[newlib-cygwin] Cygwin: new class fhandler_pipe_fifo

[newlib-cygwin] Cygwin: new class fhandler_pipe_fifo

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=085fc12948881e624921f568a29881ce38795368

commit 085fc12948881e624921f568a29881ce38795368
Author: Ken Brown <kbrown@cornell.edu>
Date:   Fri Sep 3 19:41:52 2021 -0400

    Cygwin: new class fhandler_pipe_fifo
    
    This is a parent of fhandler_pipe and fhandler_fifo for code that is
    common between the two classes.  Currently it just contains
    max_atomic_write and raw_write().  The latter is identical to what
    used to be fhandler_pipe::raw_write().

Diff:
---
 winsup/cygwin/fhandler.h       | 21 ++++++---
 winsup/cygwin/fhandler_fifo.cc | 96 +-----------------------------------------
 winsup/cygwin/fhandler_pipe.cc | 13 ++++--
 3 files changed, 25 insertions(+), 105 deletions(-)

diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
index 032ab5fb0..bb7eb09ce 100644
--- a/winsup/cygwin/fhandler.h
+++ b/winsup/cygwin/fhandler.h
@@ -1168,12 +1168,24 @@ class fhandler_socket_unix : public fhandler_socket
 
 #endif /* __WITH_AF_UNIX */
 
-class fhandler_pipe: public fhandler_base
+/* A parent of fhandler_pipe and fhandler_fifo. */
+class fhandler_pipe_fifo: public fhandler_base
+{
+ protected:
+  size_t max_atomic_write;
+
+ public:
+  fhandler_pipe_fifo ();
+
+  ssize_t __reg3 raw_write (const void *ptr, size_t len);
+
+};
+
+class fhandler_pipe: public fhandler_pipe_fifo
 {
 private:
   HANDLE read_mtx;
   pid_t popen_pid;
-  size_t max_atomic_write;
   void set_pipe_non_blocking (bool nonblocking);
 public:
   fhandler_pipe ();
@@ -1193,7 +1205,6 @@ public:
   int dup (fhandler_base *child, int);
   int close ();
   void __reg3 raw_read (void *ptr, size_t& len);
-  ssize_t __reg3 raw_write (const void *ptr, size_t len);
   int ioctl (unsigned int cmd, void *);
   int fcntl (int cmd, intptr_t);
   int __reg2 fstat (struct stat *buf);
@@ -1319,7 +1330,7 @@ public:
   { InterlockedExchange (&_sh_fc_handler_updated, val); }
 };
 
-class fhandler_fifo: public fhandler_base
+class fhandler_fifo: public fhandler_pipe_fifo
 {
   /* Handles to named events shared by all fhandlers for a given FIFO. */
   HANDLE read_ready;            /* A reader is open; OK for a writer to open. */
@@ -1342,7 +1353,6 @@ class fhandler_fifo: public fhandler_base
   int nhandlers;                       /* Number of elements in the array. */
   af_unix_spinlock_t _fifo_client_lock;
   bool reader, writer, duplexer;
-  size_t max_atomic_write;
   fifo_reader_id_t me;
 
   HANDLE shmem_handle;
@@ -1447,7 +1457,6 @@ public:
   bool isfifo () const { return true; }
   void set_close_on_exec (bool val);
   void __reg3 raw_read (void *ptr, size_t& ulen);
-  ssize_t __reg3 raw_write (const void *ptr, size_t ulen);
   void fixup_after_fork (HANDLE);
   void fixup_after_exec ();
   int __reg2 fstat (struct stat *buf);
diff --git a/winsup/cygwin/fhandler_fifo.cc b/winsup/cygwin/fhandler_fifo.cc
index 08b292cad..6709fb974 100644
--- a/winsup/cygwin/fhandler_fifo.cc
+++ b/winsup/cygwin/fhandler_fifo.cc
@@ -128,13 +128,12 @@ STATUS_PIPE_EMPTY simply means there's no data to be read. */
 static NO_COPY fifo_reader_id_t null_fr_id = { .winpid = 0, .fh = NULL };
 
 fhandler_fifo::fhandler_fifo ():
-  fhandler_base (),
+  fhandler_pipe_fifo (),
   read_ready (NULL), write_ready (NULL), writer_opening (NULL),
   owner_needed_evt (NULL), owner_found_evt (NULL), update_needed_evt (NULL),
   cancel_evt (NULL), thr_sync_evt (NULL), pipe_name_buf (NULL),
   fc_handler (NULL), shandlers (0), nhandlers (0),
   reader (false), writer (false), duplexer (false),
-  max_atomic_write (DEFAULT_PIPEBUFSIZE),
   me (null_fr_id), shmem_handle (NULL), shmem (NULL),
   shared_fc_hdl (NULL), shared_fc_handler (NULL)
 {
@@ -1138,99 +1137,6 @@ fhandler_fifo::wait (HANDLE h)
    }
 }
 
-ssize_t __reg3
-fhandler_fifo::raw_write (const void *ptr, size_t len)
-{
-  ssize_t ret = -1;
-  size_t nbytes = 0;
-  ULONG chunk;
-  NTSTATUS status = STATUS_SUCCESS;
-  IO_STATUS_BLOCK io;
-  HANDLE evt = NULL;
-
-  if (!len)
-    return 0;
-
-  if (len <= max_atomic_write)
-    chunk = len;
-  else if (is_nonblocking ())
-    chunk = len = max_atomic_write;
-  else
-    chunk = max_atomic_write;
-
-  /* Create a wait event if the FIFO is in blocking mode. */
-  if (!is_nonblocking () && !(evt = CreateEvent (NULL, false, false, NULL)))
-    {
-      __seterrno ();
-      return -1;
-    }
-
-  /* Write in chunks, accumulating a total.  If there's an error, just
-     return the accumulated total unless the first write fails, in
-     which case return -1. */
-  while (nbytes < len)
-    {
-      ULONG_PTR nbytes_now = 0;
-      size_t left = len - nbytes;
-      ULONG len1;
-      DWORD waitret = WAIT_OBJECT_0;
-
-      if (left > chunk)
-	len1 = chunk;
-      else
-	len1 = (ULONG) left;
-      nbytes_now = 0;
-      status = NtWriteFile (get_handle (), evt, NULL, NULL, &io,
-			    (PVOID) ptr, len1, NULL, NULL);
-      if (evt && status == STATUS_PENDING)
-	{
-	  waitret = cygwait (evt);
-	  if (waitret == WAIT_OBJECT_0)
-	    status = io.Status;
-	}
-      if (waitret == WAIT_CANCELED)
-	status = STATUS_THREAD_CANCELED;
-      else if (waitret == WAIT_SIGNALED)
-	status = STATUS_THREAD_SIGNALED;
-      else if (isclosed ())  /* A signal handler might have closed the fd. */
-	{
-	  if (waitret == WAIT_OBJECT_0)
-	    set_errno (EBADF);
-	  else
-	    __seterrno ();
-	}
-      else if (NT_SUCCESS (status))
-	{
-	  nbytes_now = io.Information;
-	  /* NtWriteFile returns success with # of bytes written == 0
-	     if writing on a non-blocking pipe fails because the pipe
-	     buffer doesn't have sufficient space. */
-	  if (nbytes_now == 0)
-	    set_errno (EAGAIN);
-	  ptr = ((char *) ptr) + chunk;
-	  nbytes += nbytes_now;
-	}
-      else if (STATUS_PIPE_IS_CLOSED (status))
-	{
-	  set_errno (EPIPE);
-	  raise (SIGPIPE);
-	}
-      else
-	__seterrno_from_nt_status (status);
-      if (nbytes_now == 0)
-	len = 0;		/* Terminate loop. */
-      if (nbytes > 0)
-	ret = nbytes;
-    }
-  if (evt)
-    NtClose (evt);
-  if (status == STATUS_THREAD_SIGNALED && ret < 0)
-    set_errno (EINTR);
-  else if (status == STATUS_THREAD_CANCELED)
-    pthread::static_cancel_self ();
-  return ret;
-}
-
 /* Called from raw_read and select.cc:peek_fifo. */
 int
 fhandler_fifo::take_ownership (DWORD timeout)
diff --git a/winsup/cygwin/fhandler_pipe.cc b/winsup/cygwin/fhandler_pipe.cc
index 81b1aed5e..68974eb80 100644
--- a/winsup/cygwin/fhandler_pipe.cc
+++ b/winsup/cygwin/fhandler_pipe.cc
@@ -28,10 +28,15 @@ STATUS_PIPE_EMPTY simply means there's no data to be read. */
 		   || _s == STATUS_PIPE_BROKEN \
 		   || _s == STATUS_PIPE_EMPTY; })
 
+fhandler_pipe_fifo::fhandler_pipe_fifo ()
+  : fhandler_base (), max_atomic_write (DEFAULT_PIPEBUFSIZE)
+{
+}
+
+
 fhandler_pipe::fhandler_pipe ()
-  : fhandler_base (), popen_pid (0)
+  : fhandler_pipe_fifo (), popen_pid (0)
 {
-  max_atomic_write = DEFAULT_PIPEBUFSIZE;
   need_fork_fixup (true);
 }
 
@@ -340,7 +345,7 @@ fhandler_pipe::raw_read (void *ptr, size_t& len)
 }
 
 ssize_t __reg3
-fhandler_pipe::raw_write (const void *ptr, size_t len)
+fhandler_pipe_fifo::raw_write (const void *ptr, size_t len)
 {
   size_t nbytes = 0;
   ULONG chunk;
@@ -358,7 +363,7 @@ fhandler_pipe::raw_write (const void *ptr, size_t len)
   else
     chunk = max_atomic_write;
 
-  /* Create a wait event if the pipe is in blocking mode. */
+  /* Create a wait event if the pipe or fifo is in blocking mode. */
   if (!is_nonblocking () && !(evt = CreateEvent (NULL, false, false, NULL)))
     {
       __seterrno ();