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11 * http://www.apache.org/licenses/LICENSE-2.0
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19 * ====================================================================
22 #include <apr_thread_mutex.h>
27 #include "svn_pools.h"
28 #include "svn_private_config.h"
30 #include "private/svn_mutex.h"
31 #include "private/svn_atomic.h"
33 /* A mutex to protect our global pool and cache. */
34 static svn_mutex__t *dso_mutex = NULL;
36 /* Global pool to allocate DSOs in. */
37 static apr_pool_t *dso_pool;
39 /* Global cache for storing DSO objects. */
40 static apr_hash_t *dso_cache;
42 /* Just an arbitrary location in memory... */
43 static int not_there_sentinel;
45 static volatile svn_atomic_t atomic_init_status = 0;
47 /* A specific value we store in the dso_cache to indicate that the
48 library wasn't found. This keeps us from allocating extra memory
49 from dso_pool when trying to find libraries we already know aren't
51 #define NOT_THERE ((void *) ¬_there_sentinel)
54 atomic_init_func(void *baton,
57 dso_pool = svn_pool_create(NULL);
59 SVN_ERR(svn_mutex__init(&dso_mutex, TRUE, dso_pool));
61 dso_cache = apr_hash_make(dso_pool);
66 svn_dso_initialize2(void)
68 SVN_ERR(svn_atomic__init_once(&atomic_init_status, atomic_init_func,
76 svn_dso_load_internal(apr_dso_handle_t **dso, const char *fname)
78 *dso = svn_hash_gets(dso_cache, fname);
80 /* First check to see if we've been through this before... We do this
81 to avoid calling apr_dso_load multiple times for a given library,
82 which would result in wasting small amounts of memory each time. */
83 if (*dso == NOT_THERE)
89 /* If we got nothing back from the cache, try and load the library. */
92 apr_status_t status = apr_dso_load(dso, fname, dso_pool);
98 "Dynamic loading of '%s' failed with the following error:\n%s\n",
100 apr_dso_error(*dso, buf, 1024));
104 /* It wasn't found, so set the special "we didn't find it" value. */
105 svn_hash_sets(dso_cache, apr_pstrdup(dso_pool, fname), NOT_THERE);
110 /* Stash the dso so we can use it next time. */
111 svn_hash_sets(dso_cache, apr_pstrdup(dso_pool, fname), *dso);
118 svn_dso_load(apr_dso_handle_t **dso, const char *fname)
120 SVN_ERR(svn_dso_initialize2());
122 SVN_MUTEX__WITH_LOCK(dso_mutex, svn_dso_load_internal(dso, fname));
126 #endif /* APR_HAS_DSO */