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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 07:24:22 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 07:24:22 +0000 |
commit | 45d6379135504814ab723b57f0eb8be23393a51d (patch) | |
tree | d4f2ec4acca824a8446387a758b0ce4238a4dffa /bin/tests/system/dyndb/driver/lock.c | |
parent | Initial commit. (diff) | |
download | bind9-upstream/1%9.16.44.tar.xz bind9-upstream/1%9.16.44.zip |
Adding upstream version 1:9.16.44.upstream/1%9.16.44upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | bin/tests/system/dyndb/driver/lock.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/bin/tests/system/dyndb/driver/lock.c b/bin/tests/system/dyndb/driver/lock.c new file mode 100644 index 0000000..5d73871 --- /dev/null +++ b/bin/tests/system/dyndb/driver/lock.c @@ -0,0 +1,81 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 AND 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 https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +/* + * Copyright (C) Red Hat + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND AUTHORS DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + +#include "lock.h" + +#include <isc/task.h> +#include <isc/util.h> + +/* + * Lock BIND dispatcher and allow only single task to run. + * + * @warning + * All calls to isc_task_beginexclusive() have to operate on the same task + * otherwise it would not be possible to distinguish recursive locking + * from real conflict on the dispatcher lock. + * For this reason this wrapper function always works with inst->task. + * As a result, this function have to be be called only from inst->task. + * + * Recursive locking is allowed. Auxiliary variable pointed to by "statep" + * stores information if last run_exclusive_enter() operation really locked + * something or if the lock was called recursively and was no-op. + * + * The pair (inst, state) used for run_exclusive_enter() has to be + * used for run_exclusive_exit(). + * + * @param[in] inst The instance with the only task which is allowed to + * run. + * @param[in,out] statep Lock state: ISC_R_SUCCESS or ISC_R_LOCKBUSY + */ +void +run_exclusive_enter(sample_instance_t *inst, isc_result_t *statep) { + REQUIRE(statep != NULL); + REQUIRE(*statep == ISC_R_IGNORE); + + *statep = isc_task_beginexclusive(inst->task); + RUNTIME_CHECK(*statep == ISC_R_SUCCESS || *statep == ISC_R_LOCKBUSY); +} + +/* + * Exit task-exclusive mode. + * + * @param[in] inst The instance used for previous run_exclusive_enter() call. + * @param[in] state Lock state as returned by run_exclusive_enter(). + */ +void +run_exclusive_exit(sample_instance_t *inst, isc_result_t state) { + if (state == ISC_R_SUCCESS) { + isc_task_endexclusive(inst->task); + } else { + /* Unlocking recursive lock or the lock was never locked. */ + INSIST(state == ISC_R_LOCKBUSY || state == ISC_R_IGNORE); + } + + return; +} |