1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# UNIX posix_spawn
require 'ffi'
module Spoon
class FileActions
attr_reader :pointer
SIZE = FFI::Platform.mac? ? FFI.type_size(:pointer) : 128
def initialize
@pointer = FFI::AutoPointer.new(LibC.malloc(SIZE), Releaser)
error = LibC.posix_spawn_file_actions_init(@pointer)
raise SystemCallError.new("posix_file_actions_init", error) unless error == 0
end
class Releaser
def self.call(ptr)
LibC.posix_spawn_file_actions_destroy(ptr)
LibC.free(ptr)
end
end
def open(fd, path, oflag, mode)
error = LibC.posix_spawn_file_actions_addopen(@pointer, fd, path, oflag, mode)
raise SystemCallError.new("posix_file_actions_addopen", error) unless error == 0
self
end
def close(fd)
error = LibC.posix_spawn_file_actions_addclose(@pointer, fd)
raise SystemCallError.new("posix_file_actions_addclose", error) unless error == 0
self
end
def dup2(fd, newfd)
error = LibC.posix_spawn_file_actions_adddup2(@pointer, fd, newfd)
raise SystemCallError.new("posix_file_actions_adddup2", error) unless error == 0
self
end
end
class SpawnAttributes
attr_reader :pointer
SIZE = FFI::Platform.mac? ? FFI.type_size(:pointer) : 512
def initialize
@pointer = FFI::AutoPointer.new(LibC.malloc(SIZE), Releaser)
error = LibC.posix_spawnattr_init(@pointer)
raise SystemCallError.new("posix_spawnattr_init", error) unless error == 0
end
class Releaser
def self.call(ptr)
LibC.posix_spawnattr_destroy(ptr)
LibC.free(ptr)
end
end
def pgroup=(group)
error = LibC.posix_spawnattr_setpgroup(pointer, group)
raise SystemCallError.new("posix_spawnattr_setpgroup", error) unless error == 0
group
end
def pgroup
group = FFI::MemoryPointer.new :pid_t
error = LibC.posix_spawnattr_getpgroup(pointer, group)
raise SystemCallError.new("posix_spawnattr_getpgroup", error) unless error == 0
get_pid(group)
end
end
def self.posix_spawn(path, file_actions, spawn_attr, argv, env = ENV)
pid_ptr, argv_ptr, env_ptr = _prepare_spawn_args(argv, env)
error = LibC.posix_spawnp(pid_ptr, path, file_actions, spawn_attr, argv_ptr, env_ptr)
raise SystemCallError.new(path, error) unless error == 0
get_pid(pid_ptr)
end
def self.posix_spawnp(file, file_actions, spawn_attr, argv, env = ENV)
pid_ptr, argv_ptr, env_ptr = _prepare_spawn_args(argv, env)
error = LibC.posix_spawnp(pid_ptr, file, file_actions, spawn_attr, argv_ptr, env_ptr)
raise SystemCallError.new(file, error) unless error == 0
get_pid(pid_ptr)
end
def self.spawn(*args)
posix_spawn(args[0], nil, nil, args, ENV)
end
def self.spawnp(*args)
posix_spawnp(args[0], nil, nil, args, ENV)
end
private
class PointerArray
def initialize
@ary = []
end
def <<(ptr)
@ary << ptr
self
end
def pointer
if @pointer.nil? || (@pointer.size / @pointer.type_size) <= @ary.length
ptr = FFI::MemoryPointer.new(:pointer, @ary.length + 1)
ptr.put_array_of_pointer(0, @ary)
@pointer = ptr
end
@pointer
end
end
if FFI.type_size(:pid_t) == 4
def self.get_pid(ptr)
ptr.get_int32(0)
end
else
def self.get_pid(ptr)
ptr.get_int64(0)
end
end
module LibC
extend FFI::Library
ffi_lib FFI::Library::LIBC
class PointerConverter
extend FFI::DataConverter
native_type FFI::Type::POINTER
def self.to_native(value, ctx)
value ? value.pointer : nil
end
end
typedef PointerConverter, :file_actions
typedef PointerConverter, :spawn_attr
typedef PointerConverter, :ptr_array
attach_function :posix_spawn, [:pointer, :string, :file_actions, :spawn_attr, :ptr_array, :ptr_array ], :int
attach_function :posix_spawnp, [:pointer, :string, :file_actions, :spawn_attr, :ptr_array, :ptr_array ], :int
attach_function :posix_spawn_file_actions_init, [ :pointer ], :int
attach_function :posix_spawn_file_actions_destroy, [ :pointer ], :int
attach_function :posix_spawn_file_actions_adddup2, [ :pointer, :int, :int ], :int
attach_function :posix_spawn_file_actions_addclose, [ :pointer, :int ], :int
attach_function :posix_spawn_file_actions_addopen, [ :pointer, :int, :string, :int, :mode_t ], :int
attach_function :posix_spawnattr_init, [ :pointer ], :int
attach_function :posix_spawnattr_destroy, [ :pointer ], :int
attach_function :posix_spawnattr_setpgroup, [ :pointer, :pid_t ], :int
attach_function :posix_spawnattr_getpgroup, [ :pointer, :pointer ], :int
attach_function :malloc, [ :size_t ], :pointer
attach_function :free, [ :pointer ], :void
attach_function :strerror, [ :int ], :string
end
def self._prepare_spawn_args(argv, env)
pid_ptr = FFI::MemoryPointer.new(:pid_t, 1)
args_ary = argv.inject(PointerArray.new) { |ary, str| ary << FFI::MemoryPointer.from_string(str) }
env_ary = PointerArray.new
env.each_pair { |key, value| env_ary << FFI::MemoryPointer.from_string("#{key}=#{value}") }
[pid_ptr, args_ary, env_ary]
end
end
|
