mergerfs/libfuse/lib/fuse_mt.c

/*
  FUSE: Filesystem in Userspace
  Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>

  This program can be distributed under the terms of the GNU LGPLv2.
  See the file COPYING.LIB.
*/

#include "fuse_i.h"
#include "fuse_misc.h"
#include "fuse_lowlevel.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <assert.h>

struct procdata {
	struct fuse *f;
	struct fuse_chan *prevch;
	struct fuse_session *prevse;
	fuse_processor_t proc;
	void *data;
};

static void mt_session_proc(void *data, const char *buf, size_t len,
			    struct fuse_chan *ch)
{
	struct procdata *pd = (struct procdata *) data;
	struct fuse_cmd *cmd = *(struct fuse_cmd **) buf;

	(void) len;
	(void) ch;
	pd->proc(pd->f, cmd, pd->data);
}

static void mt_session_exit(void *data, int val)
{
	struct procdata *pd = (struct procdata *) data;
	if (val)
		fuse_session_exit(pd->prevse);
	else
		fuse_session_reset(pd->prevse);
}

static int mt_session_exited(void *data)
{
	struct procdata *pd = (struct procdata *) data;
	return fuse_session_exited(pd->prevse);
}

static int mt_chan_receive(struct fuse_chan **chp, char *buf, size_t size)
{
	struct fuse_cmd *cmd;
	struct procdata *pd = (struct procdata *) fuse_chan_data(*chp);

	assert(size >= sizeof(cmd));

	cmd = fuse_read_cmd(pd->f);
	if (cmd == NULL)
		return 0;

	*(struct fuse_cmd **) buf = cmd;

	return sizeof(cmd);
}

int fuse_loop_mt_proc(struct fuse *f, fuse_processor_t proc, void *data)
{
	int res;
	struct procdata pd;
	struct fuse_session *prevse = fuse_get_session(f);
	struct fuse_session *se;
	struct fuse_chan *prevch = fuse_session_next_chan(prevse, NULL);
	struct fuse_chan *ch;
	struct fuse_session_ops sop = {
		.exit = mt_session_exit,
		.exited = mt_session_exited,
		.process = mt_session_proc,
	};
	struct fuse_chan_ops cop = {
		.receive = mt_chan_receive,
	};

	pd.f = f;
	pd.prevch = prevch;
	pd.prevse = prevse;
	pd.proc = proc;
	pd.data = data;

	se = fuse_session_new(&sop, &pd);
	if (se == NULL)
		return -1;

	ch = fuse_chan_new(&cop, fuse_chan_fd(prevch),
			   sizeof(struct fuse_cmd *), &pd);
	if (ch == NULL) {
		fuse_session_destroy(se);
		return -1;
	}
	fuse_session_add_chan(se, ch);
	res = fuse_session_loop_mt(se,
                                   fuse_config_num_threads(f));
	fuse_session_destroy(se);
	return res;
}

int fuse_loop_mt(struct fuse *f)
{
	if (f == NULL)
		return -1;

	int res = fuse_start_cleanup_thread(f);
	if (res)
		return -1;

	res = fuse_session_loop_mt(fuse_get_session(f),
                                   fuse_config_num_threads(f));
	fuse_stop_cleanup_thread(f);
	return res;
}

FUSE_SYMVER(".symver fuse_loop_mt_proc,__fuse_loop_mt@");