tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c

File Facts

System

Linux kernel

Corpus path

tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c

Extension

.c

Size

4615 bytes

Lines

168

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: implementation source

Status

source implementation candidate

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.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• errno.h
• getopt.h
• limits.h
• pthread.h
• signal.h
• stdio.h
• stdlib.h
• string.h
• atomic.h
• futextest.h
• kselftest_harness.h

Detected Declarations

• function create_rt_thread
• function handle_signal
• function TEST

Annotated Snippet

if (res > 0) {
			atomic_set(&requeued, 1);
			break;
		} else if (res < 0) {
			ksft_exit_fail_msg("FUTEX_CMP_REQUEUE_PI failed\n");
		}
	}
	ksft_print_dbg_msg("m4:f2: %x\n", f2);

	/*
	 * Signal the waiter after requeue, waiter should return from
	 * futex_wait_requeue_pi() with EWOULDBLOCK. Join the thread here so the
	 * futex_unlock_pi() can't happen before the signal wakeup is detected
	 * in the kernel.
	 */
	ksft_print_dbg_msg("Issuing SIGUSR1 to waiter\n");
	pthread_kill(waiter, SIGUSR1);
	ksft_print_dbg_msg("Waiting for waiter to return\n");
	pthread_join(waiter, NULL);

	ksft_print_dbg_msg("Calling FUTEX_UNLOCK_PI on mutex=%x @ %p\n", f2, &f2);
	futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
	ksft_print_dbg_msg("m5:f2: %x\n", f2);
}

TEST_HARNESS_MAIN

Annotation

• Immediate include surface: `errno.h`, `getopt.h`, `limits.h`, `pthread.h`, `signal.h`, `stdio.h`, `stdlib.h`, `string.h`.
• Detected declarations: `function create_rt_thread`, `function handle_signal`, `function TEST`.
• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: source implementation candidate.
• 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.