![]() |
![]()
| ![]() |
![]()
NAMEsc::MemoryGrp - The MemoryGrp abstract class provides a way of accessing distributed memory in a parallel machine. SYNOPSIS#include <memory.h> Inherits sc::DescribedClass. Inherited by sc::MsgMemoryGrp, and sc::ProcMemoryGrp. Public Member FunctionsMemoryGrp (const Ref< KeyVal > &)
Public Member Functions inherited from sc::DescribedClass
Public Member Functions inherited from sc::RefCount
Public Member Functions inherited from sc::Identity
Static Public Member Functionsstatic MemoryGrp * initial_memorygrp (int &argc,
char **argv)
Protected Member Functionsvoid obtain_local_lock (size_t start, size_t fence)
Protected Member Functions inherited from sc::RefCount
Protected Attributesint me_
Detailed DescriptionThe MemoryGrp abstract class provides a way of accessing distributed memory in a parallel machine. Several specializations are available. For one processor, ProcMemoryGrp provides a simple stub implementation. Parallel specializations include ShmMemoryGrp, MTMPIMemoryGrp, and ARMCIMemoryGrp. The particular specializations that work depend highly on the target hardware and software environment. Member Function Documentationvirtual void sc::MemoryGrp::activate () [virtual]Activate is called before the memory is to be used. Reimplemented in sc::MTMPIMemoryGrp. virtual void sc::MemoryGrp::catchup () [virtual]Processes outstanding requests. Some memory group implementations don't have access to real shared memory or even active messages. Instead, requests are processed whenever certain memory group routines are called. This can cause large latencies and buffer overflows. If this is a problem, then the catchup member can be called to process all outstanding requests. virtual void sc::MemoryGrp::deactivate () [virtual]Deactivate is called after the memory has been used. Reimplemented in sc::ARMCIMemoryGrp, and sc::MTMPIMemoryGrp. virtual void sc::MemoryGrp::free_local (void * data) [virtual]Free data that was allocated with malloc_local_double. Reimplemented in sc::ARMCIMemoryGrp. static MemoryGrp * sc::MemoryGrp::get_default_memorygrp () [static]Returns the default memory group. If the default memory group has not yet been set, then one is created. The particular specialization used is determined by configuration options and which specializations are being used for MessageGrp and ThreadGrp. static MemoryGrp * sc::MemoryGrp::initial_memorygrp (int & argc, char ** argv) [static]Create a memory group. This routine looks for a -memorygrp argument, and then the environmental variable MEMORYGRP to decide which specialization of MemoryGrp would be appropriate. The argument to -memorygrp or the value of the environmental variable should be either string for a ParsedKeyVal constructor or a classname. The default ThreadGrp and MessageGrp objects should be initialized before this is called. References initial_memorygrp(). Referenced by initial_memorygrp(). virtual void * sc::MemoryGrp::localdata () [pure virtual]Returns a pointer to the local data. Implemented in sc::ActiveMsgMemoryGrp, sc::ProcMemoryGrp, sc::RDMAMemoryGrp, and sc::ShmMemoryGrp. virtual void * sc::MemoryGrp::malloc_local (size_t nbyte) [virtual]Allocate data that will be accessed locally only. Using this for data that will be used for global operation can improve efficiency. Data allocated in this way must be freed with free_local_double. Reimplemented in sc::ARMCIMemoryGrp. virtual void * sc::MemoryGrp::obtain_readonly (distsize_t offset, int size) [pure virtual]This gives read access to the memory location. No locking is done. Implemented in sc::ActiveMsgMemoryGrp, sc::ProcMemoryGrp, sc::RDMAMemoryGrp, and sc::ShmMemoryGrp. virtual void * sc::MemoryGrp::obtain_readwrite (distsize_t offset, int size) [pure virtual]Only one thread can have an unreleased obtain_readwrite at a time. The actual memory region locked can be larger than that requested. If the memory region is already locked this will block. For this reason, data should be held as read/write for as short a time as possible. Implemented in sc::ActiveMsgMemoryGrp, sc::ProcMemoryGrp, sc::RDMAMemoryGrp, and sc::ShmMemoryGrp. virtual void * sc::MemoryGrp::obtain_writeonly (distsize_t offset, int size) [pure virtual]This gives write access to the memory location. No locking is done. Implemented in sc::ActiveMsgMemoryGrp, sc::ProcMemoryGrp, sc::RDMAMemoryGrp, and sc::ShmMemoryGrp. virtual void sc::MemoryGrp::print (std::ostream & o = ExEnv::out0()) const [virtual]Prints out information about the object. Reimplemented from sc::DescribedClass. Reimplemented in sc::ActiveMsgMemoryGrp, sc::ARMCIMemoryGrp, sc::RDMAMemoryGrp, and sc::ShmMemoryGrp. virtual void sc::MemoryGrp::release_readonly (void * data, distsize_t offset, int size) [pure virtual]This is called when read access is no longer needed. Implemented in sc::ActiveMsgMemoryGrp, sc::ProcMemoryGrp, sc::RDMAMemoryGrp, and sc::ShmMemoryGrp. virtual void sc::MemoryGrp::release_readwrite (void * data, distsize_t offset, int size) [pure virtual]This is called when read/write access is no longer needed. The memory will be unlocked. Implemented in sc::ActiveMsgMemoryGrp, sc::ProcMemoryGrp, sc::RDMAMemoryGrp, and sc::ShmMemoryGrp. virtual void sc::MemoryGrp::release_writeonly (void * data, distsize_t offset, int size) [pure virtual]This is called when write access is no longer needed. Implemented in sc::ActiveMsgMemoryGrp, sc::ProcMemoryGrp, sc::RDMAMemoryGrp, and sc::ShmMemoryGrp. virtual void sc::MemoryGrp::set_localsize (size_t) [pure virtual]Set the size of locally held memory. When memory is accessed using a global offset counting starts at node 0 and proceeds up to node n() - 1. Implemented in sc::MsgMemoryGrp, sc::RDMAMemoryGrp, sc::ActiveMsgMemoryGrp, sc::ARMCIMemoryGrp, sc::ProcMemoryGrp, and sc::ShmMemoryGrp. virtual void sc::MemoryGrp::sync () [pure virtual]Synchronizes all the nodes. This is useful after remote memory writes to be certain that all of the writes have completed and the data can be accessed locally, for example. Implemented in sc::ARMCIMemoryGrp, sc::MsgMemoryGrp, sc::MTMPIMemoryGrp, and sc::ProcMemoryGrp. AuthorGenerated automatically by Doxygen for MPQC from the source code.
|