array.c

这是一个SIGMA方案的PMP播放器的UCLINUX程序,可播放DVD,VCD,CD MP3...有很好的参考价值.

	/* to make it look like a "normal" Unix priority/nice value  */
	priority = task->counter;
	priority = 20 - (priority * 10 + DEF_COUNTER / 2) / DEF_COUNTER;
	nice = task->nice;

	read_lock(&tasklist_lock);
	ppid = task->pid ? task->p_opptr->pid : 0;
	read_unlock(&tasklist_lock);
	res = sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \
%lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld %lu %lu %ld %lu %lu %lu %lu %lu \
%lu %lu %lu %lu %lu %lu %lu %lu %d %d\n",
		task->pid,
		task->comm,
		state,
		ppid,
		task->pgrp,
		task->session,
	        tty_nr,
		tty_pgrp,
		task->flags,
		task->min_flt,
		task->cmin_flt,
		task->maj_flt,
		task->cmaj_flt,
		task->times.tms_utime,
		task->times.tms_stime,
		task->times.tms_cutime,
		task->times.tms_cstime,
		priority,
		nice,
		0UL /* removed */,
		task->it_real_value,
		task->start_time,
		vsize,
		mm ? mm->rss : 0, /* you might want to shift this left 3 */
		task->rlim[RLIMIT_RSS].rlim_cur,
		mm ? mm->start_code : 0,
		mm ? mm->end_code : 0,
		mm ? mm->start_stack : 0,
		esp,
		eip,
		/* The signal information here is obsolete.
		 * It must be decimal for Linux 2.0 compatibility.
		 * Use /proc/#/status for real-time signals.
		 */
		task->pending.signal.sig[0] & 0x7fffffffUL,
		task->blocked.sig[0] & 0x7fffffffUL,
		sigign      .sig[0] & 0x7fffffffUL,
		sigcatch    .sig[0] & 0x7fffffffUL,
		wchan,
		task->nswap,
		task->cnswap,
		task->exit_signal,
		task->processor);
	if(mm)
		mmput(mm);
	return res;
}
		
#ifndef NO_MM

static inline void statm_pte_range(pmd_t * pmd, unsigned long address, unsigned long size,
	int * pages, int * shared, int * dirty, int * total)
{
	pte_t * pte;
	unsigned long end;

	if (pmd_none(*pmd))
		return;
	if (pmd_bad(*pmd)) {
		pmd_ERROR(*pmd);
		pmd_clear(pmd);
		return;
	}
	pte = pte_offset(pmd, address);
	address &= ~PMD_MASK;
	end = address + size;
	if (end > PMD_SIZE)
		end = PMD_SIZE;
	do {
		pte_t page = *pte;
		struct page *ptpage;

		address += PAGE_SIZE;
		pte++;
		if (pte_none(page))
			continue;
		++*total;
		if (!pte_present(page))
			continue;
		ptpage = pte_page(page);
		if ((!VALID_PAGE(ptpage)) || PageReserved(ptpage))
			continue;
		++*pages;
		if (pte_dirty(page))
			++*dirty;
		if (page_count(pte_page(page)) > 1)
			++*shared;
	} while (address < end);
}

static inline void statm_pmd_range(pgd_t * pgd, unsigned long address, unsigned long size,
	int * pages, int * shared, int * dirty, int * total)
{
	pmd_t * pmd;
	unsigned long end;

	if (pgd_none(*pgd))
		return;
	if (pgd_bad(*pgd)) {
		pgd_ERROR(*pgd);
		pgd_clear(pgd);
		return;
	}
	pmd = pmd_offset(pgd, address);
	address &= ~PGDIR_MASK;
	end = address + size;
	if (end > PGDIR_SIZE)
		end = PGDIR_SIZE;
	do {
		statm_pte_range(pmd, address, end - address, pages, shared, dirty, total);
		address = (address + PMD_SIZE) & PMD_MASK;
		pmd++;
	} while (address < end);
}

static void statm_pgd_range(pgd_t * pgd, unsigned long address, unsigned long end,
	int * pages, int * shared, int * dirty, int * total)
{
	while (address < end) {
		statm_pmd_range(pgd, address, end - address, pages, shared, dirty, total);
		address = (address + PGDIR_SIZE) & PGDIR_MASK;
		pgd++;
	}
}

#endif /* !NO_MM */

int proc_pid_statm(struct task_struct *task, char * buffer)
{
	struct mm_struct *mm;
	int size=0, resident=0, share=0, trs=0, lrs=0, drs=0, dt=0;

	task_lock(task);
	mm = task->mm;
	if(mm)
		atomic_inc(&mm->mm_users);
	task_unlock(task);
	if (mm) {
#ifndef NO_MM
		struct vm_area_struct * vma;
#endif
		down_read(&mm->mmap_sem);
#ifndef NO_MM
		vma = mm->mmap;
		while (vma) {
			pgd_t *pgd = pgd_offset(mm, vma->vm_start);
			int pages = 0, shared = 0, dirty = 0, total = 0;

			statm_pgd_range(pgd, vma->vm_start, vma->vm_end, &pages, &shared, &dirty, &total);
			resident += pages;
			share += shared;
			dt += dirty;
			size += total;
			if (vma->vm_flags & VM_EXECUTABLE)
				trs += pages;	/* text */
			else if (vma->vm_flags & VM_GROWSDOWN)
				drs += pages;	/* stack */
			else if (vma->vm_end > 0x60000000)
				lrs += pages;	/* library */
			else
				drs += pages;
			vma = vma->vm_next;
		}
#else /* !NO_MM */
		/* DAVIDM - may be able to clean this up a bit */
		{
			struct mm_tblock_struct *tbp = &mm->tblock;

			size += ksize(mm);
			while (tbp) {
				if (tbp->next)
					size += ksize(tbp->next);
				if (tbp->rblock) {
					size += ksize(tbp->rblock);
					size += ksize(tbp->rblock->kblock);
					if (atomic_read(&mm->mm_count) > 1 ||
							(tbp->rblock->refcount > 1))
						share += tbp->rblock->size;
				}
				tbp = tbp->next;
			}

			size += (trs = mm->end_code - mm->start_code);
			size += (drs = mm->start_stack - mm->start_data);
			dt  = 0;
			lrs = 0;
			resident = size;
		}
#endif /* !NO_MM */
		up_read(&mm->mmap_sem);
		mmput(mm);
	}
	return sprintf(buffer,"%d %d %d %d %d %d %d\n",
		       size, resident, share, trs, lrs, drs, dt);
}

#ifndef NO_MM
/*
 * The way we support synthetic files > 4K
 * - without storing their contents in some buffer and
 * - without walking through the entire synthetic file until we reach the
 *   position of the requested data
 * is to cleverly encode the current position in the file's f_pos field.
 * There is no requirement that a read() call which returns `count' bytes
 * of data increases f_pos by exactly `count'.
 *
 * This idea is Linus' one. Bruno implemented it.
 */

/*
 * For the /proc/<pid>/maps file, we use fixed length records, each containing
 * a single line.
 *
 * f_pos = (number of the vma in the task->mm->mmap list) * PAGE_SIZE
 *         + (index into the line)
 */
/* for systems with sizeof(void*) == 4: */
#define MAPS_LINE_FORMAT4	  "%08lx-%08lx %s %08lx %s %lu"
#define MAPS_LINE_MAX4	49 /* sum of 8  1  8  1 4 1 8 1 5 1 10 1 */

/* for systems with sizeof(void*) == 8: */
#define MAPS_LINE_FORMAT8	  "%016lx-%016lx %s %016lx %s %lu"
#define MAPS_LINE_MAX8	73 /* sum of 16  1  16  1 4 1 16 1 5 1 10 1 */

#define MAPS_LINE_FORMAT	(sizeof(void*) == 4 ? MAPS_LINE_FORMAT4 : MAPS_LINE_FORMAT8)
#define MAPS_LINE_MAX	(sizeof(void*) == 4 ?  MAPS_LINE_MAX4 :  MAPS_LINE_MAX8)

static int proc_pid_maps_get_line (char *buf, struct vm_area_struct *map)
{
	/* produce the next line */
	char *line;
	char str[5];
	int flags;
	kdev_t dev;
	unsigned long ino;
	int len;

	flags = map->vm_flags;

	str[0] = flags & VM_READ ? 'r' : '-';
	str[1] = flags & VM_WRITE ? 'w' : '-';
	str[2] = flags & VM_EXEC ? 'x' : '-';
	str[3] = flags & VM_MAYSHARE ? 's' : 'p';
	str[4] = 0;

	dev = 0;
	ino = 0;
	if (map->vm_file != NULL) {
		dev = map->vm_file->f_dentry->d_inode->i_dev;
		ino = map->vm_file->f_dentry->d_inode->i_ino;
		line = d_path(map->vm_file->f_dentry,
			      map->vm_file->f_vfsmnt,
			      buf, PAGE_SIZE);
		buf[PAGE_SIZE-1] = '\n';
		line -= MAPS_LINE_MAX;
		if(line < buf)
			line = buf;
	} else
		line = buf;

	len = sprintf(line,
		      MAPS_LINE_FORMAT,
		      map->vm_start, map->vm_end, str, map->vm_pgoff << PAGE_SHIFT,
		      kdevname(dev), ino);

	if(map->vm_file) {
		int i;
		for(i = len; i < MAPS_LINE_MAX; i++)
			line[i] = ' ';
		len = buf + PAGE_SIZE - line;
		memmove(buf, line, len);
	} else
		line[len++] = '\n';
	return len;
}
#endif /* NO_MM */

ssize_t proc_pid_read_maps (struct task_struct *task, struct file * file, char * buf,
			  size_t count, loff_t *ppos)
{
#ifndef NO_MM
	struct mm_struct *mm;
	struct vm_area_struct * map;
	char *tmp, *kbuf;
	long retval;
	int off, lineno, loff;

	/* reject calls with out of range parameters immediately */
	retval = 0;
	if (*ppos > LONG_MAX)
		goto out;
	if (count == 0)
		goto out;
	off = (long)*ppos;
	/*
	 * We might sleep getting the page, so get it first.
	 */
	retval = -ENOMEM;
	kbuf = (char*)__get_free_page(GFP_KERNEL);
	if (!kbuf)
		goto out;

	tmp = (char*)__get_free_page(GFP_KERNEL);
	if (!tmp)
		goto out_free1;

	task_lock(task);
	mm = task->mm;
	if (mm)
		atomic_inc(&mm->mm_users);
	task_unlock(task);
	retval = 0;
	if (!mm)
		goto out_free2;

	down_read(&mm->mmap_sem);
	map = mm->mmap;
	lineno = 0;
	loff = 0;
	if (count > PAGE_SIZE)
		count = PAGE_SIZE;
	while (map) {
		int len;
		if (off > PAGE_SIZE) {
			off -= PAGE_SIZE;
			goto next;
		}
		len = proc_pid_maps_get_line(tmp, map);
		len -= off;
		if (len > 0) {
			if (retval+len > count) {
				/* only partial line transfer possible */
				len = count - retval;
				/* save the offset where the next read
				 * must start */
				loff = len+off;
			}
			memcpy(kbuf+retval, tmp+off, len);
			retval += len;
		}
		off = 0;
next:
		if (!loff)
			lineno++;
		if (retval >= count)
			break;
		if (loff) BUG();
		map = map->vm_next;
	}
	up_read(&mm->mmap_sem);
	mmput(mm);

	if (retval > count) BUG();
	if (copy_to_user(buf, kbuf, retval))
		retval = -EFAULT;
	else
		*ppos = (lineno << PAGE_SHIFT) + loff;

out_free2:
	free_page((unsigned long)tmp);
out_free1:
	free_page((unsigned long)kbuf);
out:
	return retval;
#else /* !NO_MM */
	/* DAVIDM - no idea if this one is possible :-) */
	return(0);
#endif /* !NO_MM */
}

#ifdef CONFIG_SMP
int proc_pid_cpu(struct task_struct *task, char * buffer)
{
	int i, len;

	len = sprintf(buffer,
		"cpu  %lu %lu\n",
		task->times.tms_utime,
		task->times.tms_stime);
		
	for (i = 0 ; i < smp_num_cpus; i++)
		len += sprintf(buffer + len, "cpu%d %lu %lu\n",
			i,
			task->per_cpu_utime[cpu_logical_map(i)],
			task->per_cpu_stime[cpu_logical_map(i)]);

	return len;
}
#endif