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Implement fhandler reference counting. 

* cygheap.h
(cygheap_fdmanip::release): Make virtual.
(cygheap_fdnew::~cygheap_fdnew): New destructor increments reference count when
fd has been allocated.
(cygheap_fdget::fh): New (old?) field.
(cygheap_fdget::cygheap_fdget): Increment reference count when we've found an
active fd.  Set fh appropriately.
(cygheap_fdget::~cygheap_fdget): Decrement reference count when appropriate.
Delete fh if reference count goes to zero.
(cygheap_fdget::release): New function.  Do more bookkeping on release.
* dtable.cc (dtable::release): Change from void to boolean return.  Only delete
the fhandler when its reference count is <= 0 (this should be a fairly unusual
case).  Return true if fhandler has been deleted.
(cygwin_attach_handle_to_fd): Increment reference count when fh is assigned.
(dtable::init_std_file_from_handle): Ditto.
* dtable.h (dtable::release): Change return to boolean.
* fhandler.cc (fhandler_base::fhandler_base): Set new isclosed flag to false.
Set _refcnt to zero.
(fhandler_base::close): Simplify paranoid debugging output.  Set new isclosed()
flag.
(fhandler_base_overlapped::wait_overlapped): Use isclosed() flag to avoid
querying the exception handle.
* fhandler.h (fhandler_base::_refcnt): New field.
(fhandler_base::refcnt): New function.
(fhandler_base::isclosed): Implement.
(fhandler_base::fhandler_base): Set isclosed to false.
* syscalls.cc: Remove space after function before parentheses for several
strace printfs.
(dup): Add standard strace "leaver" code.
(dup2): Ditto.
(dup3): Ditto.
(remove): Ditto.
(getpid): Ditto.
(getppid): Ditto.
(lseek64): Fix strace debugging to correctly use %R.
* fhandler_termios.cc (fhandler_termios::tcsetpgrp): Avoid sending signals to
other processes if we're debugging since it can cause a deadlock with the
calling debugger.
* exceptions.cc (_cygtls::call_signal_handler): Add debugging-only strace
output.
This commit is contained in:
Christopher Faylor 2011-12-17 00:03:31 +00:00
parent 6eee66418c
commit ca35d41cec
9 changed files with 141 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
winsup/cygwin/ChangeLog
View File

@ -1,3 +1,51 @@
2011-12-16 Christopher Faylor <me.cygwin2011@cgf.cx>
Implement fhandler reference counting.
* cygheap.h
(cygheap_fdmanip::release): Make virtual.
(cygheap_fdnew::~cygheap_fdnew): New destructor increments reference
count when fd has been allocated.
(cygheap_fdget::fh): New (old?) field.
(cygheap_fdget::cygheap_fdget): Increment reference count when we've
found an active fd. Set fh appropriately.
(cygheap_fdget::~cygheap_fdget): Decrement reference count when
appropriate. Delete fh if reference count goes to zero.
(cygheap_fdget::release): New function. Do more bookkeping on release.
* dtable.cc (dtable::release): Change from void to boolean return.
Only delete the fhandler when its reference count is <= 0 (this should
be a fairly unusual case). Return true if fhandler has been deleted.
(cygwin_attach_handle_to_fd): Increment reference count when fh is
assigned.
(dtable::init_std_file_from_handle): Ditto.
* dtable.h (dtable::release): Change return to boolean.
* fhandler.cc (fhandler_base::fhandler_base): Set new isclosed flag to
false. Set _refcnt to zero.
(fhandler_base::close): Simplify paranoid debugging output. Set new
isclosed() flag.
(fhandler_base_overlapped::wait_overlapped): Use isclosed() flag to
avoid querying the exception handle.
* fhandler.h (fhandler_base::_refcnt): New field.
(fhandler_base::refcnt): New function.
(fhandler_base::isclosed): Implement.
(fhandler_base::fhandler_base): Set isclosed to false.
* syscalls.cc: Remove space after function before parentheses for
several strace printfs.
(dup): Add standard strace "leaver" code.
(dup2): Ditto.
(dup3): Ditto.
(remove): Ditto.
(getpid): Ditto.
(getppid): Ditto.
(lseek64): Fix strace debugging to correctly use %R.
* fhandler_termios.cc (fhandler_termios::tcsetpgrp): Avoid sending
signals to other processes if we're debugging since it can cause a
deadlock with the calling debugger.
* exceptions.cc (_cygtls::call_signal_handler): Add debugging-only
strace output.
2011-12-16 Corinna Vinschen <vinschen@redhat.com>
* dcrt0.cc (child_info_fork::alloc_stack): Correctly check if the

34
winsup/cygwin/cygheap.h
View File

@ -328,10 +328,7 @@ class cygheap_fdmanip
if (locked)
cygheap->fdtab.unlock ();
}
void release ()
{
cygheap->fdtab.release (fd);
}
virtual void release () { cygheap->fdtab.release (fd); }
operator int &() {return fd;}
operator fhandler_base* &() {return cygheap->fdtab[fd];}
operator fhandler_socket* () const {return reinterpret_cast<fhandler_socket *> (cygheap->fdtab[fd]);}
@ -368,12 +365,18 @@ class cygheap_fdnew : public cygheap_fdmanip
locked = false;
}
}
~cygheap_fdnew ()
{
if (cygheap->fdtab[fd])
cygheap->fdtab[fd]->refcnt (1);
}
void operator = (fhandler_base *fh) {cygheap->fdtab[fd] = fh;}
};
class cygheap_fdget : public cygheap_fdmanip
{
public:
fhandler_base *fh;
public:
cygheap_fdget (int fd, bool lockit = false, bool do_set_errno = true)
{
if (lockit)
@ -382,6 +385,8 @@ class cygheap_fdget : public cygheap_fdmanip
{
this->fd = fd;
locked = lockit;
fh = cygheap->fdtab[fd];
fh->refcnt (1);
}
else
{
@ -391,8 +396,27 @@ class cygheap_fdget : public cygheap_fdmanip
if (lockit)
cygheap->fdtab.unlock ();
locked = false;
fh = NULL;
}
}
~cygheap_fdget ()
{
if (!fh)
/* nothing to do */;
else if (fh->refcnt (-1) > 0)
debug_only_printf ("fh %p, %s, refcnt %ld", fh, fh->get_name (), fh->refcnt ());
else
{
debug_only_printf ("deleting fh %p, %s, refcnt %ld", fh, fh->get_name (), fh->refcnt ());
delete fh;
}
}
void release ()
{
fh = cygheap->fdtab[fd];
if (cygheap->fdtab.release (fd))
fh = NULL;
}
};
class cygheap_fdenum : public cygheap_fdmanip

18
winsup/cygwin/dtable.cc
View File

@ -241,16 +241,26 @@ dtable::find_unused_handle (int start)
return -1;
}
void
bool
dtable::release (int fd)
{
if (!not_open (fd))
bool deleted;
if (not_open (fd))
deleted = false;
else
{
if (fds[fd]->need_fixup_before ())
dec_need_fixup_before ();
delete fds[fd];
if (fds[fd]->refcnt (-1) > 0)
deleted = false;
else
{
deleted = true;
delete fds[fd];
}
fds[fd] = NULL;
}
return deleted;
}
extern "C" int
@ -261,6 +271,7 @@ cygwin_attach_handle_to_fd (char *name, int fd, HANDLE handle, mode_t bin,
fd = cygheap->fdtab.find_unused_handle ();
fhandler_base *fh = build_fh_name (name);
cygheap->fdtab[fd] = fh;
cygheap->fdtab[fd]->refcnt (1);
fh->init (handle, myaccess, bin ?: fh->pc_binmode ());
return fd;
}
@ -395,6 +406,7 @@ dtable::init_std_file_from_handle (int fd, HANDLE handle)
fh->open_setup (openflags);
fh->usecount = 0;
cygheap->fdtab[fd] = fh;
cygheap->fdtab[fd]->refcnt (1);
set_std_handle (fd);
paranoid_printf ("fd %d, handle %p", fd, handle);
}

2
winsup/cygwin/dtable.h
View File

@ -63,7 +63,7 @@ public:
}
int find_unused_handle (int start);
int find_unused_handle () { return find_unused_handle (first_fd_for_open);}
void release (int fd);
bool release (int fd) __attribute__ ((regparm (2)));
void init_std_file_from_handle (int fd, HANDLE handle);
int dup3 (int oldfd, int newfd, int flags);
void fixup_after_exec ();

1
winsup/cygwin/exceptions.cc
View File

@ -1344,6 +1344,7 @@ _cygtls::call_signal_handler ()
if (!sig)
break;
debug_only_printf ("dealing with signal %d", sig);
this_sa_flags = sa_flags;
int thissig = sig;
void (*thisfunc) (int) = func;

11
winsup/cygwin/fhandler.cc
View File

@ -1148,11 +1148,10 @@ fhandler_base::close ()
res = 0;
else
{
paranoid_printf ("CloseHandle (%d <%s>) failed", get_handle (),
get_name ());
paranoid_printf ("CloseHandle failed, %E");
__seterrno ();
}
isclosed (true);
return res;
}
@ -1485,6 +1484,7 @@ fhandler_base::fhandler_base () :
access (0),
io_handle (NULL),
ino (0),
_refcnt (0),
openflags (0),
rabuf (NULL),
ralen (0),
@ -1495,6 +1495,7 @@ fhandler_base::fhandler_base () :
archetype (NULL),
usecount (0)
{
isclosed (false);
}
/* Normal I/O destructor */
@ -1928,8 +1929,8 @@ fhandler_base_overlapped::wait_overlapped (bool inres, bool writing, DWORD *byte
DWORD wfres = cygwait (get_overlapped ()->hEvent);
HANDLE h = writing ? get_output_handle () : get_handle ();
BOOL wores;
if (wfres == WAIT_OBJECT_0 + 1 && !get_overlapped ())
wores = 0;
if (isclosed ())
wores = 0; /* closed in another thread or via signal handler */
else
{
/* Cancelling here to prevent races. It's possible that the I/O has

6
winsup/cygwin/fhandler.h
View File

@ -142,12 +142,13 @@ class fhandler_base
read or write access */
unsigned close_on_exec : 1; /* close-on-exec */
unsigned need_fork_fixup : 1; /* Set if need to fixup after fork. */
unsigned isclosed : 1; /* Set when fhandler is closed. */
public:
status_flags () :
rbinary (0), rbinset (0), wbinary (0), wbinset (0), nohandle (0),
did_lseek (0), query_open (no_query), close_on_exec (0),
need_fork_fixup (0)
need_fork_fixup (0), isclosed (0)
{}
} status, open_status;
@ -158,6 +159,7 @@ class fhandler_base
HANDLE io_handle;
__ino64_t ino; /* file ID or hashed filename, depends on FS. */
long _refcnt;
protected:
/* File open flags from open () and fcntl () calls */
@ -176,6 +178,7 @@ class fhandler_base
HANDLE read_state;
public:
long refcnt(long i = 0) {return _refcnt += i;}
class fhandler_base *archetype;
int usecount;
@ -239,6 +242,7 @@ class fhandler_base
IMPLEMENT_STATUS_FLAG (query_state, query_open)
IMPLEMENT_STATUS_FLAG (bool, close_on_exec)
IMPLEMENT_STATUS_FLAG (bool, need_fork_fixup)
IMPLEMENT_STATUS_FLAG (bool, isclosed)
int get_default_fmode (int flags);

2
winsup/cygwin/fhandler_termios.cc
View File

@ -78,7 +78,7 @@ fhandler_termios::tcsetpgrp (const pid_t pgid)
{
case bg_ok:
tc ()->setpgid (pgid);
if (tc ()->is_console)
if (tc ()->is_console && (strace.active () || !being_debugged ()))
tc ()->kill_pgrp (__SIGSETPGRP);
res = 0;
break;

65
winsup/cygwin/syscalls.cc
View File

@ -120,51 +120,51 @@ close_all_files (bool norelease)
extern "C" int
dup (int fd)
{
return cygheap->fdtab.dup3 (fd, cygheap_fdnew (), 0);
int res = cygheap->fdtab.dup3 (fd, cygheap_fdnew (), 0);
syscall_printf ("%R = dup(%d)", res, fd);
return res;
}
extern "C" int
dup2 (int oldfd, int newfd)
{
int res;
if (newfd >= OPEN_MAX_MAX)
{
syscall_printf ("-1 = dup2 (%d, %d) (%d too large)", oldfd, newfd, newfd);
set_errno (EBADF);
return -1;
res = -1;
}
if (newfd == oldfd)
else if (newfd == oldfd)
{
cygheap_fdget cfd (oldfd);
if (cfd < 0)
{
syscall_printf ("%R = dup2(%d,%d) (oldfd not open)", -1, oldfd, newfd);
return -1;
}
syscall_printf ("%R = dup2(%d, %d) (newfd==oldfd)", oldfd, oldfd, newfd);
return oldfd;
res = (cfd >= 0) ? oldfd : -1;
}
return cygheap->fdtab.dup3 (oldfd, newfd, 0);
else
res = cygheap->fdtab.dup3 (oldfd, newfd, 0);
syscall_printf ("%R = dup2(%d, %d)", res, oldfd, newfd);
return res;
}
extern "C" int
dup3 (int oldfd, int newfd, int flags)
{
int res;
if (newfd >= OPEN_MAX_MAX)
{
syscall_printf ("-1 = dup3 (%d, %d, %p) (%d too large)",
oldfd, newfd, flags, newfd);
set_errno (EBADF);
return -1;
res = -1;
}
if (newfd == oldfd)
else if (newfd == oldfd)
{
cygheap_fdget cfd (oldfd, false, false);
set_errno (cfd < 0 ? EBADF : EINVAL);
syscall_printf ("-1 = dup3 (%d, %d, %p) (newfd==oldfd)",
oldfd, newfd, flags);
return -1;
res = -1;
}
return cygheap->fdtab.dup3 (oldfd, newfd, flags);
else
res = cygheap->fdtab.dup3 (oldfd, newfd, flags);
syscall_printf ("%R = dup2(%d, %d, %p)", res, oldfd, newfd, flags);
return res;
}
static inline void
@ -965,12 +965,15 @@ remove (const char *ourname)
return -1;
}
return win32_name.isdir () ? rmdir (ourname) : unlink (ourname);
int res = win32_name.isdir () ? rmdir (ourname) : unlink (ourname);
syscall_printf ("%R = remove(%s)", res, ourname);
return res;
}
extern "C" pid_t
getpid ()
{
syscall_printf ("%d = getpid()", myself->pid);
return myself->pid;
}
@ -984,6 +987,7 @@ _getpid_r (struct _reent *)
extern "C" pid_t
getppid ()
{
syscall_printf ("%d = getppid()", myself->ppid);
return myself->ppid;
}
@ -1041,6 +1045,7 @@ getsid (pid_t pid)
res = -1;
}
}
syscall_printf ("%R = getsid(%d)", pid);
return res;
}
@ -1066,7 +1071,7 @@ read (int fd, void *ptr, size_t len)
}
/* Could block, so let user know we at least got here. */
syscall_printf ("read (%d, %p, %d) %sblocking",
syscall_printf ("read(%d, %p, %d) %sblocking",
fd, ptr, len, cfd->is_nonblocking () ? "non" : "");
cfd->read (ptr, res = len);
@ -1108,7 +1113,7 @@ readv (int fd, const struct iovec *const iov, const int iovcnt)
}
/* Could block, so let user know we at least got here. */
syscall_printf ("readv (%d, %p, %d) %sblocking",
syscall_printf ("readv(%d, %p, %d) %sblocking",
fd, iov, iovcnt, cfd->is_nonblocking () ? "non" : "");
res = cfd->readv (iov, iovcnt, tot);
@ -1158,9 +1163,9 @@ write (int fd, const void *ptr, size_t len)
/* Could block, so let user know we at least got here. */
if (fd == 1 || fd == 2)
paranoid_printf ("write (%d, %p, %d)", fd, ptr, len);
paranoid_printf ("write(%d, %p, %d)", fd, ptr, len);
else
syscall_printf ("write (%d, %p, %d)", fd, ptr, len);
syscall_printf ("write(%d, %p, %d)", fd, ptr, len);
res = cfd->write (ptr, len);
@ -1206,9 +1211,9 @@ writev (const int fd, const struct iovec *const iov, const int iovcnt)
/* Could block, so let user know we at least got here. */
if (fd == 1 || fd == 2)
paranoid_printf ("writev (%d, %p, %d)", fd, iov, iovcnt);
paranoid_printf ("writev(%d, %p, %d)", fd, iov, iovcnt);
else
syscall_printf ("writev (%d, %p, %d)", fd, iov, iovcnt);
syscall_printf ("writev(%d, %p, %d)", fd, iov, iovcnt);
res = cfd->writev (iov, iovcnt, tot);
@ -1248,7 +1253,7 @@ open (const char *unix_path, int flags, ...)
va_list ap;
mode_t mode = 0;
syscall_printf ("open (%s, %p)", unix_path, flags);
syscall_printf ("open(%s, %p)", unix_path, flags);
pthread_testcancel ();
myfault efault;
if (efault.faulted (EFAULT))
@ -1341,7 +1346,7 @@ lseek64 (int fd, _off64_t pos, int dir)
else
res = -1;
}
syscall_printf ("%D = lseek (%d, %D, %d)", res, fd, pos, dir);
syscall_printf ("%R = lseek(%d, %D, %d)", res, fd, pos, dir);
return res;
}
@ -1361,7 +1366,7 @@ close (int fd)
{
int res;
syscall_printf ("close (%d)", fd);
syscall_printf ("close(%d)", fd);
pthread_testcancel ();