newlib-cygwin/winsup/cygwin/fhandler_fifo.cc

198 lines
4.1 KiB
C++

/* fhandler_fifo.cc - See fhandler.h for a description of the fhandler classes.
Copyright 2002, 2003, 2004, 2005 Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include "cygerrno.h"
#include "perprocess.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "pinfo.h"
fhandler_fifo::fhandler_fifo ()
: fhandler_pipe (), output_handle (NULL),
read_use (0), write_use (0)
{
}
void
fhandler_fifo::set_use (int incr)
{
long oread_use = read_use;
if (get_flags () & (O_WRONLY | O_APPEND))
write_use += incr;
else if (get_flags () & O_RDWR)
{
write_use += incr;
read_use += incr;
}
else
read_use += incr;
if (incr >= 0)
return;
if (read_use <= 0 && oread_use != read_use)
{
HANDLE h = get_handle ();
if (h)
{
set_io_handle (NULL);
CloseHandle (h);
}
}
}
int
fhandler_fifo::close ()
{
fhandler_pipe::close ();
if (get_output_handle ())
CloseHandle (get_output_handle ());
set_use (-1);
return 0;
}
#define DUMMY_O_RDONLY 4
void
fhandler_fifo::close_one_end ()
{
int testflags = (get_flags () & (O_RDWR | O_WRONLY | O_APPEND)) ?: DUMMY_O_RDONLY;
static int flagtypes[] = {DUMMY_O_RDONLY | O_RDWR, O_WRONLY | O_APPEND | O_RDWR};
HANDLE *handles[2] = {&(get_handle ()), &(get_output_handle ())};
for (int i = 0; i < 2; i++)
if (!(testflags & flagtypes[i]))
{
CloseHandle (*handles[i]);
*handles[i] = NULL;
}
else if (i == 0 && !read_state)
{
create_read_state (2);
need_fork_fixup (true);
}
}
int
fhandler_fifo::open_not_mine (int flags)
{
winpids pids;
int res = 0;
for (unsigned i = 0; i < pids.npids; i++)
{
_pinfo *p = pids[i];
commune_result r;
if (p->pid != myself->pid)
{
r = p->commune_send (PICOM_FIFO, get_win32_name ());
if (r.handles[0] == NULL)
continue; // process doesn't own fifo
debug_printf ("pid %d, handles[0] %p, handles[1] %p", p->pid,
r.handles[0], r.handles[1]);
}
else
{
/* FIXME: racy? */
fhandler_fifo *fh = cygheap->fdtab.find_fifo (get_win32_name ());
if (!fh)
continue;
if (!DuplicateHandle (hMainProc, fh->get_handle (), hMainProc,
&r.handles[0], 0, false, DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto out;
}
if (!DuplicateHandle (hMainProc, fh->get_output_handle (), hMainProc,
&r.handles[1], 0, false, DUPLICATE_SAME_ACCESS))
{
CloseHandle (r.handles[0]);
__seterrno ();
goto out;
}
}
set_io_handle (r.handles[0]);
set_output_handle (r.handles[1]);
set_flags (flags);
close_one_end ();
res = 1;
goto out;
}
set_errno (EAGAIN);
out:
debug_printf ("res %d", res);
return res;
}
int
fhandler_fifo::open (int flags, mode_t)
{
int res = 1;
set_io_handle (NULL);
set_output_handle (NULL);
if (open_not_mine (flags))
goto out;
fhandler_pipe *fhs[2];
if (create (fhs, 1, flags, true))
{
__seterrno ();
res = 0;
}
else
{
set_flags (flags);
set_io_handle (fhs[0]->get_handle ());
set_output_handle (fhs[1]->get_handle ());
guard = fhs[0]->guard;
read_state = fhs[0]->read_state;
writepipe_exists = fhs[1]->writepipe_exists;
orig_pid = fhs[0]->orig_pid;
id = fhs[0]->id;
delete (fhs[0]);
delete (fhs[1]);
set_use (1);
need_fork_fixup (true);
}
out:
debug_printf ("returning %d, errno %d", res, get_errno ());
return res;
}
int
fhandler_fifo::dup (fhandler_base *child)
{
int res = fhandler_pipe::dup (child);
if (!res)
{
fhandler_fifo *ff = (fhandler_fifo *) child;
if (!DuplicateHandle (hMainProc, get_output_handle (), hMainProc,
&ff->get_output_handle (), false, true,
DUPLICATE_SAME_ACCESS))
{
__seterrno ();
child->close ();
res = -1;
}
}
return 0;
}