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📄 adler32.c(3.16 KB)
📄 atomic.c(7.23 KB)
📄 auth.c(32.4 KB)
📄 auth.h(6.1 KB)
📄 base64.c(19.18 KB)
📄 bit_array.c(6.26 KB)
📄 cache-inprocess.c(21.2 KB)
📄 cache-membuffer.c(116.43 KB)
📄 cache-memcache.c(17.35 KB)
📄 cache-null.c(4.35 KB)
📄 cache.c(10.22 KB)
📄 cache.h(4.03 KB)
📄 cache_config.c(6.01 KB)
📄 checksum.c(24.17 KB)
📄 checksum.h(2.32 KB)
📄 cmdline.c(58.99 KB)
📄 compat.c(5.28 KB)
📄 compress_lz4.c(4.51 KB)
📄 compress_zlib.c(6.85 KB)
📄 config.c(39.66 KB)
📄 config_auth.c(8.65 KB)
📄 config_file.c(70.25 KB)
📄 config_impl.h(6.15 KB)
📄 config_keys.inc(2.65 KB)
📄 config_win.c(9.61 KB)
📄 crypto.c(25.19 KB)
📄 crypto.h(5.43 KB)
📄 ctype.c(13.81 KB)
📄 date.c(12.86 KB)
📄 debug.c(3.77 KB)
📄 deprecated.c(64.3 KB)
📄 dirent_uri.c(80.17 KB)
📄 dirent_uri.h(1.43 KB)
📄 dso.c(3.74 KB)
📄 encode.c(2.69 KB)
📄 eol.c(2.79 KB)
📄 error.c(24.52 KB)
📄 errorcode.inc(4.27 KB)
📄 fnv1a.c(6.92 KB)
📄 fnv1a.h(3.04 KB)
📄 genctype.py(3.84 KB)
📄 gpg_agent.c(22.29 KB)
📄 hash.c(19.59 KB)
📄 internal_statements.h(1.87 KB)
📄 internal_statements.sql(1.58 KB)
📄 io.c(182.6 KB)
📄 iter.c(3.84 KB)
📄 libsvn_subr.pc.in(515 B)
📄 lock.c(1.69 KB)
📄 log.c(14 KB)
📁 lz4
📄 macos_keychain.c(9.7 KB)
📄 magic.c(5.25 KB)
📄 md5.c(1.8 KB)
📄 mergeinfo.c(89.24 KB)
📄 mutex.c(3.06 KB)
📄 nls.c(3.06 KB)
📄 object_pool.c(9.76 KB)
📄 opt.c(39.34 KB)
📄 opt.h(1.89 KB)
📄 packed_data.c(33.43 KB)
📄 path.c(35.99 KB)
📄 pool.c(4.35 KB)
📄 pools.h(1.45 KB)
📄 prefix_string.c(10.65 KB)
📄 prompt.c(28.82 KB)
📄 properties.c(13.59 KB)
📄 quoprint.c(8.96 KB)
📄 root_pools.c(3.15 KB)
📄 simple_providers.c(25.54 KB)
📄 skel.c(23.04 KB)
📄 sorts.c(15.9 KB)
📄 spillbuf.c(19.78 KB)
📄 sqlite.c(49.68 KB)
📄 sqlite3wrapper.c(3.16 KB)
📄 ssl_client_cert_providers.c(6.66 KB)
📄 ssl_client_cert_pw_providers.c(18.93 KB)
📄 ssl_server_trust_providers.c(7.77 KB)
📄 stream.c(65.69 KB)
📄 string.c(40.2 KB)
📄 subst.c(67.57 KB)
📄 sysinfo.c(43.67 KB)
📄 sysinfo.h(2.58 KB)
📄 target.c(11.58 KB)
📄 temp_serializer.c(14.02 KB)
📄 time.c(9.08 KB)
📄 token.c(2.58 KB)
📄 types.c(9.43 KB)
📄 user.c(2.66 KB)
📄 username_providers.c(9.2 KB)
📄 utf.c(40.38 KB)
📁 utf8proc
📄 utf8proc.c(20.71 KB)
📄 utf_validate.c(13.3 KB)
📄 utf_width.c(10.85 KB)
📄 validate.c(3.35 KB)
📄 version.c(9.89 KB)
📄 win32_crashrpt.c(25.06 KB)
📄 win32_crashrpt.h(1.35 KB)
📄 win32_crashrpt_dll.h(4 KB)
📄 win32_crypto.c(18.12 KB)
📄 win32_xlate.c(7.3 KB)
📄 win32_xlate.h(2.11 KB)
📄 x509.h(3.75 KB)
📄 x509info.c(9.53 KB)
📄 x509parse.c(35.77 KB)
📄 xml.c(20.01 KB)

Editing: atomic.c

/* atomic.c : perform atomic initialization
 *
 * ====================================================================
 *    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 <assert.h>
#include <apr_time.h>

#include "svn_pools.h"

#include "private/svn_atomic.h"
#include "private/svn_mutex.h"

/* Magic values for atomic initialization */
#define SVN_ATOMIC_UNINITIALIZED 0
#define SVN_ATOMIC_START_INIT    1
#define SVN_ATOMIC_INIT_FAILED   2
#define SVN_ATOMIC_INITIALIZED   3

/* Baton used by init_funct_t and init_once(). */
typedef struct init_baton_t init_baton_t;

/* Initialization function wrapper. Hides API details from init_once().
   The implementation must return FALSE on failure. */
typedef svn_boolean_t (*init_func_t)(init_baton_t *init_baton);

/*
 * This is the actual atomic initialization driver.
 * Returns FALSE on failure.
 */
static svn_boolean_t
init_once(volatile svn_atomic_t *global_status,
          init_func_t init_func, init_baton_t *init_baton)
{
  /* !! Don't use localizable strings in this function, because these
     !! might cause deadlocks. This function can be used to initialize
     !! libraries that are used for generating error messages. */

/* We have to call init_func exactly once.  Because APR
     doesn't have statically-initialized mutexes, we implement a poor
     man's spinlock using svn_atomic_cas. */

svn_atomic_t status = svn_atomic_cas(global_status,
                                       SVN_ATOMIC_START_INIT,
                                       SVN_ATOMIC_UNINITIALIZED);

for (;;)
    {
      switch (status)
        {
        case SVN_ATOMIC_UNINITIALIZED:
          {
            const svn_boolean_t result = init_func(init_baton);
            const svn_atomic_t init_state = (result
                                             ? SVN_ATOMIC_INITIALIZED
                                             : SVN_ATOMIC_INIT_FAILED);

svn_atomic_cas(global_status, init_state,
                           SVN_ATOMIC_START_INIT);
            return result;
          }

case SVN_ATOMIC_START_INIT:
          /* Wait for the init function to complete. */
          apr_sleep(APR_USEC_PER_SEC / 1000);
          status = svn_atomic_cas(global_status,
                                  SVN_ATOMIC_UNINITIALIZED,
                                  SVN_ATOMIC_UNINITIALIZED);
          continue;

case SVN_ATOMIC_INIT_FAILED:
          return FALSE;

case SVN_ATOMIC_INITIALIZED:
          return TRUE;

default:
          /* Something went seriously wrong with the atomic operations. */
          abort();
        }
    }
}

/* This baton structure is used by the two flavours of init-once APIs
   to hide their differences from the init_once() driver. Each private
   API uses only selected parts of the baton.

No part of this structure changes unless a wrapped init function is
   actually invoked by init_once().
*/
struct init_baton_t
{
  /* Used only by svn_atomic__init_once()/err_init_func_wrapper() */
  svn_atomic__err_init_func_t err_init_func;
  svn_error_t *err;
  apr_pool_t *pool;

/* Used only by svn_atomic__init_no_error()/str_init_func_wrapper() */
  svn_atomic__str_init_func_t str_init_func;
  const char *errstr;

/* Used by both pairs of functions */
  void *baton;
};

/* Wrapper for the svn_atomic__init_once init function. */
static svn_boolean_t err_init_func_wrapper(init_baton_t *init_baton)
{
  init_baton->err = init_baton->err_init_func(init_baton->baton,
                                              init_baton->pool);
  return (init_baton->err == SVN_NO_ERROR);
}

svn_error_t *
svn_atomic__init_once(volatile svn_atomic_t *global_status,
                      svn_atomic__err_init_func_t err_init_func,
                      void *baton,
                      apr_pool_t* pool)
{
  init_baton_t init_baton;
  init_baton.err_init_func = err_init_func;
  init_baton.err = NULL;
  init_baton.pool = pool;
  init_baton.baton = baton;

if (init_once(global_status, err_init_func_wrapper, &init_baton))
    return SVN_NO_ERROR;

return svn_error_create(SVN_ERR_ATOMIC_INIT_FAILURE, init_baton.err,
                          "Couldn't perform atomic initialization");
}

/* Wrapper for the svn_atomic__init_no_error init function. */
static svn_boolean_t str_init_func_wrapper(init_baton_t *init_baton)
{
  init_baton->errstr = init_baton->str_init_func(init_baton->baton);
  return (init_baton->errstr == NULL);
}

const char *
svn_atomic__init_once_no_error(volatile svn_atomic_t *global_status,
                               svn_atomic__str_init_func_t str_init_func,
                               void *baton)
{
  init_baton_t init_baton;
  init_baton.str_init_func = str_init_func;
  init_baton.errstr = NULL;
  init_baton.baton = baton;

if (init_once(global_status, str_init_func_wrapper, &init_baton))
    return NULL;

/* Our init function wrapper may not have been called; make sure
     that we return generic error message in that case. */
  if (!init_baton.errstr)
    return "Couldn't perform atomic initialization";
  else
    return init_baton.errstr;
}

/* The process-global counter that we use to produce process-wide unique
 * values.  Since APR has no 64 bit atomics, all access to this will be
 * serialized through COUNTER_MUTEX. */
static apr_uint64_t uniqiue_counter = 0;

/* The corresponding mutex and initialization state. */
static volatile svn_atomic_t counter_status = SVN_ATOMIC_UNINITIALIZED;
static svn_mutex__t *counter_mutex = NULL;

/* svn_atomic__err_init_func_t implementation that initializes COUNTER_MUTEX.
 * Note that neither argument will be used and should be NULL. */
static svn_error_t *
init_unique_counter(void *null_baton,
                    apr_pool_t *null_pool)
{
  /* COUNTER_MUTEX is global, so it needs to live in a global pool.
   * APR also makes those thread-safe by default. */
  SVN_ERR(svn_mutex__init(&counter_mutex, TRUE, svn_pool_create(NULL)));
  return SVN_NO_ERROR;
}

/* Read and increment UNIQIUE_COUNTER. Return the new value in *VALUE.
 * Call this function only while having acquired the COUNTER_MUTEX. */
static svn_error_t *
read_unique_counter(apr_uint64_t *value)
{
  *value = ++uniqiue_counter;
  return SVN_NO_ERROR;
}

svn_error_t *
svn_atomic__unique_counter(apr_uint64_t *value)
{
  SVN_ERR(svn_atomic__init_once(&counter_status, init_unique_counter, NULL,
                                NULL));
  SVN_MUTEX__WITH_LOCK(counter_mutex, read_unique_counter(value));
  return SVN_NO_ERROR;
}

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Editing: atomic.c

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