Apache Portable Runtime Utility Library: include/apr

00001 /* Licensed to the Apache Software Foundation (ASF) under one or more
00002  * contributor license agreements.  See the NOTICE file distributed with
00003  * this work for additional information regarding copyright ownership.
00004  * The ASF licenses this file to You under the Apache License, Version 2.0
00005  * (the "License"); you may not use this file except in compliance with
00006  * the License.  You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef APR_HOOKS_H
00018 #define APR_HOOKS_H
00019 
00020 #include "apu.h"
00021 /* For apr_array_header_t */
00022 #include "apr_tables.h"
00023 
00024 #ifdef APR_DTRACE_PROVIDER
00025 #include <sys/sdt.h>
00026 #ifndef OLD_DTRACE_PROBE
00027 #define OLD_DTRACE_PROBE(name) __dtrace_ap___##name()
00028 #endif
00029 #ifndef OLD_DTRACE_PROBE1
00030 #define OLD_DTRACE_PROBE1(name,a) __dtrace_ap___##name(a)
00031 #endif
00032 #ifndef OLD_DTRACE_PROBE2
00033 #define OLD_DTRACE_PROBE2(name,a,b) __dtrace_ap___##name(a,b)
00034 #endif
00035 #else
00036 #define OLD_DTRACE_PROBE(a)
00037 #define OLD_DTRACE_PROBE1(a,b)
00038 #define OLD_DTRACE_PROBE2(a,b,c)
00039 #endif
00040 
00046 #ifdef __cplusplus
00047 extern "C" {
00048 #endif
00049 
00055 #define APR_IMPLEMENT_HOOK_GET_PROTO(ns,link,name) \
00056 link##_DECLARE(apr_array_header_t *) ns##_hook_get_##name(void)
00057 
00059 #define APR_DECLARE_EXTERNAL_HOOK(ns,link,ret,name,args) \
00060 typedef ret ns##_HOOK_##name##_t args; \
00061 link##_DECLARE(void) ns##_hook_##name(ns##_HOOK_##name##_t *pf, \
00062                                       const char * const *aszPre, \
00063                                       const char * const *aszSucc, int nOrder); \
00064 link##_DECLARE(ret) ns##_run_##name args; \
00065 APR_IMPLEMENT_HOOK_GET_PROTO(ns,link,name); \
00066 typedef struct ns##_LINK_##name##_t \
00067     { \
00068     ns##_HOOK_##name##_t *pFunc; \
00069     const char *szName; \
00070     const char * const *aszPredecessors; \
00071     const char * const *aszSuccessors; \
00072     int nOrder; \
00073     } ns##_LINK_##name##_t;
00074 
00076 #define APR_HOOK_STRUCT(members) \
00077 static struct { members } _hooks;
00078 
00080 #define APR_HOOK_LINK(name) \
00081     apr_array_header_t *link_##name;
00082 
00084 #define APR_IMPLEMENT_EXTERNAL_HOOK_BASE(ns,link,name) \
00085 link##_DECLARE(void) ns##_hook_##name(ns##_HOOK_##name##_t *pf,const char * const *aszPre, \
00086                                       const char * const *aszSucc,int nOrder) \
00087     { \
00088     ns##_LINK_##name##_t *pHook; \
00089     if(!_hooks.link_##name) \
00090         { \
00091         _hooks.link_##name=apr_array_make(apr_hook_global_pool,1,sizeof(ns##_LINK_##name##_t)); \
00092         apr_hook_sort_register(#name,&_hooks.link_##name); \
00093         } \
00094     pHook=apr_array_push(_hooks.link_##name); \
00095     pHook->pFunc=pf; \
00096     pHook->aszPredecessors=aszPre; \
00097     pHook->aszSuccessors=aszSucc; \
00098     pHook->nOrder=nOrder; \
00099     pHook->szName=apr_hook_debug_current; \
00100     if(apr_hook_debug_enabled) \
00101         apr_hook_debug_show(#name,aszPre,aszSucc); \
00102     } \
00103     APR_IMPLEMENT_HOOK_GET_PROTO(ns,link,name) \
00104     { \
00105         return _hooks.link_##name; \
00106     }
00107 
00120 #define APR_IMPLEMENT_EXTERNAL_HOOK_VOID(ns,link,name,args_decl,args_use) \
00121 APR_IMPLEMENT_EXTERNAL_HOOK_BASE(ns,link,name) \
00122 link##_DECLARE(void) ns##_run_##name args_decl \
00123     { \
00124     ns##_LINK_##name##_t *pHook; \
00125     int n; \
00126 \
00127     OLD_DTRACE_PROBE(name##__entry); \
00128 \
00129     if(_hooks.link_##name) \
00130         { \
00131         pHook=(ns##_LINK_##name##_t *)_hooks.link_##name->elts; \
00132         for(n=0 ; n < _hooks.link_##name->nelts ; ++n) \
00133             { \
00134             OLD_DTRACE_PROBE1(name##__dispatch__invoke, (char *)pHook[n].szName); \
00135             pHook[n].pFunc args_use; \
00136             OLD_DTRACE_PROBE2(name##__dispatch__complete, (char *)pHook[n].szName, 0); \
00137             } \
00138         } \
00139 \
00140     OLD_DTRACE_PROBE1(name##__return, 0); \
00141 \
00142     }
00143 
00144 /* FIXME: note that this returns ok when nothing is run. I suspect it should
00145    really return decline, but that breaks Apache currently - Ben
00146 */
00162 #define APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(ns,link,ret,name,args_decl,args_use,ok,decline) \
00163 APR_IMPLEMENT_EXTERNAL_HOOK_BASE(ns,link,name) \
00164 link##_DECLARE(ret) ns##_run_##name args_decl \
00165     { \
00166     ns##_LINK_##name##_t *pHook; \
00167     int n; \
00168     ret rv = ok; \
00169 \
00170     OLD_DTRACE_PROBE(name##__entry); \
00171 \
00172     if(_hooks.link_##name) \
00173         { \
00174         pHook=(ns##_LINK_##name##_t *)_hooks.link_##name->elts; \
00175         for(n=0 ; n < _hooks.link_##name->nelts ; ++n) \
00176             { \
00177             OLD_DTRACE_PROBE1(name##__dispatch__invoke, (char *)pHook[n].szName); \
00178             rv=pHook[n].pFunc args_use; \
00179             OLD_DTRACE_PROBE2(name##__dispatch__complete, (char *)pHook[n].szName, rv); \
00180             if(rv != ok && rv != decline) \
00181                 break; \
00182             rv = ok; \
00183             } \
00184         } \
00185 \
00186     OLD_DTRACE_PROBE1(name##__return, rv); \
00187 \
00188     return rv; \
00189     }
00190 
00191 
00206 #define APR_IMPLEMENT_EXTERNAL_HOOK_RUN_FIRST(ns,link,ret,name,args_decl,args_use,decline) \
00207 APR_IMPLEMENT_EXTERNAL_HOOK_BASE(ns,link,name) \
00208 link##_DECLARE(ret) ns##_run_##name args_decl \
00209     { \
00210     ns##_LINK_##name##_t *pHook; \
00211     int n; \
00212     ret rv = decline; \
00213 \
00214     OLD_DTRACE_PROBE(name##__entry); \
00215 \
00216     if(_hooks.link_##name) \
00217         { \
00218         pHook=(ns##_LINK_##name##_t *)_hooks.link_##name->elts; \
00219         for(n=0 ; n < _hooks.link_##name->nelts ; ++n) \
00220             { \
00221             OLD_DTRACE_PROBE1(name##__dispatch__invoke, (char *)pHook[n].szName); \
00222             rv=pHook[n].pFunc args_use; \
00223             OLD_DTRACE_PROBE2(name##__dispatch__complete, (char *)pHook[n].szName, rv); \
00224 \
00225             if(rv != decline) \
00226                 break; \
00227             } \
00228         } \
00229 \
00230     OLD_DTRACE_PROBE1(name##__return, rv); \
00231 \
00232     return rv; \
00233     }
00234 
00235     /* Hook orderings */
00237 #define APR_HOOK_REALLY_FIRST   (-10)
00238 
00239 #define APR_HOOK_FIRST          0
00240 
00241 #define APR_HOOK_MIDDLE         10
00242 
00243 #define APR_HOOK_LAST           20
00244 
00245 #define APR_HOOK_REALLY_LAST    30
00246 
00250 APU_DECLARE_DATA extern apr_pool_t *apr_hook_global_pool;
00251 
00256 APU_DECLARE_DATA extern int apr_hook_debug_enabled;
00257 
00261 APU_DECLARE_DATA extern const char *apr_hook_debug_current;
00262 
00268 APU_DECLARE(void) apr_hook_sort_register(const char *szHookName, 
00269                                         apr_array_header_t **aHooks);
00273 APU_DECLARE(void) apr_hook_sort_all(void);
00274 
00282 APU_DECLARE(void) apr_hook_debug_show(const char *szName,
00283                                       const char * const *aszPre,
00284                                       const char * const *aszSucc);
00285 
00289 APU_DECLARE(void) apr_hook_deregister_all(void);
00290 
00292 #ifdef __cplusplus
00293 }
00294 #endif
00295 
00296 #endif /* APR_HOOKS_H */
include/apr_hooks.h
