tools/memory-model/litmus-tests/Z6.0+pooncelock+pooncelock+pombonce.litmus

File Facts

System

Linux kernel

Corpus path

tools/memory-model/litmus-tests/Z6.0+pooncelock+pooncelock+pombonce.litmus

Extension

.litmus

Size

658 bytes

Lines

41

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: tools

Status

atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

• Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.

Dependency Surface

• No C-style include directives detected by the generator.

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

C Z6.0+pooncelock+pooncelock+pombonce

(*
 * Result: Sometimes
 *
 * This example demonstrates that a pair of accesses made by different
 * processes each while holding a given lock will not necessarily be
 * seen as ordered by a third process not holding that lock.
 *)

{}

P0(int *x, int *y, spinlock_t *mylock)
{
	spin_lock(mylock);
	WRITE_ONCE(*x, 1);
	WRITE_ONCE(*y, 1);
	spin_unlock(mylock);
}

P1(int *y, int *z, spinlock_t *mylock)
{
	int r0;

	spin_lock(mylock);
	r0 = READ_ONCE(*y);
	WRITE_ONCE(*z, 1);
	spin_unlock(mylock);
}

P2(int *x, int *z)
{
	int r1;

	WRITE_ONCE(*z, 2);
	smp_mb();
	r1 = READ_ONCE(*x);
}

exists (1:r0=1 /\ z=2 /\ 2:r1=0)

Annotation

• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: atlas-only.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.