Returns the number of online processors.
The result is intended as the number of processes to use all available processors.
This method is implemented using:
sched_getaffinity(): Linux
sysconf(_SC_NPROCESSORS_ONLN): GNU/Linux, NetBSD, FreeBSD, OpenBSD, DragonFly BSD, OpenIndiana, Mac OS X, AIX
Example:
require 'etc' p Etc.nprocessors #=> 4
The result might be smaller number than physical cpus especially when ruby process is bound to specific cpus. This is intended for getting better parallel processing.
Example: (Linux)
linux$ taskset 0x3 ./ruby -retc -e "p Etc.nprocessors" #=> 2
See any remaining errors held in queue.
Any errors you see here are probably due to a bug in ruby’s OpenSSL implementation.
See Process#getpriority.
Process.setpriority(Process::PRIO_USER, 0, 19) #=> 0 Process.setpriority(Process::PRIO_PROCESS, 0, 19) #=> 0 Process.getpriority(Process::PRIO_USER, 0) #=> 19 Process.getpriority(Process::PRIO_PROCESS, 0) #=> 19
Sets the process title that appears on the ps(1) command. Not necessarily effective on all platforms. No exception will be raised regardless of the result, nor will NotImplementedError be raised even if the platform does not support the feature.
Calling this method does not affect the value of $0.
Process.setproctitle('myapp: worker #%d' % worker_id)
This method first appeared in Ruby 2.1 to serve as a global variable free means to change the process title.
Adds a section with title and content to the parser help view. Used for adding command arguments and default arguments.
Add the install/update options to the option parser.
Add local/remote options to the command line parser.
Add the –bulk-threshold option
Add the –update-sources option
creates TCP/IP server sockets for host and port. host is optional.
If no block given, it returns an array of listening sockets.
If a block is given, the block is called with the sockets. The value of the block is returned. The socket is closed when this method returns.
If port is 0, actual port number is chosen dynamically. However all sockets in the result has same port number.
# tcp_server_sockets returns two sockets. sockets = Socket.tcp_server_sockets(1296) p sockets #=> [#<Socket:fd 3>, #<Socket:fd 4>] # The sockets contains IPv6 and IPv4 sockets. sockets.each {|s| p s.local_address } #=> #<Addrinfo: [::]:1296 TCP> # #<Addrinfo: 0.0.0.0:1296 TCP> # IPv6 and IPv4 socket has same port number, 53114, even if it is chosen dynamically. sockets = Socket.tcp_server_sockets(0) sockets.each {|s| p s.local_address } #=> #<Addrinfo: [::]:53114 TCP> # #<Addrinfo: 0.0.0.0:53114 TCP> # The block is called with the sockets. Socket.tcp_server_sockets(0) {|sockets| p sockets #=> [#<Socket:fd 3>, #<Socket:fd 4>] }
Creates UDP/IP sockets for a UDP server.
If no block given, it returns an array of sockets.
If a block is given, the block is called with the sockets. The value of the block is returned. The sockets are closed when this method returns.
If port is zero, some port is chosen. But the chosen port is used for the all sockets.
# UDP/IP echo server Socket.udp_server_sockets(0) {|sockets| p sockets.first.local_address.ip_port #=> 32963 Socket.udp_server_loop_on(sockets) {|msg, msg_src| msg_src.reply msg } }
Receive UDP/IP packets from the given sockets. For each packet received, the block is called.
The block receives msg and msg_src. msg is a string which is the payload of the received packet. msg_src is a Socket::UDPSource object which is used for reply.
Socket.udp_server_loop can be implemented using this method as follows.
udp_server_sockets(host, port) {|sockets|
loop {
readable, _, _ = IO.select(sockets)
udp_server_recv(readable) {|msg, msg_src| ... }
}
}
creates a UNIX server socket on path
If no block given, it returns a listening socket.
If a block is given, it is called with the socket and the block value is returned. When the block exits, the socket is closed and the socket file is removed.
socket = Socket.unix_server_socket("/tmp/s") p socket #=> #<Socket:fd 3> p socket.local_address #=> #<Addrinfo: /tmp/s SOCK_STREAM> Socket.unix_server_socket("/tmp/sock") {|s| p s #=> #<Socket:fd 3> p s.local_address #=> # #<Addrinfo: /tmp/sock SOCK_STREAM> }
Makes hsh compare its keys by their identity, i.e. it will consider exact same objects as same keys.
h1 = { "a" => 100, "b" => 200, :c => "c" } h1["a"] #=> 100 h1.compare_by_identity h1.compare_by_identity? #=> true h1["a".dup] #=> nil # different objects. h1[:c] #=> "c" # same symbols are all same.
Returns true if hsh will compare its keys by their identity. Also see Hash#compare_by_identity.
Raises PStore::Error if the calling code is not in a PStore#transaction or if the code is in a read-only PStore#transaction.