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- /****************************************************************************
- * fs/procfs/fs_procfscpuload.c
- *
- * Copyright (C) 2014, 2017 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * 3. Neither the name NuttX nor the names of its contributors may be
- * used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <sys/types.h>
- #include <sys/statfs.h>
- #include <sys/stat.h>
- #include <stdint.h>
- #include <stdbool.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <time.h>
- #include <string.h>
- #include <fcntl.h>
- #include <assert.h>
- #include <errno.h>
- #include <debug.h>
- #include <nuttx/clock.h>
- #include <nuttx/kmalloc.h>
- #include <nuttx/fs/fs.h>
- #include <nuttx/fs/procfs.h>
- #if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_FS_PROCFS)
- #if defined(CONFIG_SCHED_CPULOAD) && !defined(CONFIG_FS_PROCFS_EXCLUDE_CPULOAD)
- /****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
- /* Determines the size of an intermediate buffer that must be large enough
- * to handle the longest line generated by this logic.
- */
- #define CPULOAD_LINELEN 16
- /****************************************************************************
- * Private Types
- ****************************************************************************/
- /* This structure describes one open "file" */
- struct cpuload_file_s
- {
- struct procfs_file_s base; /* Base open file structure */
- unsigned int linesize; /* Number of valid characters in line[] */
- char line[CPULOAD_LINELEN]; /* Pre-allocated buffer for formatted lines */
- };
- /****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
- /* File system methods */
- static int cpuload_open(FAR struct file *filep, FAR const char *relpath,
- int oflags, mode_t mode);
- static int cpuload_close(FAR struct file *filep);
- static ssize_t cpuload_read(FAR struct file *filep, FAR char *buffer,
- size_t buflen);
- static int cpuload_dup(FAR const struct file *oldp,
- FAR struct file *newp);
- static int cpuload_stat(FAR const char *relpath, FAR struct stat *buf);
- /****************************************************************************
- * Public Data
- ****************************************************************************/
- /* See fs_mount.c -- this structure is explicitly externed there.
- * We use the old-fashioned kind of initializers so that this will compile
- * with any compiler.
- */
- const struct procfs_operations cpuload_operations =
- {
- cpuload_open, /* open */
- cpuload_close, /* close */
- cpuload_read, /* read */
- NULL, /* write */
- cpuload_dup, /* dup */
- NULL, /* opendir */
- NULL, /* closedir */
- NULL, /* readdir */
- NULL, /* rewinddir */
- cpuload_stat /* stat */
- };
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: cpuload_open
- ****************************************************************************/
- static int cpuload_open(FAR struct file *filep, FAR const char *relpath,
- int oflags, mode_t mode)
- {
- FAR struct cpuload_file_s *attr;
- finfo("Open '%s'\n", relpath);
- /* PROCFS is read-only. Any attempt to open with any kind of write
- * access is not permitted.
- *
- * REVISIT: Write-able proc files could be quite useful.
- */
- if ((oflags & O_WRONLY) != 0 || (oflags & O_RDONLY) == 0)
- {
- ferr("ERROR: Only O_RDONLY supported\n");
- return -EACCES;
- }
- /* "cpuload" is the only acceptable value for the relpath */
- if (strcmp(relpath, "cpuload") != 0)
- {
- ferr("ERROR: relpath is '%s'\n", relpath);
- return -ENOENT;
- }
- /* Allocate a container to hold the file attributes */
- attr = (FAR struct cpuload_file_s *)kmm_zalloc(sizeof(struct cpuload_file_s));
- if (!attr)
- {
- ferr("ERROR: Failed to allocate file attributes\n");
- return -ENOMEM;
- }
- /* Save the attributes as the open-specific state in filep->f_priv */
- filep->f_priv = (FAR void *)attr;
- return OK;
- }
- /****************************************************************************
- * Name: cpuload_close
- ****************************************************************************/
- static int cpuload_close(FAR struct file *filep)
- {
- FAR struct cpuload_file_s *attr;
- /* Recover our private data from the struct file instance */
- attr = (FAR struct cpuload_file_s *)filep->f_priv;
- DEBUGASSERT(attr);
- /* Release the file attributes structure */
- kmm_free(attr);
- filep->f_priv = NULL;
- return OK;
- }
- /****************************************************************************
- * Name: cpuload_read
- ****************************************************************************/
- static ssize_t cpuload_read(FAR struct file *filep, FAR char *buffer,
- size_t buflen)
- {
- FAR struct cpuload_file_s *attr;
- size_t linesize;
- off_t offset;
- ssize_t ret;
- finfo("buffer=%p buflen=%d\n", buffer, (int)buflen);
- /* Recover our private data from the struct file instance */
- attr = (FAR struct cpuload_file_s *)filep->f_priv;
- DEBUGASSERT(attr);
- /* If f_pos is zero, then sample the system time. Otherwise, use
- * the cached system time from the previous read(). It is necessary
- * save the cached value in case, for example, the user is reading
- * the time one byte at a time. In that case, the time must remain
- * stable throughout the reads.
- */
- if (filep->f_pos == 0)
- {
- struct cpuload_s cpuload;
- uint32_t intpart;
- uint32_t fracpart;
- /* Sample the counts for the IDLE thread. clock_cpuload should only
- * fail if the PID is not valid. This, however, should never happen
- * for the IDLE thread.
- */
- DEBUGVERIFY(clock_cpuload(0, &cpuload));
- /* On the simulator, you may hit cpuload.total == 0, but probably never on
- * real hardware.
- */
- if (cpuload.total > 0)
- {
- uint32_t tmp;
- tmp = 1000 - (1000 * cpuload.active) / cpuload.total;
- intpart = tmp / 10;
- fracpart = tmp - 10 * intpart;
- }
- else
- {
- intpart = 0;
- fracpart = 0;
- }
- linesize = snprintf(attr->line, CPULOAD_LINELEN, "%3d.%01d%%",
- intpart, fracpart);
- /* Save the linesize in case we are re-entered with f_pos > 0 */
- attr->linesize = linesize;
- }
- /* Transfer the system up time to user receive buffer */
- offset = filep->f_pos;
- ret = procfs_memcpy(attr->line, attr->linesize, buffer, buflen, &offset);
- /* Update the file offset */
- if (ret > 0)
- {
- filep->f_pos += ret;
- }
- return ret;
- }
- /****************************************************************************
- * Name: cpuload_dup
- *
- * Description:
- * Duplicate open file data in the new file structure.
- *
- ****************************************************************************/
- static int cpuload_dup(FAR const struct file *oldp, FAR struct file *newp)
- {
- FAR struct cpuload_file_s *oldattr;
- FAR struct cpuload_file_s *newattr;
- finfo("Dup %p->%p\n", oldp, newp);
- /* Recover our private data from the old struct file instance */
- oldattr = (FAR struct cpuload_file_s *)oldp->f_priv;
- DEBUGASSERT(oldattr);
- /* Allocate a new container to hold the task and attribute selection */
- newattr = (FAR struct cpuload_file_s *)kmm_malloc(sizeof(struct cpuload_file_s));
- if (!newattr)
- {
- ferr("ERROR: Failed to allocate file attributes\n");
- return -ENOMEM;
- }
- /* The copy the file attributes from the old attributes to the new */
- memcpy(newattr, oldattr, sizeof(struct cpuload_file_s));
- /* Save the new attributes in the new file structure */
- newp->f_priv = (FAR void *)newattr;
- return OK;
- }
- /****************************************************************************
- * Name: cpuload_stat
- *
- * Description: Return information about a file or directory
- *
- ****************************************************************************/
- static int cpuload_stat(const char *relpath, struct stat *buf)
- {
- /* "cpuload" is the only acceptable value for the relpath */
- if (strcmp(relpath, "cpuload") != 0)
- {
- ferr("ERROR: relpath is '%s'\n", relpath);
- return -ENOENT;
- }
- /* "cpuload" is the name for a read-only file */
- memset(buf, 0, sizeof(struct stat));
- buf->st_mode = S_IFREG | S_IROTH | S_IRGRP | S_IRUSR;
- return OK;
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- #endif /* CONFIG_FS_PROCFS_EXCLUDE_CPULOAD */
- #endif /* !CONFIG_DISABLE_MOUNTPOINT && CONFIG_FS_PROCFS */
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