class Thread::Mutex

Thread::Mutex implements a simple semaphore that can be used to coordinate access to shared data from multiple concurrent threads.

Example:

semaphore = Thread::Mutex.new

a = Thread.new {
  semaphore.synchronize {
    # access shared resource
  }
}

b = Thread.new {
  semaphore.synchronize {
    # access shared resource
  }
}

Public Class Methods

Thread::Mutex.new → mutex

Creates a new Mutex

# File thread_sync.rb, line 336
def initialize
end

Public Instance Methods

lock → self

Attempts to grab the lock and waits if it isn’t available. Raises ThreadError if mutex was locked by the current thread.

# File thread_sync.rb, line 360
def lock
  Primitive.rb_mut_lock
end

locked? → true or false

Returns true if this lock is currently held by some thread.

# File thread_sync.rb, line 343
def locked?
  Primitive.cexpr! %q{ RBOOL(mutex_locked_p(mutex_ptr(self))) }
end

owned? → true or false

Returns true if this lock is currently held by current thread.

# File thread_sync.rb, line 351
def owned?
  Primitive.rb_mut_owned_p
end

sleep(timeout = nil) → number or nil

Releases the lock and sleeps timeout seconds if it is given and non-nil or forever. Raises ThreadError if mutex wasn’t locked by the current thread.

When the thread is next woken up, it will attempt to reacquire the lock.

Note that this method can wakeup without explicit Thread#wakeup call. For example, receiving signal and so on.

Returns the slept time in seconds if woken up, or nil if timed out.

# File thread_sync.rb, line 407
def sleep(timeout = nil)
  Primitive.rb_mut_sleep(timeout)
end

synchronize { ... } → result of the block

Obtains a lock, runs the block, and releases the lock when the block completes. See the example under Thread::Mutex.

# File thread_sync.rb, line 387
def synchronize
  raise ThreadError, "must be called with a block" unless defined?(yield)

  Primitive.rb_mut_synchronize
end

try_lock → true or false

Attempts to obtain the lock and returns immediately. Returns true if the lock was granted.

# File thread_sync.rb, line 369
def try_lock
  Primitive.rb_mut_trylock
end

unlock → self

Releases the lock. Raises ThreadError if mutex wasn’t locked by the current thread.

# File thread_sync.rb, line 378
def unlock
  Primitive.rb_mut_unlock
end