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Posted to commits@subversion.apache.org by st...@apache.org on 2013/09/28 03:34:14 UTC
svn commit: r1527140 - in /subversion/trunk: build.conf
subversion/include/private/svn_subr_private.h
subversion/libsvn_subr/root_pools.c
subversion/tests/libsvn_subr/root-pools-test.c
Author: stefan2
Date: Sat Sep 28 01:34:13 2013
New Revision: 1527140
URL: http://svn.apache.org/r1527140
Log:
Introduce a small new private API that allows for recycling root pools
as piloted by svnserve in r1523465. Provide some basic testing as well.
* subversion/include/private/svn_subr_private.h
(svn_root_pools__t): declare new API data types
(svn_root_pools__create,
svn_root_pools__acquire_pool,
svn_root_pools__release_pool): declare new API functions
* subversion/libsvn_subr/root_pools.c
(): new file
(svn_root_pools__t): define new API data type
(acquire_pool_internal): new utility function
(svn_root_pools__create,
svn_root_pools__acquire_pool,
svn_root_pools__release_pool): implement new API functions
* subversion/tests/libsvn_subr/root-pools-test.c
(): tests for the new API
* build.conf
(root-pools-test): new build target
(__ALL_TESTS__): add new test as dependency
Added:
subversion/trunk/subversion/libsvn_subr/root_pools.c
subversion/trunk/subversion/tests/libsvn_subr/root-pools-test.c
Modified:
subversion/trunk/build.conf
subversion/trunk/subversion/include/private/svn_subr_private.h
Modified: subversion/trunk/build.conf
URL: http://svn.apache.org/viewvc/subversion/trunk/build.conf?rev=1527140&r1=1527139&r2=1527140&view=diff
==============================================================================
--- subversion/trunk/build.conf (original)
+++ subversion/trunk/build.conf Sat Sep 28 01:34:13 2013
@@ -1008,6 +1008,14 @@ sources = revision-test.c
install = test
libs = libsvn_test libsvn_subr apr
+[root-pools-test]
+description = Test time functions
+type = exe
+path = subversion/tests/libsvn_subr
+sources = root-pools-test.c
+install = test
+libs = libsvn_test libsvn_subr apriconv apr
+
[skel-test]
description = Test skels in libsvn_subr
type = exe
@@ -1390,7 +1398,8 @@ libs = __ALL__
skel-test strings-reps-test changes-test locks-test repos-test
checksum-test compat-test config-test hashdump-test mergeinfo-test
opt-test packed-data-test path-test prefix-string-test
- priority-queue-test stream-test string-test time-test utf-test
+ priority-queue-test root-pools-test stream-test
+ string-test time-test utf-test
error-test error-code-test cache-test spillbuf-test crypto-test
named_atomic-test named_atomic-proc-test revision-test
subst_translate-test io-test
Modified: subversion/trunk/subversion/include/private/svn_subr_private.h
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/include/private/svn_subr_private.h?rev=1527140&r1=1527139&r2=1527140&view=diff
==============================================================================
--- subversion/trunk/subversion/include/private/svn_subr_private.h (original)
+++ subversion/trunk/subversion/include/private/svn_subr_private.h Sat Sep 28 01:34:13 2013
@@ -429,6 +429,40 @@ svn__decompress(svn_stringbuf_t *in,
/** @} */
+/**
+ * @defgroup svn_root_pools Recycle-able root pools API
+ * @{
+ */
+
+/* Opaque thread-safe container for unused / recylcleable root pools.
+ *
+ * Recyling root pools (actually, their allocators) circumvents a
+ * scalability bottleneck in the OS memory management when multi-threaded
+ * applications frequently create and destroy allocators.
+ */
+typedef struct svn_root_pools__t svn_root_pools__t;
+
+/* Create a new root pools container and return it in *POOLS.
+ */
+svn_error_t *
+svn_root_pools__create(svn_root_pools__t **pools);
+
+/* Return a currently unused pool from POOLS. If POOLS is empty, create a
+ * new root pool and return that. The pool returned is not thread-safe.
+ */
+apr_pool_t *
+svn_root_pools__acquire_pool(svn_root_pools__t *pools);
+
+/* Clear and release the given root POOL and put it back into POOLS.
+ * If that fails, destroy POOL.
+ */
+void
+svn_root_pools__release_pool(apr_pool_t *pool,
+ svn_root_pools__t *pools);
+
+/** @} */
+
+
#ifdef __cplusplus
}
Added: subversion/trunk/subversion/libsvn_subr/root_pools.c
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_subr/root_pools.c?rev=1527140&view=auto
==============================================================================
--- subversion/trunk/subversion/libsvn_subr/root_pools.c (added)
+++ subversion/trunk/subversion/libsvn_subr/root_pools.c Sat Sep 28 01:34:13 2013
@@ -0,0 +1,110 @@
+/*
+ * root_pools.c : Implement svn_root_pools__* API
+ *
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * ====================================================================
+ */
+
+#include "svn_pools.h"
+
+#include "private/svn_subr_private.h"
+#include "private/svn_mutex.h"
+
+typedef struct svn_root_pools__t
+{
+ /* unused pools.
+ * Use MUTEX to serialize access to this collection.
+ */
+ apr_array_header_t *unused_pools;
+
+ /* Mutex to serialize access to UNUSED_POOLS */
+ svn_mutex__t *mutex;
+
+} svn_root_pools__t;
+
+svn_error_t *
+svn_root_pools__create(svn_root_pools__t **pools)
+{
+ /* the collection of root pools must be managed independently from
+ any other pool */
+ apr_pool_t *pool
+ = apr_allocator_owner_get(svn_pool_create_allocator(FALSE));
+
+ /* construct result object */
+ svn_root_pools__t *result = apr_pcalloc(pool, sizeof(*result));
+ SVN_ERR(svn_mutex__init(&result->mutex, TRUE, pool));
+ result->unused_pools = apr_array_make(pool, 16, sizeof(apr_pool_t *));
+
+ /* done */
+ *pools = result;
+
+ return SVN_NO_ERROR;
+}
+
+/* Return a currently unused connection pool in *POOL. If no such pool
+ * exists, create a new root pool and return that in *POOL.
+ */
+static svn_error_t *
+acquire_pool_internal(apr_pool_t **pool,
+ svn_root_pools__t *pools)
+{
+ SVN_ERR(svn_mutex__lock(pools->mutex));
+ *pool = pools->unused_pools->nelts
+ ? *(apr_pool_t **)apr_array_pop(pools->unused_pools)
+ : apr_allocator_owner_get(svn_pool_create_allocator(FALSE));
+ SVN_ERR(svn_mutex__unlock(pools->mutex, SVN_NO_ERROR));
+
+ return SVN_NO_ERROR;
+}
+
+apr_pool_t *
+svn_root_pools__acquire_pool(svn_root_pools__t *pools)
+{
+ apr_pool_t *pool;
+ svn_error_t *err = acquire_pool_internal(&pool, pools);
+ if (err)
+ {
+ /* Mutex failure?! Well, try to continue with unrecycled data. */
+ svn_error_clear(err);
+ pool = apr_allocator_owner_get(svn_pool_create_allocator(FALSE));
+ }
+
+ return pool;
+}
+
+void
+svn_root_pools__release_pool(apr_pool_t *pool,
+ svn_root_pools__t *pools)
+{
+ svn_error_t *err;
+
+ svn_pool_clear(pool);
+
+ err = svn_mutex__lock(pools->mutex);
+ if (err)
+ {
+ svn_error_clear(err);
+ svn_pool_destroy(pool);
+ }
+ else
+ {
+ APR_ARRAY_PUSH(pools->unused_pools, apr_pool_t *) = pool;
+ svn_error_clear(svn_mutex__unlock(pools->mutex, SVN_NO_ERROR));
+ }
+}
Added: subversion/trunk/subversion/tests/libsvn_subr/root-pools-test.c
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/tests/libsvn_subr/root-pools-test.c?rev=1527140&view=auto
==============================================================================
--- subversion/trunk/subversion/tests/libsvn_subr/root-pools-test.c (added)
+++ subversion/trunk/subversion/tests/libsvn_subr/root-pools-test.c Sat Sep 28 01:34:13 2013
@@ -0,0 +1,130 @@
+/*
+ * root-pools-test.c -- test the svn_root_pools__* API
+ *
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * ====================================================================
+ */
+
+#include <apr_pools.h>
+#include <apr_thread_proc.h>
+#include <apr_thread_cond.h>
+
+#include "private/svn_atomic.h"
+#include "private/svn_subr_private.h"
+
+#include "../svn_test.h"
+
+/* do a few allocations of various sizes from POOL */
+static void
+do_some_allocations(apr_pool_t *pool)
+{
+ int i;
+ apr_size_t fib = 1, fib1 = 0, fib2 = 0;
+ for (i = 0; i < 25; ++i) /* fib(25) = 75025 */
+ {
+ apr_pcalloc(pool, fib1);
+ fib2 = fib1;
+ fib1 = fib;
+ fib += fib2;
+ }
+}
+
+/* allocate, use and recycle a pool from POOLs a few times */
+static void
+use_root_pool(svn_root_pools__t *pools)
+{
+ int i;
+ for (i = 0; i < 1000; ++i)
+ {
+ apr_pool_t *pool = svn_root_pools__acquire_pool(pools);
+ do_some_allocations(pool);
+ svn_root_pools__release_pool(pool, pools);
+ }
+}
+
+static void *
+APR_THREAD_FUNC thread_func(apr_thread_t *tid, void *data)
+{
+ /* give all threads a good chance to get started by the scheduler */
+ apr_thread_yield();
+
+ use_root_pool(data);
+
+ return NULL;
+}
+
+static svn_error_t *
+test_root_pool(apr_pool_t *pool)
+{
+ svn_root_pools__t *pools;
+ SVN_ERR(svn_root_pools__create(&pools));
+ use_root_pool(pools);
+
+ return SVN_NO_ERROR;
+}
+
+#define APR_ERR(expr) \
+ do { \
+ apr_status_t status = (expr); \
+ if (status) \
+ return svn_error_wrap_apr(status, NULL); \
+ } while (0)
+
+static svn_error_t *
+test_root_pool_concurrency(apr_pool_t *pool)
+{
+#if APR_HAS_THREADS
+ /* The svn_root_pools__t container is supposed to be thread-safe.
+ Do some multi-threaded access and hope that there are no segfaults.
+ */
+ enum { THREAD_COUNT = 10 };
+ svn_root_pools__t *pools;
+ apr_thread_t *threads[THREAD_COUNT];
+ int i;
+
+ SVN_ERR(svn_root_pools__create(&pools));
+
+ for (i = 0; i < THREAD_COUNT; ++i)
+ APR_ERR(apr_thread_create(&threads[i], NULL, thread_func, pools, pool));
+
+ /* wait for the threads to finish */
+ for (i = 0; i < THREAD_COUNT; ++i)
+ {
+ apr_status_t retval;
+ APR_ERR(apr_thread_join(&retval, threads[i]));
+ APR_ERR(retval);
+ }
+#endif
+
+ return SVN_NO_ERROR;
+}
+
+
+/* The test table. */
+
+struct svn_test_descriptor_t test_funcs[] =
+ {
+ SVN_TEST_NULL,
+ SVN_TEST_PASS2(test_root_pool,
+ "test root pool recycling"),
+ SVN_TEST_SKIP2(test_root_pool_concurrency,
+ ! APR_HAS_THREADS,
+ "test concurrent root pool recycling"),
+ SVN_TEST_NULL
+ };