doc/examples/lfstack/cds_lfs_pop_blocking
doc/examples/lfstack/cds_lfs_pop_all_blocking
+doc/examples/rculfhash/cds_lfht_add
+doc/examples/rculfhash/cds_lfht_del
+
#automake
/config.h
.deps/
rculfqueue/cds_lfq_enqueue.c \
rculfqueue/cds_lfq_dequeue.c
+doc_examples_rculfhashdir = ${doc_examplesdir}/rculfhash
+
+dist_doc_examples_rculfhash_DATA = \
+ rculfhash/Makefile \
+ rculfhash/jhash.h \
+ rculfhash/Makefile.cds_lfht_add \
+ rculfhash/Makefile.cds_lfht_del \
+ rculfhash/cds_lfht_add.c \
+ rculfhash/cds_lfht_del.c
+
if NO_SHARED
# Don't build examples if shared libraries support was explicitly
# disabled.
$(CC) $(CFLAGS) $(LDFLAGS) $(AM_CFLAGS) $(AM_LDFLAGS) \
$(LIBS) -o $@ $(OBJECTS)
-$(OBJECTS): $(SOURCES)
+$(OBJECTS): $(SOURCES) $(DEPS)
$(CC) $(CPPFLAGS) $(CFLAGS) $(AM_CPPFLAGS) $(AM_CFLAGS) \
-c -o $@ $(SOURCES)
$(MAKE) -C rculfqueue
$(MAKE) -C wfstack
$(MAKE) -C lfstack
+ $(MAKE) -C rculfhash
.PHONY: clean
clean:
$(MAKE) -C rculfqueue clean
$(MAKE) -C wfstack clean
$(MAKE) -C lfstack clean
+ $(MAKE) -C rculfhash clean
--- /dev/null
+# Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+#
+# THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+# OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+#
+# Permission is hereby granted to use or copy this program for any
+# purpose, provided the above notices are retained on all copies.
+# Permission to modify the code and to distribute modified code is
+# granted, provided the above notices are retained, and a notice that
+# the code was modified is included with the above copyright notice.
+#
+# This makefile is purposefully kept simple to support GNU and BSD make.
+
+all:
+ $(MAKE) -f Makefile.cds_lfht_add
+ $(MAKE) -f Makefile.cds_lfht_del
+
+.PHONY: clean
+clean:
+ $(MAKE) -f Makefile.cds_lfht_del clean
--- /dev/null
+# Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+#
+# THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+# OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+#
+# Permission is hereby granted to use or copy this program for any
+# purpose, provided the above notices are retained on all copies.
+# Permission to modify the code and to distribute modified code is
+# granted, provided the above notices are retained, and a notice that
+# the code was modified is included with the above copyright notice.
+#
+# This makefile is purposefully kept simple to support GNU and BSD make.
+
+EXAMPLE_NAME = cds_lfht_add
+
+SOURCES = $(EXAMPLE_NAME).c
+DEPS = jhash.h
+OBJECTS = $(EXAMPLE_NAME).o
+BINARY = $(EXAMPLE_NAME)
+LIBS = -lurcu-cds -lurcu
+
+include ../Makefile.examples.template
--- /dev/null
+# Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+#
+# THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+# OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+#
+# Permission is hereby granted to use or copy this program for any
+# purpose, provided the above notices are retained on all copies.
+# Permission to modify the code and to distribute modified code is
+# granted, provided the above notices are retained, and a notice that
+# the code was modified is included with the above copyright notice.
+#
+# This makefile is purposefully kept simple to support GNU and BSD make.
+
+EXAMPLE_NAME = cds_lfht_del
+
+SOURCES = $(EXAMPLE_NAME).c
+DEPS = jhash.h
+OBJECTS = $(EXAMPLE_NAME).o
+BINARY = $(EXAMPLE_NAME)
+LIBS = -lurcu-cds -lurcu
+
+include ../Makefile.examples.template
--- /dev/null
+/*
+ * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program for any
+ * purpose, provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is
+ * granted, provided the above notices are retained, and a notice that
+ * the code was modified is included with the above copyright notice.
+ *
+ * This example shows how to add nodes (allowing duplicate keys) into a
+ * RCU lock-free hash table.
+ * This hash table requires using a RCU scheme.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include <urcu.h> /* RCU flavor */
+#include <urcu/rculfhash.h> /* RCU Lock-free hash table */
+#include <urcu/compiler.h> /* For CAA_ARRAY_SIZE */
+#include "jhash.h" /* Example hash function */
+
+/*
+ * Nodes populated into the hash table.
+ */
+struct mynode {
+ int value; /* Node content */
+ struct cds_lfht_node node; /* Chaining in hash table */
+};
+
+int main(int argc, char **argv)
+{
+ int values[] = { -5, 42, 42, 36, 24, }; /* 42 is duplicated */
+ struct cds_lfht *ht; /* Hash table */
+ unsigned int i;
+ int ret = 0;
+ uint32_t seed;
+ struct cds_lfht_iter iter; /* For iteration on hash table */
+ struct mynode *node;
+
+ /*
+ * Each thread need using RCU read-side need to be explicitly
+ * registered.
+ */
+ rcu_register_thread();
+
+ /* Use time as seed for hash table hashing. */
+ seed = (uint32_t) time(NULL);
+
+ /*
+ * Allocate hash table.
+ */
+ ht = cds_lfht_new(1, 1, 0,
+ CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING,
+ NULL);
+ if (!ht) {
+ printf("Error allocating hash table\n");
+ ret = -1;
+ goto end;
+ }
+
+ /*
+ * Add nodes to hash table.
+ */
+ for (i = 0; i < CAA_ARRAY_SIZE(values); i++) {
+ unsigned long hash;
+
+ node = malloc(sizeof(*node));
+ if (!node) {
+ ret = -1;
+ goto end;
+ }
+
+ cds_lfht_node_init(&node->node);
+ node->value = values[i];
+ hash = jhash(&values[i], sizeof(values[i]), seed);
+
+ /*
+ * cds_lfht_add() needs to be called from RCU read-side
+ * critical section.
+ */
+ rcu_read_lock();
+ cds_lfht_add(ht, hash, &node->node);
+ rcu_read_unlock();
+ }
+
+ /*
+ * Iterate over each hash table node. Those will appear in
+ * random order, depending on the hash seed. Iteration needs to
+ * be performed within RCU read-side critical section.
+ */
+ printf("hash table content (random order):");
+ rcu_read_lock();
+ cds_lfht_for_each_entry(ht, &iter, node, node) {
+ printf(" %d", node->value);
+ }
+ rcu_read_unlock();
+ printf("\n");
+end:
+ rcu_unregister_thread();
+ return ret;
+}
--- /dev/null
+/*
+ * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program for any
+ * purpose, provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is
+ * granted, provided the above notices are retained, and a notice that
+ * the code was modified is included with the above copyright notice.
+ *
+ * This example shows how to remove nodes from a RCU lock-free hash table.
+ * This hash table requires using a RCU scheme.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include <urcu.h> /* RCU flavor */
+#include <urcu/rculfhash.h> /* RCU Lock-free hash table */
+#include <urcu/compiler.h> /* For CAA_ARRAY_SIZE */
+#include "jhash.h" /* Example hash function */
+
+/*
+ * Nodes populated into the hash table.
+ */
+struct mynode {
+ int value; /* Node content */
+ struct cds_lfht_node node; /* Chaining in hash table */
+ struct rcu_head rcu_head; /* For call_rcu() */
+};
+
+int match(struct cds_lfht_node *ht_node, const void *_key)
+{
+ struct mynode *node =
+ caa_container_of(ht_node, struct mynode, node);
+ const unsigned int *key = _key;
+
+ return *key == node->value;
+}
+
+int main(int argc, char **argv)
+{
+ int values[] = { -5, 42, 42, 36, 24, }; /* 42 is duplicated */
+ int remove_values[] = { 42, 36, 24, 123, };
+ struct cds_lfht *ht; /* Hash table */
+ unsigned int i;
+ int ret = 0;
+ uint32_t seed;
+ struct cds_lfht_iter iter; /* For iteration on hash table */
+ struct cds_lfht_node *ht_node;
+ struct mynode *node;
+
+ /*
+ * Each thread need using RCU read-side need to be explicitly
+ * registered.
+ */
+ rcu_register_thread();
+
+ /* Use time as seed for hash table hashing. */
+ seed = (uint32_t) time(NULL);
+
+ /*
+ * Allocate hash table.
+ */
+ ht = cds_lfht_new(1, 1, 0,
+ CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING,
+ NULL);
+ if (!ht) {
+ printf("Error allocating hash table\n");
+ ret = -1;
+ goto end;
+ }
+
+ /*
+ * Add nodes to hash table.
+ */
+ for (i = 0; i < CAA_ARRAY_SIZE(values); i++) {
+ unsigned long hash;
+ int value;
+
+ node = malloc(sizeof(*node));
+ if (!node) {
+ ret = -1;
+ goto end;
+ }
+
+ cds_lfht_node_init(&node->node);
+ value = values[i];
+ node->value = value;
+ hash = jhash(&value, sizeof(value), seed);
+
+ /*
+ * cds_lfht_add() needs to be called from RCU read-side
+ * critical section.
+ */
+ rcu_read_lock();
+ cds_lfht_add(ht, hash, &node->node);
+ rcu_read_unlock();
+ }
+
+ /*
+ * Iterate over each hash table node. Those will appear in
+ * random order, depending on the hash seed. Iteration needs to
+ * be performed within RCU read-side critical section.
+ */
+ printf("hash table content (random order):");
+ rcu_read_lock();
+ cds_lfht_for_each_entry(ht, &iter, node, node) {
+ printf(" %d", node->value);
+ }
+ rcu_read_unlock();
+ printf("\n");
+
+ /*
+ * Remove one node for each key, if such a node is present.
+ */
+ printf("removing keys (single key, not duplicates):");
+ for (i = 0; i < CAA_ARRAY_SIZE(remove_values); i++) {
+ unsigned long hash;
+ int value;
+
+ value = remove_values[i];
+ hash = jhash(&value, sizeof(value), seed);
+ printf(" %d", value);
+ rcu_read_lock();
+ cds_lfht_lookup(ht, hash, match, &value, &iter);
+ ht_node = cds_lfht_iter_get_node(&iter);
+ if (ht_node) {
+ ret = cds_lfht_del(ht, ht_node);
+ if (ret) {
+ printf(" (concurrently deleted)");
+ }
+ } else {
+ printf(" (not found)");
+ }
+ rcu_read_unlock();
+ }
+ printf("\n");
+
+ printf("hash table content (random order):");
+ rcu_read_lock();
+ cds_lfht_for_each_entry(ht, &iter, node, node) {
+ printf(" %d", node->value);
+ }
+ rcu_read_unlock();
+ printf("\n");
+
+end:
+ rcu_unregister_thread();
+ return ret;
+}
--- /dev/null
+#ifndef _JHASH_H
+#define _JHASH_H
+
+/*
+ * jhash.h
+ *
+ * Example hash function.
+ *
+ * Copyright 2009-2012 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program for any
+ * purpose, provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is
+ * granted, provided the above notices are retained, and a notice that
+ * the code was modified is included with the above copyright notice.
+ */
+
+/*
+ * Hash function
+ * Source: http://burtleburtle.net/bob/c/lookup3.c
+ * Originally Public Domain
+ */
+
+#define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k))))
+
+#define mix(a, b, c) \
+do { \
+ a -= c; a ^= rot(c, 4); c += b; \
+ b -= a; b ^= rot(a, 6); a += c; \
+ c -= b; c ^= rot(b, 8); b += a; \
+ a -= c; a ^= rot(c, 16); c += b; \
+ b -= a; b ^= rot(a, 19); a += c; \
+ c -= b; c ^= rot(b, 4); b += a; \
+} while (0)
+
+#define final(a, b, c) \
+{ \
+ c ^= b; c -= rot(b, 14); \
+ a ^= c; a -= rot(c, 11); \
+ b ^= a; b -= rot(a, 25); \
+ c ^= b; c -= rot(b, 16); \
+ a ^= c; a -= rot(c, 4); \
+ b ^= a; b -= rot(a, 14); \
+ c ^= b; c -= rot(b, 24); \
+}
+
+#if (BYTE_ORDER == LITTLE_ENDIAN)
+#define HASH_LITTLE_ENDIAN 1
+#else
+#define HASH_LITTLE_ENDIAN 0
+#endif
+
+/*
+ *
+ * hashlittle() -- hash a variable-length key into a 32-bit value
+ * k : the key (the unaligned variable-length array of bytes)
+ * length : the length of the key, counting by bytes
+ * initval : can be any 4-byte value
+ * Returns a 32-bit value. Every bit of the key affects every bit of
+ * the return value. Two keys differing by one or two bits will have
+ * totally different hash values.
+ *
+ * The best hash table sizes are powers of 2. There is no need to do
+ * mod a prime (mod is sooo slow!). If you need less than 32 bits,
+ * use a bitmask. For example, if you need only 10 bits, do
+ * h = (h & hashmask(10));
+ * In which case, the hash table should have hashsize(10) elements.
+ *
+ * If you are hashing n strings (uint8_t **)k, do it like this:
+ * for (i = 0, h = 0; i < n; ++i) h = hashlittle(k[i], len[i], h);
+ *
+ * By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this
+ * code any way you wish, private, educational, or commercial. It's free.
+ *
+ * Use for hash table lookup, or anything where one collision in 2^^32 is
+ * acceptable. Do NOT use for cryptographic purposes.
+ */
+static
+uint32_t hashlittle(const void *key, size_t length, uint32_t initval)
+{
+ uint32_t a, b, c; /* internal state */
+ union {
+ const void *ptr;
+ size_t i;
+ } u;
+
+ /* Set up the internal state */
+ a = b = c = 0xdeadbeef + ((uint32_t)length) + initval;
+
+ u.ptr = key;
+ if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) {
+ const uint32_t *k = (const uint32_t *) key; /* read 32-bit chunks */
+
+ /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */
+ while (length > 12) {
+ a += k[0];
+ b += k[1];
+ c += k[2];
+ mix(a, b, c);
+ length -= 12;
+ k += 3;
+ }
+
+ /*----------------------------- handle the last (probably partial) block */
+ /*
+ * "k[2]&0xffffff" actually reads beyond the end of the string, but
+ * then masks off the part it's not allowed to read. Because the
+ * string is aligned, the masked-off tail is in the same word as the
+ * rest of the string. Every machine with memory protection I've seen
+ * does it on word boundaries, so is OK with this. But VALGRIND will
+ * still catch it and complain. The masking trick does make the hash
+ * noticably faster for short strings (like English words).
+ */
+#ifndef VALGRIND
+
+ switch (length) {
+ case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
+ case 11: c+=k[2]&0xffffff; b+=k[1]; a+=k[0]; break;
+ case 10: c+=k[2]&0xffff; b+=k[1]; a+=k[0]; break;
+ case 9 : c+=k[2]&0xff; b+=k[1]; a+=k[0]; break;
+ case 8 : b+=k[1]; a+=k[0]; break;
+ case 7 : b+=k[1]&0xffffff; a+=k[0]; break;
+ case 6 : b+=k[1]&0xffff; a+=k[0]; break;
+ case 5 : b+=k[1]&0xff; a+=k[0]; break;
+ case 4 : a+=k[0]; break;
+ case 3 : a+=k[0]&0xffffff; break;
+ case 2 : a+=k[0]&0xffff; break;
+ case 1 : a+=k[0]&0xff; break;
+ case 0 : return c; /* zero length strings require no mixing */
+ }
+
+#else /* make valgrind happy */
+ {
+ const uint8_t *k8;
+
+ k8 = (const uint8_t *) k;
+ switch (length) {
+ case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
+ case 11: c+=((uint32_t) k8[10])<<16; /* fall through */
+ case 10: c+=((uint32_t) k8[9])<<8; /* fall through */
+ case 9 : c+=k8[8]; /* fall through */
+ case 8 : b+=k[1]; a+=k[0]; break;
+ case 7 : b+=((uint32_t) k8[6])<<16; /* fall through */
+ case 6 : b+=((uint32_t) k8[5])<<8; /* fall through */
+ case 5 : b+=k8[4]; /* fall through */
+ case 4 : a+=k[0]; break;
+ case 3 : a+=((uint32_t) k8[2])<<16; /* fall through */
+ case 2 : a+=((uint32_t) k8[1])<<8; /* fall through */
+ case 1 : a+=k8[0]; break;
+ case 0 : return c;
+ }
+ }
+#endif /* !valgrind */
+
+ } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) {
+ const uint16_t *k = (const uint16_t *) key; /* read 16-bit chunks */
+ const uint8_t *k8;
+
+ /*--------------- all but last block: aligned reads and different mixing */
+ while (length > 12)
+ {
+ a += k[0] + (((uint32_t) k[1])<<16);
+ b += k[2] + (((uint32_t) k[3])<<16);
+ c += k[4] + (((uint32_t) k[5])<<16);
+ mix(a, b, c);
+ length -= 12;
+ k += 6;
+ }
+
+ /*----------------------------- handle the last (probably partial) block */
+ k8 = (const uint8_t *) k;
+ switch(length)
+ {
+ case 12: c+=k[4]+(((uint32_t) k[5])<<16);
+ b+=k[2]+(((uint32_t) k[3])<<16);
+ a+=k[0]+(((uint32_t) k[1])<<16);
+ break;
+ case 11: c+=((uint32_t) k8[10])<<16; /* fall through */
+ case 10: c+=k[4];
+ b+=k[2]+(((uint32_t) k[3])<<16);
+ a+=k[0]+(((uint32_t) k[1])<<16);
+ break;
+ case 9 : c+=k8[8]; /* fall through */
+ case 8 : b+=k[2]+(((uint32_t) k[3])<<16);
+ a+=k[0]+(((uint32_t) k[1])<<16);
+ break;
+ case 7 : b+=((uint32_t) k8[6])<<16; /* fall through */
+ case 6 : b+=k[2];
+ a+=k[0]+(((uint32_t) k[1])<<16);
+ break;
+ case 5 : b+=k8[4]; /* fall through */
+ case 4 : a+=k[0]+(((uint32_t) k[1])<<16);
+ break;
+ case 3 : a+=((uint32_t) k8[2])<<16; /* fall through */
+ case 2 : a+=k[0];
+ break;
+ case 1 : a+=k8[0];
+ break;
+ case 0 : return c; /* zero length requires no mixing */
+ }
+
+ } else { /* need to read the key one byte at a time */
+ const uint8_t *k = (const uint8_t *)key;
+
+ /*--------------- all but the last block: affect some 32 bits of (a, b, c) */
+ while (length > 12) {
+ a += k[0];
+ a += ((uint32_t) k[1])<<8;
+ a += ((uint32_t) k[2])<<16;
+ a += ((uint32_t) k[3])<<24;
+ b += k[4];
+ b += ((uint32_t) k[5])<<8;
+ b += ((uint32_t) k[6])<<16;
+ b += ((uint32_t) k[7])<<24;
+ c += k[8];
+ c += ((uint32_t) k[9])<<8;
+ c += ((uint32_t) k[10])<<16;
+ c += ((uint32_t) k[11])<<24;
+ mix(a,b,c);
+ length -= 12;
+ k += 12;
+ }
+
+ /*-------------------------------- last block: affect all 32 bits of (c) */
+ switch (length) { /* all the case statements fall through */
+ case 12: c+=((uint32_t) k[11])<<24;
+ case 11: c+=((uint32_t) k[10])<<16;
+ case 10: c+=((uint32_t) k[9])<<8;
+ case 9 : c+=k[8];
+ case 8 : b+=((uint32_t) k[7])<<24;
+ case 7 : b+=((uint32_t) k[6])<<16;
+ case 6 : b+=((uint32_t) k[5])<<8;
+ case 5 : b+=k[4];
+ case 4 : a+=((uint32_t) k[3])<<24;
+ case 3 : a+=((uint32_t) k[2])<<16;
+ case 2 : a+=((uint32_t) k[1])<<8;
+ case 1 : a+=k[0];
+ break;
+ case 0 : return c;
+ }
+ }
+
+ final(a, b, c);
+ return c;
+}
+
+static inline
+uint32_t jhash(const void *key, size_t length, uint32_t seed)
+{
+ return hashlittle(key, length, seed);
+}
+
+#endif /* _JHASH_H */
projects / userspace-rcu.git / commitdiff
