1251881Speter/* 2251881Speter * ==================================================================== 3251881Speter * Licensed to the Apache Software Foundation (ASF) under one 4251881Speter * or more contributor license agreements. See the NOTICE file 5251881Speter * distributed with this work for additional information 6251881Speter * regarding copyright ownership. The ASF licenses this file 7251881Speter * to you under the Apache License, Version 2.0 (the 8251881Speter * "License"); you may not use this file except in compliance 9251881Speter * with the License. You may obtain a copy of the License at 10251881Speter * 11251881Speter * http://www.apache.org/licenses/LICENSE-2.0 12251881Speter * 13251881Speter * Unless required by applicable law or agreed to in writing, 14251881Speter * software distributed under the License is distributed on an 15251881Speter * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16251881Speter * KIND, either express or implied. See the License for the 17251881Speter * specific language governing permissions and limitations 18251881Speter * under the License. 19251881Speter * ==================================================================== 20251881Speter */ 21251881Speter 22251881Speter#include <apr_hash.h> 23251881Speter 24251881Speter#include "svn_hash.h" 25251881Speter#include "svn_dso.h" 26251881Speter#include "svn_pools.h" 27251881Speter#include "svn_private_config.h" 28251881Speter 29251881Speter#include "private/svn_mutex.h" 30286506Speter#include "private/svn_atomic.h" 31289180Speter#include "private/svn_subr_private.h" 32251881Speter 33251881Speter/* A mutex to protect our global pool and cache. */ 34251881Speterstatic svn_mutex__t *dso_mutex = NULL; 35251881Speter 36251881Speter/* Global pool to allocate DSOs in. */ 37251881Speterstatic apr_pool_t *dso_pool; 38251881Speter 39251881Speter/* Global cache for storing DSO objects. */ 40251881Speterstatic apr_hash_t *dso_cache; 41251881Speter 42251881Speter/* Just an arbitrary location in memory... */ 43251881Speterstatic int not_there_sentinel; 44251881Speter 45286506Speterstatic volatile svn_atomic_t atomic_init_status = 0; 46286506Speter 47251881Speter/* A specific value we store in the dso_cache to indicate that the 48251881Speter library wasn't found. This keeps us from allocating extra memory 49251881Speter from dso_pool when trying to find libraries we already know aren't 50251881Speter there. */ 51251881Speter#define NOT_THERE ((void *) ¬_there_sentinel) 52251881Speter 53286506Speterstatic svn_error_t * 54286506Speteratomic_init_func(void *baton, 55286506Speter apr_pool_t *pool) 56251881Speter{ 57251881Speter dso_pool = svn_pool_create(NULL); 58251881Speter 59251881Speter SVN_ERR(svn_mutex__init(&dso_mutex, TRUE, dso_pool)); 60251881Speter 61251881Speter dso_cache = apr_hash_make(dso_pool); 62251881Speter return SVN_NO_ERROR; 63251881Speter} 64251881Speter 65286506Spetersvn_error_t * 66286506Spetersvn_dso_initialize2(void) 67286506Speter{ 68286506Speter SVN_ERR(svn_atomic__init_once(&atomic_init_status, atomic_init_func, 69286506Speter NULL, NULL)); 70286506Speter 71286506Speter return SVN_NO_ERROR; 72286506Speter} 73286506Speter 74251881Speter#if APR_HAS_DSO 75251881Speterstatic svn_error_t * 76251881Spetersvn_dso_load_internal(apr_dso_handle_t **dso, const char *fname) 77251881Speter{ 78251881Speter *dso = svn_hash_gets(dso_cache, fname); 79251881Speter 80251881Speter /* First check to see if we've been through this before... We do this 81251881Speter to avoid calling apr_dso_load multiple times for a given library, 82251881Speter which would result in wasting small amounts of memory each time. */ 83251881Speter if (*dso == NOT_THERE) 84251881Speter { 85251881Speter *dso = NULL; 86251881Speter return SVN_NO_ERROR; 87251881Speter } 88251881Speter 89251881Speter /* If we got nothing back from the cache, try and load the library. */ 90251881Speter if (! *dso) 91251881Speter { 92251881Speter apr_status_t status = apr_dso_load(dso, fname, dso_pool); 93251881Speter if (status) 94251881Speter { 95251881Speter#ifdef SVN_DEBUG_DSO 96251881Speter char buf[1024]; 97251881Speter fprintf(stderr, 98251881Speter "Dynamic loading of '%s' failed with the following error:\n%s\n", 99251881Speter fname, 100251881Speter apr_dso_error(*dso, buf, 1024)); 101251881Speter#endif 102251881Speter *dso = NULL; 103251881Speter 104251881Speter /* It wasn't found, so set the special "we didn't find it" value. */ 105251881Speter svn_hash_sets(dso_cache, apr_pstrdup(dso_pool, fname), NOT_THERE); 106251881Speter 107251881Speter return SVN_NO_ERROR; 108251881Speter } 109251881Speter 110251881Speter /* Stash the dso so we can use it next time. */ 111251881Speter svn_hash_sets(dso_cache, apr_pstrdup(dso_pool, fname), *dso); 112251881Speter } 113251881Speter 114251881Speter return SVN_NO_ERROR; 115251881Speter} 116251881Speter 117251881Spetersvn_error_t * 118251881Spetersvn_dso_load(apr_dso_handle_t **dso, const char *fname) 119251881Speter{ 120286506Speter SVN_ERR(svn_dso_initialize2()); 121251881Speter 122251881Speter SVN_MUTEX__WITH_LOCK(dso_mutex, svn_dso_load_internal(dso, fname)); 123251881Speter 124251881Speter return SVN_NO_ERROR; 125251881Speter} 126289180Speter 127289180Speterapr_pool_t * 128289180Spetersvn_dso__pool(void) 129289180Speter{ 130289180Speter return dso_pool; 131289180Speter} 132289180Speter 133251881Speter#endif /* APR_HAS_DSO */ 134