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
|
class IO
# other IO methods are defined in io.c
# call-seq:
# ios.read_nonblock(maxlen [, options]) -> string
# ios.read_nonblock(maxlen, outbuf [, options]) -> outbuf
#
# Reads at most <i>maxlen</i> bytes from <em>ios</em> using
# the read(2) system call after O_NONBLOCK is set for
# the underlying file descriptor.
#
# If the optional <i>outbuf</i> argument is present,
# it must reference a String, which will receive the data.
# The <i>outbuf</i> will contain only the received data after the method call
# even if it is not empty at the beginning.
#
# read_nonblock just calls the read(2) system call.
# It causes all errors the read(2) system call causes: Errno::EWOULDBLOCK, Errno::EINTR, etc.
# The caller should care such errors.
#
# If the exception is Errno::EWOULDBLOCK or Errno::EAGAIN,
# it is extended by IO::WaitReadable.
# So IO::WaitReadable can be used to rescue the exceptions for retrying
# read_nonblock.
#
# read_nonblock causes EOFError on EOF.
#
# On some platforms, such as Windows, non-blocking mode is not supported
# on IO objects other than sockets. In such cases, Errno::EBADF will
# be raised.
#
# If the read byte buffer is not empty,
# read_nonblock reads from the buffer like readpartial.
# In this case, the read(2) system call is not called.
#
# When read_nonblock raises an exception kind of IO::WaitReadable,
# read_nonblock should not be called
# until io is readable for avoiding busy loop.
# This can be done as follows.
#
# # emulates blocking read (readpartial).
# begin
# result = io.read_nonblock(maxlen)
# rescue IO::WaitReadable
# IO.select([io])
# retry
# end
#
# Although IO#read_nonblock doesn't raise IO::WaitWritable.
# OpenSSL::Buffering#read_nonblock can raise IO::WaitWritable.
# If IO and SSL should be used polymorphically,
# IO::WaitWritable should be rescued too.
# See the document of OpenSSL::Buffering#read_nonblock for sample code.
#
# Note that this method is identical to readpartial
# except the non-blocking flag is set.
#
# By specifying a keyword argument _exception_ to +false+, you can indicate
# that read_nonblock should not raise an IO::WaitReadable exception, but
# return the symbol +:wait_readable+ instead. At EOF, it will return nil
# instead of raising EOFError.
def read_nonblock(len, buf = nil, exception: true)
Primitive.io_read_nonblock(len, buf, exception)
end
# call-seq:
# ios.write_nonblock(string) -> integer
# ios.write_nonblock(string [, options]) -> integer
#
# Writes the given string to <em>ios</em> using
# the write(2) system call after O_NONBLOCK is set for
# the underlying file descriptor.
#
# It returns the number of bytes written.
#
# write_nonblock just calls the write(2) system call.
# It causes all errors the write(2) system call causes: Errno::EWOULDBLOCK, Errno::EINTR, etc.
# The result may also be smaller than string.length (partial write).
# The caller should care such errors and partial write.
#
# If the exception is Errno::EWOULDBLOCK or Errno::EAGAIN,
# it is extended by IO::WaitWritable.
# So IO::WaitWritable can be used to rescue the exceptions for retrying write_nonblock.
#
# # Creates a pipe.
# r, w = IO.pipe
#
# # write_nonblock writes only 65536 bytes and return 65536.
# # (The pipe size is 65536 bytes on this environment.)
# s = "a" * 100000
# p w.write_nonblock(s) #=> 65536
#
# # write_nonblock cannot write a byte and raise EWOULDBLOCK (EAGAIN).
# p w.write_nonblock("b") # Resource temporarily unavailable (Errno::EAGAIN)
#
# If the write buffer is not empty, it is flushed at first.
#
# When write_nonblock raises an exception kind of IO::WaitWritable,
# write_nonblock should not be called
# until io is writable for avoiding busy loop.
# This can be done as follows.
#
# begin
# result = io.write_nonblock(string)
# rescue IO::WaitWritable, Errno::EINTR
# IO.select(nil, [io])
# retry
# end
#
# Note that this doesn't guarantee to write all data in string.
# The length written is reported as result and it should be checked later.
#
# On some platforms such as Windows, write_nonblock is not supported
# according to the kind of the IO object.
# In such cases, write_nonblock raises <code>Errno::EBADF</code>.
#
# By specifying a keyword argument _exception_ to +false+, you can indicate
# that write_nonblock should not raise an IO::WaitWritable exception, but
# return the symbol +:wait_writable+ instead.
def write_nonblock(buf, exception: true)
Primitive.io_write_nonblock(buf, exception)
end
end
|
