commit | 76b44be49b34d5104a9a0fcbe32226126dbcbde5 | [log] [tgz] |
---|---|---|
author | David Grove <groved@us.ibm.com> | Wed May 24 11:14:14 2017 -0400 |
committer | David Grove <groved@us.ibm.com> | Wed May 24 11:14:14 2017 -0400 |
tree | 8fd4c7613e123e8e53c61b624040afdd465b70f2 | |
parent | 0b6c22e28980d4db1a98064809eccb8513aee8d5 [diff] |
Loosen test deadlines to reduce spurious failures in Swift CI Add build flag that defaults to true when building with Swift support enabled (like when in Swift CI) that relaxes the passing criteria for timing-sensitive dispatch tests. We continue to see occasional spurious failures of dispatch tests in the Swift CI caused by test machine load; this is an attempt to reduce the frequency of load-induced failures without removing the test cases entirely.
Grand Central Dispatch (GCD or libdispatch) provides comprehensive support for concurrent code execution on multicore hardware.
libdispatch is currently available on all Darwin platforms. This project aims to make a modern version of libdispatch available on all other Swift platforms. To do this, we will implement as much of the portable subset of the API as possible, using the existing open source C implementation.
libdispatch on Darwin is a combination of logic in the xnu
kernel alongside the user-space Library. The kernel has the most information available to balance workload across the entire system. As a first step, however, we believe it is useful to bring up the basic functionality of the library using user-space pthread primitives on Linux. Eventually, a Linux kernel module could be developed to support more informed thread scheduling.
A port of libdispatch to Linux has been completed. On Linux, since Swift 3, swift-corelibs-libdispatch has been included in all Swift releases and is used by other swift-corelibs projects.
Opportunities to contribute and on-going work include:
For detailed instructions on building and installing libdispatch, see INSTALL.md
For detailed instructions on testing libdispatch, see TESTING.md