PASGAL

PASGAL: Parallel And Scalable Graph Algorithm Library.

Prerequisite

• g++ or clang with C++17 features support (tested with g++ 13.2.1 and clang 14.0.6) on Linux machines.
• We use ParlayLib to support fork-join parallelism and some parallel primitives. It is provided as a submodule in our repository.

Algorithms

We include the following four algorithms in our repository. The source code can be found under src/.

• BFS: Breadth-First Search.
• SSSP: Single-Source Shortest Paths. The SSSP algorithms are from the paper [1].
• BCC: Biconnected Components. The BCC algorithm is from the paper [2].
• SCC: Strongly Connected Components. The SCC algorithm is from the paper [3].

Compilation

A Makefile is provided in each subdirectory. For example, to compile BFS:

cd src/BFS  
make  

Running the code

Instructions on running the code will be provided when running the executables without any command line options. A sample output from BFS:

Usage: ./bfs [-i input_file] [-s] [-v]
Options:
-i, input file path
-s, symmetrized input graph
-v, verify result

Graph Formats

The application can auto-detect the format of the input graph based on the suffix of the filename. Here is a list of supported graph formats:

• .bin The binary graph format from GBBS. It uses the compressed sparse row (CSR) format and is organized as follows:
  • $n$ - number of vertices (64-bit variable)
  • $m$ - number of edges (64-bit variable)
  • sizes - sizes of this file in bytes, which is equal to $3\times8+(n+1)\times8+m\times4$ (64-bit variable)
  • offset[] - offset[ $i$ ] (inclusive) and offset[ $i+1$ ] (exclusive) represents the range of neighbors list of the $i$-th vertex in the edges array (64-bit array of length $n+1$)
  • edges[] - edges list (32-bit array of length $m$)
• .adj The adjacency graph format from Problem Based Benchmark suite.

References

If you use our code, please cite our paper:

@inproceedings{dong2024pasgal,
  title = {Brief Announcement: PASGAL: Parallel And Scalable Graph Algorithm Library},
  author = {Dong, Xiaojun and Gu, Yan and Sun, Yihan and Wang, Letong},
  booktitle = {ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)},
  year = {2024},
}

[1] Xiaojun Dong, Yan Gu, Yihan Sun, and Yunming Zhang. 2021. Efficient Stepping Algorithms and Implementations for Parallel Shortest Paths. In ACM Symposium on Parallelism in Algorithms and Architectures (SPAA). 184–197.

[2] Xiaojun Dong, Letong Wang, Yan Gu, and Yihan Sun. 2023. Provably Fast and Space-Efficient Parallel Biconnectivity. In ACM Symposium on Principles and Practice of Parallel Programming (PPOPP). 52–65.

[3] Letong Wang, Xiaojun Dong, Yan Gu, and Yihan Sun. 2023. Parallel Strong Connectivity Based on Faster Reachability. ACM SIGMOD International Conference on Management of Data (SIGMOD) 1, 2 (2023), 1–29.