this is a mechanism to allow safe lock-free data structures.
backtrace.@O@ base32.@O@ base64.@O@ \
bind9.@O@ buffer.@O@ bufferlist.@O@ \
commandline.@O@ counter.@O@ crc64.@O@ error.@O@ entropy.@O@ \
- event.@O@ hash.@O@ ht.@O@ heap.@O@ hex.@O@ hmac.@O@ \
- httpd.@O@ iterated_hash.@O@ \
+ event.@O@ hash.@O@ ht.@O@ heap.@O@ hex.@O@ \
+ hmac.@O@ hp.@O@ httpd.@O@ iterated_hash.@O@ \
lex.@O@ lfsr.@O@ lib.@O@ log.@O@ \
md.@O@ mem.@O@ mutexblock.@O@ \
netaddr.@O@ netscope.@O@ nonce.@O@ openssl_shim.@O@ pool.@O@ \
aes.c app.c assertions.c \
backtrace.c base32.c base64.c bind9.c \
buffer.c bufferlist.c commandline.c counter.c crc64.c \
- entropy.c error.c event.c hash.c ht.c heap.c hex.c hmac.c \
- httpd.c iterated_hash.c \
+ entropy.c error.c event.c hash.c ht.c heap.c \
+ hex.c hmac.c hp.c httpd.c iterated_hash.c \
lex.c lfsr.c lib.c log.c \
md.c mem.c mutexblock.c \
netaddr.c netscope.c nonce.c openssl_shim.c pool.c \
--- /dev/null
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*
+ * Hazard Pointer implementation.
+ *
+ * This work is based on C++ code available from:
+ * https://github.com/pramalhe/ConcurrencyFreaks/
+ *
+ * Copyright (c) 2014-2016, Pedro Ramalhete, Andreia Correia
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * 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.
+ * * Neither the name of Concurrency Freaks nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 <COPYRIGHT HOLDER>
+ * 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 <inttypes.h>
+
+#include <isc/atomic.h>
+#include <isc/hp.h>
+#include <isc/string.h>
+#include <isc/mem.h>
+#include <isc/util.h>
+
+#define HP_MAX_THREADS 128
+#define HP_MAX_HPS 4 /* This is named 'K' in the HP paper */
+#define CLPAD (128 / sizeof(uintptr_t))
+#define HP_THRESHOLD_R 0 /* This is named 'R' in the HP paper */
+
+/* Maximum number of retired objects per thread */
+#define MAX_RETIRED (HP_MAX_THREADS * HP_MAX_HPS)
+
+#define TID_UNKNOWN -1
+
+static atomic_int_fast32_t tid_v_base;
+static bool tid_v_initialized;
+
+#if defined(HAVE_TLS)
+#if defined(HAVE_THREAD_LOCAL)
+#include <threads.h>
+static thread_local int tid_v = TID_UNKNOWN;
+#elif defined(HAVE___THREAD)
+static __thread int tid_v = TID_UNKNOWN;
+#elif defined(HAVE___DECLSPEC_THREAD)
+static __declspec( thread ) int tid_v = TID_UNKNOWN;
+#else /* if defined(HAVE_THREAD_LOCAL) */
+#error "Unknown method for defining a TLS variable!"
+#endif /* if defined(HAVE_THREAD_LOCAL) */
+#else /* if defined(HAVE_TLS) */
+#error "Thread-local storage support is required!"
+#endif /* if defined(HAVE_TLS) */
+
+typedef struct retirelist {
+ int size;
+ uintptr_t list[MAX_RETIRED];
+} retirelist_t;
+
+struct isc_hp {
+ int max_hps;
+ isc_mem_t *mctx;
+ atomic_uintptr_t *hp[HP_MAX_THREADS];
+ retirelist_t *rl[HP_MAX_THREADS];
+ isc_hp_deletefunc_t *deletefunc;
+};
+
+static inline int
+tid() {
+ if (!tid_v_initialized) {
+ atomic_init(&tid_v_base, 0);
+ tid_v_initialized = true;
+ }
+ if (tid_v == TID_UNKNOWN) {
+ tid_v = atomic_fetch_add(&tid_v_base, 1);
+ REQUIRE(tid_v < HP_MAX_THREADS);
+ }
+
+ return (tid_v);
+}
+
+isc_hp_t *
+isc_hp_new(isc_mem_t *mctx, size_t max_hps, isc_hp_deletefunc_t *deletefunc) {
+ isc_hp_t *hp = isc_mem_get(mctx, sizeof(*hp));
+
+ if (max_hps == 0) {
+ max_hps = HP_MAX_HPS;
+ }
+
+ *hp = (isc_hp_t){
+ .max_hps = max_hps,
+ .deletefunc = deletefunc
+ };
+
+ isc_mem_attach(mctx, &hp->mctx);
+
+ for (int i = 0; i < HP_MAX_THREADS; i++) {
+ hp->hp[i] = isc_mem_get(mctx, CLPAD * 2 * sizeof(hp->hp[i][0]));
+ hp->rl[i] = isc_mem_get(mctx, sizeof(*hp->rl[0]));
+ *hp->rl[i] = (retirelist_t) { .size = 0 };
+
+ for (int j = 0; j < hp->max_hps; j++) {
+ atomic_init(&hp->hp[i][j], 0);
+ }
+ }
+
+ return (hp);
+}
+
+void
+isc_hp_destroy(isc_hp_t *hp) {
+ for (int i = 0; i < HP_MAX_THREADS; i++) {
+ isc_mem_put(hp->mctx, hp->hp[i],
+ CLPAD * 2 * sizeof(uintptr_t));
+
+ for (int j = 0; j < hp->rl[i]->size; j++) {
+ void *data = (void *)hp->rl[i]->list[j];
+ hp->deletefunc(data);
+ }
+
+ isc_mem_put(hp->mctx, hp->rl[i], sizeof(*hp->rl[0]));
+ }
+
+ isc_mem_putanddetach(&hp->mctx, hp, sizeof(*hp));
+}
+
+void
+isc_hp_clear(isc_hp_t *hp) {
+ for (int i = 0; i < hp->max_hps; i++) {
+ atomic_store_release(&hp->hp[tid()][i], 0);
+ }
+}
+
+void isc_hp_clear_one(isc_hp_t *hp, int ihp) {
+ atomic_store_release(&hp->hp[tid()][ihp], 0);
+}
+
+uintptr_t
+isc_hp_protect(isc_hp_t *hp, int ihp, atomic_uintptr_t *atom) {
+ uintptr_t n = 0;
+ uintptr_t ret;
+ while ((ret = atomic_load(atom)) != n) {
+ atomic_store(&hp->hp[tid()][ihp], ret);
+ n = ret;
+ }
+ return (ret);
+}
+
+uintptr_t
+isc_hp_protect_ptr(isc_hp_t *hp, int ihp, atomic_uintptr_t ptr) {
+ atomic_store(&hp->hp[tid()][ihp], atomic_load(&ptr));
+ return (atomic_load(&ptr));
+}
+
+uintptr_t
+isc_hp_protect_release(isc_hp_t *hp, int ihp, atomic_uintptr_t ptr) {
+ atomic_store_release(&hp->hp[tid()][ihp], atomic_load(&ptr));
+ return (atomic_load(&ptr));
+}
+
+void
+isc_hp_retire(isc_hp_t *hp, uintptr_t ptr) {
+ hp->rl[tid()]->list[hp->rl[tid()]->size++] = ptr;
+ INSIST(hp->rl[tid()]->size < MAX_RETIRED);
+
+ if (hp->rl[tid()]->size < HP_THRESHOLD_R) {
+ return;
+ }
+
+ for (int iret = 0; iret < hp->rl[tid()]->size; iret++) {
+ uintptr_t obj = hp->rl[tid()]->list[iret];
+ bool can_delete = true;
+ for (int itid = 0;
+ itid < HP_MAX_THREADS && can_delete;
+ itid++)
+ {
+ for (int ihp = hp->max_hps-1; ihp >= 0; ihp--) {
+ if (atomic_load(&hp->hp[itid][ihp]) == obj) {
+ can_delete = false;
+ break;
+ }
+ }
+ }
+
+ if (can_delete) {
+ size_t bytes = (hp->rl[tid()]->size - iret) *
+ sizeof(hp->rl[tid()]->list[0]);
+ memmove(&hp->rl[tid()]->list[iret],
+ &hp->rl[tid()]->list[iret + 1],
+ bytes);
+ hp->rl[tid()]->size--;
+ hp->deletefunc((void *)obj);
+ }
+ }
+}
commandline.h counter.h crc64.h deprecated.h \
endian.h errno.h error.h event.h eventclass.h \
file.h formatcheck.h fsaccess.h fuzz.h \
- hash.h heap.h hex.h hmac.h ht.h httpd.h \
+ hash.h heap.h hex.h hmac.h hp.h ht.h httpd.h \
interfaceiter.h iterated_hash.h \
lang.h lex.h lfsr.h lib.h likely.h list.h log.h \
magic.h md.h mem.h meminfo.h mutexblock.h \
--- /dev/null
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*
+ * Hazard Pointer implementation.
+ *
+ * This work is based on C++ code available from:
+ * https://github.com/pramalhe/ConcurrencyFreaks/
+ *
+ * Copyright (c) 2014-2016, Pedro Ramalhete, Andreia Correia
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * 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.
+ * * Neither the name of Concurrency Freaks nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 <COPYRIGHT HOLDER>
+ * 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 <isc/atomic.h>
+#include <isc/string.h>
+#include <isc/mem.h>
+#include <isc/types.h>
+#include <isc/util.h>
+
+/*%
+ * Hazard pointers are a mechanism for protecting objects in memory
+ * from being deleted by other threads while in use. This allows
+ * safe lock-free data structures.
+ *
+ * This is an adaptation of the ConcurrencyFreaks implementation in C.
+ * More details available at https://github.com/pramalhe/ConcurrencyFreaks,
+ * in the file HazardPointers.hpp.
+ */
+
+typedef void
+(isc_hp_deletefunc_t)(void *);
+
+isc_hp_t *
+isc_hp_new(isc_mem_t *mctx, size_t max_hps, isc_hp_deletefunc_t *deletefunc);
+/*%<
+ * Create a new hazard pointer array of size 'max_hps' (or a reasonable
+ * default value if 'max_hps' is 0). The function 'deletefunc' will be
+ * used to delete objects protected by hazard pointers when it becomes
+ * safe to retire them.
+ */
+
+void
+isc_hp_destroy(isc_hp_t *hp);
+/*%<
+ * Destroy a hazard pointer array and clean up all objects protected
+ * by hazard pointers.
+ */
+
+void
+isc_hp_clear(isc_hp_t *hp);
+/*%<
+ * Clear all hazard pointers in the array for the current thread.
+ *
+ * Progress condition: wait-free bounded (by max_hps)
+ */
+
+void
+isc_hp_clear_one(isc_hp_t *hp, int ihp);
+/*%<
+ * Clear a specified hazard pointer in the array for the current thread.
+ *
+ * Progress condition: wait-free population oblivious.
+ */
+
+uintptr_t
+isc_hp_protect(isc_hp_t *hp, int ihp, atomic_uintptr_t *atom);
+/*%<
+ * Protect an object referenced by 'atom' with a hazard pointer for the
+ * current thread.
+ *
+ * Progress condition: lock-free.
+ */
+
+uintptr_t
+isc_hp_protect_ptr(isc_hp_t *hp, int ihp, atomic_uintptr_t ptr);
+/*%<
+ * This returns the same value that is passed as ptr, which is sometimes
+ * useful.
+ *
+ * Progress condition: wait-free population oblivious.
+ */
+
+uintptr_t
+isc_hp_protect_release(isc_hp_t *hp, int ihp, atomic_uintptr_t ptr);
+/*%<
+ * Same as isc_hp_protect_ptr(), but explicitly uses memory_order_release.
+ *
+ * Progress condition: wait-free population oblivious.
+ */
+
+void
+isc_hp_retire(isc_hp_t *hp, uintptr_t ptr);
+/*%<
+ * Retire an object that is no longer in use by any thread, calling
+ * the delete function that was specified in isc_hp_new().
+ *
+ * Progress condition: wait-free bounded (by the number of threads squared)
+ */
typedef unsigned int isc_eventtype_t; /*%< Event Type */
typedef uint32_t isc_fsaccess_t; /*%< FS Access */
typedef struct isc_hash isc_hash_t; /*%< Hash */
+typedef struct isc_hp isc_hp_t; /*%< Hazard
+ pointer */
typedef struct isc_httpd isc_httpd_t; /*%< HTTP client */
typedef void (isc_httpdfree_t)(isc_buffer_t *, void *); /*%< HTTP free function */
typedef struct isc_httpdmgr isc_httpdmgr_t; /*%< HTTP manager */
isc_hex_decodestring
isc_hex_tobuffer
isc_hex_totext
+isc_hp_clear
+isc_hp_destroy
+isc_hp_protect
+isc_hp_protect_ptr
+isc_hp_protect_release
+isc_hp_new
+isc_hp_retire
isc_hmac
isc_hmac_new
isc_hmac_free
isc_hmac_get_md_type
isc_hmac_get_size
isc_hmac_get_block_size
+isc_hp_new
+isc_hp_destroy
+isc_hp_clear
+isc_hp_protect
+isc_hp_protect_ptr
+isc_hp_protect_release
+isc_hp_retire
isc_ht_add
isc_ht_count
isc_ht_delete
<ClInclude Include="..\include\isc\hmac.h">
<Filter>Library Header Files</Filter>
</ClInclude>
+ <ClInclude Include="..\include\isc\hp.h">
+ <Filter>Library Header Files</Filter>
+ </ClInclude>
<ClInclude Include="..\include\isc\ht.h">
<Filter>Library Header Files</Filter>
</ClInclude>
<ClCompile Include="..\hmac.c">
<Filter>Library Source Files</Filter>
</ClCompile>
+ <ClCompile Include="..\hp.c">
+ <Filter>Library Source Files</Filter>
+ </ClCompile>
<ClCompile Include="..\ht.c">
<Filter>Library Source Files</Filter>
</ClCompile>
<ClInclude Include="..\include\isc\heap.h" />
<ClInclude Include="..\include\isc\hex.h" />
<ClInclude Include="..\include\isc\hmac.h" />
+ <ClInclude Include="..\include\isc\hp.h" />
<ClInclude Include="..\include\isc\ht.h" />
<ClInclude Include="..\include\isc\httpd.h" />
<ClInclude Include="..\include\isc\interfaceiter.h" />
<ClCompile Include="..\heap.c" />
<ClCompile Include="..\hex.c" />
<ClCompile Include="..\hmac.c" />
+ <ClCompile Include="..\hp.c" />
<ClCompile Include="..\ht.c" />
<ClCompile Include="..\httpd.c" />
<ClCompile Include="..\iterated_hash.c" />
./lib/isc/heap.c C 1997,1998,1999,2000,2001,2004,2005,2006,2007,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019
./lib/isc/hex.c C 2000,2001,2002,2003,2004,2005,2007,2008,2013,2014,2015,2016,2018,2019
./lib/isc/hmac.c C 2000,2001,2004,2005,2006,2007,2009,2011,2012,2013,2014,2015,2016,2017,2018,2019
+./lib/isc/hp.c C 2019
./lib/isc/ht.c C 2016,2017,2018,2019
./lib/isc/httpd.c C 2006,2007,2008,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019
./lib/isc/include/Makefile.in MAKE 1998,1999,2000,2001,2004,2007,2012,2014,2016,2018,2019
./lib/isc/include/isc/heap.h C 1997,1998,1999,2000,2001,2004,2005,2006,2007,2009,2012,2016,2018,2019
./lib/isc/include/isc/hex.h C 2000,2001,2004,2005,2006,2007,2008,2016,2018,2019
./lib/isc/include/isc/hmac.h C 2000,2001,2004,2005,2006,2007,2009,2011,2012,2013,2014,2015,2016,2017,2018,2019
+./lib/isc/include/isc/hp.h C 2019
./lib/isc/include/isc/ht.h C 2016,2017,2018,2019
./lib/isc/include/isc/httpd.h C 2006,2007,2008,2014,2016,2018,2019
./lib/isc/include/isc/interfaceiter.h C 1999,2000,2001,2004,2005,2006,2007,2016,2018,2019
projects / thirdparty / bind9.git / commitdiff
