Class: Unicorn::Worker

Relationships & Source Files
Inherits:	Object
Defined in:	lib/unicorn/worker.rb

Overview

This class and its members can be considered a stable interface and will not change in a backwards-incompatible fashion between releases of unicorn. Knowledge of this class is generally not not needed for most users of unicorn.

Some users may want to access it in the before_fork/after_fork hooks. See the Configurator RDoc for examples.

Constant Summary

DROPS = Internal use only
# File 'lib/unicorn/worker.rb', line 19
```
[]
```
PER_DROP = Internal use only
# File 'lib/unicorn/worker.rb', line 18
```
Raindrops::PAGE_SIZE / Raindrops::SIZE
```

Class Method Summary

.new(nr, pipe = nil) ⇒ Worker constructor Internal use only

Instance Attribute Summary

#master readonly Internal use only
#nr rw Internal use only
#switched rw Internal use only
#tick rw Internal use only

called in the master process.
#tick=(value) rw Internal use only

called in the worker process.
#to_io readonly Internal use only

IO.select-compatible

Instance Method Summary

#user(user, group = nil, chroot = false)

In most cases, you should be using the Configurator#user directive instead.
#==(other_nr) Internal use only

worker objects may be compared to just plain Integers.
#accept_nonblock(*_unused) Internal use only

this only runs when the Rack app.call is not running act like Socket#accept_nonblock(exception: false).
#atfork_child Internal use only
#atfork_parent Internal use only

parent does not read.
#close Internal use only

called in both the master (reaping worker) and worker (SIGQUIT handler).
#fake_sig(sig) Internal use only

call a signal handler immediately without triggering EINTR We do not use the more obvious Process.kill(sig, $$) here since that signal delivery may be deferred.
#quit Internal use only

master fakes SIGQUIT using this.
#soft_kill(sig) Internal use only

master sends fake signals to children.

Constructor Details

.new(nr, pipe = nil) ⇒ `Worker`

This method is for internal use only.

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 21


def initialize(nr, pipe=nil)
  drop_index = nr / PER_DROP
  @raindrop = DROPS[drop_index] ||= Raindrops.new(PER_DROP)
  @offset = nr % PER_DROP
  @raindrop[@offset] = 0
  @nr = nr
  @switched = false
  @to_io, @master = pipe || Unicorn.pipe
end

Instance Attribute Details

#master (readonly)

This method is for internal use only.

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 16


attr_reader :master

#nr (rw)

This method is for internal use only.

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 14


attr_accessor :nr, :switched

#switched (rw)

This method is for internal use only.

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 14


attr_accessor :nr, :switched

#tick (rw)

This method is for internal use only.

called in the master process

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 101


def tick # :nodoc:
  @raindrop[@offset]
end

#tick=(value) (rw)

This method is for internal use only.

called in the worker process

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 96


def tick=(value) # :nodoc:
  @raindrop[@offset] = value
end

#to_io (readonly)

This method is for internal use only.

IO.select-compatible

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 15


attr_reader :to_io # IO.select-compatible

Instance Method Details

#==(other_nr)

This method is for internal use only.

worker objects may be compared to just plain Integers

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 91


def ==(other_nr) # :nodoc:
  @nr == other_nr
end

#accept_nonblock(*_unused)

This method is for internal use only.

this only runs when the Rack app.call is not running act like Socket#accept_nonblock(exception: false)

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 76


def accept_nonblock(*_unused) # :nodoc:
  case buf = @to_io.read_nonblock(4, exception: false)
  when String
    # unpack the buffer and trigger the signal handler
    signum = buf.unpack('l')
    fake_sig(signum[0])
    # keep looping, more signals may be queued
  when nil # EOF: master died, but we are at a safe place to exit
    fake_sig(:QUIT)
  when :wait_readable # keep waiting
    return :wait_readable
  end while true # loop, as multiple signals may be sent
end

#atfork_child

This method is for internal use only.

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 31


def atfork_child # :nodoc:
  # we _must_ close in child, parent just holds this open to signal
  @master = @master.close
end

#atfork_parent

This method is for internal use only.

parent does not read

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 42


def atfork_parent # :nodoc:
  @to_io = @to_io.close
end

#close

This method is for internal use only.

called in both the master (reaping worker) and worker (SIGQUIT handler)

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 106


def close # :nodoc:
  @master.close if @master
  @to_io.close if @to_io
end

#fake_sig(sig)

This method is for internal use only.

call a signal handler immediately without triggering EINTR We do not use the more obvious Process.kill(sig, $$) here since that signal delivery may be deferred. We want to avoid signal delivery while the Rack app.call is running because some database drivers (e.g. ruby-pg) may cancel pending requests.

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 51


def fake_sig(sig) # :nodoc:
  old_cb = trap(sig, "IGNORE")
  old_cb.call
ensure
  trap(sig, old_cb)
end

#quit

This method is for internal use only.

master fakes SIGQUIT using this

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 37


def quit # :nodoc:
  @master = @master.close if @master
end

#soft_kill(sig)

This method is for internal use only.

master sends fake signals to children

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 59


def soft_kill(sig) # :nodoc:
  case sig
  when Integer
    signum = sig
  else
    signum = Signal.list[sig.to_s] or
        raise ArgumentError, "BUG: bad signal: #{sig.inspect}"
  end
  # writing and reading 4 bytes on a pipe is atomic on all POSIX platforms
  # Do not care in the odd case the buffer is full, here.
  @master.write_nonblock([signum].pack('l'), exception: false)
rescue Errno::EPIPE
  # worker will be reaped soon
end

#user(user, group = nil, chroot = false)

In most cases, you should be using the Configurator#user directive instead. This method should only be used if you need fine-grained control of exactly when you want to change permissions in your after_fork or after_worker_ready hooks, or if you want to use the chroot support.

Changes the worker process to the specified user and group, and chroots to the current working directory if chroot is set. This is only intended to be called from within the worker process from the after_fork hook. This should be called in the after_fork hook after any privileged functions need to be run (e.g. to set per-worker CPU affinity, niceness, etc)

group can be specified as a string, or as an array of two strings. If an array of two strings is given, the first string is used as the primary group of the process, and the second is used as the group of the log files.

Any and all errors raised within this method will be propagated directly back to the caller (usually the after_fork hook. These errors commonly include ArgumentError for specifying an invalid user/group and Errno::EPERM for insufficient privileges.

chroot support is only available in unicorn 5.3.0+ user and group switching appeared in unicorn 0.94.0 (2009-11-05)

[ GitHub ]

# File 'lib/unicorn/worker.rb', line 138


def user(user, group = nil, chroot = false)
  # we do not protect the caller, checking Process.euid == 0 is
  # insufficient because modern systems have fine-grained
  # capabilities.  Let the caller handle any and all errors.
  uid = Etc.getpwnam(user).uid

  if group
    if group.is_a?(Array)
      group, log_group = group
      log_gid = Etc.getgrnam(log_group).gid
    end
    gid = Etc.getgrnam(group).gid
    log_gid ||= gid
  end

  Unicorn::Util.chown_logs(uid, log_gid)
  if gid && Process.egid != gid
    Process.initgroups(user, gid)
    Process::GID.change_privilege(gid)
  end
  if chroot
    chroot = Dir.pwd if chroot == true
    Dir.chroot(chroot)
    Dir.chdir('/')
  end
  Process.euid != uid and Process::UID.change_privilege(uid)
  @switched = true
end

Class: Unicorn::Worker

Overview

Constant Summary

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new(nr, pipe = nil) ⇒ Worker

Instance Attribute Details

#master (readonly)

#nr (rw)

#switched (rw)

#tick (rw)

#tick=(value) (rw)

#to_io (readonly)

Instance Method Details

#==(other_nr)

#accept_nonblock(*_unused)

#atfork_child

#atfork_parent

#close

#fake_sig(sig)

#quit

#soft_kill(sig)

#user(user, group = nil, chroot = false)

.new(nr, pipe = nil) ⇒ `Worker`