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_thread_mutex.h> 23251881Speter#include <apr_hash.h> 24251881Speter 25251881Speter#include "svn_hash.h" 26251881Speter#include "svn_dso.h" 27251881Speter#include "svn_pools.h" 28251881Speter#include "svn_private_config.h" 29251881Speter 30251881Speter#include "private/svn_mutex.h" 31251881Speter 32251881Speter/* A mutex to protect our global pool and cache. */ 33251881Speterstatic svn_mutex__t *dso_mutex = NULL; 34251881Speter 35251881Speter/* Global pool to allocate DSOs in. */ 36251881Speterstatic apr_pool_t *dso_pool; 37251881Speter 38251881Speter/* Global cache for storing DSO objects. */ 39251881Speterstatic apr_hash_t *dso_cache; 40251881Speter 41251881Speter/* Just an arbitrary location in memory... */ 42251881Speterstatic int not_there_sentinel; 43251881Speter 44251881Speter/* A specific value we store in the dso_cache to indicate that the 45251881Speter library wasn't found. This keeps us from allocating extra memory 46251881Speter from dso_pool when trying to find libraries we already know aren't 47251881Speter there. */ 48251881Speter#define NOT_THERE ((void *) ¬_there_sentinel) 49251881Speter 50251881Spetersvn_error_t * 51251881Spetersvn_dso_initialize2(void) 52251881Speter{ 53251881Speter if (dso_pool) 54251881Speter return SVN_NO_ERROR; 55251881Speter 56251881Speter dso_pool = svn_pool_create(NULL); 57251881Speter 58251881Speter SVN_ERR(svn_mutex__init(&dso_mutex, TRUE, dso_pool)); 59251881Speter 60251881Speter dso_cache = apr_hash_make(dso_pool); 61251881Speter return SVN_NO_ERROR; 62251881Speter} 63251881Speter 64251881Speter#if APR_HAS_DSO 65251881Speterstatic svn_error_t * 66251881Spetersvn_dso_load_internal(apr_dso_handle_t **dso, const char *fname) 67251881Speter{ 68251881Speter *dso = svn_hash_gets(dso_cache, fname); 69251881Speter 70251881Speter /* First check to see if we've been through this before... We do this 71251881Speter to avoid calling apr_dso_load multiple times for a given library, 72251881Speter which would result in wasting small amounts of memory each time. */ 73251881Speter if (*dso == NOT_THERE) 74251881Speter { 75251881Speter *dso = NULL; 76251881Speter return SVN_NO_ERROR; 77251881Speter } 78251881Speter 79251881Speter /* If we got nothing back from the cache, try and load the library. */ 80251881Speter if (! *dso) 81251881Speter { 82251881Speter apr_status_t status = apr_dso_load(dso, fname, dso_pool); 83251881Speter if (status) 84251881Speter { 85251881Speter#ifdef SVN_DEBUG_DSO 86251881Speter char buf[1024]; 87251881Speter fprintf(stderr, 88251881Speter "Dynamic loading of '%s' failed with the following error:\n%s\n", 89251881Speter fname, 90251881Speter apr_dso_error(*dso, buf, 1024)); 91251881Speter#endif 92251881Speter *dso = NULL; 93251881Speter 94251881Speter /* It wasn't found, so set the special "we didn't find it" value. */ 95251881Speter svn_hash_sets(dso_cache, apr_pstrdup(dso_pool, fname), NOT_THERE); 96251881Speter 97251881Speter return SVN_NO_ERROR; 98251881Speter } 99251881Speter 100251881Speter /* Stash the dso so we can use it next time. */ 101251881Speter svn_hash_sets(dso_cache, apr_pstrdup(dso_pool, fname), *dso); 102251881Speter } 103251881Speter 104251881Speter return SVN_NO_ERROR; 105251881Speter} 106251881Speter 107251881Spetersvn_error_t * 108251881Spetersvn_dso_load(apr_dso_handle_t **dso, const char *fname) 109251881Speter{ 110251881Speter if (! dso_pool) 111251881Speter SVN_ERR(svn_dso_initialize2()); 112251881Speter 113251881Speter SVN_MUTEX__WITH_LOCK(dso_mutex, svn_dso_load_internal(dso, fname)); 114251881Speter 115251881Speter return SVN_NO_ERROR; 116251881Speter} 117251881Speter#endif /* APR_HAS_DSO */ 118