if(!curl) {
    fprintf(stderr, "curl_easy_init() failed\n");
    close_file_descriptors();
    curl_global_cleanup();
    return TEST_ERR_MAJOR_BAD;
  }

  test_setopt(curl, CURLOPT_URL, URL);
  test_setopt(curl, CURLOPT_HEADER, 1L);

  res = curl_easy_perform(curl);

test_cleanup:

  close_file_descriptors();
  curl_easy_cleanup(curl);
  curl_global_cleanup();

  return (int)res;
}

/**
 * inode_newsize_ok - may this inode be truncated to a given size
 * @inode:	the inode to be truncated
 * @offset:	the new size to assign to the inode
 * @Returns:	0 on success, -ve errno on failure
 *
 * inode_newsize_ok must be called with i_mutex held.
 *
 * inode_newsize_ok will check filesystem limits and ulimits to check that the
 * new inode size is within limits. inode_newsize_ok will also send SIGXFSZ
 * when necessary. Caller must not proceed with inode size change if failure is
 * returned. @inode must be a file (not directory), with appropriate
 * permissions to allow truncate (inode_newsize_ok does NOT check these
 * conditions).
 */
int inode_newsize_ok(const struct inode *inode, loff_t offset)
{
	if (inode->i_size < offset) {
		unsigned long limit;

		limit = rlimit(RLIMIT_FSIZE);
		if (limit != RLIM_INFINITY && offset > limit)
			goto out_sig;
		if (offset > inode->i_sb->s_maxbytes)
			goto out_big;
	} else {
		/*
		 * truncation of in-use swapfiles is disallowed - it would
		 * cause subsequent swapout to scribble on the now-freed
		 * blocks.
		 */
		if (IS_SWAPFILE(inode))
			return -ETXTBSY;
	}

	return 0;
out_sig:
	send_sig(SIGXFSZ, current, 0);
out_big:
	return -EFBIG;
}

int inode_newsize_ok(const struct inode *inode, loff_t offset)
{
	if (inode->i_size < offset) {
		unsigned long limit;

		limit = rlimit(RLIMIT_FSIZE);
		if (limit != RLIM_INFINITY && offset > limit)
			goto out_sig;
		if (offset > inode->i_sb->s_maxbytes)
			goto out_big;
	} else {
		/*
                                                            
                                                          
            
   */
		if (IS_SWAPFILE(inode))
			return -ETXTBSY;
	}

	return 0;
out_sig:
	send_sig(SIGXFSZ, current, 0);
out_big:
	return -EFBIG;
}

void arch_pick_mmap_layout(struct mm_struct *mm)
{
	unsigned long random_factor = mmap_rnd();
	unsigned long gap;

	/*
	 * Fall back to the standard layout if the personality
	 * bit is set, or if the expected stack growth is unlimited:
	 */
	gap = rlimit(RLIMIT_STACK);
	if (!test_thread_flag(TIF_32BIT) ||
	    (current->personality & ADDR_COMPAT_LAYOUT) ||
	    gap == RLIM_INFINITY ||
	    sysctl_legacy_va_layout) {
		mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
		mm->get_unmapped_area = arch_get_unmapped_area;
		mm->unmap_area = arch_unmap_area;
	} else {
		/* We know it's 32-bit */
		unsigned long task_size = STACK_TOP32;

		if (gap < 128 * 1024 * 1024)
			gap = 128 * 1024 * 1024;
		if (gap > (task_size / 6 * 5))
			gap = (task_size / 6 * 5);

		mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
		mm->get_unmapped_area = arch_get_unmapped_area_topdown;
		mm->unmap_area = arch_unmap_area_topdown;
	}
}

static inline int mmap_is_legacy(void)
{
	if (current->personality & ADDR_COMPAT_LAYOUT)
		return 1;
	if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
		return 1;
	return sysctl_legacy_va_layout;
}

void
memobj_init(void)
{
	unsigned long min_bytes, max_bytes;
	unsigned long mem_bytes = GetPhysicalPages() * 0.90 * TILT_PAGESIZE;
	unsigned long cache_bytes = GetBcacheSize() * 2;

	min_bytes = 2048 * 1024;
	min_bytes = Max(min_bytes, cache_bytes);

	max_bytes = (unsigned long)INT_MAX;
	max_bytes = Min(max_bytes, mem_bytes);
	max_bytes = Min(max_bytes, rlimit(RLIMIT_DATA));
	max_bytes = Min(max_bytes, rlimit(RLIMIT_AS));
#ifdef RLIMIT_VMEM
	max_bytes = Min(max_bytes, rlimit(RLIMIT_VMEM));
#endif

	init_int(&MinHeapByte, min_bytes);
	init_int(&MaxHeapByte, 0.40 * max_bytes);
	assert(MinHeapByte <= MaxHeapByte);

#ifdef sparc
	assert(TILT_PAGESIZE == sysconf(_SC_PAGESIZE));
#else
	assert(TILT_PAGESIZE == sysconf(_SC_PAGE_SIZE));
#endif
	StackInitialize();
	HeapInitialize();
	GuardStackletSize = TILT_PAGESIZE / kilobyte;
	stackletOffset = (GuardStackletSize + MLStackletSize + CStackletSize) *
		kilobyte;
	primaryStackletOffset = 0;
	replicaStackletOffset = stackletOffset;
	/* So we don't pay mmap for first thread - general case? XXXX */
	{ 
		int i;
		Stacklet_t *temp[5];
		for (i=0; i<5; i++)
			temp[i] = Stacklet_Alloc(NULL);
		for (i=0; i<5; i++)
			Stacklet_Dealloc(temp[i]);
	}
}

static inline unsigned long mmap_base(void)
{
	unsigned long gap = rlimit(RLIMIT_STACK);

	if (gap < MIN_GAP)
		gap = MIN_GAP;
	else if (gap > MAX_GAP)
		gap = MAX_GAP;

	return PAGE_ALIGN(TASK_SIZE - gap - mmap_rnd());
}

static unsigned long mmap_base(unsigned long rnd)
{
	unsigned long gap = rlimit(RLIMIT_STACK);

	if (gap < MIN_GAP)
		gap = MIN_GAP;
	else if (gap > MAX_GAP)
		gap = MAX_GAP;

	return PAGE_ALIGN(TASK_SIZE - gap - rnd);
}

static inline unsigned long mmap_base(void)
{
	unsigned long gap = rlimit(RLIMIT_STACK);

	if (gap < MIN_GAP)
		gap = MIN_GAP;
	else if (gap > MAX_GAP)
		gap = MAX_GAP;
	gap &= PAGE_MASK;
	return STACK_TOP - stack_maxrandom_size() - mmap_rnd() - gap;
}

static inline unsigned long mmap_base(void)
{
    unsigned long gap = rlimit(RLIMIT_STACK);

    if (gap < MIN_GAP)
        gap = MIN_GAP;
    else if (gap > MAX_GAP)
        gap = MAX_GAP;

    return STACK_TOP - (gap & PAGE_MASK);
}

static inline int mmap_is_legacy(void)
{
#ifdef CONFIG_64BIT
    /*
     * Force standard allocation for 64 bit programs.
     */
    if (!is_compat_task())
        return 1;
#endif
    return sysctl_legacy_va_layout ||
           (current->personality & ADDR_COMPAT_LAYOUT) ||
           rlimit(RLIMIT_STACK) == RLIM_INFINITY;
}

SYSCALL_DEFINE1(brk, unsigned long, brk)
{
	unsigned long rlim, retval;
	unsigned long newbrk, oldbrk;
	struct mm_struct *mm = current->mm;
	unsigned long min_brk;

	down_write(&mm->mmap_sem);

#ifdef CONFIG_COMPAT_BRK
	if (current->brk_randomized)
		min_brk = mm->start_brk;
	else
		min_brk = mm->end_data;
#else
	min_brk = mm->start_brk;
#endif
	if (brk < min_brk)
		goto out;

	rlim = rlimit(RLIMIT_DATA);
	if (rlim < RLIM_INFINITY && (brk - mm->start_brk) +
			(mm->end_data - mm->start_data) > rlim)
		goto out;

	newbrk = PAGE_ALIGN(brk);
	oldbrk = PAGE_ALIGN(mm->brk);
	if (oldbrk == newbrk)
		goto set_brk;

	
	if (brk <= mm->brk) {
		if (!do_munmap(mm, newbrk, oldbrk-newbrk))
			goto set_brk;
		goto out;
	}

	
	if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE))
		goto out;

	
	if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
		goto out;
set_brk:
	mm->brk = brk;
out:
	retval = mm->brk;
	up_write(&mm->mmap_sem);
	return retval;
}

static inline unsigned long mmap_base(struct mm_struct *mm)
{
	unsigned long gap = rlimit(RLIMIT_STACK);
	unsigned long random_factor = 0;

	if (current->flags & PF_RANDOMIZE)
		random_factor = get_random_int() % (1024*1024);

	if (gap < MIN_GAP)
		gap = MIN_GAP;
	else if (gap > MAX_GAP)
		gap = MAX_GAP;

	return PAGE_ALIGN(TASK_SIZE - gap - random_factor);
}

/*
 * These are the only things you should do on a core-file: use only these
 * functions to write out all the necessary info.
 */
static int spufs_dump_write(struct file *file, const void *addr, int nr, loff_t *foffset)
{
	unsigned long limit = rlimit(RLIMIT_CORE);
	ssize_t written;

	if (*foffset + nr > limit)
		return -EIO;

	written = file->f_op->write(file, addr, nr, &file->f_pos);
	*foffset += written;

	if (written != nr)
		return -EIO;

	return 0;
}

/*
 * siw_reg_user_mr()
 *
 * Register Memory Region.
 *
 * @ofa_pd:	OFA PD contained in siw PD.
 * @start:	starting address of MR (virtual address)
 * @len:	len of MR
 * @rnic_va:	not used by siw
 * @rights:	MR access rights
 * @udata:	user buffer to communicate STag and Key.
 */
struct ib_mr *siw_reg_user_mr(struct ib_pd *ofa_pd, u64 start, u64 len,
			      u64 rnic_va, int rights, struct ib_udata *udata)
{
	struct siw_mr		*mr = NULL;
	struct siw_pd		*pd = siw_pd_ofa2siw(ofa_pd);
	struct siw_umem		*umem = NULL;
	struct siw_ureq_reg_mr	ureq;
	struct siw_uresp_reg_mr	uresp;
	struct siw_dev		*sdev = pd->hdr.sdev;

	unsigned long mem_limit = rlimit(RLIMIT_MEMLOCK);
	int rv;

	dprint(DBG_MM|DBG_OBJ, " start: 0x%016llx, "
		"va: 0x%016llx, len: %llu, ctx: %p\n",
		(unsigned long long)start,
		(unsigned long long)rnic_va,
		(unsigned long long)len,
		ofa_pd->uobject->context);
	if (atomic_inc_return(&sdev->num_mem) > SIW_MAX_MR) {
		dprint(DBG_ON, ": Out of MRs: %d\n",
			atomic_read(&sdev->num_mem));
		rv = -ENOMEM;
		goto err_out;
	}
	if (!len) {
		rv = -EINVAL;
		goto err_out;
	}
	if (mem_limit != RLIM_INFINITY) {
		unsigned long num_pages =
			(PAGE_ALIGN(len + (start & ~PAGE_MASK))) >> PAGE_SHIFT;
		mem_limit >>= PAGE_SHIFT;

		if (num_pages > mem_limit - current->mm->locked_vm) {
			dprint(DBG_ON|DBG_MM,
				": pages req: %lu, limit: %lu, locked: %lu\n",
				num_pages, mem_limit, current->mm->locked_vm);
			rv = -ENOMEM;
			goto err_out;
		}
	}