/**************************************************************************** * fs/procfs/fs_procfscpuload.c * * Copyright (C) 2014, 2017 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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 */