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.

1 files changed, 5 insertions, 1 deletions

diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index b1324c563..0a73af82f 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -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);