I was wondering if std.container.array.Array supports threadsafe
parallel reads similar to std::vector. I've created a small
program for demonstration
https://github.com/carun/parallel-read-tester
It works fine with just couple of problems though:
1. D version takes way too long compared to C++ version.
```
bash build-and-run.sh
g++ (Ubuntu 7.2.0-8ubuntu3) 7.2.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
LDC - the LLVM D compiler (1.6.0):
based on DMD v2.076.1 and LLVM 5.0.0
built with LDC - the LLVM D compiler (1.6.0)
Default target: x86_64-unknown-linux-gnu
Host CPU: skylake
http://dlang.org - http://wiki.dlang.org/LDC
Registered Targets:
aarch64 - AArch64 (little endian)
aarch64_be - AArch64 (big endian)
arm - ARM
arm64 - ARM64 (little endian)
armeb - ARM (big endian)
nvptx - NVIDIA PTX 32-bit
nvptx64 - NVIDIA PTX 64-bit
ppc32 - PowerPC 32
ppc64 - PowerPC 64
ppc64le - PowerPC 64 LE
thumb - Thumb
thumbeb - Thumb (big endian)
x86 - 32-bit X86: Pentium-Pro and above
x86-64 - 64-bit X86: EM64T and AMD64
=== Starting CPP version ===
Took 3.7583 to load 2000000 items. Gonna search in parallel...
5 4000000
6 4000000
2 4000000
0 4000000
1 4000000
7 4000000
4 4000000
3 4000000
Took 7.0247 to search
=== Starting D version ===
Took 1 sec, 506 ms, 672 μs, and 4 hnsecs to load 2000000 items.
Gonna search in parallel...
3 4000000
4 4000000
2 4000000
6 4000000
7 4000000
5 4000000
1 4000000
0 4000000
Took 13 secs, 53 ms, 790 μs, and 3 hnsecs to search.
```
2. I'm on an 8 CPU box and I don't seem to hit 800% CPU with D
version (max 720%). However I can get 800% CPU usage with the C++
version.
2. Introducing a string in the struct Data results in
"std.container.Array.reserve failed to allocate memory", whereas
adding a similar std::string in the C++ struct seems to work fine.
Am I missing anything obvious here?
Also why doesn't std.container.array support an equivalent of
std::vector::erase?
Cheers,
Arun
