The extension library to use System V IPC system calls from Ruby. It provides a simple object interface to message queues, semaphore sets, and shared memory segments.
SystemVIPC (module)
SystemVIPC is the module which provides the other features in System V IPC. See ipc(5) for more details.
ftok(path, id)Convert a path of an existing accessible file and an identifier to a System V IPC key.
SystemVIPC::Error is exception class. While doing some sanity checks before calling real system calls, errors are reported by this class.
StandardError
The root interface in the System V IPC classes hierarchy.
Object
IPCObject#removeRequest the kernel to remove immediately the current IPC object.
Provides an object interface to using System V IPC message queue.
MessageQueue.new(key[,flags])Returns a message queue associated with key. If no existing queue is associated to key, and IPC_CREAT is asserted in flags, a new queue is created.
MessageQueue#send(type,buf[,flags])Place a message on the queue with the data from buf and with type. The constants for flags are defined in SystemVIPC module.
MessageQueue#recv(type,len[,flags])Receives data from the queue and returns as an string. The constants for flags are defined in SystemVIPC module.
Provides an object interface to using System V IPC semaphores.
Semaphore.new(key[,nsems,flags])Returns a semaphore set associated with key. If no existing semaphore set is associated to key, and IPC_CREAT is asserted in flags, a new set of nsems semaphores is created. The constants for flags are defined in SystemVIPC module.
Semaphore#to_aReturns the values of the semaphore set as an array.
Semaphore#set_all(ary)Sets all values in the semaphore set to those given on ary. ary must contain the correct number of values.
Semaphore#value(pos)Returns the current value of the semaphore given as pos.
Semaphore#set_value(pos,v)Set the value of the semaphore given as pos to v.
Semaphore#n_count(pos)Returns the number of processed waiting for the semaphore given as pos to become greater than its current value.
Semaphore#z_count(pos)Returns the number of processed waiting for the semaphore given as pos to become zero.
Semaphore#pid(pos)Returns the process id of the last process that performed an operation on the semaphore given as pos.
Semaphore#sizeReturns the number of semaphores.
Semaphore#apply(ops)Applies all of the semaphore operations given on ops. The argument ops is an array of SemaphoreOperation.
Provides an object interface to using System V IPC shared memory.
SharedMemory.new(key[,nsems,flags])Returns a shared memory segment associated with key. If no existing memory is associated to key, and IPC_CREAT is asserted in flags, a new shared memory segment is created. The constants for flags are defined in SystemVIPC module.
SharedMemory#attach([flags])Attaches the shared memory segment.
SharedMemory#detachDetaches the shared memory segment.
SharedMemory#read([len])Returns a string of bytes peeked from the shared memory segment.
SharedMemory#write(string)Writes a string to the shared memory segment.
SharedMemory#sizeReturns size of segment in bytes.
Provides an object to represent semaphore operation.
Object
SemaphoreOperation.new (pos,value[,flags])Returns an operation to be performed on a semaphore.
SemaphoreOperation#posReturns the semaphore number.
SemaphoreOperation#valueReturns the value of the semaphore operation.
SemaphoreOperation#flagsReturns the operation flags.
Provides an object to represent permissions of IPC objects.
Object
Permission.new(ipc)Returns a permission information extracted from ipc. The argument ipc is an instance of the class IPCObject.
Permission#cuidReturns the user id of the creator.
Permission#cgidReturns the group id of the creator.
Permission#uidReturns the user id of the owner.
Permission#gidReturns the group id of the owner.
Permission#modeReturns the read/write permission.