Adding upstream version 0.6.0.upstream/0.6.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 1495 insertions, 0 deletions

diff --git a/regressions/ck_epoch/validate/Makefile b/regressions/ck_epoch/validate/Makefile
new file mode 100644
index 0000000..446c008
--- /dev/null
+++ b/regressions/ck_epoch/validate/Makefile
@@ -0,0 +1,42 @@
+.PHONY: check clean distribution
+
+OBJECTS=ck_stack ck_epoch_synchronize ck_epoch_poll ck_epoch_call \
+	ck_epoch_section ck_epoch_section_2 torture
+HALF=`expr $(CORES) / 2`
+
+all: $(OBJECTS)
+
+check: all
+	./ck_stack $(CORES) 1
+	./ck_epoch_synchronize $(HALF) $(HALF) 1
+	./ck_epoch_poll $(CORES) 1 1
+	./ck_epoch_section
+	./ck_epoch_section_2 $(HALF) $(HALF) 1
+	./torture $(HALF) $(HALF) 1
+
+ck_epoch_synchronize: ck_epoch_synchronize.c ../../../include/ck_stack.h ../../../include/ck_epoch.h ../../../src/ck_epoch.c
+	$(CC) $(CFLAGS) -o ck_epoch_synchronize ck_epoch_synchronize.c ../../../src/ck_epoch.c
+
+ck_epoch_poll: ck_epoch_poll.c ../../../include/ck_stack.h ../../../include/ck_epoch.h ../../../src/ck_epoch.c
+	$(CC) $(CFLAGS) -o ck_epoch_poll ck_epoch_poll.c ../../../src/ck_epoch.c
+
+torture: torture.c ../../../include/ck_epoch.h ../../../src/ck_epoch.c
+	$(CC) $(CFLAGS) -o torture torture.c ../../../src/ck_epoch.c
+
+ck_epoch_section: ck_epoch_section.c ../../../include/ck_epoch.h ../../../src/ck_epoch.c
+	$(CC) $(CFLAGS) -o ck_epoch_section ck_epoch_section.c ../../../src/ck_epoch.c
+
+ck_epoch_section_2: ck_epoch_section_2.c ../../../include/ck_epoch.h ../../../src/ck_epoch.c
+	$(CC) $(CFLAGS) -o ck_epoch_section_2 ck_epoch_section_2.c ../../../src/ck_epoch.c
+
+ck_epoch_call: ck_epoch_call.c ../../../include/ck_stack.h ../../../include/ck_epoch.h ../../../src/ck_epoch.c
+	$(CC) $(CFLAGS) -o ck_epoch_call ck_epoch_call.c ../../../src/ck_epoch.c
+
+ck_stack: ck_stack.c ../../../include/ck_stack.h ../../../include/ck_epoch.h ../../../src/ck_epoch.c
+	$(CC) $(CFLAGS) -o ck_stack ck_stack.c ../../../src/ck_epoch.c
+
+clean:
+	rm -rf *~ *.o $(OBJECTS) *.dSYM *.exe
+
+include ../../../build/regressions.build
+CFLAGS+=$(PTHREAD_CFLAGS) -D_GNU_SOURCE
diff --git a/regressions/ck_epoch/validate/ck_epoch_call.c b/regressions/ck_epoch/validate/ck_epoch_call.c
new file mode 100644
index 0000000..29e0df8
--- /dev/null
+++ b/regressions/ck_epoch/validate/ck_epoch_call.c
@@ -0,0 +1,64 @@
+/*
+ * 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.
+ */
+
+#include <stdio.h>
+#include <ck_epoch.h>
+
+#include "../../common.h"
+
+static ck_epoch_t epoch;
+static unsigned int counter;
+static ck_epoch_record_t record[2];
+
+static void
+cb(ck_epoch_entry_t *p)
+{
+
+	if (counter == 0)
+		ck_epoch_call(&record[1], p, cb);
+
+	printf("Counter value: %u -> %u\n",
+	    counter, counter + 1);
+	counter++;
+	return;
+}
+
+int
+main(void)
+{
+	ck_epoch_entry_t entry;
+
+	ck_epoch_register(&epoch, &record[0]);
+	ck_epoch_register(&epoch, &record[1]);
+
+	ck_epoch_call(&record[1], &entry, cb);
+	ck_epoch_barrier(&record[1]);
+	ck_epoch_barrier(&record[1]);
+	if (counter != 2)
+		ck_error("Expected counter value 2, read %u.\n", counter);
+
+	return 0;
+}
diff --git a/regressions/ck_epoch/validate/ck_epoch_poll.c b/regressions/ck_epoch/validate/ck_epoch_poll.c
new file mode 100644
index 0000000..aec6dd0
--- /dev/null
+++ b/regressions/ck_epoch/validate/ck_epoch_poll.c
@@ -0,0 +1,236 @@
+/*
+ * Copyright 2010-2015 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 <string.h>
+#include <ck_epoch.h>
+#include <ck_stack.h>
+
+#include "../../common.h"
+
+static unsigned int n_rd;
+static unsigned int n_wr;
+static unsigned int n_threads;
+static unsigned int barrier;
+static unsigned int e_barrier;
+static unsigned int readers;
+static unsigned int writers;
+
+#ifndef PAIRS_S
+#define PAIRS_S 100000
+#endif
+
+#ifndef ITERATE_S
+#define ITERATE_S 20
+#endif
+
+struct node {
+	unsigned int value;
+	ck_stack_entry_t stack_entry;
+	ck_epoch_entry_t epoch_entry;
+};
+static ck_stack_t stack = CK_STACK_INITIALIZER;
+static ck_epoch_t stack_epoch;
+CK_STACK_CONTAINER(struct node, stack_entry, stack_container)
+CK_EPOCH_CONTAINER(struct node, epoch_entry, epoch_container)
+static struct affinity a;
+static const char animate[] = "-/|\\";
+
+static void
+destructor(ck_epoch_entry_t *p)
+{
+	struct node *e = epoch_container(p);
+
+	free(e);
+	return;
+}
+
+static void *
+read_thread(void *unused CK_CC_UNUSED)
+{
+	unsigned int j;
+	ck_epoch_record_t record CK_CC_CACHELINE;
+	ck_stack_entry_t *cursor, *n;
+
+	ck_epoch_register(&stack_epoch, &record);
+
+	if (aff_iterate(&a)) {
+		perror("ERROR: failed to affine thread");
+		exit(EXIT_FAILURE);
+	}
+
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	while (CK_STACK_ISEMPTY(&stack) == true) {
+		if (ck_pr_load_uint(&readers) != 0)
+			break;
+
+		ck_pr_stall();
+	}
+
+	j = 0;
+	for (;;) {
+		ck_epoch_begin(&record, NULL);
+		CK_STACK_FOREACH(&stack, cursor) {
+			if (cursor == NULL)
+				continue;
+
+			n = CK_STACK_NEXT(cursor);
+			j += ck_pr_load_ptr(&n) != NULL;
+		}
+		ck_epoch_end(&record, NULL);
+
+		if (j != 0 && ck_pr_load_uint(&readers) == 0)
+			ck_pr_store_uint(&readers, 1);
+
+		if (CK_STACK_ISEMPTY(&stack) == true &&
+		    ck_pr_load_uint(&e_barrier) != 0)
+			break;
+	}
+
+	ck_pr_inc_uint(&e_barrier);
+	while (ck_pr_load_uint(&e_barrier) < n_threads);
+
+	fprintf(stderr, "[R] Observed entries: %u\n", j);
+	return (NULL);
+}
+
+static void *
+write_thread(void *unused CK_CC_UNUSED)
+{
+	struct node **entry, *e;
+	unsigned int i, j, tid;
+	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);
+	}
+
+	tid = ck_pr_faa_uint(&writers, 1);
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	entry = malloc(sizeof(struct node *) * PAIRS_S);
+	if (entry == NULL) {
+		ck_error("Failed allocation.\n");
+	}
+
+	for (j = 0; j < ITERATE_S; j++) {
+		for (i = 0; i < PAIRS_S; i++) {
+			entry[i] = malloc(sizeof(struct node));
+			if (entry == NULL) {
+				ck_error("Failed individual allocation\n");
+			}
+		}
+
+		for (i = 0; i < PAIRS_S; i++) {
+			ck_stack_push_upmc(&stack, &entry[i]->stack_entry);
+		}
+
+		while (ck_pr_load_uint(&readers) == 0)
+			ck_pr_stall();
+
+		if (tid == 0) {
+			fprintf(stderr, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b[W] %2.2f: %c",
+			    (double)j / ITERATE_S, animate[i % strlen(animate)]);
+		}
+
+		for (i = 0; i < PAIRS_S; i++) {
+			ck_epoch_begin(&record, NULL);
+			s = ck_stack_pop_upmc(&stack);
+			e = stack_container(s);
+			ck_epoch_end(&record, NULL);
+
+			ck_epoch_call(&record, &e->epoch_entry, destructor);
+			ck_epoch_poll(&record);
+		}
+	}
+
+	ck_epoch_barrier(&record);
+
+	if (tid == 0) {
+		fprintf(stderr, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b[W] Peak: %u (%2.2f%%)\n    Reclamations: %lu\n\n",
+			record.n_peak,
+			(double)record.n_peak / ((double)PAIRS_S * ITERATE_S) * 100,
+			record.n_dispatch);
+	}
+
+	ck_pr_inc_uint(&e_barrier);
+	while (ck_pr_load_uint(&e_barrier) < n_threads);
+	return (NULL);
+}
+
+int
+main(int argc, char *argv[])
+{
+	unsigned int i;
+	pthread_t *threads;
+
+	if (argc != 4) {
+		ck_error("Usage: stack <#readers> <#writers> <affinity delta>\n");
+	}
+
+	n_rd = atoi(argv[1]);
+	n_wr = atoi(argv[2]);
+	n_threads = n_wr + n_rd;
+
+	a.delta = atoi(argv[3]);
+	a.request = 0;
+
+	threads = malloc(sizeof(pthread_t) * n_threads);
+	ck_epoch_init(&stack_epoch);
+
+	for (i = 0; i < n_rd; i++)
+		pthread_create(threads + i, NULL, read_thread, NULL);
+
+	do {
+		pthread_create(threads + i, NULL, write_thread, NULL);
+	} while (++i < n_wr + n_rd);
+
+	for (i = 0; i < n_threads; i++)
+		pthread_join(threads[i], NULL);
+
+	return (0);
+}
diff --git a/regressions/ck_epoch/validate/ck_epoch_section.c b/regressions/ck_epoch/validate/ck_epoch_section.c
new file mode 100644
index 0000000..12bcca1
--- /dev/null
+++ b/regressions/ck_epoch/validate/ck_epoch_section.c
@@ -0,0 +1,311 @@
+/*
+ * Copyright 2015 John Esmet.
+ * 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 <assert.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <ck_epoch.h>
+
+#include "../../common.h"
+
+static ck_epoch_t epc;
+static ck_epoch_record_t record, record2;
+static unsigned int cleanup_calls;
+
+static void
+setup_test(void)
+{
+
+	ck_epoch_init(&epc);
+	ck_epoch_register(&epc, &record);
+	ck_epoch_register(&epc, &record2);
+	cleanup_calls = 0;
+
+	return;
+}
+
+static void
+teardown_test(void)
+{
+
+	memset(&epc, 0, sizeof(ck_epoch_t));
+	ck_epoch_unregister(&record);
+	memset(&record, 0, sizeof(ck_epoch_record_t));
+	memset(&record2, 0, sizeof(ck_epoch_record_t));
+	cleanup_calls = 0;
+
+	return;
+}
+
+static void
+cleanup(ck_epoch_entry_t *e)
+{
+	(void) e;
+
+	cleanup_calls++;
+
+	return;
+}
+
+static void
+test_simple_read_section(void)
+{
+	ck_epoch_entry_t entry;
+	ck_epoch_section_t section;
+
+	memset(&entry, 0, sizeof(ck_epoch_entry_t));
+	setup_test();
+
+	ck_epoch_begin(&record, &section);
+	ck_epoch_call(&record, &entry, cleanup);
+	assert(cleanup_calls == 0);
+	ck_epoch_end(&record, &section);
+	ck_epoch_barrier(&record);
+	assert(cleanup_calls == 1);
+
+	teardown_test();
+	return;
+}
+
+static void
+test_nested_read_section(void)
+{
+	ck_epoch_entry_t entry1, entry2;
+	ck_epoch_section_t section1, section2;
+
+	memset(&entry1, 0, sizeof(ck_epoch_entry_t));
+	memset(&entry2, 0, sizeof(ck_epoch_entry_t));
+	setup_test();
+
+	ck_epoch_begin(&record, &section1);
+	ck_epoch_call(&record, &entry1, cleanup);
+	assert(cleanup_calls == 0);
+
+	ck_epoch_begin(&record, &section2);
+	ck_epoch_call(&record, &entry2, cleanup);
+	assert(cleanup_calls == 0);
+
+	ck_epoch_end(&record, &section2);
+	assert(cleanup_calls == 0);
+
+	ck_epoch_end(&record, &section1);
+	assert(cleanup_calls == 0);
+
+	ck_epoch_barrier(&record);
+	assert(cleanup_calls == 2);
+
+	teardown_test();
+	return;
+}
+
+struct obj {
+	ck_epoch_entry_t entry;
+	unsigned int destroyed;
+};
+
+static void *
+barrier_work(void *arg)
+{
+	unsigned int *run;
+
+	run = (unsigned int *)arg;
+	while (ck_pr_load_uint(run) != 0) {
+		/*
+		 * Need to use record2, as record is local
+		 * to the test thread.
+		 */
+		ck_epoch_barrier(&record2);
+		usleep(5 * 1000);
+	}
+
+	return NULL;
+}
+
+static void *
+reader_work(void *arg)
+{
+	ck_epoch_record_t local_record;
+	ck_epoch_section_t section;
+	struct obj *o;
+
+	ck_epoch_register(&epc, &local_record);
+
+	o = (struct obj *)arg;
+
+	/*
+	 * Begin a read section. The calling thread has an open read section,
+	 * so the object should not be destroyed for the lifetime of this
+	 * thread.
+	 */
+	ck_epoch_begin(&local_record, &section);
+	usleep((common_rand() % 100) * 1000);
+	assert(ck_pr_load_uint(&o->destroyed) == 0);
+	ck_epoch_end(&local_record, &section);
+
+	ck_epoch_unregister(&local_record);
+
+	return NULL;
+}
+
+static void
+obj_destroy(ck_epoch_entry_t *e)
+{
+	struct obj *o;
+
+	o = (struct obj *)e;
+	ck_pr_fas_uint(&o->destroyed, 1);
+
+	return;
+}
+
+static void
+test_single_reader_with_barrier_thread(void)
+{
+	const int num_sections = 10;
+	struct obj o;
+	unsigned int run;
+	pthread_t thread;
+	ck_epoch_section_t sections[num_sections];
+	int shuffled[num_sections];
+
+	run = 1;
+	memset(&o, 0, sizeof(struct obj));
+	common_srand(time(NULL));
+	setup_test();
+
+	if (pthread_create(&thread, NULL, barrier_work, &run) != 0) {
+		abort();
+	}
+
+	/* Start a bunch of sections. */
+	for (int i = 0; i < num_sections; i++) {
+		ck_epoch_begin(&record, &sections[i]);
+		shuffled[i] = i;
+		if (i == num_sections / 2) {
+			usleep(1 * 1000);
+		}
+	}
+
+	/* Generate a shuffle. */
+	for (int i = num_sections - 1; i >= 0; i--) {
+		int k = common_rand() % (i + 1);
+		int tmp = shuffled[k];
+		shuffled[k] = shuffled[i];
+		shuffled[i] = tmp;
+	}
+
+	ck_epoch_call(&record, &o.entry, obj_destroy);
+
+	/* Close the sections in shuffle-order. */
+	for (int i = 0; i < num_sections; i++) {
+		ck_epoch_end(&record, &sections[shuffled[i]]);
+		if (i != num_sections - 1) {
+			assert(ck_pr_load_uint(&o.destroyed) == 0);
+			usleep(3 * 1000);
+		}
+	}
+
+	ck_pr_store_uint(&run, 0);
+	if (pthread_join(thread, NULL) != 0) {
+		abort();
+	}
+
+	ck_epoch_barrier(&record);
+	assert(ck_pr_load_uint(&o.destroyed) == 1);
+
+	teardown_test();
+
+	return;
+}
+
+static void
+test_multiple_readers_with_barrier_thread(void)
+{
+	const int num_readers = 10;
+	struct obj o;
+	unsigned int run;
+	ck_epoch_section_t section;
+	pthread_t threads[num_readers + 1];
+
+	run = 1;
+	memset(&o, 0, sizeof(struct obj));
+	memset(&section, 0, sizeof(ck_epoch_section_t));
+	common_srand(time(NULL));
+	setup_test();
+
+	/* Create a thread to call barrier() while we create reader threads.
+	 * Each barrier will attempt to move the global epoch forward so
+	 * it will make the read section code coverage more interesting. */
+	if (pthread_create(&threads[num_readers], NULL,
+	    barrier_work, &run) != 0) {
+		abort();
+	}
+
+	ck_epoch_begin(&record, &section);
+	ck_epoch_call(&record, &o.entry, obj_destroy);
+
+	for (int i = 0; i < num_readers; i++) {
+		if (pthread_create(&threads[i], NULL, reader_work, &o) != 0) {
+			abort();
+		}
+	}
+
+	ck_epoch_end(&record, &section);
+
+	ck_pr_store_uint(&run, 0);
+	if (pthread_join(threads[num_readers], NULL) != 0) {
+		abort();
+	}
+
+	/* After the barrier, the object should be destroyed and readers
+	 * should return. */
+	for (int i = 0; i < num_readers; i++) {
+		if (pthread_join(threads[i], NULL) != 0) {
+			abort();
+		}
+	}
+
+	teardown_test();
+	return;
+}
+
+int
+main(void)
+{
+
+	test_simple_read_section();
+	test_nested_read_section();
+	test_single_reader_with_barrier_thread();
+	test_multiple_readers_with_barrier_thread();
+
+	return 0;
+}
diff --git a/regressions/ck_epoch/validate/ck_epoch_section_2.c b/regressions/ck_epoch/validate/ck_epoch_section_2.c
new file mode 100644
index 0000000..aed3661
--- /dev/null
+++ b/regressions/ck_epoch/validate/ck_epoch_section_2.c
@@ -0,0 +1,195 @@
+/*
+ * Copyright 2010-2015 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 <assert.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <ck_cc.h>
+#include <ck_pr.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+#include <ck_epoch.h>
+#include <ck_stack.h>
+
+#include "../../common.h"
+
+static unsigned int n_rd;
+static unsigned int n_wr;
+static unsigned int n_threads;
+static unsigned int barrier;
+static unsigned int leave;
+
+#ifndef PAIRS_S
+#define PAIRS_S 10000
+#endif
+
+#ifndef CK_EPOCH_T_DEPTH
+#define CK_EPOCH_T_DEPTH	8
+#endif
+
+static ck_epoch_t epoch;
+static struct affinity a;
+
+static void *
+read_thread(void *unused CK_CC_UNUSED)
+{
+	ck_epoch_record_t *record;
+	unsigned long long i = 0;
+
+	record = malloc(sizeof *record);
+	assert(record != NULL);
+	ck_epoch_register(&epoch, record);
+
+	if (aff_iterate(&a)) {
+		perror("ERROR: failed to affine thread");
+		exit(EXIT_FAILURE);
+	}
+
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	for (;;) {
+		ck_epoch_section_t section[2];
+		ck_epoch_section_t junk[CK_EPOCH_T_DEPTH];
+		unsigned int j;
+
+		ck_epoch_begin(record, &section[0]);
+
+		for (j = 0; j < CK_EPOCH_T_DEPTH; j++)
+			ck_epoch_begin(record, &junk[j]);
+		for (j = 0; j < CK_EPOCH_T_DEPTH; j++)
+			ck_epoch_end(record, &junk[j]);
+
+		if (i > 0)
+			ck_epoch_end(record, &section[1]);
+
+		/* Wait for the next synchronize operation. */
+		while ((ck_pr_load_uint(&epoch.epoch) & 1) ==
+		    section[0].bucket) {
+			i++;
+
+			if (!(i % 10000000)) {
+				fprintf(stderr, "%u %u %u\n",
+				    ck_pr_load_uint(&epoch.epoch),
+				    section[0].bucket, record->epoch);
+			}
+
+			while ((ck_pr_load_uint(&epoch.epoch) & 1) ==
+			    section[0].bucket) {
+				if (ck_pr_load_uint(&leave) == 1)
+					break;
+
+				ck_pr_stall();
+			}
+		}
+
+		ck_epoch_begin(record, &section[1]);
+
+		assert(section[0].bucket != section[1].bucket);
+		ck_epoch_end(record, &section[0]);
+
+		assert(ck_pr_load_uint(&record->active) > 0);
+
+		if (ck_pr_load_uint(&leave) == 1) {
+			ck_epoch_end(record, &section[1]);
+			break;
+		}
+
+		i++;
+	}
+
+	return NULL;
+}
+
+static void *
+write_thread(void *unused CK_CC_UNUSED)
+{
+	ck_epoch_record_t record;
+	unsigned long iterations = 0;
+
+	ck_epoch_register(&epoch, &record);
+
+	if (aff_iterate(&a)) {
+		perror("ERROR: failed to affine thread");
+		exit(EXIT_FAILURE);
+	}
+
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	for (;;) {
+		if (!(iterations % 1048575))
+			fprintf(stderr, ".");
+
+		ck_epoch_synchronize(&record);
+		iterations++;
+
+		if (ck_pr_load_uint(&leave) == 1)
+			break;
+	}
+
+	fprintf(stderr, "%lu iterations\n", iterations);
+	return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+	unsigned int i;
+	pthread_t *threads;
+
+	if (argc != 4) {
+		ck_error("Usage: stack <#readers> <#writers> <affinity delta>\n");
+	}
+
+	n_rd = atoi(argv[1]);
+	n_wr = atoi(argv[2]);
+	n_threads = n_wr + n_rd;
+
+	a.delta = atoi(argv[3]);
+	a.request = 0;
+
+	threads = malloc(sizeof(pthread_t) * n_threads);
+	ck_epoch_init(&epoch);
+
+	for (i = 0; i < n_rd; i++)
+		pthread_create(threads + i, NULL, read_thread, NULL);
+
+	do {
+		pthread_create(threads + i, NULL, write_thread, NULL);
+	} while (++i < n_wr + n_rd);
+
+	common_sleep(10);
+	ck_pr_store_uint(&leave, 1);
+
+	for (i = 0; i < n_threads; i++)
+		pthread_join(threads[i], NULL);
+
+	return (0);
+}
diff --git a/regressions/ck_epoch/validate/ck_epoch_synchronize.c b/regressions/ck_epoch/validate/ck_epoch_synchronize.c
new file mode 100644
index 0000000..a03a4f7
--- /dev/null
+++ b/regressions/ck_epoch/validate/ck_epoch_synchronize.c
@@ -0,0 +1,249 @@
+/*
+ * Copyright 2010-2015 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 <string.h>
+#include <ck_epoch.h>
+#include <ck_stack.h>
+
+#include "../../common.h"
+
+static unsigned int n_rd;
+static unsigned int n_wr;
+static unsigned int n_threads;
+static unsigned int barrier;
+static unsigned int e_barrier;
+static unsigned int readers;
+static unsigned int writers;
+
+#ifndef PAIRS_S
+#define PAIRS_S 10000
+#endif
+
+#ifndef ITERATE_S
+#define ITERATE_S 20
+#endif
+
+struct node {
+	unsigned int value;
+	ck_stack_entry_t stack_entry;
+	ck_epoch_entry_t epoch_entry;
+};
+static ck_stack_t stack = CK_STACK_INITIALIZER;
+static ck_epoch_t stack_epoch;
+CK_STACK_CONTAINER(struct node, stack_entry, stack_container)
+CK_EPOCH_CONTAINER(struct node, epoch_entry, epoch_container)
+static struct affinity a;
+static const char animate[] = "-/|\\";
+
+static void
+destructor(ck_epoch_entry_t *p)
+{
+	struct node *e = epoch_container(p);
+
+	free(e);
+	return;
+}
+
+static void *
+read_thread(void *unused CK_CC_UNUSED)
+{
+	unsigned int j;
+	ck_epoch_record_t record CK_CC_CACHELINE;
+	ck_stack_entry_t *cursor;
+	ck_stack_entry_t *n;
+	unsigned int i;
+
+	ck_epoch_register(&stack_epoch, &record);
+
+	if (aff_iterate(&a)) {
+		perror("ERROR: failed to affine thread");
+		exit(EXIT_FAILURE);
+	}
+
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	while (CK_STACK_ISEMPTY(&stack) == true) {
+		if (ck_pr_load_uint(&readers) != 0)
+			break;
+
+		ck_pr_stall();
+	}
+
+	j = 0;
+	for (;;) {
+		i = 0;
+
+		ck_epoch_begin(&record, NULL);
+		CK_STACK_FOREACH(&stack, cursor) {
+			if (cursor == NULL)
+				continue;
+
+			n = CK_STACK_NEXT(cursor);
+			j += ck_pr_load_ptr(&n) != NULL;
+
+			if (i++ > 4098)
+				break;
+		}
+		ck_epoch_end(&record, NULL);
+
+		if (j != 0 && ck_pr_load_uint(&readers) == 0)
+			ck_pr_store_uint(&readers, 1);
+
+		if (CK_STACK_ISEMPTY(&stack) == true &&
+		    ck_pr_load_uint(&e_barrier) != 0)
+			break;
+	}
+
+	ck_pr_inc_uint(&e_barrier);
+	while (ck_pr_load_uint(&e_barrier) < n_threads);
+
+	fprintf(stderr, "[R] Observed entries: %u\n", j);
+	return (NULL);
+}
+
+static void *
+write_thread(void *unused CK_CC_UNUSED)
+{
+	struct node **entry, *e;
+	unsigned int i, j, tid;
+	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);
+	}
+
+	tid = ck_pr_faa_uint(&writers, 1);
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	entry = malloc(sizeof(struct node *) * PAIRS_S);
+	if (entry == NULL) {
+		ck_error("Failed allocation.\n");
+	}
+
+	for (j = 0; j < ITERATE_S; j++) {
+		for (i = 0; i < PAIRS_S; i++) {
+			entry[i] = malloc(sizeof(struct node));
+			if (entry == NULL) {
+				ck_error("Failed individual allocation\n");
+			}
+		}
+
+		for (i = 0; i < PAIRS_S; i++) {
+			ck_stack_push_upmc(&stack, &entry[i]->stack_entry);
+		}
+
+		while (ck_pr_load_uint(&readers) == 0)
+			ck_pr_stall();
+
+		for (i = 0; i < PAIRS_S; i++) {
+			ck_epoch_begin(&record, NULL);
+			s = ck_stack_pop_upmc(&stack);
+			e = stack_container(s);
+			ck_epoch_end(&record, NULL);
+
+			if (i & 1) {
+				ck_epoch_synchronize(&record);
+				ck_epoch_reclaim(&record);
+				ck_epoch_call(&record, &e->epoch_entry, destructor);
+			} else {
+				ck_epoch_barrier(&record);
+				destructor(&e->epoch_entry);
+			}
+
+			if (tid == 0 && (i % 16384) == 0) {
+				fprintf(stderr, "[W] %2.2f: %c\n",
+				    (double)j / ITERATE_S, animate[i % strlen(animate)]);
+			}
+		}
+	}
+
+	ck_epoch_synchronize(&record);
+
+	if (tid == 0) {
+		fprintf(stderr, "[W] Peak: %u (%2.2f%%)\n    Reclamations: %lu\n\n",
+			record.n_peak,
+			(double)record.n_peak / ((double)PAIRS_S * ITERATE_S) * 100,
+			record.n_dispatch);
+	}
+
+	ck_pr_inc_uint(&e_barrier);
+	while (ck_pr_load_uint(&e_barrier) < n_threads);
+	return (NULL);
+}
+
+int
+main(int argc, char *argv[])
+{
+	unsigned int i;
+	pthread_t *threads;
+
+	if (argc != 4) {
+		ck_error("Usage: stack <#readers> <#writers> <affinity delta>\n");
+	}
+
+	n_rd = atoi(argv[1]);
+	n_wr = atoi(argv[2]);
+	n_threads = n_wr + n_rd;
+
+	a.delta = atoi(argv[3]);
+	a.request = 0;
+
+	threads = malloc(sizeof(pthread_t) * n_threads);
+	ck_epoch_init(&stack_epoch);
+
+	for (i = 0; i < n_rd; i++)
+		pthread_create(threads + i, NULL, read_thread, NULL);
+
+	do {
+		pthread_create(threads + i, NULL, write_thread, NULL);
+	} while (++i < n_wr + n_rd);
+
+	for (i = 0; i < n_threads; i++)
+		pthread_join(threads[i], NULL);
+
+	return (0);
+}
diff --git a/regressions/ck_epoch/validate/ck_stack.c b/regressions/ck_epoch/validate/ck_stack.c
new file mode 100644
index 0000000..fc50228
--- /dev/null
+++ b/regressions/ck_epoch/validate/ck_stack.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright 2010-2015 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 n_threads;
+static unsigned int barrier;
+static unsigned int e_barrier;
+
+#ifndef PAIRS
+#define PAIRS 5000000
+#endif
+
+struct node {
+	unsigned int value;
+	ck_epoch_entry_t epoch_entry;
+	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)
+CK_EPOCH_CONTAINER(struct node, epoch_entry, epoch_container)
+static struct affinity a;
+
+static void
+destructor(ck_epoch_entry_t *p)
+{
+	struct node *e = epoch_container(p);
+
+	free(e);
+	return;
+}
+
+static void *
+thread(void *unused CK_CC_UNUSED)
+{
+	struct node **entry, *e;
+	ck_epoch_record_t record;
+	ck_stack_entry_t *s;
+	unsigned long smr = 0;
+	unsigned int i;
+
+	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) {
+		ck_error("Failed allocation.\n");
+	}
+
+	for (i = 0; i < PAIRS; i++) {
+		entry[i] = malloc(sizeof(struct node));
+		if (entry == NULL) {
+			ck_error("Failed individual allocation\n");
+		}
+	}
+
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	for (i = 0; i < PAIRS; i++) {
+		ck_epoch_begin(&record, NULL);
+		ck_stack_push_upmc(&stack, &entry[i]->stack_entry);
+		s = ck_stack_pop_upmc(&stack);
+		ck_epoch_end(&record, NULL);
+
+		e = stack_container(s);
+		ck_epoch_call(&record, &e->epoch_entry, destructor);
+		smr += ck_epoch_poll(&record) == false;
+	}
+
+	ck_pr_inc_uint(&e_barrier);
+	while (ck_pr_load_uint(&e_barrier) < n_threads);
+
+	fprintf(stderr, "Deferrals: %lu (%2.2f)\n", smr, (double)smr / PAIRS);
+	fprintf(stderr, "Peak: %u (%2.2f%%), %u pending\nReclamations: %lu\n\n",
+			record.n_peak,
+			(double)record.n_peak / PAIRS * 100,
+			record.n_pending,
+			record.n_dispatch);
+
+	ck_epoch_barrier(&record);
+	ck_pr_inc_uint(&e_barrier);
+	while (ck_pr_load_uint(&e_barrier) < (n_threads << 1));
+
+	if (record.n_pending != 0) {
+		ck_error("ERROR: %u pending, expecting none.\n",
+				record.n_pending);
+	}
+
+	return (NULL);
+}
+
+int
+main(int argc, char *argv[])
+{
+	unsigned int i;
+	pthread_t *threads;
+
+	if (argc != 3) {
+		ck_error("Usage: stack <threads> <affinity delta>\n");
+	}
+
+	n_threads = atoi(argv[1]);
+	a.delta = atoi(argv[2]);
+	a.request = 0;
+
+	threads = malloc(sizeof(pthread_t) * n_threads);
+
+	ck_epoch_init(&stack_epoch);
+
+	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);
+}
diff --git a/regressions/ck_epoch/validate/torture.c b/regressions/ck_epoch/validate/torture.c
new file mode 100644
index 0000000..ce3c049
--- /dev/null
+++ b/regressions/ck_epoch/validate/torture.c
@@ -0,0 +1,234 @@
+/*
+ * Copyright 2010-2015 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 <assert.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <ck_cc.h>
+#include <ck_pr.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+#include <ck_epoch.h>
+#include <ck_stack.h>
+
+#include "../../common.h"
+
+static unsigned int n_rd;
+static unsigned int n_wr;
+static unsigned int n_threads;
+static unsigned int barrier;
+static unsigned int leave;
+static unsigned int first;
+
+struct {
+	unsigned int value;
+} valid CK_CC_CACHELINE = { 1 };
+
+struct {
+	unsigned int value;
+} invalid CK_CC_CACHELINE;
+
+#ifndef PAIRS_S
+#define PAIRS_S 10000
+#endif
+
+#ifndef CK_EPOCH_T_DEPTH
+#define CK_EPOCH_T_DEPTH	8
+#endif
+
+static ck_epoch_t epoch;
+static struct affinity a;
+
+static void
+test(struct ck_epoch_record *record)
+{
+	unsigned int j[3];
+	unsigned int b, c;
+	const unsigned int r = 100;
+	size_t i;
+
+	for (i = 0; i < 8; i++) {
+		ck_epoch_begin(record, NULL);
+		c = ck_pr_load_uint(&invalid.value);
+		ck_pr_fence_load();
+		b = ck_pr_load_uint(&valid.value);
+		ck_test(c > b, "Invalid value: %u > %u\n", c, b);
+		ck_epoch_end(record, NULL);
+	}
+
+	ck_epoch_begin(record, NULL);
+
+	/* This implies no early load of epoch occurs. */
+	j[0] = record->epoch;
+
+
+	/* We should observe up to one epoch migration. */
+	do {
+		ck_pr_fence_load();
+		j[1] = ck_pr_load_uint(&epoch.epoch);
+
+		if (ck_pr_load_uint(&leave) == 1) {
+			ck_epoch_end(record, NULL);
+			return;
+		}
+	} while (j[1] == j[0]);
+
+	/* No more epoch migrations should occur */
+	for (i = 0; i < r; i++) {
+		ck_pr_fence_strict_load();
+		j[2] = ck_pr_load_uint(&epoch.epoch);
+
+		ck_test(j[2] != j[1], "Inconsistency detected: %u %u %u\n",
+		    j[0], j[1], j[2]);
+	}
+
+	ck_epoch_end(record, NULL);
+	return;
+}
+
+static void *
+read_thread(void *unused CK_CC_UNUSED)
+{
+	ck_epoch_record_t *record;
+
+	record = malloc(sizeof *record);
+	assert(record != NULL);
+	ck_epoch_register(&epoch, record);
+
+	if (aff_iterate(&a)) {
+		perror("ERROR: failed to affine thread");
+		exit(EXIT_FAILURE);
+	}
+
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	do {
+		test(record);
+		test(record);
+		test(record);
+		test(record);
+	} while (ck_pr_load_uint(&leave) == 0);
+
+	ck_pr_dec_uint(&n_rd);
+
+	return NULL;
+}
+
+static void *
+write_thread(void *unused CK_CC_UNUSED)
+{
+	ck_epoch_record_t *record;
+	unsigned long iterations = 0;
+	bool c = ck_pr_faa_uint(&first, 1);
+
+	record = malloc(sizeof *record);
+	assert(record != NULL);
+	ck_epoch_register(&epoch, record);
+
+	if (aff_iterate(&a)) {
+		perror("ERROR: failed to affine thread");
+		exit(EXIT_FAILURE);
+	}
+
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	do {
+		/*
+		 * A thread should never observe invalid.value > valid.value.
+		 * inside a protected section. Only
+		 * invalid.value <= valid.value is valid.
+		 */
+		if (!c) ck_pr_store_uint(&valid.value, 1);
+		ck_epoch_synchronize(record);
+		if (!c) ck_pr_store_uint(&invalid.value, 1);
+
+		ck_pr_fence_store();
+		if (!c) ck_pr_store_uint(&valid.value, 2);
+		ck_epoch_synchronize(record);
+		if (!c) ck_pr_store_uint(&invalid.value, 2);
+
+		ck_pr_fence_store();
+		if (!c) ck_pr_store_uint(&valid.value, 3);
+		ck_epoch_synchronize(record);
+		if (!c) ck_pr_store_uint(&invalid.value, 3);
+
+		ck_pr_fence_store();
+		if (!c) ck_pr_store_uint(&valid.value, 4);
+		ck_epoch_synchronize(record);
+		if (!c) ck_pr_store_uint(&invalid.value, 4);
+
+		ck_epoch_synchronize(record);
+		if (!c) ck_pr_store_uint(&invalid.value, 0);
+		ck_epoch_synchronize(record);
+
+		iterations += 4;
+	} while (ck_pr_load_uint(&leave) == 0 &&
+		 ck_pr_load_uint(&n_rd) > 0);
+
+	fprintf(stderr, "%lu iterations\n", iterations);
+	return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+	unsigned int i;
+	pthread_t *threads;
+
+	if (argc != 4) {
+		ck_error("Usage: stack <#readers> <#writers> <affinity delta>\n");
+	}
+
+	n_rd = atoi(argv[1]);
+	n_wr = atoi(argv[2]);
+	n_threads = n_wr + n_rd;
+
+	a.delta = atoi(argv[3]);
+	a.request = 0;
+
+	threads = malloc(sizeof(pthread_t) * n_threads);
+	ck_epoch_init(&epoch);
+
+	for (i = 0; i < n_rd; i++)
+		pthread_create(threads + i, NULL, read_thread, NULL);
+
+	do {
+		pthread_create(threads + i, NULL, write_thread, NULL);
+	} while (++i < n_wr + n_rd);
+
+	common_sleep(30);
+	ck_pr_store_uint(&leave, 1);
+
+	for (i = 0; i < n_threads; i++)
+		pthread_join(threads[i], NULL);
+
+	return 0;
+}