From 466d5efa888a9f066ed679385afc76c5a37f7142 Mon Sep 17 00:00:00 2001
From: joe maley <joe@tiledb.io>
Date: Tue, 11 Aug 2020 09:44:18 -0400
Subject: [PATCH] Disable TBB by default (#1762)

This disables TBB by default in the bootstrap script.

Using our `/test/benchmarking` benchmarks, there is no discernible difference
between the end-to-end execution times or the individual execution times of the
parallel functions. For example, here is are the results of the `bench_large_io`
between the two:

// Without TBB
end-to-end: 267829 ms
`parallel_for`: 271120 ms
`parallel_for_2d`: 104 ms
`parallel_sort`: 14447 ms

// With TBB
end-to-end: 269911 ms
`parallel_for`: 273447 ms
`parallel_for_2d`: 107 ms
`parallel_sort`: 14382 ms

Note that the "end-to-end" was measured with a different timing mechanism than
the individual function timers. The individual function timers are also
cumulative per thread.

Co-authored-by: Joe Maley <joe@tiledb.com>
---
 CMakeLists.txt      | 2 +-
 HISTORY.md          | 1 +
 azure-pipelines.yml | 1 -
 bootstrap           | 2 +-
 4 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9b2c04f7067..c5b76212a6a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -98,7 +98,7 @@ option(TILEDB_HDFS "Enables HDFS support using the official Hadoop JNI bindings"
 option(TILEDB_WERROR "Enables the -Werror flag during compilation." ON)
 option(TILEDB_CPP_API "Enables building of the TileDB C++ API." ON)
 option(TILEDB_CMAKE_IDE "(Used for CLion builds). Disables superbuild and sets the EP install dir." OFF)
-option(TILEDB_TBB "Enables use of TBB for parallelization." ON)
+option(TILEDB_TBB "Enables use of TBB for parallelization." OFF)
 option(TILEDB_TBB_SHARED "If TBB is enabled, builds TBB as a shared library instead of static." OFF)
 option(TILEDB_STATS "Enables internal TileDB statistics gathering." ON)
 option(TILEDB_STATIC "Enables building TileDB as a static library." OFF)
diff --git a/HISTORY.md b/HISTORY.md
index 4dffb79523b..75434c30b99 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -25,6 +25,7 @@
 ## Deprecations
 
 * Support for MacOS older than 10.13 is being dropped when using the AWS SDK. Prebuilt Binaries now target 10.13 [#1753](https://github.com/TileDB-Inc/TileDB/pull/1753)
+* Use of Intel's Thread Building Blocks (TBB) will be discontinued in the future. It is now disabled by default [#1762](https://github.com/TileDB-Inc/TileDB/pull/1762)
 
 ## Bug fixes
 
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index f842a30fcbd..60a5e98c8d7 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -49,7 +49,6 @@ stages:
           linux_asan:
             imageName: 'ubuntu-16.04'
             TILEDB_CI_ASAN: ON
-            TILEDB_TBB: OFF
             TILEDB_SERIALIZATION: ON
             CXX: g++-7
           linux_serialization:
diff --git a/bootstrap b/bootstrap
index ee4335dfc0f..9f1c6517bf5 100755
--- a/bootstrap
+++ b/bootstrap
@@ -89,7 +89,7 @@ tiledb_werror="ON"
 tiledb_tests="ON"
 tiledb_cpp_api="ON"
 tiledb_force_all_deps="OFF"
-tiledb_tbb="ON"
+tiledb_tbb="OFF"
 tiledb_stats="ON"
 tiledb_static="OFF"
 tiledb_disable_avx2=""