[Xcb] [PATCH xcb-proto 1/3] xcbgen: Add support for lists of FDs

[Daniel Stone]

Add a special case in ListType to support lists of file descriptors,
which also requires explicit support within clients.

File descriptors are not supported as children of other complex types,
e.g. switch.

Signed-off-by: Daniel Stone <***@collabora.com>
---
xcbgen/xtypes.py | 28 ++++++++++++++++++++++++----
1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/xcbgen/xtypes.py b/xcbgen/xtypes.py
index c1f5986..1e270ae 100644
--- a/xcbgen/xtypes.py
+++ b/xcbgen/xtypes.py
@@ -42,6 +42,7 @@ class Type(object):
self.is_case_or_bitcase = False
self.is_bitcase = False
self.is_case = False
+ self.is_fd = False
self.required_start_align = Alignment()

# the biggest align value of an align-pad contained in this type
@@ -68,7 +69,7 @@ class Type(object):
'''
raise Exception('abstract fixed_size method not overridden!')

- def make_member_of(self, module, complex_type, field_type, field_name, visible, wire, auto, enum=None):
+ def make_member_of(self, module, complex_type, field_type, field_name, visible, wire, auto, enum=None, is_fd=False):
'''
Default method for making a data type a member of a structure.
Extend this if the data type needs to add an additional length field or something.
@@ -77,7 +78,7 @@ class Type(object):
complex_type is the structure object.
see Field for the meaning of the other parameters.
'''
- new_field = Field(self, field_type, field_name, visible, wire, auto, enum)
+ new_field = Field(self, field_type, field_name, visible, wire, auto, enum, is_fd)

# We dump the _placeholder_byte if any fields are added.
for (idx, field) in enumerate(complex_type.fields):
@@ -217,6 +218,18 @@ tchar = SimpleType(('char',), 1)
tfloat = SimpleType(('float',), 4)
tdouble = SimpleType(('double',), 8)

+class FileDescriptor(SimpleType):
+ '''
+ Derived class which represents a file descriptor.
+ '''
+ def __init__(self):
+ SimpleType.__init__(self, ('int'), 4)
+ self.is_fd = True
+
+ def fixed_size(self):
+ return True
+
+ out = __main__.output['simple']

class Enum(SimpleType):
'''
@@ -310,7 +323,9 @@ class ListType(Type):
type.make_member_of(module, complex_type, lenfield_type, lenfield_name, True, lenwire, False, enum)

# Add ourself to the structure by calling our original method.
- Type.make_member_of(self, module, complex_type, field_type, field_name, visible, wire, auto, enum)
+ if self.member.is_fd:
+ wire = False
+ Type.make_member_of(self, module, complex_type, field_type, field_name, visible, wire, auto, enum, self.member.is_fd)

def resolve(self, module):
if self.resolved:
@@ -532,7 +547,12 @@ class ComplexType(Type):
elif child.tag == 'list':
field_name = child.get('name')
fkey = child.get('type')
- type = ListType(child, module.get_type(fkey), *self.lenfield_parent)
+ if fkey == 'fd':
+ ftype = FileDescriptor()
+ fkey = 'INT32'
+ else:
+ ftype = module.get_type(fkey)
+ type = ListType(child, ftype, *self.lenfield_parent)
visible = True
elif child.tag == 'switch':
field_name = child.get('name')

[Daniel Stone]

Matching xcbgen changes, add support having a ListType which contains
file descriptors. Use this to send a variable number of FDs to the
server, including when the list size is not fixed.

Signed-off-by: Daniel Stone <***@collabora.com>
---
src/c_client.py | 38 +++++++++++++++++++++++++++++---------
1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/src/c_client.py b/src/c_client.py
index 7358826..1609125 100644
--- a/src/c_client.py
+++ b/src/c_client.py
@@ -2336,12 +2336,30 @@ def _c_request_helper(self, name, void, regular, aux=False, reply_fds=False):
if aux:
_c(' void *xcb_aux%d = 0;' % (idx))
if list_with_var_size_elems:
- _c(' unsigned int i;')
_c(' unsigned int xcb_tmp_len;')
_c(' char *xcb_tmp;')
- num_fds = len([field for field in param_fields if field.isfd])
- if num_fds > 0:
- _c(' int fds[%d];' % (num_fds))
+
+ num_fds_fixed = 0
+ num_fds_expr = []
+ for field in param_fields:
+ if field.isfd:
+ if not field.type.is_list:
+ num_fds_fixed += 1
+ else:
+ num_fds_expr.append(_c_accessor_get_expr(field.type.expr, None))
+
+ if list_with_var_size_elems or len(num_fds_expr) > 0:
+ _c(' unsigned int i;')
+
+ if num_fds_fixed > 0:
+ num_fds_expr.append('%d' % (num_fds_fixed))
+ if len(num_fds_expr) > 0:
+ num_fds = '+'.join(num_fds_expr)
+ _c(' int fds[%s];' % (num_fds))
+ _c(' int fd_index = 0;')
+ else:
+ num_fds = None
+
_c('')

# fixed size fields
@@ -2447,16 +2465,18 @@ def _c_request_helper(self, name, void, regular, aux=False, reply_fds=False):
# no padding necessary - _serialize() keeps track of padding automatically

_c('')
- fd_index = 0
for field in param_fields:
if field.isfd:
- _c(' fds[%d] = %s;', fd_index, field.c_field_name)
- fd_index = fd_index + 1
+ if not field.type.is_list:
+ _c(' fds[fd_index++] = %s;', field.c_field_name)
+ else:
+ _c(' for (i = 0; i < %s; i++)', _c_accessor_get_expr(field.type.expr, None))
+ _c(' fds[fd_index++] = %s[i];', field.c_field_name)

- if num_fds == 0:
+ if not num_fds:
_c(' xcb_ret.sequence = xcb_send_request(c, %s, xcb_parts + 2, &xcb_req);', func_flags)
else:
- _c(' xcb_ret.sequence = xcb_send_request_with_fds(c, %s, xcb_parts + 2, &xcb_req, %d, fds);', func_flags, num_fds)
+ _c(' xcb_ret.sequence = xcb_send_request_with_fds(c, %s, xcb_parts + 2, &xcb_req, %s, fds);', func_flags, num_fds)

# free dyn. all. data, if any
for f in free_calls:

[Daniel Stone]

For when we have a variable-sized field followed by a fixed field, make
sure we do not serialise non-wire fields.

Signed-off-by: Daniel Stone <***@collabora.com>
---
src/c_client.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/c_client.py b/src/c_client.py
index 0cbdf30..7358826 100644
--- a/src/c_client.py
+++ b/src/c_client.py
@@ -2379,7 +2379,7 @@ def _c_request_helper(self, name, void, regular, aux=False, reply_fds=False):
count = 4

for field in param_fields:
- if not field.type.fixed_size():
+ if field.wire and not field.type.fixed_size():
_c(' /* %s %s */', field.type.c_type, field.c_field_name)
# default: simple cast to char *
if not field.type.c_need_serialize and not field.type.c_need_sizeof: