sc::ShmMemoryGrp Class Reference
The ShmMemoryGrp concrete class provides an implementation of MsgMemoryGrp. More...
#include <util/group/memshm.h>
Inheritance diagram for sc::ShmMemoryGrp:
Public Member Functions | |
| ShmMemoryGrp (const Ref< MessageGrp > &msg) | |
| ShmMemoryGrp (const Ref< KeyVal > &) | |
| void | set_localsize (size_t) |
| Set the size of locally held memory. More... | |
| void * | localdata () |
| Returns a pointer to the local data. | |
| void * | obtain_readwrite (distsize_t offset, size_t size) |
| Only one thread can have an unreleased obtain_readwrite at a time. More... | |
| void * | obtain_readonly (distsize_t offset, size_t size) |
| This gives read access to the memory location. No locking is done. | |
| void * | obtain_writeonly (distsize_t offset, size_t size) |
| This gives write access to the memory location. No locking is done. | |
| void | release_readonly (void *data, distsize_t offset, size_t size) |
| This is called when read access is no longer needed. | |
| void | release_writeonly (void *data, distsize_t offset, size_t size) |
| This is called when write access is no longer needed. | |
| void | release_readwrite (void *data, distsize_t offset, size_t size) |
| This is called when read/write access is no longer needed. More... | |
| void | print (std::ostream &o=ExEnv::out0()) const |
| Prints out information about the object. | |
 Public Member Functions inherited from sc::MsgMemoryGrp | |
| MsgMemoryGrp (const Ref< MessageGrp > &msg) | |
| MsgMemoryGrp (const Ref< KeyVal > &keyval) | |
| void | sync () |
| Synchronizes all the nodes. More... | |
| Public Member Functions inherited from sc::MemoryGrp | |
| MemoryGrp (const Ref< KeyVal > &) | |
| int | me () const |
| Returns who I am. | |
| int | n () const |
| Returns how many nodes there are. | |
| size_t | localsize () |
| Returns the amount of memory residing locally on me(). | |
| distsize_t | localoffset () |
| Returns the global offset to this node's memory. | |
| int | size (int node) |
| Returns the amount of memory residing on node. | |
| distsize_t | offset (int node) |
| Returns the global offset to node's memory. | |
| distsize_t | totalsize () |
| Returns the sum of all memory allocated on all nodes. | |
| virtual void | activate () |
| Activate is called before the memory is to be used. | |
| virtual void | deactivate () |
| Deactivate is called after the memory has been used. | |
| virtual void | write (const void *data, distsize_t offset, size_t size) |
| This is used to write data directly. More... | |
| virtual void | sum_reduction (double *data, distsize_t doffset, size_t dsize) |
| Perform a sum reduction on double data. More... | |
| virtual void | sum_reduction_on_node (double *data, size_t doffset, size_t dsize, int node=-1) |
| Perform a sum reduction on double data localized to a single node. More... | |
| virtual void * | malloc_local (size_t nbyte) |
| Allocate data that will be accessed locally only. More... | |
| double * | malloc_local_double (size_t ndouble) |
| Allocate double data that will be accessed locally only. More... | |
| virtual void | free_local (void *&data) |
| Free data that was allocated with malloc_local, and set the pointer to 0. | |
| void | free_local_double (double *&data) |
| Free data that was allocated with malloc_local_double, and set the pointer to 0 | |
| virtual void | catchup () |
| Processes outstanding requests. More... | |
| virtual Ref< MemoryGrp > | clone (void) |
| Returns a copy of this MemoryGrp specialization that provides an independent communication context. More... | |
| Public Member Functions inherited from sc::DescribedClass | |
| DescribedClass (const DescribedClass &) | |
| DescribedClass & | operator= (const DescribedClass &) |
| ClassDesc * | class_desc () const MPQC__NOEXCEPT |
| This returns the unique pointer to the ClassDesc corresponding to the given type_info object. More... | |
| const char * | class_name () const |
| Return the name of the object's exact type. | |
| int | class_version () const |
| Return the version of the class. | |
| Ref< DescribedClass > | ref () |
| Return this object wrapped up in a Ref smart pointer. More... | |
| Public Member Functions inherited from sc::RefCount | |
| size_t | identifier () const |
| Return the unique identifier for this object that can be compared for different objects of different types. More... | |
| int | lock_ptr () const |
| Lock this object. | |
| int | unlock_ptr () const |
| Unlock this object. | |
| void | use_locks (bool inVal) |
| start and stop using locks on this object | |
| refcount_t | nreference () const |
| Return the reference count. | |
| refcount_t | reference () |
| Increment the reference count and return the new count. | |
| refcount_t | dereference () |
| Decrement the reference count and return the new count. | |
| int | managed () const |
| void | unmanage () |
| Turn off the reference counting mechanism for this object. More... | |
Additional Inherited Members | |
| Static Public Member Functions inherited from sc::MemoryGrp | |
| static MemoryGrp * | initial_memorygrp (int &argc, char **argv) |
| Create a memory group. More... | |
| static MemoryGrp * | initial_memorygrp () |
| Create a memory group. More... | |
| static void | set_default_memorygrp (const Ref< MemoryGrp > &) |
| The default memory group contains the primary memory group to be used by an application. | |
| static MemoryGrp * | get_default_memorygrp () |
| Returns the default memory group. More... | |
| Protected Member Functions inherited from sc::MemoryGrp | |
| void | obtain_local_lock (size_t start, size_t fence) |
| void | release_local_lock (size_t start, size_t fence) |
| Protected Member Functions inherited from sc::RefCount | |
| RefCount (const RefCount &) | |
| RefCount & | operator= (const RefCount &) |
| Protected Attributes inherited from sc::MsgMemoryGrp | |
| Ref< MessageGrp > | msg_ |
| Protected Attributes inherited from sc::MemoryGrp | |
| int | me_ |
| int | n_ |
| distsize_t * | offsets_ |
| int | debug_ |
Detailed Description
The ShmMemoryGrp concrete class provides an implementation of MsgMemoryGrp.
It uses SYSV IPC to provided shared memory in a system that provide shared memory in hardware. It is very fast and reliable.
Member Function Documentation
◆ obtain_readwrite()
|
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.
Implements sc::MemoryGrp.
◆ release_readwrite()
|
virtual |
This is called when read/write access is no longer needed.
The memory will be unlocked.
Implements sc::MemoryGrp.
◆ set_localsize()
|
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.
Reimplemented from sc::MsgMemoryGrp.
The documentation for this class was generated from the following file:
- src/lib/util/group/memshm.h