/****************************************************************************
* fs/procfs/fs_procfscritmon.c
*
* Copyright (C) 2018 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/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) && \
defined(CONFIG_SCHED_CRITMONITOR)
/****************************************************************************
* 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 CRITMON_LINELEN 64
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure describes one open "file" */
struct critmon_file_s
{
struct procfs_file_s base; /* Base open file structure */
unsigned int linesize; /* Number of valid characters in line[] */
char line[CRITMON_LINELEN]; /* Pre-allocated buffer for formatted lines */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* File system methods */
static int critmon_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode);
static int critmon_close(FAR struct file *filep);
static ssize_t critmon_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static int critmon_dup(FAR const struct file *oldp,
FAR struct file *newp);
static int critmon_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 critmon_operations =
{
critmon_open, /* open */
critmon_close, /* close */
critmon_read, /* read */
NULL, /* write */
critmon_dup, /* dup */
NULL, /* opendir */
NULL, /* closedir */
NULL, /* readdir */
NULL, /* rewinddir */
critmon_stat /* stat */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: critmon_open
****************************************************************************/
static int critmon_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode)
{
FAR struct critmon_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;
}
/* "critmon" is the only acceptable value for the relpath */
if (strcmp(relpath, "critmon") != 0)
{
ferr("ERROR: relpath is '%s'\n", relpath);
return -ENOENT;
}
/* Allocate a container to hold the file attributes */
attr = kmm_zalloc(sizeof(struct critmon_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: critmon_close
****************************************************************************/
static int critmon_close(FAR struct file *filep)
{
FAR struct critmon_file_s *attr;
/* Recover our private data from the struct file instance */
attr = (FAR struct critmon_file_s *)filep->f_priv;
DEBUGASSERT(attr);
/* Release the file attributes structure */
kmm_free(attr);
filep->f_priv = NULL;
return OK;
}
/****************************************************************************
* Name: critmon_read_cpu
****************************************************************************/
static ssize_t critmon_read_cpu(FAR struct critmon_file_s *attr,
FAR char *buffer, size_t buflen,
FAR off_t *offset, int cpu)
{
struct timespec maxtime;
size_t remaining;
size_t linesize;
size_t copysize;
size_t totalsize;
remaining = buflen;
totalsize = 0;
/* Convert the for maximum time pre-emption disabled */
if (g_premp_max[cpu] > 0)
{
up_critmon_convert(g_premp_max[cpu], &maxtime);
}
else
{
maxtime.tv_sec = 0;
maxtime.tv_nsec = 0;
}
/* Reset the maximum */
g_premp_max[cpu] = 0;
/* Generate output for maximum time pre-emption disabled */
linesize = snprintf(attr->line, CRITMON_LINELEN, "%d,%lu.%09lu,",
cpu, (unsigned long)maxtime.tv_sec,
(unsigned long)maxtime.tv_nsec);
copysize = procfs_memcpy(attr->line, linesize, buffer, buflen, offset);
totalsize += copysize;
buffer += copysize;
remaining -= copysize;
if (totalsize >= buflen)
{
return totalsize;
}
/* Convert and generate output for maximum time in a critical section */
if (g_crit_max[cpu] > 0)
{
up_critmon_convert(g_crit_max[cpu], &maxtime);
}
else
{
maxtime.tv_sec = 0;
maxtime.tv_nsec = 0;
}
/* Reset the maximum */
g_crit_max[cpu] = 0;
/* Generate output for maximum time in a critical section */
linesize = snprintf(attr->line, CRITMON_LINELEN, "%lu.%09lu\n",
(unsigned long)maxtime.tv_sec,
(unsigned long)maxtime.tv_nsec);
copysize = procfs_memcpy(attr->line, linesize, buffer, buflen, offset);
totalsize += copysize;
return totalsize;
}
/****************************************************************************
* Name: critmon_read
****************************************************************************/
static ssize_t critmon_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct critmon_file_s *attr;
off_t offset;
ssize_t ret;
#ifdef CONFIG_SMP
int cpu;
#endif
finfo("buffer=%p buflen=%d\n", buffer, (int)buflen);
/* Recover our private data from the struct file instance */
attr = (FAR struct critmon_file_s *)filep->f_priv;
DEBUGASSERT(attr);
ret = 0;
offset = filep->f_pos;
#ifdef CONFIG_SMP
/* Get the status for each CPU */
for (cpu = 0; cpu < CONFIG_SMP_NCPUS; cpu++)
{
ssize_t nbytes = critmon_read_cpu(attr, buffer + ret, buflen - ret,
&offset, cpu);
ret += nbytes;
if (ret > buflen)
{
break;
}
offset += nbytes;
}
#else
/* Get status for the single CPU */
ret = critmon_read_cpu(attr, buffer + ret, buflen -ret, &offset, 0);
#endif
if (ret > 0)
{
filep->f_pos += ret;
}
return ret;
}
/****************************************************************************
* Name: critmon_dup
*
* Description:
* Duplicate open file data in the new file structure.
*
****************************************************************************/
static int critmon_dup(FAR const struct file *oldp, FAR struct file *newp)
{
FAR struct critmon_file_s *oldattr;
FAR struct critmon_file_s *newattr;
finfo("Dup %p->%p\n", oldp, newp);
/* Recover our private data from the old struct file instance */
oldattr = (FAR struct critmon_file_s *)oldp->f_priv;
DEBUGASSERT(oldattr);
/* Allocate a new container to hold the task and attribute selection */
newattr = kmm_malloc(sizeof(struct critmon_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 critmon_file_s));
/* Save the new attributes in the new file structure */
newp->f_priv = (FAR void *)newattr;
return OK;
}
/****************************************************************************
* Name: critmon_stat
*
* Description: Return information about a file or directory
*
****************************************************************************/
static int critmon_stat(const char *relpath, struct stat *buf)
{
/* "critmon" is the only acceptable value for the relpath */
if (strcmp(relpath, "critmon") != 0)
{
ferr("ERROR: relpath is '%s'\n", relpath);
return -ENOENT;
}
/* "critmon" 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_DISABLE_MOUNTPOINT && CONFIG_FS_PROCFS && CONFIG_SCHED_CRITMONITOR */