6 /* This file is property of and copyright by the ALICE HLT Project *
7 * ALICE Experiment at CERN, All rights reserved. *
8 * See cxx source for full Copyright notice */
10 /** @file AliHLTTask.h
11 @author Matthias Richter
13 @brief base class for HLT tasks
16 // see below for class documentation
18 // refer to README to build package
20 // visit http://web.ift.uib.no/~kjeks/doc/alice-hlt
25 #include "AliHLTDataTypes.h"
26 #include "AliHLTLogging.h"
27 #include "AliHLTDataBuffer.h"
29 struct AliHLTComponentBlockData;
30 class AliHLTComponent;
31 class AliHLTComponentHandler;
32 class AliHLTConfiguration;
35 typedef vector<AliHLTTask*> AliHLTTaskPList;
37 /******************************************************************************/
41 * A task collects all the information which is necessary to process a certain
42 * step in the HLT data processing chain.
43 * - the instance of the component
44 * the task object creates and deletes the component object
45 * - the data buffer which receives the result of the component and provides
46 * the data to other tasks/components
47 * - a list of all dependencies
48 * - a list of consumers
49 * - the task object holds an external pointer to the configuration object;
50 * \b Note: the configuration object must exist through the existence of the
54 * @note This class is only used for the @ref alihlt_system.
56 * @ingroup alihlt_system
58 class AliHLTTask : public TObject, public AliHLTLogging {
60 /** standard constructor */
63 @param pConf pointer to configuration descriptor
65 AliHLTTask(AliHLTConfiguration* pConf);
67 virtual ~AliHLTTask();
70 * Initialize the task.
71 * The task is initialized with a configuration descriptor. It needs a
72 * component handler instance to create the analysis component. The
73 * component is created and initialized.
74 * @param pConf pointer to configuration descriptor, can be NULL if it
75 * was already provided to the constructor
76 * @param pCH the HLT component handler
78 int Init(AliHLTConfiguration* pConf, AliHLTComponentHandler* pCH);
81 * Create the component.
82 * @param pConf configuration descritption
83 * @param pCH component handler
84 * @param pComponent [OUT] target to get the component instance
85 * @return component instance
87 virtual int CreateComponent(AliHLTConfiguration* pConf, AliHLTComponentHandler* pCH, AliHLTComponent*& pComponent) const;
90 * De-Initialize the task.
91 * Final cleanup after the run. The @ref AliHLTComponent::Deinit method of
92 * the component is called. The analysis component is deleted.
97 * Get the name of the object.
98 * This is an overridden TObject function in order to return the configuration
99 * name instead of the class name. Enables use of TList standard functions.
100 * @return name of the configuration
102 const char *GetName() const;
105 * Return pointer to configuration.
106 * The tasks holds internally the configuration object.
107 * @return pointer to configuration
109 AliHLTConfiguration* GetConf() const;
112 * Return pointer to component, which the task internally holds.
113 * <b>Never delete this object!!!</b>
114 * @return instance of the component
116 AliHLTComponent* GetComponent() const;
119 * Find a dependency with a certain <i>name id</i>.
120 * Searches in the list of dependencies for a task.
121 * @param id the id of the <b>CONFIGURATION</b><br>
122 * <b>NOTE:</b> the id does NOT specify a COMPONENT
123 * @return pointer to task
125 AliHLTTask* FindDependency(const char* id);
128 * Add a dependency for the task.
129 * The task maintains a list of other tasks it depends on.
130 * @param pDep pointer to a task descriptor
131 * @return 0 if suceeded, neg error code if failed <br>
132 * -EEXIST : the dependencie exists already
135 int SetDependency(AliHLTTask* pDep);
138 * Clear a dependency.
139 * The ROOT TList touches the object which is in the list, even though
140 * it shouldn't care about. Thats why all lists have to be cleared before
141 * objects are deleted.
143 int UnsetDependency(AliHLTTask* pDep);
146 * Return number of unresolved dependencies.
147 * Iterate through all the configurations the task depends on and check
148 * whether a corresponding task is available in the list.
149 * @return number of unresolved dependencies
151 int CheckDependencies();
154 * Check whether the current task depends on the task pTask.
155 * @param pTask pointer to Task descriptor
156 * @return 1 the current task depends on pTask <br>
157 * 0 no dependency <br>
158 * neg. error code if failed
160 int Depends(AliHLTTask* pTask);
163 * Find a target with a certain id.
164 * Tasks which depend on the current task are referred to be <i>targets</i>.
165 * @param id configuration id to search for
166 * @return pointer to task instance
168 AliHLTTask* FindTarget(const char* id);
171 * Insert task into target list.
172 * The target list specifies all the tasks which depend on the current task.
173 * @param pDep pointer task object
174 * @return >=0 if succeeded, neg. error code if failed
176 int SetTarget(AliHLTTask* pDep);
180 * The ROOT TList touches the object which is in the list, even though
181 * it shouldn't care about. Thats why all lists have to be cleared before
182 * objects are deleted.
184 int UnsetTarget(AliHLTTask* pTarget);
187 * Prepare the task for event processing.
188 * The method initializes the Data Buffer and calls the
189 * @ref AliHLTComponent::Init method of the component.<br>
190 * The @ref ProcessTask method can be called an arbitrary number of times
191 * as soon as the task is in <i>running</i> mode.
196 * Clean-up the task after event processing.
197 * The method cleans up internal structures.
203 * If all dependencies are resolved the tasks subscribes to the data of
204 * all source tasks, builds the block descriptor and calls the
205 * @ref AliHLTComponent::ProcessEvent method of the component, after
206 * processing, the data blocks are released. <br>
207 * The @ref StartRun method must be called before.
209 int ProcessTask(Int_t eventNo, AliHLTUInt32_t eventType=gkAliEventTypeData);
212 * Determine the number of matching data block between the component and the
213 * data buffer of a consumer component. It checks which data types from the
214 * list of input data types of the consumer component can be provided by data
215 * blocks of the current component.
216 * @param pConsumerTask the task which subscribes to the data
217 * @return number of matching data blocks
219 int GetNofMatchingDataBlocks(const AliHLTTask* pConsumerTask) const;
222 * Determine the number of matching data types between the component and a
223 * consumer component. It checks which data types from the list of input data
224 * types of the consumer component can be provided by the current component.
225 * @param pConsumerTask the task which subscribes to the data
226 * @return number of matching data types
228 int GetNofMatchingDataTypes(const AliHLTTask* pConsumerTask) const;
231 * Subscribe to the data of a source task.
232 * The function prepares the block descriptors for subsequent use with the
233 * @ref AliHLTComponent::ProcessEvent method, the method prepares all block
234 * descriptors which match the input data type of the consumer the function
235 * returns the number of blocks which would be prepared in case the target
236 * array is big enough.
237 * @param pConsumerTask the task which subscribes to the data
238 * @param blockDescList block descriptor list to be filled
239 * @return number of matching data blocks, negative error code if failed
241 int Subscribe(const AliHLTTask* pConsumerTask, AliHLTComponentBlockDataList& blockDescList);
244 * Release a block descriptor.
245 * Notification from consumer task.
246 * @param pBlockDesc descriptor of the data segment
247 * @param pConsumerTask the task which subscribed to the data
248 * @return: >0 if success, negative error code if failed
250 int Release(AliHLTComponentBlockData* pBlockDesc,
251 const AliHLTTask* pConsumerTask);
254 * Print the status of the task with component, dependencies and targets.
259 * Search task dependency list recursively to find a dependency.
260 * @param id id of the task to search for
261 * @param pTgtList (optional) target list to receive dependency tree
262 * @return 0 if not found, >0 found in the n-th level,
263 dependency list in the target list
265 int FollowDependency(const char* id, TList* pTgtList=NULL);
268 * Print the tree for a certain dependency either from the task or
269 * configuration list.
270 * Each task posseses two "link lists": The configurations are the origin
271 * of the task list. In case of an error during the built of the task list,
272 * the dependencies for the task list might be incomplete. In this case the
273 * configurations can give infomation on the error reason.
274 * @param id id of the dependency to search for
275 * @param bMode 0 (default) from task dependency list, <br>
276 * 1 from configuration list
278 void PrintDependencyTree(const char* id, int bMode=0);
281 * Get number of source tasks.
282 * @return number of source tasks
284 int GetNofSources() const {return fListDependencies.GetSize();}
287 * Customized logging function.
288 * The task id and pointer is added at the beginning of each message.
290 int LoggingVarargs(AliHLTComponentLogSeverity severity,
291 const char* originClass, const char* originFunc,
292 const char* file, int line, ... ) const;
295 /** prohibited copy constructor */
296 AliHLTTask(const AliHLTTask&);
297 /** prohibited assignment operator */
298 AliHLTTask& operator=(const AliHLTTask&);
301 * Custom initialization for child tasks.
303 virtual int CustomInit(AliHLTComponentHandler* pCH);
306 * Custom clean up for child tasks.
308 virtual int CustomCleanup();
311 /** the configuration descriptor (external pointer) */
312 AliHLTConfiguration* fpConfiguration; //! transient
313 /** the component described by this task (created and deleted internally) */
314 AliHLTComponent* fpComponent; //! transient
315 /** the data buffer for the component processing */
316 AliHLTDataBuffer* fpDataBuffer; //! transient
319 /** the list of targets (tasks which depend upon the current one) */
320 TList fListTargets; // see above
321 /** the list of sources (tasks upon which the current one depends) */
322 TList fListDependencies; // see above
325 * block data array to be passed as argument to the
326 * @ref AliHLTComponent::ProcessEvent method.
327 * Filled through subscription to source tasks (@ref Subscribe).
329 vector<AliHLTComponentBlockData> fBlockDataArray; //! transient
331 ClassDef(AliHLTTask, 2);