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newlib/winsup/cygwin/fhandler_fifo.cc

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/* fhandler_fifo.cc - See fhandler.h for a description of the fhandler classes.
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 <w32api/winioctl.h>
#include "miscfuncs.h"
#include "cygerrno.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "sigproc.h"
#include "cygtls.h"
#include "shared_info.h"
#include "ntdll.h"
#include "cygwait.h"
#include <sys/param.h>
/*
Overview:
Currently a FIFO can be opened once for reading and multiple
times for writing. Any attempt to open the FIFO a second time
for reading fails with EACCES (from STATUS_ACCESS_DENIED).
When a FIFO is opened for reading,
fhandler_fifo::create_pipe_instance is called to create the first
instance of a Windows named pipe server (Windows terminology). A
"fifo_reader" thread is also started; it waits for pipe clients
(Windows terminology again) to connect. This happens every time
a process opens the FIFO for writing.
The fifo_reader thread creates new instances of the pipe server
as needed, so that there is always an instance available for a
writer to connect to.
The reader maintains a list of "fifo_client_handlers", one for
each pipe instance. A fifo_client_handler manages the connection
between the pipe instance and a writer connected to that pipe
instance.
TODO: Allow a FIFO to be opened multiple times for reading.
Maybe this could be done by using shared memory, so that all
readers could have access to the same list of writers.
*/
/* This is only to be used for writers. When reading,
STATUS_PIPE_EMPTY simply means there's no data to be read. */
#define STATUS_PIPE_IS_CLOSED(status) \
({ NTSTATUS _s = (status); \
_s == STATUS_PIPE_CLOSING \
|| _s == STATUS_PIPE_BROKEN \
|| _s == STATUS_PIPE_EMPTY; })
#define STATUS_PIPE_NO_INSTANCE_AVAILABLE(status) \
({ NTSTATUS _s = (status); \
_s == STATUS_INSTANCE_NOT_AVAILABLE \
|| _s == STATUS_PIPE_NOT_AVAILABLE \
|| _s == STATUS_PIPE_BUSY; })
/* Number of pages reserved for shared_fc_handler. */
#define SH_FC_HANDLER_PAGES 100
static NO_COPY fifo_reader_id_t null_fr_id = { .winpid = 0, .fh = NULL };
fhandler_fifo::fhandler_fifo ():
fhandler_base (),
read_ready (NULL), write_ready (NULL), writer_opening (NULL),
owner_needed_evt (NULL), owner_found_evt (NULL), update_needed_evt (NULL),
check_write_ready_evt (NULL), write_ready_ok_evt (NULL),
cancel_evt (NULL), thr_sync_evt (NULL), _maybe_eof (false),
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)
{
pipe_name_buf[0] = L'\0';
need_fork_fixup (true);
}
PUNICODE_STRING
fhandler_fifo::get_pipe_name ()
{
if (!pipe_name_buf[0])
{
__small_swprintf (pipe_name_buf, L"%S-fifo.%08x.%016X",
&cygheap->installation_key, get_dev (), get_ino ());
RtlInitUnicodeString (&pipe_name, pipe_name_buf);
}
return &pipe_name;
}
inline PSECURITY_ATTRIBUTES
sec_user_cloexec (bool cloexec, PSECURITY_ATTRIBUTES sa, PSID sid)
{
return cloexec ? sec_user_nih (sa, sid) : sec_user (sa, sid);
}
static HANDLE
create_event (bool inherit = false)
{
NTSTATUS status;
OBJECT_ATTRIBUTES attr;
HANDLE evt = NULL;
InitializeObjectAttributes (&attr, NULL, inherit ? OBJ_INHERIT : 0,
NULL, NULL);
status = NtCreateEvent (&evt, EVENT_ALL_ACCESS, &attr,
NotificationEvent, FALSE);
if (!NT_SUCCESS (status))
__seterrno_from_nt_status (status);
return evt;
}
static void
set_pipe_non_blocking (HANDLE ph, bool nonblocking)
{
NTSTATUS status;
IO_STATUS_BLOCK io;
FILE_PIPE_INFORMATION fpi;
fpi.ReadMode = FILE_PIPE_MESSAGE_MODE;
fpi.CompletionMode = nonblocking ? FILE_PIPE_COMPLETE_OPERATION
: FILE_PIPE_QUEUE_OPERATION;
status = NtSetInformationFile (ph, &io, &fpi, sizeof fpi,
FilePipeInformation);
if (!NT_SUCCESS (status))
debug_printf ("NtSetInformationFile(FilePipeInformation): %y", status);
}
NTSTATUS
fhandler_fifo::npfs_handle (HANDLE &nph)
{
static NO_COPY SRWLOCK npfs_lock;
static NO_COPY HANDLE npfs_dirh;
NTSTATUS status = STATUS_SUCCESS;
OBJECT_ATTRIBUTES attr;
IO_STATUS_BLOCK io;
/* Lockless after first call. */
if (npfs_dirh)
{
nph = npfs_dirh;
return STATUS_SUCCESS;
}
AcquireSRWLockExclusive (&npfs_lock);
if (!npfs_dirh)
{
InitializeObjectAttributes (&attr, &ro_u_npfs, 0, NULL, NULL);
status = NtOpenFile (&npfs_dirh, FILE_READ_ATTRIBUTES | SYNCHRONIZE,
&attr, &io, FILE_SHARE_READ | FILE_SHARE_WRITE,
0);
}
ReleaseSRWLockExclusive (&npfs_lock);
if (NT_SUCCESS (status))
nph = npfs_dirh;
return status;
}
/* Called when a FIFO is first opened for reading and again each time
a new client handler is needed. Each pipe instance is created in
blocking mode so that we can easily wait for a connection. After
it is connected, it is put in nonblocking mode. */
HANDLE
fhandler_fifo::create_pipe_instance ()
{
NTSTATUS status;
HANDLE npfsh;
HANDLE ph = NULL;
ACCESS_MASK access;
OBJECT_ATTRIBUTES attr;
IO_STATUS_BLOCK io;
ULONG hattr;
ULONG sharing;
ULONG nonblocking = FILE_PIPE_QUEUE_OPERATION;
ULONG max_instances = -1;
LARGE_INTEGER timeout;
status = npfs_handle (npfsh);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
return NULL;
}
access = GENERIC_READ | FILE_READ_ATTRIBUTES | FILE_WRITE_ATTRIBUTES
| SYNCHRONIZE;
sharing = FILE_SHARE_READ | FILE_SHARE_WRITE;
hattr = (openflags & O_CLOEXEC ? 0 : OBJ_INHERIT) | OBJ_CASE_INSENSITIVE;
InitializeObjectAttributes (&attr, get_pipe_name (),
hattr, npfsh, NULL);
timeout.QuadPart = -500000;
status = NtCreateNamedPipeFile (&ph, access, &attr, &io, sharing,
FILE_OPEN_IF, 0,
FILE_PIPE_MESSAGE_TYPE
| FILE_PIPE_REJECT_REMOTE_CLIENTS,
FILE_PIPE_MESSAGE_MODE,
nonblocking, max_instances,
DEFAULT_PIPEBUFSIZE, DEFAULT_PIPEBUFSIZE,
&timeout);
if (!NT_SUCCESS (status))
__seterrno_from_nt_status (status);
return ph;
}
/* Connect to a pipe instance. */
NTSTATUS
fhandler_fifo::open_pipe (HANDLE& ph)
{
NTSTATUS status;
HANDLE npfsh;
ACCESS_MASK access;
OBJECT_ATTRIBUTES attr;
IO_STATUS_BLOCK io;
ULONG sharing;
status = npfs_handle (npfsh);
if (!NT_SUCCESS (status))
return status;
access = GENERIC_WRITE | SYNCHRONIZE;
InitializeObjectAttributes (&attr, get_pipe_name (),
openflags & O_CLOEXEC ? 0 : OBJ_INHERIT,
npfsh, NULL);
sharing = FILE_SHARE_READ | FILE_SHARE_WRITE;
return NtOpenFile (&ph, access, &attr, &io, sharing, 0);
}
/* Wait up to 100ms for a pipe instance to be available, then connect. */
NTSTATUS
fhandler_fifo::wait_open_pipe (HANDLE& ph)
{
HANDLE npfsh;
HANDLE evt;
NTSTATUS status;
IO_STATUS_BLOCK io;
ULONG pwbuf_size;
PFILE_PIPE_WAIT_FOR_BUFFER pwbuf;
LONGLONG stamp;
LONGLONG orig_timeout = -100 * NS100PERSEC / MSPERSEC; /* 100ms */
status = npfs_handle (npfsh);
if (!NT_SUCCESS (status))
return status;
if (!(evt = create_event ()))
api_fatal ("Can't create event, %E");
pwbuf_size
= offsetof (FILE_PIPE_WAIT_FOR_BUFFER, Name) + get_pipe_name ()->Length;
pwbuf = (PFILE_PIPE_WAIT_FOR_BUFFER) alloca (pwbuf_size);
pwbuf->Timeout.QuadPart = orig_timeout;
pwbuf->NameLength = get_pipe_name ()->Length;
pwbuf->TimeoutSpecified = TRUE;
memcpy (pwbuf->Name, get_pipe_name ()->Buffer, get_pipe_name ()->Length);
stamp = get_clock (CLOCK_MONOTONIC)->n100secs ();
bool retry;
do
{
retry = false;
status = NtFsControlFile (npfsh, evt, NULL, NULL, &io, FSCTL_PIPE_WAIT,
pwbuf, pwbuf_size, NULL, 0);
if (status == STATUS_PENDING)
{
if (WaitForSingleObject (evt, INFINITE) == WAIT_OBJECT_0)
status = io.Status;
else
api_fatal ("WFSO failed, %E");
}
if (NT_SUCCESS (status))
status = open_pipe (ph);
if (STATUS_PIPE_NO_INSTANCE_AVAILABLE (status))
{
/* Another writer has grabbed the pipe instance. Adjust
the timeout and keep waiting if there's time left. */
pwbuf->Timeout.QuadPart = orig_timeout
+ get_clock (CLOCK_MONOTONIC)->n100secs () - stamp;
if (pwbuf->Timeout.QuadPart < 0)
retry = true;
else
status = STATUS_IO_TIMEOUT;
}
}
while (retry);
NtClose (evt);
return status;
}
int
fhandler_fifo::add_client_handler (bool new_pipe_instance)
{
fifo_client_handler fc;
if (nhandlers >= shandlers)
{
void *temp = realloc (fc_handler,
(shandlers += 64) * sizeof (fc_handler[0]));
if (!temp)
{
shandlers -= 64;
set_errno (ENOMEM);
return -1;
}
fc_handler = (fifo_client_handler *) temp;
}
if (new_pipe_instance)
{
HANDLE ph = create_pipe_instance ();
if (!ph)
return -1;
fc.h = ph;
fc.state = fc_listening;
}
fc_handler[nhandlers++] = fc;
return 0;
}
void
fhandler_fifo::delete_client_handler (int i)
{
fc_handler[i].close ();
if (i < --nhandlers)
memmove (fc_handler + i, fc_handler + i + 1,
(nhandlers - i) * sizeof (fc_handler[i]));
}
/* Delete invalid handlers. */
void
fhandler_fifo::cleanup_handlers ()
{
int i = 0;
while (i < nhandlers)
{
if (fc_handler[i].state < fc_connected)
delete_client_handler (i);
else
i++;
}
}
void
fhandler_fifo::record_connection (fifo_client_handler& fc,
fifo_client_connect_state s)
{
fc.state = s;
maybe_eof (false);
ResetEvent (writer_opening);
set_pipe_non_blocking (fc.h, true);
}
/* Called from fifo_reader_thread_func with owner_lock in place, also
from fixup_after_exec with shared handles useable as they are. */
int
fhandler_fifo::update_my_handlers (bool from_exec)
{
if (from_exec)
{
nhandlers = get_shared_nhandlers ();
if (nhandlers > shandlers)
{
int save = shandlers;
shandlers = nhandlers + 64;
void *temp = realloc (fc_handler,
shandlers * sizeof (fc_handler[0]));
if (!temp)
{
shandlers = save;
nhandlers = 0;
set_errno (ENOMEM);
return -1;
}
fc_handler = (fifo_client_handler *) temp;
}
memcpy (fc_handler, shared_fc_handler,
nhandlers * sizeof (fc_handler[0]));
}
else
{
close_all_handlers ();
fifo_reader_id_t prev = get_prev_owner ();
if (!prev)
{
debug_printf ("No previous owner to copy handles from");
return 0;
}
HANDLE prev_proc;
if (prev.winpid == me.winpid)
prev_proc = GetCurrentProcess ();
else
prev_proc = OpenProcess (PROCESS_DUP_HANDLE, false, prev.winpid);
if (!prev_proc)
{
debug_printf ("Can't open process of previous owner, %E");
__seterrno ();
return -1;
}
for (int i = 0; i < get_shared_nhandlers (); i++)
{
/* Should never happen. */
if (shared_fc_handler[i].state < fc_connected)
continue;
if (add_client_handler (false) < 0)
api_fatal ("Can't add client handler, %E");
fifo_client_handler &fc = fc_handler[nhandlers - 1];
if (!DuplicateHandle (prev_proc, shared_fc_handler[i].h,
GetCurrentProcess (), &fc.h, 0,
!close_on_exec (), DUPLICATE_SAME_ACCESS))
{
debug_printf ("Can't duplicate handle of previous owner, %E");
--nhandlers;
__seterrno ();
return -1;
}
fc.state = shared_fc_handler[i].state;
}
}
return 0;
}
int
fhandler_fifo::update_shared_handlers ()
{
cleanup_handlers ();
if (nhandlers > get_shared_shandlers ())
{
if (remap_shared_fc_handler (nhandlers * sizeof (fc_handler[0])) < 0)
return -1;
}
set_shared_nhandlers (nhandlers);
memcpy (shared_fc_handler, fc_handler, nhandlers * sizeof (fc_handler[0]));
shared_fc_handler_updated (true);
set_prev_owner (me);
return 0;
}
/* The write_ready event gets set when a writer opens, to indicate
that a blocking reader can open. If a second reader wants to open,
we need to see if there are still any writers open. */
void
fhandler_fifo::check_write_ready ()
{
bool set = false;
fifo_client_lock ();
for (int i = 0; i < nhandlers && !set; i++)
switch (fc_handler[i].pipe_state ())
{
case FILE_PIPE_CONNECTED_STATE:
fc_handler[i].state = fc_connected;
set = true;
break;
case FILE_PIPE_INPUT_AVAILABLE_STATE:
fc_handler[i].state = fc_input_avail;
set = true;
break;
case FILE_PIPE_DISCONNECTED_STATE:
fc_handler[i].state = fc_disconnected;
break;
case FILE_PIPE_LISTENING_STATE:
fc_handler[i].state = fc_listening;
case FILE_PIPE_CLOSING_STATE:
fc_handler[i].state = fc_closing;
default:
fc_handler[i].state = fc_error;
break;
}
fifo_client_unlock ();
if (set || IsEventSignalled (writer_opening))
SetEvent (write_ready);
else
ResetEvent (write_ready);
SetEvent (write_ready_ok_evt);
}
static DWORD WINAPI
fifo_reader_thread (LPVOID param)
{
fhandler_fifo *fh = (fhandler_fifo *) param;
return fh->fifo_reader_thread_func ();
}
DWORD
fhandler_fifo::fifo_reader_thread_func ()
{
HANDLE conn_evt;
if (!(conn_evt = CreateEvent (NULL, false, false, NULL)))
api_fatal ("Can't create connection event, %E");
while (1)
{
fifo_reader_id_t cur_owner, pending_owner;
bool idle = false, take_ownership = false;
owner_lock ();
cur_owner = get_owner ();
pending_owner = get_pending_owner ();
if (pending_owner)
{
if (pending_owner != me)
idle = true;
else
take_ownership = true;
}
else if (!cur_owner)
take_ownership = true;
else if (cur_owner != me)
idle = true;
if (take_ownership)
{
if (!shared_fc_handler_updated ())
{
owner_unlock ();
yield ();
continue;
}
else
{
set_owner (me);
set_pending_owner (null_fr_id);
if (update_my_handlers () < 0)
api_fatal ("Can't update my handlers, %E");
owner_found ();
owner_unlock ();
continue;
}
}
else if (idle)
{
owner_unlock ();
HANDLE w[2] = { owner_needed_evt, cancel_evt };
switch (WaitForMultipleObjects (2, w, false, INFINITE))
{
case WAIT_OBJECT_0:
continue;
case WAIT_OBJECT_0 + 1:
goto canceled;
default:
api_fatal ("WFMO failed, %E");
}
}
else
{
/* I'm the owner */
fifo_client_lock ();
cleanup_handlers ();
if (add_client_handler () < 0)
api_fatal ("Can't add a client handler, %E");
/* Listen for a writer to connect to the new client handler. */
fifo_client_handler& fc = fc_handler[nhandlers - 1];
fifo_client_unlock ();
shared_fc_handler_updated (false);
owner_unlock ();
NTSTATUS status;
IO_STATUS_BLOCK io;
bool cancel = false;
bool update = false;
bool check = false;
status = NtFsControlFile (fc.h, conn_evt, NULL, NULL, &io,
FSCTL_PIPE_LISTEN, NULL, 0, NULL, 0);
if (status == STATUS_PENDING)
{
HANDLE w[4] = { conn_evt, update_needed_evt,
check_write_ready_evt, cancel_evt };
switch (WaitForMultipleObjects (4, w, false, INFINITE))
{
case WAIT_OBJECT_0:
status = io.Status;
debug_printf ("NtFsControlFile STATUS_PENDING, then %y",
status);
break;
case WAIT_OBJECT_0 + 1:
status = STATUS_WAIT_1;
update = true;
break;
case WAIT_OBJECT_0 + 2:
status = STATUS_WAIT_2;
check = true;
break;
case WAIT_OBJECT_0 + 3:
status = STATUS_THREAD_IS_TERMINATING;
cancel = true;
update = true;
break;
default:
api_fatal ("WFMO failed, %E");
}
}
else
debug_printf ("NtFsControlFile status %y, no STATUS_PENDING",
status);
HANDLE ph = NULL;
NTSTATUS status1;
fifo_client_lock ();
switch (status)
{
case STATUS_SUCCESS:
case STATUS_PIPE_CONNECTED:
record_connection (fc);
break;
case STATUS_PIPE_CLOSING:
record_connection (fc, fc_closing);
break;
case STATUS_THREAD_IS_TERMINATING:
case STATUS_WAIT_1:
case STATUS_WAIT_2:
/* Try to connect a bogus client. Otherwise fc is still
listening, and the next connection might not get recorded. */
status1 = open_pipe (ph);
WaitForSingleObject (conn_evt, INFINITE);
if (NT_SUCCESS (status1))
/* Bogus cilent connected. */
delete_client_handler (nhandlers - 1);
else
/* Did a real client connect? */
switch (io.Status)
{
case STATUS_SUCCESS:
case STATUS_PIPE_CONNECTED:
record_connection (fc);
break;
case STATUS_PIPE_CLOSING:
record_connection (fc, fc_closing);
break;
default:
debug_printf ("NtFsControlFile status %y after failing to connect bogus client or real client", io.Status);
fc.state = fc_unknown;
break;
}
break;
default:
break;
}
fifo_client_unlock ();
if (ph)
NtClose (ph);
if (update && update_shared_handlers () < 0)
api_fatal ("Can't update shared handlers, %E");
if (check)
check_write_ready ();
if (cancel)
goto canceled;
}
}
canceled:
if (conn_evt)
NtClose (conn_evt);
/* automatically return the cygthread to the cygthread pool */
_my_tls._ctinfo->auto_release ();
return 0;
}
int
fhandler_fifo::create_shmem ()
{
HANDLE sect;
OBJECT_ATTRIBUTES attr;
NTSTATUS status;
LARGE_INTEGER size = { .QuadPart = sizeof (fifo_shmem_t) };
SIZE_T viewsize = sizeof (fifo_shmem_t);
PVOID addr = NULL;
UNICODE_STRING uname;
WCHAR shmem_name[MAX_PATH];
__small_swprintf (shmem_name, L"fifo-shmem.%08x.%016X", get_dev (),
get_ino ());
RtlInitUnicodeString (&uname, shmem_name);
InitializeObjectAttributes (&attr, &uname, OBJ_INHERIT,
get_shared_parent_dir (), NULL);
status = NtCreateSection (&sect, STANDARD_RIGHTS_REQUIRED | SECTION_QUERY
| SECTION_MAP_READ | SECTION_MAP_WRITE,
&attr, &size, PAGE_READWRITE, SEC_COMMIT, NULL);
if (status == STATUS_OBJECT_NAME_COLLISION)
status = NtOpenSection (&sect, STANDARD_RIGHTS_REQUIRED | SECTION_QUERY
| SECTION_MAP_READ | SECTION_MAP_WRITE, &attr);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
return -1;
}
status = NtMapViewOfSection (sect, NtCurrentProcess (), &addr, 0, viewsize,
NULL, &viewsize, ViewShare, 0, PAGE_READWRITE);
if (!NT_SUCCESS (status))
{
NtClose (sect);
__seterrno_from_nt_status (status);
return -1;
}
shmem_handle = sect;
shmem = (fifo_shmem_t *) addr;
return 0;
}
/* shmem_handle must be valid when this is called. */
int
fhandler_fifo::reopen_shmem ()
{
NTSTATUS status;
SIZE_T viewsize = sizeof (fifo_shmem_t);
PVOID addr = NULL;
status = NtMapViewOfSection (shmem_handle, NtCurrentProcess (), &addr,
0, viewsize, NULL, &viewsize, ViewShare,
0, PAGE_READWRITE);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
return -1;
}
shmem = (fifo_shmem_t *) addr;
return 0;
}
/* On first creation, map and commit one page of memory. */
int
fhandler_fifo::create_shared_fc_handler ()
{
HANDLE sect;
OBJECT_ATTRIBUTES attr;
NTSTATUS status;
LARGE_INTEGER size
= { .QuadPart = (LONGLONG) (SH_FC_HANDLER_PAGES * wincap.page_size ()) };
SIZE_T viewsize = get_shared_fc_handler_committed () ?: wincap.page_size ();
PVOID addr = NULL;
UNICODE_STRING uname;
WCHAR shared_fc_name[MAX_PATH];
__small_swprintf (shared_fc_name, L"fifo-shared-fc.%08x.%016X", get_dev (),
get_ino ());
RtlInitUnicodeString (&uname, shared_fc_name);
InitializeObjectAttributes (&attr, &uname, OBJ_INHERIT,
get_shared_parent_dir (), NULL);
status = NtCreateSection (&sect, STANDARD_RIGHTS_REQUIRED | SECTION_QUERY
| SECTION_MAP_READ | SECTION_MAP_WRITE, &attr,
&size, PAGE_READWRITE, SEC_RESERVE, NULL);
if (status == STATUS_OBJECT_NAME_COLLISION)
status = NtOpenSection (&sect, STANDARD_RIGHTS_REQUIRED | SECTION_QUERY
| SECTION_MAP_READ | SECTION_MAP_WRITE, &attr);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
return -1;
}
status = NtMapViewOfSection (sect, NtCurrentProcess (), &addr, 0, viewsize,
NULL, &viewsize, ViewShare, 0, PAGE_READWRITE);
if (!NT_SUCCESS (status))
{
NtClose (sect);
__seterrno_from_nt_status (status);
return -1;
}
shared_fc_hdl = sect;
shared_fc_handler = (fifo_client_handler *) addr;
if (!get_shared_fc_handler_committed ())
set_shared_fc_handler_committed (viewsize);
set_shared_shandlers (viewsize / sizeof (fifo_client_handler));
return 0;
}
/* shared_fc_hdl must be valid when this is called. */
int
fhandler_fifo::reopen_shared_fc_handler ()
{
NTSTATUS status;
SIZE_T viewsize = get_shared_fc_handler_committed ();
PVOID addr = NULL;
status = NtMapViewOfSection (shared_fc_hdl, NtCurrentProcess (),
&addr, 0, viewsize, NULL, &viewsize,
ViewShare, 0, PAGE_READWRITE);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
return -1;
}
shared_fc_handler = (fifo_client_handler *) addr;
return 0;
}
int
fhandler_fifo::remap_shared_fc_handler (size_t nbytes)
{
NTSTATUS status;
SIZE_T viewsize = roundup2 (nbytes, wincap.page_size ());
PVOID addr = NULL;
if (viewsize > SH_FC_HANDLER_PAGES * wincap.page_size ())
{
set_errno (ENOMEM);
return -1;
}
NtUnmapViewOfSection (NtCurrentProcess (), shared_fc_handler);
status = NtMapViewOfSection (shared_fc_hdl, NtCurrentProcess (),
&addr, 0, viewsize, NULL, &viewsize,
ViewShare, 0, PAGE_READWRITE);
if (!NT_SUCCESS (status))
{
__seterrno_from_nt_status (status);
return -1;
}
shared_fc_handler = (fifo_client_handler *) addr;
set_shared_fc_handler_committed (viewsize);
set_shared_shandlers (viewsize / sizeof (fc_handler[0]));
return 0;
}
int
fhandler_fifo::open (int flags, mode_t)
{
int saved_errno = 0;
if (flags & O_PATH)
return open_fs (flags);
/* Determine what we're doing with this fhandler: reading, writing, both */
switch (flags & O_ACCMODE)
{
case O_RDONLY:
reader = true;
break;
case O_WRONLY:
writer = true;
break;
case O_RDWR:
reader = true;
duplexer = true;
break;
default:
set_errno (EINVAL);
goto err;
}
debug_only_printf ("reader %d, writer %d, duplexer %d", reader, writer, duplexer);
set_flags (flags);
if (reader && !duplexer)
nohandle (true);
/* Create control events for this named pipe */
char char_sa_buf[1024];
LPSECURITY_ATTRIBUTES sa_buf;
sa_buf = sec_user_cloexec (flags & O_CLOEXEC, (PSECURITY_ATTRIBUTES) char_sa_buf,
cygheap->user.sid());
char npbuf[MAX_PATH];
__small_sprintf (npbuf, "r-event.%08x.%016X", get_dev (), get_ino ());
if (!(read_ready = CreateEvent (sa_buf, true, false, npbuf)))
{
debug_printf ("CreateEvent for %s failed, %E", npbuf);
__seterrno ();
goto err;
}
npbuf[0] = 'w';
if (!(write_ready = CreateEvent (sa_buf, true, false, npbuf)))
{
debug_printf ("CreateEvent for %s failed, %E", npbuf);
__seterrno ();
goto err_close_read_ready;
}
npbuf[0] = 'o';
if (!(writer_opening = CreateEvent (sa_buf, true, false, npbuf)))
{
debug_printf ("CreateEvent for %s failed, %E", npbuf);
__seterrno ();
goto err_close_write_ready;
}
/* If we're reading, signal read_ready, create the shared memory,
and start the fifo_reader_thread. */
if (reader)
{
bool first = true;
SetEvent (read_ready);
if (create_shmem () < 0)
goto err_close_writer_opening;
if (create_shared_fc_handler () < 0)
goto err_close_shmem;
reader_opening_lock ();
if (inc_nreaders () == 1)
/* Reinitialize _sh_fc_handler_updated, which starts as 0. */
shared_fc_handler_updated (true);
else
first = false;
npbuf[0] = 'n';
if (!(owner_needed_evt = CreateEvent (sa_buf, true, false, npbuf)))
{
debug_printf ("CreateEvent for %s failed, %E", npbuf);
__seterrno ();
goto err_dec_nreaders;
}
npbuf[0] = 'f';
if (!(owner_found_evt = CreateEvent (sa_buf, true, false, npbuf)))
{
debug_printf ("CreateEvent for %s failed, %E", npbuf);
__seterrno ();
goto err_close_owner_needed_evt;
}
npbuf[0] = 'u';
if (!(update_needed_evt = CreateEvent (sa_buf, false, false, npbuf)))
{
debug_printf ("CreateEvent for %s failed, %E", npbuf);
__seterrno ();
goto err_close_owner_found_evt;
}
npbuf[0] = 'c';
if (!(check_write_ready_evt = CreateEvent (sa_buf, false, false, npbuf)))
{
debug_printf ("CreateEvent for %s failed, %E", npbuf);
__seterrno ();
goto err_close_update_needed_evt;
}
npbuf[0] = 'k';
if (!(write_ready_ok_evt = CreateEvent (sa_buf, false, false, npbuf)))
{
debug_printf ("CreateEvent for %s failed, %E", npbuf);
__seterrno ();
goto err_close_check_write_ready_evt;
}
/* Make cancel and sync inheritable for exec. */
if (!(cancel_evt = create_event (true)))
goto err_close_write_ready_ok_evt;
if (!(thr_sync_evt = create_event (true)))
goto err_close_cancel_evt;
me.winpid = GetCurrentProcessId ();
me.fh = this;
new cygthread (fifo_reader_thread, this, "fifo_reader", thr_sync_evt);
/* Wait until there's an owner. */
owner_lock ();
while (!get_owner ())
{
owner_unlock ();
yield ();
owner_lock ();
}
owner_unlock ();
/* If we're a duplexer, we need a handle for writing. */
if (duplexer)
{
HANDLE ph = NULL;
NTSTATUS status;
while (1)
{
status = open_pipe (ph);
if (NT_SUCCESS (status))
{
set_handle (ph);
set_pipe_non_blocking (ph, flags & O_NONBLOCK);
break;
}
else if (status == STATUS_OBJECT_NAME_NOT_FOUND)
{
/* The pipe hasn't been created yet. */
yield ();
continue;
}
else
{
__seterrno_from_nt_status (status);
goto err_close_reader;
}
}
}
/* Not a duplexer; wait for a writer to connect if we're blocking. */
else if (!(flags & O_NONBLOCK))
{
if (!first)
{
/* Ask the owner to update write_ready. */
SetEvent (check_write_ready_evt);
WaitForSingleObject (write_ready_ok_evt, INFINITE);
}
if (!wait (write_ready))
goto err_close_reader;
}
reader_opening_unlock ();
goto success;
}
/* If we're writing, wait for read_ready, connect to the pipe, and
signal write_ready. */
if (writer)
{
NTSTATUS status;
SetEvent (writer_opening);
if (!wait (read_ready))
{
ResetEvent (writer_opening);
goto err_close_writer_opening;
}
while (1)
{
status = open_pipe (get_handle ());
if (NT_SUCCESS (status))
goto writer_success;
else if (status == STATUS_OBJECT_NAME_NOT_FOUND)
{
/* The pipe hasn't been created yet. */
yield ();
continue;
}
else if (STATUS_PIPE_NO_INSTANCE_AVAILABLE (status))
break;
else
{
debug_printf ("create of writer failed");
__seterrno_from_nt_status (status);
ResetEvent (writer_opening);
goto err_close_writer_opening;
}
}
/* We should get here only if the system is heavily loaded
and/or many writers are trying to connect simultaneously */
while (1)
{
SetEvent (writer_opening);
if (!wait (read_ready))
{
ResetEvent (writer_opening);
goto err_close_writer_opening;
}
status = wait_open_pipe (get_handle ());
if (NT_SUCCESS (status))
goto writer_success;
else if (status == STATUS_IO_TIMEOUT)
continue;
else
{
debug_printf ("create of writer failed");
__seterrno_from_nt_status (status);
ResetEvent (writer_opening);
goto err_close_writer_opening;
}
}
}
writer_success:
set_pipe_non_blocking (get_handle (), flags & O_NONBLOCK);
SetEvent (write_ready);
success:
return 1;
err_close_reader:
saved_errno = get_errno ();
close ();
set_errno (saved_errno);
return 0;
err_close_cancel_evt:
NtClose (cancel_evt);
err_close_write_ready_ok_evt:
NtClose (write_ready_ok_evt);
err_close_check_write_ready_evt:
NtClose (check_write_ready_evt);
err_close_update_needed_evt:
NtClose (update_needed_evt);
err_close_owner_found_evt:
NtClose (owner_found_evt);
err_close_owner_needed_evt:
NtClose (owner_needed_evt);
err_dec_nreaders:
if (dec_nreaders () == 0)
ResetEvent (read_ready);
reader_opening_unlock ();
/* err_close_shared_fc_handler: */
NtUnmapViewOfSection (NtCurrentProcess (), shared_fc_handler);
NtClose (shared_fc_hdl);
err_close_shmem:
NtUnmapViewOfSection (NtCurrentProcess (), shmem);
NtClose (shmem_handle);
err_close_writer_opening:
NtClose (writer_opening);
err_close_write_ready:
NtClose (write_ready);
err_close_read_ready:
NtClose (read_ready);
err:
if (get_handle ())
NtClose (get_handle ());
return 0;
}
off_t
fhandler_fifo::lseek (off_t offset, int whence)
{
debug_printf ("(%D, %d)", offset, whence);
set_errno (ESPIPE);
return -1;
}
bool
fhandler_fifo::wait (HANDLE h)
{
#ifdef DEBUGGING
const char *what;
if (h == read_ready)
what = "reader";
else
what = "writer";
#endif
/* Set the wait to zero for non-blocking I/O-related events. */
DWORD wait = ((h == read_ready || h == write_ready)
&& get_flags () & O_NONBLOCK) ? 0 : INFINITE;
debug_only_printf ("waiting for %s", what);
/* Wait for the event. Set errno, as appropriate if something goes wrong. */
switch (cygwait (h, wait))
{
case WAIT_OBJECT_0:
debug_only_printf ("successfully waited for %s", what);
return true;
case WAIT_SIGNALED:
debug_only_printf ("interrupted by signal while waiting for %s", what);
set_errno (EINTR);
return false;
case WAIT_CANCELED:
debug_only_printf ("cancellable interruption while waiting for %s", what);
pthread::static_cancel_self (); /* never returns */
break;
case WAIT_TIMEOUT:
if (h == write_ready)
{
debug_only_printf ("wait timed out waiting for write but will still open reader since non-blocking mode");
return true;
}
else
{
set_errno (ENXIO);
return false;
}
break;
default:
debug_only_printf ("unknown error while waiting for %s", what);
__seterrno ();
return false;
}
}
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;
}
/* A reader is at EOF if the pipe is empty and no writers are open.
hit_eof is called by raw_read and select.cc:peek_fifo if it appears
that we are at EOF after polling the fc_handlers. We recheck this
in case a writer opened while we were polling. */
bool
fhandler_fifo::hit_eof ()
{
bool ret = maybe_eof () && !IsEventSignalled (writer_opening);
if (ret)
{
yield ();
/* Wait for the reader thread to finish recording any connection. */
fifo_client_lock ();
fifo_client_unlock ();
ret = maybe_eof ();
}
return ret;
}
/* Called from raw_read and select.cc:peek_fifo. */
void
fhandler_fifo::take_ownership ()
{
owner_lock ();
if (get_owner () == me)
{
owner_unlock ();
return;
}
set_pending_owner (me);
owner_needed ();
SetEvent (update_needed_evt);
owner_unlock ();
/* The reader threads should now do the transfer. */
WaitForSingleObject (owner_found_evt, INFINITE);
}
void __reg3
fhandler_fifo::raw_read (void *in_ptr, size_t& len)
{
if (!len)
return;
while (1)
{
/* No one else can take ownership while we hold the reading_lock. */
reading_lock ();
take_ownership ();
/* Poll the connected clients for input. */
int nconnected = 0;
fifo_client_lock ();
for (int i = 0; i < nhandlers; i++)
if (fc_handler[i].state >= fc_connected)
{
NTSTATUS status;
IO_STATUS_BLOCK io;
size_t nbytes = 0;
nconnected++;
status = NtReadFile (fc_handler[i].h, NULL, NULL, NULL,
&io, in_ptr, len, NULL, NULL);
switch (status)
{
case STATUS_SUCCESS:
case STATUS_BUFFER_OVERFLOW:
/* io.Information is supposedly valid. */
nbytes = io.Information;
if (nbytes > 0)
{
len = nbytes;
fifo_client_unlock ();
reading_unlock ();
return;
}
break;
case STATUS_PIPE_EMPTY:
break;
case STATUS_PIPE_BROKEN:
fc_handler[i].state = fc_disconnected;
nconnected--;
break;
default:
debug_printf ("NtReadFile status %y", status);
fc_handler[i].state = fc_error;
nconnected--;
break;
}
}
maybe_eof (!nconnected && !IsEventSignalled (writer_opening));
fifo_client_unlock ();
if (maybe_eof () && hit_eof ())
{
reading_unlock ();
len = 0;
return;
}
reading_unlock ();
if (is_nonblocking ())
{
set_errno (EAGAIN);
goto errout;
}
else
{
/* Allow interruption. */
DWORD waitret = cygwait (NULL, cw_nowait, cw_cancel | cw_sig_eintr);
if (waitret == WAIT_CANCELED)
pthread::static_cancel_self ();
else if (waitret == WAIT_SIGNALED)
{
if (_my_tls.call_signal_handler ())
continue;
else
{
set_errno (EINTR);
goto errout;
}
}
}
/* We might have been closed by a signal handler or another thread. */
if (isclosed ())
{
set_errno (EBADF);
goto errout;
}
/* Don't hog the CPU. */
Sleep (1);
}
errout:
len = (size_t) -1;
}
int __reg2
fhandler_fifo::fstatvfs (struct statvfs *sfs)
{
if (get_flags () & O_PATH)
/* We already have a handle. */
{
HANDLE h = get_handle ();
if (h)
return fstatvfs_by_handle (h, sfs);
}
fhandler_disk_file fh (pc);
fh.get_device () = FH_FS;
return fh.fstatvfs (sfs);
}
void
fhandler_fifo::close_all_handlers ()
{
for (int i = 0; i < nhandlers; i++)
fc_handler[i].close ();
nhandlers = 0;
}
int
fifo_client_handler::pipe_state ()
{
IO_STATUS_BLOCK io;
FILE_PIPE_LOCAL_INFORMATION fpli;
NTSTATUS status;
status = NtQueryInformationFile (h, &io, &fpli,
sizeof (fpli), FilePipeLocalInformation);
if (!NT_SUCCESS (status))
{
debug_printf ("NtQueryInformationFile status %y", status);
__seterrno_from_nt_status (status);
return -1;
}
else if (fpli.ReadDataAvailable > 0)
return FILE_PIPE_INPUT_AVAILABLE_STATE;
else
return fpli.NamedPipeState;
}
void
fhandler_fifo::cancel_reader_thread ()
{
if (cancel_evt)
SetEvent (cancel_evt);
if (thr_sync_evt)
WaitForSingleObject (thr_sync_evt, INFINITE);
}
int
fhandler_fifo::close ()
{
if (reader)
{
/* If we're the owner, try to find a new owner. */
bool find_new_owner = false;
cancel_reader_thread ();
owner_lock ();
if (get_owner () == me)
{
find_new_owner = true;
set_owner (null_fr_id);
set_prev_owner (me);
owner_needed ();
}
owner_unlock ();
if (dec_nreaders () == 0)
ResetEvent (read_ready);
else if (find_new_owner && !IsEventSignalled (owner_found_evt))
{
bool found = false;
do
if (dec_nreaders () >= 0)
{
/* There's still another reader open. */
if (WaitForSingleObject (owner_found_evt, 1) == WAIT_OBJECT_0)
found = true;
else
{
owner_lock ();
if (get_owner ()) /* We missed owner_found_evt? */
found = true;
else
owner_needed ();
owner_unlock ();
}
}
while (inc_nreaders () > 0 && !found);
}
close_all_handlers ();
if (fc_handler)
free (fc_handler);
if (owner_needed_evt)
NtClose (owner_needed_evt);
if (owner_found_evt)
NtClose (owner_found_evt);
if (update_needed_evt)
NtClose (update_needed_evt);
if (check_write_ready_evt)
NtClose (check_write_ready_evt);
if (write_ready_ok_evt)
NtClose (write_ready_ok_evt);
if (cancel_evt)
NtClose (cancel_evt);
if (thr_sync_evt)
NtClose (thr_sync_evt);
if (shmem)
NtUnmapViewOfSection (NtCurrentProcess (), shmem);
if (shmem_handle)
NtClose (shmem_handle);
if (shared_fc_handler)
NtUnmapViewOfSection (NtCurrentProcess (), shared_fc_handler);
if (shared_fc_hdl)
NtClose (shared_fc_hdl);
}
if (read_ready)
NtClose (read_ready);
if (write_ready)
NtClose (write_ready);
if (writer_opening)
NtClose (writer_opening);
if (nohandle ())
return 0;
else
return fhandler_base::close ();
}
/* If we have a write handle (i.e., we're a duplexer or a writer),
keep the nonblocking state of the windows pipe in sync with our
nonblocking state. */
int
fhandler_fifo::fcntl (int cmd, intptr_t arg)
{
if (cmd != F_SETFL || nohandle () || (get_flags () & O_PATH))
return fhandler_base::fcntl (cmd, arg);
const bool was_nonblocking = is_nonblocking ();
int res = fhandler_base::fcntl (cmd, arg);
const bool now_nonblocking = is_nonblocking ();
if (now_nonblocking != was_nonblocking)
set_pipe_non_blocking (get_handle (), now_nonblocking);
return res;
}
int
fhandler_fifo::dup (fhandler_base *child, int flags)
{
fhandler_fifo *fhf = NULL;
if (get_flags () & O_PATH)
return fhandler_base::dup (child, flags);
if (fhandler_base::dup (child, flags))
goto err;
fhf = (fhandler_fifo *) child;
if (!DuplicateHandle (GetCurrentProcess (), read_ready,
GetCurrentProcess (), &fhf->read_ready,
0, !(flags & O_CLOEXEC), DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto err;
}
if (!DuplicateHandle (GetCurrentProcess (), write_ready,
GetCurrentProcess (), &fhf->write_ready,
0, !(flags & O_CLOEXEC), DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto err_close_read_ready;
}
if (!DuplicateHandle (GetCurrentProcess (), writer_opening,
GetCurrentProcess (), &fhf->writer_opening,
0, !(flags & O_CLOEXEC), DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto err_close_write_ready;
}
if (reader)
{
/* Make sure the child starts unlocked. */
fhf->fifo_client_unlock ();
/* Clear fc_handler list; the child never starts as owner. */
fhf->nhandlers = fhf->shandlers = 0;
fhf->fc_handler = NULL;
if (!DuplicateHandle (GetCurrentProcess (), shmem_handle,
GetCurrentProcess (), &fhf->shmem_handle,
0, !(flags & O_CLOEXEC), DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto err_close_writer_opening;
}
if (fhf->reopen_shmem () < 0)
goto err_close_shmem_handle;
if (!DuplicateHandle (GetCurrentProcess (), shared_fc_hdl,
GetCurrentProcess (), &fhf->shared_fc_hdl,
0, !(flags & O_CLOEXEC), DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto err_close_shmem;
}
if (fhf->reopen_shared_fc_handler () < 0)
goto err_close_shared_fc_hdl;
if (!DuplicateHandle (GetCurrentProcess (), owner_needed_evt,
GetCurrentProcess (), &fhf->owner_needed_evt,
0, !(flags & O_CLOEXEC), DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto err_close_shared_fc_handler;
}
if (!DuplicateHandle (GetCurrentProcess (), owner_found_evt,
GetCurrentProcess (), &fhf->owner_found_evt,
0, !(flags & O_CLOEXEC), DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto err_close_owner_needed_evt;
}
if (!DuplicateHandle (GetCurrentProcess (), update_needed_evt,
GetCurrentProcess (), &fhf->update_needed_evt,
0, !(flags & O_CLOEXEC), DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto err_close_owner_found_evt;
}
if (!DuplicateHandle (GetCurrentProcess (), check_write_ready_evt,
GetCurrentProcess (), &fhf->check_write_ready_evt,
0, !(flags & O_CLOEXEC), DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto err_close_update_needed_evt;
}
if (!DuplicateHandle (GetCurrentProcess (), write_ready_ok_evt,
GetCurrentProcess (), &fhf->write_ready_ok_evt,
0, !(flags & O_CLOEXEC), DUPLICATE_SAME_ACCESS))
{
__seterrno ();
goto err_close_check_write_ready_evt;
}
if (!(fhf->cancel_evt = create_event (true)))
goto err_close_write_ready_ok_evt;
if (!(fhf->thr_sync_evt = create_event (true)))
goto err_close_cancel_evt;
inc_nreaders ();
fhf->me.fh = fhf;
new cygthread (fifo_reader_thread, fhf, "fifo_reader", fhf->thr_sync_evt);
}
return 0;
err_close_cancel_evt:
NtClose (fhf->cancel_evt);
err_close_write_ready_ok_evt:
NtClose (fhf->write_ready_ok_evt);
err_close_check_write_ready_evt:
NtClose (fhf->check_write_ready_evt);
err_close_update_needed_evt:
NtClose (fhf->update_needed_evt);
err_close_owner_found_evt:
NtClose (fhf->owner_found_evt);
err_close_owner_needed_evt:
NtClose (fhf->owner_needed_evt);
err_close_shared_fc_handler:
NtUnmapViewOfSection (GetCurrentProcess (), fhf->shared_fc_handler);
err_close_shared_fc_hdl:
NtClose (fhf->shared_fc_hdl);
err_close_shmem:
NtUnmapViewOfSection (GetCurrentProcess (), fhf->shmem);
err_close_shmem_handle:
NtClose (fhf->shmem_handle);
err_close_writer_opening:
NtClose (fhf->writer_opening);
err_close_write_ready:
NtClose (fhf->write_ready);
err_close_read_ready:
NtClose (fhf->read_ready);
err:
return -1;
}
void
fhandler_fifo::fixup_after_fork (HANDLE parent)
{
fhandler_base::fixup_after_fork (parent);
fork_fixup (parent, read_ready, "read_ready");
fork_fixup (parent, write_ready, "write_ready");
fork_fixup (parent, writer_opening, "writer_opening");
if (reader)
{
/* Make sure the child starts unlocked. */
fifo_client_unlock ();
fork_fixup (parent, shmem_handle, "shmem_handle");
if (reopen_shmem () < 0)
api_fatal ("Can't reopen shared memory during fork, %E");
fork_fixup (parent, shared_fc_hdl, "shared_fc_hdl");
if (reopen_shared_fc_handler () < 0)
api_fatal ("Can't reopen shared fc_handler memory during fork, %E");
fork_fixup (parent, owner_needed_evt, "owner_needed_evt");
fork_fixup (parent, owner_found_evt, "owner_found_evt");
fork_fixup (parent, update_needed_evt, "update_needed_evt");
fork_fixup (parent, check_write_ready_evt, "check_write_ready_evt");
fork_fixup (parent, write_ready_ok_evt, "write_ready_ok_evt");
if (close_on_exec ())
/* Prevent a later attempt to close the non-inherited
pipe-instance handles copied from the parent. */
nhandlers = 0;
else
{
/* Close inherited handles needed only by exec. */
if (cancel_evt)
NtClose (cancel_evt);
if (thr_sync_evt)
NtClose (thr_sync_evt);
}
if (!(cancel_evt = create_event (true)))
api_fatal ("Can't create reader thread cancel event during fork, %E");
if (!(thr_sync_evt = create_event (true)))
api_fatal ("Can't create reader thread sync event during fork, %E");
inc_nreaders ();
me.winpid = GetCurrentProcessId ();
new cygthread (fifo_reader_thread, this, "fifo_reader", thr_sync_evt);
}
}
void
fhandler_fifo::fixup_after_exec ()
{
fhandler_base::fixup_after_exec ();
if (reader && !close_on_exec ())
{
/* Make sure the child starts unlocked. */
fifo_client_unlock ();
if (reopen_shmem () < 0)
api_fatal ("Can't reopen shared memory during exec, %E");
if (reopen_shared_fc_handler () < 0)
api_fatal ("Can't reopen shared fc_handler memory during exec, %E");
fc_handler = NULL;
nhandlers = shandlers = 0;
/* Cancel parent's reader thread */
if (cancel_evt)
SetEvent (cancel_evt);
if (thr_sync_evt)
WaitForSingleObject (thr_sync_evt, INFINITE);
/* Take ownership if parent is owner. */
fifo_reader_id_t parent_fr = me;
me.winpid = GetCurrentProcessId ();
owner_lock ();
if (get_owner () == parent_fr)
{
set_owner (me);
if (update_my_handlers (true) < 0)
api_fatal ("Can't update my handlers, %E");
}
owner_unlock ();
/* Close inherited cancel_evt and thr_sync_evt. */
if (cancel_evt)
NtClose (cancel_evt);
if (thr_sync_evt)
NtClose (thr_sync_evt);
if (!(cancel_evt = create_event (true)))
api_fatal ("Can't create reader thread cancel event during exec, %E");
if (!(thr_sync_evt = create_event (true)))
api_fatal ("Can't create reader thread sync event during exec, %E");
/* At this moment we're a new reader. The count will be
decremented when the parent closes. */
inc_nreaders ();
new cygthread (fifo_reader_thread, this, "fifo_reader", thr_sync_evt);
}
}
void
fhandler_fifo::set_close_on_exec (bool val)
{
fhandler_base::set_close_on_exec (val);
set_no_inheritance (read_ready, val);
set_no_inheritance (write_ready, val);
set_no_inheritance (writer_opening, val);
if (reader)
{
set_no_inheritance (owner_needed_evt, val);
set_no_inheritance (owner_found_evt, val);
set_no_inheritance (update_needed_evt, val);
set_no_inheritance (check_write_ready_evt, val);
set_no_inheritance (write_ready_ok_evt, val);
set_no_inheritance (cancel_evt, val);
set_no_inheritance (thr_sync_evt, val);
fifo_client_lock ();
for (int i = 0; i < nhandlers; i++)
set_no_inheritance (fc_handler[i].h, val);
fifo_client_unlock ();
}
}
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