newlib/winsup/cygwin/pipe.cc

324 lines
7.2 KiB
C++

/* pipe.cc: pipe for Cygwin.
Copyright 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004 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. */
/* FIXME: Should this really be fhandler_pipe.cc? */
#include "winsup.h"
#include <unistd.h>
#include <sys/socket.h>
#include "cygerrno.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "thread.h"
#include "pinfo.h"
#include "cygthread.h"
static unsigned pipecount;
static const NO_COPY char pipeid_fmt[] = "stupid_pipe.%u.%u";
fhandler_pipe::fhandler_pipe ()
: fhandler_base (), guard (NULL), broken_pipe (false), writepipe_exists(0),
orig_pid (0), id (0)
{
}
_off64_t
fhandler_pipe::lseek (_off64_t offset, int whence)
{
debug_printf ("(%d, %d)", offset, whence);
set_errno (ESPIPE);
return -1;
}
void
fhandler_pipe::set_close_on_exec (int val)
{
fhandler_base::set_close_on_exec (val);
if (guard)
set_no_inheritance (guard, val);
if (writepipe_exists)
set_no_inheritance (writepipe_exists, val);
}
struct pipeargs
{
fhandler_base *fh;
void *ptr;
size_t *len;
};
static DWORD WINAPI
read_pipe (void *arg)
{
pipeargs *pi = (pipeargs *) arg;
pi->fh->fhandler_base::read (pi->ptr, *pi->len);
return 0;
}
void __stdcall
fhandler_pipe::read (void *in_ptr, size_t& in_len)
{
if (broken_pipe)
in_len = 0;
else
{
pipeargs pi = {dynamic_cast<fhandler_base *>(this), in_ptr, &in_len};
ResetEvent (read_state);
cygthread *th = new cygthread (read_pipe, &pi, "read_pipe");
if (th->detach (read_state) && !in_len)
in_len = (size_t) -1; /* received a signal */
}
(void) ReleaseMutex (guard);
return;
}
int
fhandler_pipe::close ()
{
if (guard)
CloseHandle (guard);
if (writepipe_exists)
CloseHandle (writepipe_exists);
#ifndef NEWVFORK
if (read_state)
#else
// FIXME is this vfork_cleanup test right? Is it responsible for some of
// the strange pipe behavior that has been reported in the cygwin mailing
// list?
if (read_state && !cygheap->fdtab.in_vfork_cleanup ())
#endif
ForceCloseHandle (read_state);
if (get_handle ())
{
CloseHandle (get_handle ());
set_io_handle (NULL);
}
return 0;
}
bool
fhandler_pipe::hit_eof ()
{
char buf[80];
HANDLE ev;
if (broken_pipe)
return 1;
if (!orig_pid)
return false;
__small_sprintf (buf, pipeid_fmt, orig_pid, id);
if ((ev = OpenEvent (EVENT_ALL_ACCESS, FALSE, buf)))
CloseHandle (ev);
debug_printf ("%s %p", buf, ev);
return ev == NULL;
}
void
fhandler_pipe::fixup_after_exec ()
{
if (read_state)
{
read_state = CreateEvent (&sec_none_nih, FALSE, FALSE, NULL);
ProtectHandle (read_state);
}
}
void
fhandler_pipe::fixup_after_fork (HANDLE parent)
{
fhandler_base::fixup_after_fork (parent);
if (guard)
fork_fixup (parent, guard, "guard");
if (writepipe_exists)
fork_fixup (parent, writepipe_exists, "guard");
fixup_after_exec ();
}
int
fhandler_pipe::dup (fhandler_base *child)
{
int res = -1;
fhandler_pipe *ftp = (fhandler_pipe *) child;
ftp->guard = ftp->writepipe_exists = ftp->read_state = NULL;
if (get_handle ())
{
res = fhandler_base::dup (child);
if (res)
goto err;
}
/* FIXME: This leaks handles in the failing condition */
if (guard == NULL)
ftp->guard = NULL;
else if (!DuplicateHandle (hMainProc, guard, hMainProc, &ftp->guard, 0, 1,
DUPLICATE_SAME_ACCESS))
{
debug_printf ("couldn't duplicate guard %p, %E", guard);
goto err;
}
if (writepipe_exists == NULL)
ftp->writepipe_exists = NULL;
else if (!DuplicateHandle (hMainProc, writepipe_exists, hMainProc,
&ftp->writepipe_exists, 0, 1,
DUPLICATE_SAME_ACCESS))
{
debug_printf ("couldn't duplicate writepipe_exists %p, %E", writepipe_exists);
goto err;
}
if (read_state == NULL)
ftp->read_state = NULL;
else if (!DuplicateHandle (hMainProc, read_state, hMainProc,
&ftp->read_state, 0, 1,
DUPLICATE_SAME_ACCESS))
{
debug_printf ("couldn't duplicate read_state %p, %E", writepipe_exists);
goto err;
}
res = 0;
goto out;
err:
if (!ftp->guard)
CloseHandle (ftp->guard);
if (!ftp->writepipe_exists)
CloseHandle (ftp->writepipe_exists);
if (!ftp->read_state)
CloseHandle (ftp->read_state);
goto leave;
out:
ftp->id = id;
ftp->orig_pid = orig_pid;
VerifyHandle (ftp->guard);
VerifyHandle (ftp->writepipe_exists);
VerifyHandle (ftp->read_state);
leave:
debug_printf ("res %d", res);
return res;
}
int
fhandler_pipe::create (fhandler_pipe *fhs[2], unsigned psize, int mode, bool fifo)
{
HANDLE r, w;
SECURITY_ATTRIBUTES *sa = (mode & O_NOINHERIT) ? &sec_none_nih : &sec_none;
int res = -1;
if (!CreatePipe (&r, &w, sa, psize))
__seterrno ();
else
{
fhs[0] = (fhandler_pipe *) build_fh_dev (*piper_dev);
fhs[1] = (fhandler_pipe *) build_fh_dev (*pipew_dev);
int binmode = mode & O_TEXT ?: O_BINARY;
fhs[0]->init (r, GENERIC_READ, binmode);
fhs[1]->init (w, GENERIC_WRITE, binmode);
if (mode & O_NOINHERIT)
{
fhs[0]->set_close_on_exec_flag (1);
fhs[1]->set_close_on_exec_flag (1);
}
fhs[0]->read_state = CreateEvent (&sec_none_nih, FALSE, FALSE, NULL);
fhs[0]->set_need_fork_fixup ();
ProtectHandle1 (fhs[0]->read_state, read_state);
res = 0;
fhs[0]->create_guard (sa);
if (wincap.has_unreliable_pipes ())
{
char buf[80];
int count = pipecount++; /* FIXME: Should this be InterlockedIncrement? */
__small_sprintf (buf, pipeid_fmt, myself->pid, count);
fhs[1]->writepipe_exists = CreateEvent (sa, TRUE, FALSE, buf);
fhs[0]->orig_pid = myself->pid;
fhs[0]->id = count;
}
}
syscall_printf ("%d = ([%p, %p], %d, %p)", res, fhs[0], fhs[1], psize, mode);
return res;
}
int
fhandler_pipe::ioctl (unsigned int cmd, void *p)
{
int n;
switch (cmd)
{
case FIONREAD:
if (get_device () == FH_PIPEW)
{
set_errno (EINVAL);
return -1;
}
if (!PeekNamedPipe (get_handle (), NULL, 0, NULL, (DWORD *) &n, NULL))
{
__seterrno ();
return -1;
}
break;
default:
return fhandler_base::ioctl (cmd, p);
break;
}
*(int *) p = n;
return 0;
}
extern "C" int
pipe (int filedes[2])
{
extern DWORD binmode;
fhandler_pipe *fhs[2];
int res = fhandler_pipe::create (fhs, 16384, (!binmode || binmode == O_BINARY)
? O_BINARY : O_TEXT);
if (res == 0)
{
cygheap_fdnew fdin;
cygheap_fdnew fdout (fdin, false);
fdin = fhs[0];
fdout = fhs[1];
filedes[0] = fdin;
filedes[1] = fdout;
}
return res;
}
extern "C" int
_pipe (int filedes[2], unsigned int psize, int mode)
{
fhandler_pipe *fhs[2];
int res = fhandler_pipe::create (fhs, psize, mode);
/* This type of pipe is not interruptible so set the appropriate flag. */
if (!res)
{
cygheap_fdnew fdin;
cygheap_fdnew fdout (fdin, false);
fhs[0]->set_r_no_interrupt (1);
fdin = fhs[0];
fdout = fhs[1];
filedes[0] = fdin;
filedes[1] = fdout;
}
return res;
}