sc::ShmMemoryGrp(3)

💖 NAME 💖

okay bestie, this is the sc::ShmMemoryGrp(3) page from MPQC — and the tea is: the ShmMemoryGrp concrete class provides an implementation of MsgMemoryGrp. That's the whole NAME section, but make it cute: it's giving "shared-memory group has entered the chat" 💅.

✨ SYNOPSIS ✨

#include <memshm.h>

Inherits sc::MsgMemoryGrp.

💅 Public Member Functions 💅

• ShmMemoryGrp (const Ref< MessageGrp > &msg) — constructor vibes with a const Ref< MessageGrp > &msg.
• ShmMemoryGrp (const Ref< KeyVal > &) — constructor vibes with a const Ref< KeyVal > &.
• void set_localsize (size_t) — set the size of locally held memory. 🎀
• void * localdata () — returns a pointer to the local data. periodt.
• void * obtain_readwrite (distsize_t offset, int size) — only one thread can have an unreleased obtain_readwrite at a time. that's the rule, bestie.
• void * obtain_readonly (distsize_t offset, int size) — gives read access to the memory location. No locking is done. like, none at all 🙈.
• void * obtain_writeonly (distsize_t offset, int size) — gives write access to the memory location. No locking is done. same energy.
• void release_readonly (void *data, distsize_t offset, int size) — called when read access is no longer needed. release the ghost 👻.
• void release_writeonly (void *data, distsize_t offset, int size) — called when write access is no longer needed.
• void release_readwrite (void *data, distsize_t offset, int size) — called when read/write access is no longer needed.
• void print (std::ostream &o=ExEnv::out0()) const — prints out information about the object. default arg is right there, and it's const.

🫶 Additional Inherited Members 🫶

This heading is here in the original too, bestie — and it doesn't list any extra bullet details under it. mysterious inherited-member energy, iykyk. ✨

🌸 Detailed Description 🌸

The ShmMemoryGrp concrete class provides an implementation of MsgMemoryGrp. no cap.

It uses SYSV IPC to provide shared memory on a system that provides shared memory in hardware. It is very fast and reliable. literally iconic.

🔥 Member Function Documentation 🔥

💜 void* sc::ShmMemoryGrp::obtain_readwrite (distsize_t offset, int size) 💜

[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. so don't hold it forever, bestie 😭.

Implements sc::MemoryGrp.

💖 void sc::ShmMemoryGrp::release_readwrite (void * data, distsize_t offset, int size) 💖

[virtual]

This is called when read/write access is no longer needed. The memory will be unlocked. slay, release it. ✨

Implements sc::MemoryGrp.

🦋 void sc::ShmMemoryGrp::set_localsize (size_t) 🦋

[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. that's the whole journey, no cap. 🫶

Reimplemented from sc::MsgMemoryGrp.

👑 Author 👑

Generated automatically by Doxygen for MPQC from the source code. the robots wrote it, not me 💅.

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✨ cute sign-off: this sc::ShmMemoryGrp(3) page is from MPQC version 2.3.1, dated Sun Oct 4 2020 — thanks for reading, bestie, mwah 💋🎀