Intel(R) Threading Building Blocks Doxygen Documentation  version 4.2.3
scheduler_utility.h
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1 /*
2  Copyright (c) 2005-2019 Intel Corporation
3 
4  Licensed under the Apache License, Version 2.0 (the "License");
5  you may not use this file except in compliance with the License.
6  You may obtain a copy of the License at
7 
8  http://www.apache.org/licenses/LICENSE-2.0
9 
10  Unless required by applicable law or agreed to in writing, software
11  distributed under the License is distributed on an "AS IS" BASIS,
12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  See the License for the specific language governing permissions and
14  limitations under the License.
15 */
16 
17 #ifndef _TBB_scheduler_utility_H
18 #define _TBB_scheduler_utility_H
19 
20 #include "scheduler.h"
21 
22 namespace tbb {
23 namespace internal {
24 
25 //------------------------------------------------------------------------
26 // auto_empty_task
27 //------------------------------------------------------------------------
28 
33 public:
35  : my_task( new(&s->allocate_task(sizeof(empty_task), __TBB_CONTEXT_ARG(NULL, context))) empty_task )
36  , my_scheduler(s)
37  {}
38  // empty_task has trivial destructor, so there's no need to call it.
39  ~auto_empty_task () { my_scheduler->free_task<small_local_task>(*my_task); }
40 
41  operator task& () { return *my_task; }
42  task* operator & () { return my_task; }
43  task_prefix& prefix () { return my_task->prefix(); }
44 }; // class auto_empty_task
45 
46 //------------------------------------------------------------------------
47 // fast_reverse_vector
48 //------------------------------------------------------------------------
49 
51 
55 template<typename T, size_t max_segments = 16>
57 {
58 public:
59  fast_reverse_vector ( T* initial_segment, size_t segment_size )
60  : m_cur_segment(initial_segment)
61  , m_cur_segment_size(segment_size)
62  , m_pos(segment_size)
63  , m_num_segments(0)
64  , m_size(0)
65  {
66  __TBB_ASSERT ( initial_segment && segment_size, "Nonempty initial segment must be supplied");
67  }
68 
70  {
71  for ( size_t i = 1; i < m_num_segments; ++i )
72  NFS_Free( m_segments[i] );
73  }
74 
75  size_t size () const { return m_size + m_cur_segment_size - m_pos; }
76 
77  void push_back ( const T& val )
78  {
79  if ( !m_pos ) {
80  if ( !m_num_segments ) m_segments[m_num_segments++] = m_cur_segment;
81  m_size += m_cur_segment_size;
82  m_cur_segment_size *= 2;
83  m_pos = m_cur_segment_size;
84  m_segments[m_num_segments++] = m_cur_segment = (T*)NFS_Allocate( m_cur_segment_size, sizeof(T), NULL );
85  __TBB_ASSERT ( m_num_segments < max_segments, "Maximal capacity exceeded" );
86  }
87  m_cur_segment[--m_pos] = val;
88  }
89 
91 
92  void copy_memory ( T* dst ) const
93  {
94  size_t sz = m_cur_segment_size - m_pos;
95  memcpy( dst, m_cur_segment + m_pos, sz * sizeof(T) );
96  dst += sz;
97  sz = m_cur_segment_size / 2;
98  for ( long i = (long)m_num_segments - 2; i >= 0; --i ) {
99  memcpy( dst, m_segments[i], sz * sizeof(T) );
100  dst += sz;
101  sz /= 2;
102  }
103  }
104 
105 protected:
108 
111 
113  size_t m_pos;
114 
116  T *m_segments[max_segments];
117 
120 
122  size_t m_size;
123 
124 }; // class fast_reverse_vector
125 
126 } // namespace internal
127 } // namespace tbb
128 
129 #endif /* _TBB_scheduler_utility_H */
internal::task_prefix & prefix(internal::version_tag *=NULL) const
Get reference to corresponding task_prefix.
Definition: task.h:946
Bitwise-OR of local_task and small_task.
void free_task(task &t)
Put task on free list.
Definition: scheduler.h:648
auto_empty_task(__TBB_CONTEXT_ARG(generic_scheduler *s, task_group_context *context))
void copy_memory(T *dst) const
Copies the contents of the vector into the dst array.
size_t m_pos
Insertion position in m_cur_segment.
void const char const char int ITT_FORMAT __itt_group_sync s
generic_scheduler * my_scheduler
The graph class.
void __TBB_EXPORTED_FUNC NFS_Free(void *)
Free memory allocated by NFS_Allocate.
Memory prefix to a task object.
Definition: task.h:184
#define __TBB_ASSERT(predicate, comment)
No-op version of __TBB_ASSERT.
Definition: tbb_stddef.h:165
#define __TBB_CONTEXT_ARG(arg1, context)
size_t m_size
Number of items in the segments in m_segments.
task that does nothing. Useful for synchronization.
Definition: task.h:964
Used to form groups of tasks.
Definition: task.h:332
Vector that grows without reallocations, and stores items in the reverse order.
Base class for user-defined tasks.
Definition: task.h:589
Work stealing task scheduler.
Definition: scheduler.h:120
size_t m_num_segments
Number of segments (the size of m_segments)
size_t m_cur_segment_size
Capacity of m_cur_segment.
Smart holder for the empty task class with automatic destruction.
T * m_cur_segment
The current (not completely filled) segment.
fast_reverse_vector(T *initial_segment, size_t segment_size)
void *__TBB_EXPORTED_FUNC NFS_Allocate(size_t n_element, size_t element_size, void *hint)
Allocate memory on cache/sector line boundary.

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