ck_epoch: Remove debug output, update comments.

include/ck_epoch.h

@@ -0,0 +1,237 @@
+/*
+ * Copyright 2011 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_EPOCH_H
+#define _CK_EPOCH_H
+
+#include <ck_backoff.h>
+#include <ck_cc.h>
+#include <ck_pr.h>
+#include <ck_stack.h>
+#include <stdbool.h>
+
+/*
+ * CK_EPOCH_LENGTH must be a power of 2.
+ */
+#ifndef CK_EPOCH_LENGTH
+#define CK_EPOCH_LENGTH 4
+#endif
+
+typedef void (*ck_epoch_destructor_t)(ck_stack_entry_t *);
+
+enum {
+	CK_EPOCH_USED = 0,
+	CK_EPOCH_FREE = 1
+};
+
+struct ck_epoch;
+struct ck_epoch_record {
+	unsigned int active;
+	unsigned int status;
+	unsigned int epoch;
+	ck_stack_t pending[CK_EPOCH_LENGTH];
+	unsigned int delta;
+	struct ck_epoch *global;
+	ck_stack_entry_t record_next;
+} CK_CC_CACHELINE;
+typedef struct ck_epoch_record ck_epoch_record_t;
+
+struct ck_epoch {
+	ck_stack_t records;
+	unsigned int threshold;
+	unsigned int epoch;
+	unsigned int n_free;
+	ck_epoch_destructor_t destroy;
+};
+typedef struct ck_epoch ck_epoch_t;
+
+CK_STACK_CONTAINER(struct ck_epoch_record, record_next, ck_epoch_record_container)
+
+CK_CC_INLINE static void
+ck_epoch_init(struct ck_epoch *global,
+	      unsigned int threshold,
+	      ck_epoch_destructor_t destroy)
+{
+
+	ck_stack_init(&global->records);
+	global->epoch = 1;
+	global->n_free = 0;
+	global->destroy = destroy;
+	global->threshold = threshold;
+	ck_pr_fence_store();	
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_register(struct ck_epoch *global, struct ck_epoch_record *record)
+{
+	size_t i;
+
+	record->status = CK_EPOCH_USED;
+	record->active = 0;
+	record->epoch = 0;
+	record->delta = 0;
+	record->global = global;
+
+	for (i = 0; i < CK_EPOCH_LENGTH; i++)
+		ck_stack_init(&record->pending[i]);
+
+	ck_pr_fence_store();
+	ck_stack_push_upmc(&global->records, &record->record_next);
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_unregister(struct ck_epoch_record *record)
+{
+
+	record->status = CK_EPOCH_FREE;
+	ck_pr_fence_store();
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_update(struct ck_epoch *global, struct ck_epoch_record *record)
+{
+	struct ck_epoch_record *c_record;
+	ck_stack_entry_t *cursor;
+	unsigned int g_epoch = ck_pr_load_uint(&global->epoch);
+
+	CK_STACK_FOREACH(&global->records, cursor) {
+		c_record = ck_epoch_record_container(cursor);
+		if (ck_pr_load_uint(&c_record->status) == CK_EPOCH_FREE || c_record == record)
+			continue;
+
+		if (ck_pr_load_uint(&c_record->active) == true && ck_pr_load_uint(&c_record->epoch) != g_epoch)
+			return;
+	}
+
+	ck_pr_inc_uint(&global->epoch);
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_activate(struct ck_epoch_record *record)
+{
+
+	ck_pr_store_uint(&record->active, 1);
+	ck_pr_fence_store();
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_deactivate(struct ck_epoch_record *record)
+{
+
+	ck_pr_fence_store();
+	ck_pr_store_uint(&record->active, 0);
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_start(struct ck_epoch_record *record)
+{
+	struct ck_epoch *global = record->global;
+	unsigned int g_epoch;
+
+	for (;;) {
+		g_epoch = ck_pr_load_uint(&global->epoch);
+		if (record->epoch != g_epoch) {
+			ck_stack_entry_t *next, *cursor;
+			unsigned int epoch = record->epoch & (CK_EPOCH_LENGTH - 1);
+
+			/*
+			 * This means all threads with a potential reference to a hazard pointer
+			 * will have a view as new as or newer than the calling thread. No active
+			 * reference should exist to any object in the record's pending list.
+			 */
+			CK_STACK_FOREACH_SAFE(&record->pending[epoch], cursor, next)
+				global->destroy(cursor);
+
+			ck_stack_init(&record->pending[epoch]);
+
+			record->epoch = g_epoch;
+			record->delta = 0;
+			break;
+		}
+
+		if (++record->delta >= global->threshold) {
+			record->delta = 0;
+			ck_epoch_update(global, record);
+			continue;
+		}
+
+		break;
+	}
+
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_stop(struct ck_epoch_record *record CK_CC_UNUSED)
+{
+
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_begin(struct ck_epoch_record *record)
+{
+
+	ck_epoch_activate(record);
+	ck_epoch_start(record);
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_end(struct ck_epoch_record *record)
+{
+
+	ck_epoch_deactivate(record);
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_flush(struct ck_epoch_record *record)
+{
+
+	ck_epoch_update(record->global, record);
+	ck_epoch_start(record);
+
+	return;
+}
+
+CK_CC_INLINE static void
+ck_epoch_free(struct ck_epoch_record *record, ck_stack_entry_t *entry)
+{
+	unsigned int epoch = ck_pr_load_uint(&record->epoch) & (CK_EPOCH_LENGTH - 1);
+
+	ck_stack_push_spnc(&record->pending[epoch], entry);
+	record->delta++;
+	return;
+}
+
+#endif /* _CK_EPOCH_H */

regressions/ck_epoch/validate/Makefile

@@ -0,0 +1,14 @@
+.PHONY: clean distribution
+
+OBJECTS=ck_stack
+
+all: $(OBJECTS)
+
+ck_stack: ck_stack.c ../../../include/ck_stack.h ../../../include/ck_epoch.h
+	$(CC) $(CFLAGS) -o ck_stack ck_stack.c
+
+clean:
+	rm -rf *~ *.o $(OBJECTS) *.dSYM
+
+include ../../../build/regressions.build
+CFLAGS+=-lpthread -D_GNU_SOURCE

regressions/ck_epoch/validate/ck_stack.c

@@ -0,0 +1,152 @@
+/*
+ * Copyright 2010-2011 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.
+ */
+
+#include <errno.h>
+#include <inttypes.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <strings.h>
+#include <unistd.h>
+#include <sys/time.h>
+
+#include <ck_backoff.h>
+#include <ck_cc.h>
+#include <ck_pr.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <ck_epoch.h>
+#include <ck_stack.h>
+
+#include "../../common.h"
+
+static unsigned int threshold;
+static unsigned int n_threads;
+static unsigned int barrier;
+static unsigned int e_barrier;
+
+#ifndef PAIRS
+#define PAIRS 1000000 
+#endif
+
+struct node {
+	unsigned int value;
+	ck_stack_entry_t stack_entry;
+};
+static ck_stack_t stack = {NULL, NULL};
+static ck_epoch_t stack_epoch;
+CK_STACK_CONTAINER(struct node, stack_entry, stack_container)
+static struct affinity a;
+
+static void *
+thread(void *unused CK_CC_UNUSED)
+{
+	struct node **entry, *e;
+	unsigned int i;
+	ck_epoch_record_t record;
+	ck_stack_entry_t *s;
+
+	ck_epoch_register(&stack_epoch, &record);
+
+	if (aff_iterate(&a)) {
+		perror("ERROR: failed to affine thread");
+		exit(EXIT_FAILURE);
+	}
+
+	entry = malloc(sizeof(struct node *) * PAIRS);
+	if (entry == NULL) {
+		fprintf(stderr, "Failed allocation.\n");
+		exit(EXIT_FAILURE);
+	}
+
+	for (i = 0; i < PAIRS; i++) {
+		entry[i] = malloc(sizeof(struct node));
+		if (entry == NULL) {
+			fprintf(stderr, "Failed individual allocation\n");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	for (i = 0; i < PAIRS; i++) {
+		ck_epoch_begin(&record);
+		ck_stack_push_upmc(&stack, &entry[i]->stack_entry);
+		ck_epoch_end(&record);
+
+		ck_epoch_begin(&record);
+		s = ck_stack_pop_upmc(&stack);
+		ck_epoch_end(&record);
+
+		e = stack_container(s);
+		ck_epoch_free(&record, &e->stack_entry);
+	}
+
+	ck_pr_inc_uint(&e_barrier);
+	while (ck_pr_load_uint(&e_barrier) < n_threads);
+
+	return (NULL);
+}
+
+static void
+destructor(ck_stack_entry_t *p)
+{
+	struct node *e = stack_container(p);
+
+	free(e);
+	return;
+}
+
+int
+main(int argc, char *argv[])
+{
+	unsigned int i;
+	pthread_t *threads;
+
+	if (argc != 4) {
+		fprintf(stderr, "Usage: stack <threads> <threshold> <delta>\n");
+		exit(EXIT_FAILURE);
+	}
+
+	n_threads = atoi(argv[1]);
+	threshold = atoi(argv[2]);
+	a.delta = atoi(argv[3]);
+	a.request = 0;
+
+	threads = malloc(sizeof(pthread_t) * n_threads);
+
+	ck_epoch_init(&stack_epoch, threshold, destructor);
+
+	for (i = 0; i < n_threads; i++) 
+		pthread_create(threads + i, NULL, thread, NULL);
+
+	for (i = 0; i < n_threads; i++) 
+		pthread_join(threads[i], NULL);
+
+	return (0);
+}