TY - GEN
T1 - Forkscan
T2 - 12th European Conference on Computer Systems, EuroSys 2017
AU - Alistarh, Dan
AU - Leiserson, William
AU - Matveev, Alexander
AU - Shavit, Nir
N1 - Publisher Copyright:
© 2017 Copyright held by the owner/author(s).
PY - 2017/4/23
Y1 - 2017/4/23
N2 - The problem of efficient concurrent memory reclamation in unmanaged languages such as C or C++ is one of the major challenges facing the parallelization of billions of lines of legacy code. Garbage collectors for C/C++ can be inefficient; thus, programmers are often forced to use finely-crafted concurrent memory reclamation techniques. These techniques can provide good performance, but require considerable programming effort to deploy, and have strict requirements, allowing the programmer very little room for error. In this work, we present Forkscan, a new conservative concurrent memory reclamation scheme which is fully automatic and surprisingly scalable. Forkscan's semantics place it between automatic garbage collectors (it requires the programmer to explicitly retire nodes before they can be reclaimed), and concurrent memory reclamation techniques (as it does not assume that nodes are completely unlinked from the data structure for correctness). Forkscan's implementation exploits these new semantics for efficiency: we leverage parallelism and optimized implementations of signaling and copy-on-write in modern operating systems to efficiently obtain and process consistent snapshots of memory that can be scanned concurrently with the normal program operation. Empirical evaluation on a range of classical concurrent data structure microbenchmarks shows that Forkscan can preserve the scalability of the original code, while maintaining an order of magnitude lower latency than automatic garbage collection, and demonstrating competitive performance with finely crafted memory reclamation techniques.
AB - The problem of efficient concurrent memory reclamation in unmanaged languages such as C or C++ is one of the major challenges facing the parallelization of billions of lines of legacy code. Garbage collectors for C/C++ can be inefficient; thus, programmers are often forced to use finely-crafted concurrent memory reclamation techniques. These techniques can provide good performance, but require considerable programming effort to deploy, and have strict requirements, allowing the programmer very little room for error. In this work, we present Forkscan, a new conservative concurrent memory reclamation scheme which is fully automatic and surprisingly scalable. Forkscan's semantics place it between automatic garbage collectors (it requires the programmer to explicitly retire nodes before they can be reclaimed), and concurrent memory reclamation techniques (as it does not assume that nodes are completely unlinked from the data structure for correctness). Forkscan's implementation exploits these new semantics for efficiency: we leverage parallelism and optimized implementations of signaling and copy-on-write in modern operating systems to efficiently obtain and process consistent snapshots of memory that can be scanned concurrently with the normal program operation. Empirical evaluation on a range of classical concurrent data structure microbenchmarks shows that Forkscan can preserve the scalability of the original code, while maintaining an order of magnitude lower latency than automatic garbage collection, and demonstrating competitive performance with finely crafted memory reclamation techniques.
KW - Memory management
KW - Synchronization
UR - http://www.scopus.com/inward/record.url?scp=85019172823&partnerID=8YFLogxK
U2 - 10.1145/3064176.3064214
DO - 10.1145/3064176.3064214
M3 - ???researchoutput.researchoutputtypes.contributiontobookanthology.conference???
AN - SCOPUS:85019172823
T3 - Proceedings of the 12th European Conference on Computer Systems, EuroSys 2017
SP - 483
EP - 498
BT - Proceedings of the 12th European Conference on Computer Systems, EuroSys 2017
PB - Association for Computing Machinery, Inc
Y2 - 23 April 2017 through 26 April 2017
ER -