CK_PR_FENCE_MEMORY(3)

💖 ck_pr_fence_memory — bestie, it's a fence, but for MEMORY 💖

okay so this page is ck_pr_fence_memory(3), and it lives in the Concurrency Kit library — that's libck, and you link it with -lck. 🎀

It's giving "enforce partial ordering of all memory operations." Slay.

✨ LIBRARY ✨

Concurrency Kit, aka libck, and you link it with the -lck flag. no cap, that's the whole vibe. 🦋

🌸 SYNOPSIS 🌸

#include <ck_pr.h>

void
ck_pr_fence_memory();

void
ck_pr_fence_strict_memory();

two little functions, zero arguments, zero drama. 💅

💫 DESCRIPTION 💫

so ck_pr_fence_memory(3) enforces the ordering of any memory operations with respect to the invocation of the function itself. like, everything before it stays before it, everything after it stays after it. periodt. 🔥

this function always serves as an implicit compiler barrier. always. even when nothing else happens, the compiler knows to behave. 👑

now the architecture tea ☕: architectures implementing CK_MD_TSO do not emit a barrier — but the compiler barrier semantics still remain, so don't panic. meanwhile, architectures implementing CK_MD_PSO and CK_MD_RMO always emit an instruction that provides the specified ordering guarantees.

and if you want to force the unconditional emission of a memory fence, no matter what the architecture thinks it can get away with? that's what ck_pr_fence_strict_memory() is for. she does not negotiate. 💀✨

🧚 EXAMPLE 🧚

#include <ck_pr.h>

static int a = 0;
static int b;
static int c;
static int d;

void
function(void)
{
        int snapshot_a;

        ck_pr_store_int(&b, 1);
        snapshot_a = ck_pr_load_int(&a);

        /*
         * Make sure previous memory operations are
         * ordered with respect to memory operations
         * following the ck_pr_fence_memory.
         */
        ck_pr_fence_memory();

        ck_pr_store_int(&d, 3);
        ck_pr_store_int(&c, 2);

        return;
}

see how she just chills there in the middle, holding the line between the before and the after? main character energy fr fr. 💜

🍓 RETURN VALUES 🍓

this function has no return value. nothing to return, nothing to check, just vibes. 🫶

🌈 SEE ALSO 🌈

• ck_pr_stall(3)
• ck_pr_fence_atomic(3)
• ck_pr_fence_atomic_store(3)
• ck_pr_fence_atomic_load(3)
• ck_pr_fence_load(3)
• ck_pr_fence_load_depends(3)
• ck_pr_fence_store(3)
• ck_pr_barrier(3)
• ck_pr_fas(3)
• ck_pr_load(3)
• ck_pr_store(3)
• ck_pr_faa(3)
• ck_pr_inc(3)
• ck_pr_dec(3)
• ck_pr_neg(3)
• ck_pr_not(3)
• ck_pr_add(3)
• ck_pr_sub(3)
• ck_pr_and(3)
• ck_pr_or(3)
• ck_pr_xor(3)
• ck_pr_cas(3)
• ck_pr_btc(3)
• ck_pr_bts(3)
• ck_pr_btr(3)

additional info is available at http://concurrencykit.org/ — go look, iykyk. 🌟

okay that's the whole page bestie, you ate this one 💖 this was the ck_pr_fence_memory(3) page from April 7, 2013, so like, she's an elder but she still serves ✨ mwah, go write some correct concurrent code, i'm obsessed 🎀