mirror of
https://github.com/wjakob/tbb.git
synced 2026-08-30 00:50:40 +08:00
Hans Johnson
e32d75f876
The new release TBB is now under a new more
open license.
Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
The list of most significant changes made over time in
Intel(R) Threading Building Blocks (Intel(R) TBB).
Intel TBB 2017
TBB_INTERFACE_VERSION == 9100
Changes (w.r.t. Intel TBB 4.4 Update 5):
- static_partitioner class is now a fully supported feature.
- async_node class is now a fully supported feature.
- Improved dynamic memory allocation replacement on Windows* OS to skip
DLLs for which replacement cannot be done, instead of aborting.
- Intel TBB no longer performs dynamic memory allocation replacement
for Microsoft* Visual Studio* 2008.
- For 64-bit platforms, quadrupled the worst-case limit on the amount
of memory the Intel TBB allocator can handle.
- Added TBB_USE_GLIBCXX_VERSION macro to specify the version of GNU
libstdc++ when it cannot be properly recognized, e.g. when used
with Clang on Linux* OS. Inspired by a contribution from David A.
- Added graph/stereo example to demostrate tbb::flow::async_msg.
- Removed a few cases of excessive user data copying in the flow graph.
- Reworked split_node to eliminate unnecessary overheads.
- Added support for C++11 move semantics to the argument of
tbb::parallel_do_feeder::add() method.
- Added C++11 move constructor and assignment operator to
tbb::combinable template class.
- Added tbb::this_task_arena::max_concurrency() function and
max_concurrency() method of class task_arena returning the maximal
number of threads that can work inside an arena.
- Deprecated tbb::task_arena::current_thread_index() static method;
use tbb::this_task_arena::current_thread_index() function instead.
- All examples for commercial version of library moved online:
https://software.intel.com/en-us/product-code-samples. Examples are
available as a standalone package or as a part of Intel(R) Parallel
Studio XE or Intel(R) System Studio Online Samples packages.
Changes affecting backward compatibility:
- Renamed following methods and types in async_node class:
Old New
async_gateway_type => gateway_type
async_gateway() => gateway()
async_try_put() => try_put()
async_reserve() => reserve_wait()
async_commit() => release_wait()
- Internal layout of some flow graph nodes has changed; recompilation
is recommended for all binaries that use the flow graph.
Preview Features:
- Added template class streaming_node to the flow graph API. It allows
a flow graph to offload computations to other devices through
streaming or offloading APIs.
- Template class opencl_node reimplemented as a specialization of
streaming_node that works with OpenCL*.
- Added tbb::this_task_arena::isolate() function to isolate execution
of a group of tasks or an algorithm from other tasks submitted
to the scheduler.
Bugs fixed:
- Added a workaround for GCC bug #62258 in std::rethrow_exception()
to prevent possible problems in case of exception propagation.
- Fixed parallel_scan to provide correct result if the initial value
of an accumulator is not the operation identity value.
- Fixed a memory corruption in the memory allocator when it meets
internal limits.
- Fixed the memory allocator on 64-bit platforms to align memory
to 16 bytes by default for all allocations bigger than 8 bytes.
- As a workaround for crashes in the Intel TBB library compiled with
GCC 6, added -flifetime-dse=1 to compilation options on Linux* OS.
- Fixed a race in the flow graph implementation.
Open-source contributions integrated:
- Enabling use of C++11 'override' keyword by Raf Schietekat.
------------------------------------------------------------------------
70 lines
2.1 KiB
C++
70 lines
2.1 KiB
C++
/*
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Copyright (c) 2005-2016 Intel Corporation
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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#include "common.h"
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#include "tbb/task.h"
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class OptimizedSumTask: public tbb::task {
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Value* const sum;
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TreeNode* root;
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bool is_continuation;
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Value x, y;
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public:
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OptimizedSumTask( TreeNode* root_, Value* sum_ ) : root(root_), sum(sum_), is_continuation(false) {
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}
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tbb::task* execute() /*override*/ {
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tbb::task* next = NULL;
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if( !is_continuation ) {
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if( root->node_count<1000 ) {
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*sum = SerialSumTree(root);
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} else {
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// Create tasks before spawning any of them.
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tbb::task* a = NULL;
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tbb::task* b = NULL;
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if( root->left )
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a = new( allocate_child() ) OptimizedSumTask(root->left,&x);
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if( root->right )
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b = new( allocate_child() ) OptimizedSumTask(root->right,&y);
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recycle_as_continuation();
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is_continuation = true;
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set_ref_count( (a!=NULL)+(b!=NULL) );
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if( a ) {
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if( b ) spawn(*b);
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} else
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a = b;
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next = a;
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}
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} else {
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*sum = root->value;
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if( root->left ) *sum += x;
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if( root->right ) *sum += y;
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}
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return next;
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}
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};
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Value OptimizedParallelSumTree( TreeNode* root ) {
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Value sum;
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OptimizedSumTask& a = *new(tbb::task::allocate_root()) OptimizedSumTask(root,&sum);
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tbb::task::spawn_root_and_wait(a);
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return sum;
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}
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