Adding upstream version 0.6.0.

Signed-off-by: Daniel Baumann <daniel@debian.org>
2025-02-09 07:35:45 +01:00 · 2025-02-09 07:35:45 +01:00 · 7f70a05c55
commit 7f70a05c55
parent c49a9029dc
465 changed files with 60158 additions and 0 deletions
--- a/include/ck_tflock.h
+++ b/include/ck_tflock.h
@ -0,0 +1,136 @@
+/*
+ * Copyright 2014 Samy Al Bahra.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef CK_TFLOCK_TICKET_H
+#define CK_TFLOCK_TICKET_H
+
+/*
+ * This is an implementation of task-fair locks derived from the work
+ * described in:
+ *	John M. Mellor-Crummey and Michael L. Scott. 1991.
+ *	Scalable reader-writer synchronization for shared-memory
+ *	multiprocessors. SIGPLAN Not. 26, 7 (April 1991), 106-113.
+ */
+
+#include <ck_cc.h>
+#include <ck_pr.h>
+
+struct ck_tflock_ticket {
+	uint32_t request;
+	uint32_t completion;
+};
+typedef struct ck_tflock_ticket ck_tflock_ticket_t;
+
+#define CK_TFLOCK_TICKET_INITIALIZER { 0, 0 }
+
+#define CK_TFLOCK_TICKET_RC_INCR	0x10000U	/* Read-side increment. */
+#define CK_TFLOCK_TICKET_WC_INCR	0x1U		/* Write-side increment. */
+#define CK_TFLOCK_TICKET_W_MASK		0xffffU		/* Write-side mask. */
+#define CK_TFLOCK_TICKET_WC_TOPMSK	0x8000U		/* Write clear mask for overflow. */
+#define CK_TFLOCK_TICKET_RC_TOPMSK	0x80000000U	/* Read clear mask for overflow. */
+
+CK_CC_INLINE static uint32_t
+ck_tflock_ticket_fca_32(uint32_t *target, uint32_t mask, uint32_t delta)
+{
+	uint32_t snapshot = ck_pr_load_32(target);
+	uint32_t goal;
+
+	for (;;) {
+		goal = (snapshot & ~mask) + delta;
+		if (ck_pr_cas_32_value(target, snapshot, goal, &snapshot) == true)
+			break;
+
+		ck_pr_stall();
+	}
+
+	return snapshot;
+}
+
+CK_CC_INLINE static void
+ck_tflock_ticket_init(struct ck_tflock_ticket *pf)
+{
+
+	pf->request = pf->completion = 0;
+	ck_pr_barrier();
+	return;
+}
+
+CK_CC_INLINE static void
+ck_tflock_ticket_write_lock(struct ck_tflock_ticket *lock)
+{
+	uint32_t previous;
+
+	previous = ck_tflock_ticket_fca_32(&lock->request, CK_TFLOCK_TICKET_WC_TOPMSK,
+	    CK_TFLOCK_TICKET_WC_INCR);
+	ck_pr_fence_atomic_load();
+	while (ck_pr_load_32(&lock->completion) != previous)
+		ck_pr_stall();
+
+	ck_pr_fence_lock();
+	return;
+}
+
+CK_CC_INLINE static void
+ck_tflock_ticket_write_unlock(struct ck_tflock_ticket *lock)
+{
+
+	ck_pr_fence_unlock();
+	ck_tflock_ticket_fca_32(&lock->completion, CK_TFLOCK_TICKET_WC_TOPMSK,
+	    CK_TFLOCK_TICKET_WC_INCR);
+	return;
+}
+
+CK_CC_INLINE static void
+ck_tflock_ticket_read_lock(struct ck_tflock_ticket *lock)
+{
+	uint32_t previous;
+
+	previous = ck_tflock_ticket_fca_32(&lock->request,
+	    CK_TFLOCK_TICKET_RC_TOPMSK, CK_TFLOCK_TICKET_RC_INCR) &
+	    CK_TFLOCK_TICKET_W_MASK;
+
+	ck_pr_fence_atomic_load();
+
+	while ((ck_pr_load_32(&lock->completion) &
+	    CK_TFLOCK_TICKET_W_MASK) != previous) {
+		ck_pr_stall();
+	}
+
+	ck_pr_fence_lock();
+	return;
+}
+
+CK_CC_INLINE static void
+ck_tflock_ticket_read_unlock(struct ck_tflock_ticket *lock)
+{
+
+	ck_pr_fence_unlock();
+	ck_tflock_ticket_fca_32(&lock->completion, CK_TFLOCK_TICKET_RC_TOPMSK,
+	    CK_TFLOCK_TICKET_RC_INCR);
+	return;
+}
+
+#endif /* CK_TFLOCK_TICKET_H */