diff options
Diffstat (limited to 'runtime/apc.c')
| -rw-r--r-- | runtime/apc.c | 402 |
1 files changed, 0 insertions, 402 deletions
diff --git a/runtime/apc.c b/runtime/apc.c deleted file mode 100644 index 3c6b7ec4..00000000 --- a/runtime/apc.c +++ /dev/null @@ -1,402 +0,0 @@ -/* apc.c - asynchronous procedure call support - * - * An asynchronous procedure call (APC) is a procedure call (guess what) that is potentially run - * asynchronously to its main thread. It can be scheduled to occur at a caller-provided time. - * As long as the procedure has not been called, the APC entry may be modified by the caller - * or deleted. It is the caller's purpose to make sure proper synchronization is in place. - * The APC object only case about APC's own control structures (which *are* properly - * guarded by synchronization primitives). - * - * Module begun 2009-06-15 by Rainer Gerhards - * - * Copyright 2009 Rainer Gerhards and Adiscon GmbH. - * - * This file is part of the rsyslog runtime library. - * - * The rsyslog runtime library is free software: you can redistribute it and/or modify - * it under the terms of the GNU Lesser General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * The rsyslog runtime library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public License - * along with the rsyslog runtime library. If not, see <http://www.gnu.org/licenses/>. - * - * A copy of the GPL can be found in the file "COPYING" in this distribution. - * A copy of the LGPL can be found in the file "COPYING.LESSER" in this distribution. - */ - -#include "config.h" -#include <stdlib.h> -#include <string.h> -#include <assert.h> -#include <pthread.h> - -#include "rsyslog.h" -#include "obj.h" -#include "apc.h" -#include "srUtils.h" -#include "datetime.h" - -/* static data */ -DEFobjStaticHelpers -DEFobjCurrIf(datetime) - -/* following is a used to implement a monotonically increasing id for the apcs. That - * ID can be used to cancel an apc request. Note that the ID is generated with modulo - * arithmetic, so at some point, it will wrap. Howerver, this happens at 2^32-1 at - * earliest, so this is not considered a problem. - */ -apc_id_t apcID = 0; - -/* private data structures */ - -/* the apc list and its entries - * This is a doubly-linked list as we need to be able to do inserts - * and deletes right in the middle of the list. It is inspired by the - * Unix callout mechanism. - * Note that we support two generic caller-provided parameters as - * experience shows that at most two are often used. This causes very - * little overhead, but simplifies caller code in cases where exactly - * two parameters are needed. We hope this is a useful optimizaton. - * rgerhards, 2009-06-15 - */ -typedef struct apc_list_s { - struct apc_list_s *pNext; - struct apc_list_s *pPrev; - apc_id_t id; - apc_t *pApc; /* pointer to the APC object to be scheduled */ -} apc_list_t; - -apc_list_t *apcListRoot = NULL; -apc_list_t *apcListTail = NULL; -pthread_mutex_t listMutex; /* needs to be locked for all list operations */ - - -/* destructor for the apc object */ -BEGINobjDestruct(apc) /* be sure to specify the object type also in END and CODESTART macros! */ -CODESTARTobjDestruct(apc) -ENDobjDestruct(apc) - - -/* ------------------------------ APC list handling functions ------------------------------ */ - -/* Function that handles changes to the list root. Most importantly, this function - * needs to schedule a new timer. It is OK to call this function with an empty list. - */ -static rsRetVal -listRootChanged(void) -{ - DEFiRet; - - if(apcListRoot == NULL) - FINALIZE; - - // TODO: implement! - -finalize_it: - RETiRet; -} - - -/* insert an apc entry into the APC list. The same entry MUST NOT already be present! - */ -static rsRetVal -insertApc(apc_t *pThis, apc_id_t *pID) -{ - apc_list_t *pCurr; - apc_list_t *pNew; - DEFiRet; - - CHKmalloc(pNew = (apc_list_t*) calloc(1, sizeof(apc_list_t))); - pNew->pApc = pThis; - pNew->id = *pID = apcID++; -dbgprintf("insert apc %p, id %ld\n", pThis, pNew->id); - - /* find right list location */ - if(apcListRoot == NULL) { - /* no need to search, list is empty */ - apcListRoot = pNew; - apcListTail = pNew; - CHKiRet(listRootChanged()); - } else { - for(pCurr = apcListRoot ; pCurr != NULL ; pCurr = pCurr->pNext) { - if(pCurr->pApc->ttExec > pThis->ttExec) - break; - } - - if(pCurr == NULL) { - /* insert at tail */ - pNew->pPrev = apcListTail; - apcListTail->pNext = pNew; - apcListTail = pNew; - } else { - if(pCurr == apcListRoot) { - /* new first entry */ - pCurr->pPrev = pNew; - pNew->pNext = pCurr; - apcListRoot = pNew; - CHKiRet(listRootChanged()); - } else { - /* in the middle of the list */ - pCurr->pPrev = pNew; - pNew->pNext = pCurr; - } - } - } - - -finalize_it: - RETiRet; -} - - -/* Delete an apc entry from the APC list. It is OK if the entry is not found, - * in this case we assume it already has been processed. - */ -static rsRetVal -deleteApc(apc_id_t id) -{ - apc_list_t *pCurr; - DEFiRet; - -dbgprintf("trying to delete apc %ld\n", id); - for(pCurr = apcListRoot ; pCurr != NULL ; pCurr = pCurr->pNext) { - if(pCurr->id == id) { -RUNLOG_STR("apc id found, now deleting!\n"); - if(pCurr == apcListRoot) { - apcListRoot = pCurr->pNext; - CHKiRet(listRootChanged()); - } else { - pCurr->pPrev->pNext = pCurr->pNext; - } - if(pCurr->pNext == NULL) { - apcListTail = pCurr->pPrev; - } else { - pCurr->pNext->pPrev = pCurr->pPrev; - } - free(pCurr); - pCurr = NULL; - break; - } - } - -finalize_it: - RETiRet; -} - - -/* unlist all elements up to the current timestamp. Return this as a seperate list - * to the caller. Returns an empty (NULL ptr) list if there are no such elements. - * The caller must handle that gracefully. The list is returned in the parameter. - */ -static rsRetVal -unlistCurrent(apc_list_t **ppList) -{ - apc_list_t *pCurr; - time_t tCurr; - DEFiRet; - assert(ppList != NULL); - - datetime.GetTime(&tCurr); - - if(apcListRoot == NULL || apcListRoot->pApc->ttExec > tCurr) { - *ppList = NULL; - FINALIZE; - } - - *ppList = apcListRoot; - /* now search up to which entry we need to execute */ - for(pCurr = apcListRoot ; pCurr != NULL && pCurr->pApc->ttExec <= tCurr ; pCurr = pCurr->pNext) { - /*JUST SKIP TO LAST ELEMENT*/; - } - - if(pCurr == NULL) { - /* all elements can be unlisted */ - apcListRoot = NULL; - apcListTail = NULL; - } else { - /* need to set a new root */ - pCurr->pPrev->pNext = NULL; /* terminate newly unlisted list */ - pCurr->pPrev = NULL; /* we are the new root */ - apcListRoot = pCurr; - } - -finalize_it: - RETiRet; -} - - -/* ------------------------------ END APC list handling functions ------------------------------ */ - - -/* execute all list elements that are currently scheduled for execution. We do this in two phases. - * In the first phase, we look the list mutex and move everything from the head of the queue to - * the current timestamp to a new to-be-executed list. Then we unlock the mutex and do the actual - * exec (which may take some time). - * Note that the caller is responsible for proper - * caller-level synchronization. The caller may schedule another Apc, this module must - * ensure that (and it does so by not locking the list mutex while we call the Apc). - * Note: this function "consumes" the apc_t, so it is no longer existing after this - * function returns. - */ -// TODO make static and associated with our own pthread-based timer -rsRetVal -execScheduled(void) -{ - apc_list_t *pExecList; - apc_list_t *pCurr; - apc_list_t *pNext; - DEFiRet; - - d_pthread_mutex_lock(&listMutex); - iRet = unlistCurrent(&pExecList); - d_pthread_mutex_unlock(&listMutex); - CHKiRet(iRet); - - if(pExecList != NULL) { - DBGPRINTF("running apc scheduler - we have %s to execute\n", - pExecList == NULL ? "nothing" : "something"); - } - - for(pCurr = pExecList ; pCurr != NULL ; pCurr = pNext) { -dbgprintf("executing apc list entry %p, apc %p\n", pCurr, pCurr->pApc); - pNext = pCurr->pNext; - pCurr->pApc->pProc(pCurr->pApc->param1, pCurr->pApc->param2); - apcDestruct(&pCurr->pApc); - free(pCurr); - } - -finalize_it: - RETiRet; -} - - -/* Standard-Constructor - */ -BEGINobjConstruct(apc) /* be sure to specify the object type also in END macro! */ -ENDobjConstruct(apc) - - -/* ConstructionFinalizer - * Note that we use a non-standard calling interface: pID returns the current APC - * id. This is the only way to handle the situation without the need for extra - * locking. - * rgerhards, 2008-01-09 - */ -static rsRetVal -apcConstructFinalize(apc_t *pThis, apc_id_t *pID) -{ - DEFiRet; - ISOBJ_TYPE_assert(pThis, apc); - assert(pID != NULL); - d_pthread_mutex_lock(&listMutex); - insertApc(pThis, pID); - d_pthread_mutex_unlock(&listMutex); - RETiRet; -} - - -/* some set methods */ -static rsRetVal -SetProcedure(apc_t *pThis, void (*pProc)(void*, void*)) -{ - ISOBJ_TYPE_assert(pThis, apc); - pThis->pProc = pProc; - return RS_RET_OK; -} -static rsRetVal -SetParam1(apc_t *pThis, void *param1) -{ - ISOBJ_TYPE_assert(pThis, apc); - pThis->param1 = param1; - return RS_RET_OK; -} -static rsRetVal -SetParam2(apc_t *pThis, void *param2) -{ - ISOBJ_TYPE_assert(pThis, apc); - pThis->param1 = param2; - return RS_RET_OK; -} - - -/* cancel an Apc request, ID is provided. It is OK if the ID can not be found, this may - * happen if the Apc was executed in the mean time. So it is safe to call CancelApc() at - * any time. - */ -static rsRetVal -CancelApc(apc_id_t id) -{ - BEGINfunc - d_pthread_mutex_lock(&listMutex); - deleteApc(id); - d_pthread_mutex_unlock(&listMutex); - ENDfunc - return RS_RET_OK; -} - - -/* debugprint for the apc object */ -BEGINobjDebugPrint(apc) /* be sure to specify the object type also in END and CODESTART macros! */ -CODESTARTobjDebugPrint(apc) - dbgoprint((obj_t*) pThis, "APC module, currently no state info available\n"); -ENDobjDebugPrint(apc) - - -/* queryInterface function - */ -BEGINobjQueryInterface(apc) -CODESTARTobjQueryInterface(apc) - if(pIf->ifVersion != apcCURR_IF_VERSION) { /* check for current version, increment on each change */ - ABORT_FINALIZE(RS_RET_INTERFACE_NOT_SUPPORTED); - } - - /* ok, we have the right interface, so let's fill it - * Please note that we may also do some backwards-compatibility - * work here (if we can support an older interface version - that, - * of course, also affects the "if" above). - */ - pIf->Construct = apcConstruct; - pIf->ConstructFinalize = apcConstructFinalize; - pIf->Destruct = apcDestruct; - pIf->DebugPrint = apcDebugPrint; - pIf->CancelApc = CancelApc; - pIf->SetProcedure = SetProcedure; - pIf->SetParam1 = SetParam1; - pIf->SetParam2 = SetParam2; -finalize_it: -ENDobjQueryInterface(apc) - - -/* Exit the apc class. - * rgerhards, 2009-04-06 - */ -BEGINObjClassExit(apc, OBJ_IS_CORE_MODULE) /* class, version */ - objRelease(datetime, CORE_COMPONENT); - pthread_mutex_destroy(&listMutex); -ENDObjClassExit(apc) - - -/* Initialize the apc class. Must be called as the very first method - * before anything else is called inside this class. - * rgerhards, 2008-02-19 - */ -BEGINObjClassInit(apc, 1, OBJ_IS_CORE_MODULE) /* class, version */ - /* request objects we use */ - CHKiRet(objUse(datetime, CORE_COMPONENT)); - - /* set our own handlers */ - OBJSetMethodHandler(objMethod_DEBUGPRINT, apcDebugPrint); - OBJSetMethodHandler(objMethod_CONSTRUCTION_FINALIZER, apcConstructFinalize); - - /* do other initializations */ - pthread_mutex_init(&listMutex, NULL); -ENDObjClassInit(apc) - -/* vi:set ai: - */ |