EventCore

This is a high-performance native event loop abstraction for D, focused on asynchronous I/O and GUI message integration. The API is callback (delegate) based. For a higher level fiber based abstraction, take a look at vibe.d.

The API documentation is part of vibe.d:

• EventDriver
• eventDriver
• Experimental eventcore.socket

Supported drivers and operating systems

Driver	Linux	Windows	macOS	FreeBSD	Android	iOS
SelectEventDriver	yes	yes	yes	yes¹	yes	yes
EpollEventDriver	yes	—	—	—	yes	—
WinAPIEventDriver	—	yes	—	—	—	—
KqueueEventDriver	—	—	yes	yes¹	—	yes
CFRunloopEventDriver	—	—	yes	—	—	yes
LibasyncEventDriver	—¹	—¹	—¹	—¹	—	—

¹ planned, but not currenly implemented

Supported compilers

The following compilers are tested and supported:

• DMD 2.103.0
• DMD 2.086.1
• LDC 1.32.0
• LDC 1.16.0

Driver development status

Feature \ EventDriver	Select	Epoll	WinAPI	Kqueue	CFRunloop	Libasync
TCP Sockets	yes	yes	yes	yes	yes	—
UDP Sockets	yes	yes	yes	yes	yes	—
USDS	yes	yes	—	yes	yes	—
DNS	yes	yes	yes	yes	yes	—
Timers	yes	yes	yes	yes	yes	—
Events	yes	yes	yes	yes	yes	—
Unix Signals	yes²	yes	—	—	—	—
Files	yes	yes	yes	yes	yes	—
UI Integration	yes¹	yes¹	yes	yes¹	yes¹	—
File watcher	yes²	yes	yes	yes²	yes²	—
Pipes	yes	yes	—	yes	yes	—
Processes	yes	yes	—	yes	yes	—

¹ Manually, by adopting the X11 display connection socket

² Systems other than Linux use a polling implementation

Compile-time configuration

Configurations

The DUB configuration meachnism can be used to force choosing a particular event driver implementation. The following configurations are available:

EventcoreCFRunLoopDriver: Forces using the CFRunLoop driver (for DUB, use the "cfrunloop" configuration instead) EventcoreKqueueDriver: Forces using the kqueue driver (for DUB, use the "kqueue" configuration instead) EventcoreWinAPIDriver: Forces using the WinAPI driver (for DUB, use the "winapi" configuration instead) EventcoreLibasyncDriver: Forces using the libasync driver (for DUB, use the "libasync" configuration instead) EventcoreSelectDriver: Forces using the select driver (for DUB, use the "select" configuration instead) EventcoreUseGAIA: Forces using getaddressinfo_a for the epoll driver (for DUB, use the "epoll-gaia" configuration instead)

Version identifiers

Several version identifiers can be set to configure the behavior of the library at compile time. Simply insert any of the following identifiers as a "version" to the compiler command line or into your DUB recipe:

dub.sdl:

versions "EventCoreSilenceLeakWarnings"

dub.json:

{
	...
	"versions": ["EventCoreSilenceLeakWarnings"]
	...
}

• EventCoreSilenceLeakWarnings: Disables checking for leaked handles at shutdown
• EventcoreCFRunLoopDriver: Forces using the CFRunLoop driver (for DUB, use the "cfrunloop" configuration instead)
• EventcoreKqueueDriver: Forces using the kqueue driver (for DUB, use the "kqueue" configuration instead)
• EventcoreWinAPIDriver: Forces using the WinAPI driver (for DUB, use the "winapi" configuration instead)
• EventcoreLibasyncDriver: Forces using the libasync driver (for DUB, use the "libasync" configuration instead)
• EventcoreSelectDriver: Forces using the select driver (for DUB, use the "select" configuration instead)
• EventcoreUseGAIA: Forces using getaddressinfo_a for the epoll driver (for DUB, use the "epoll-gaia" configuration instead)

Debug identifiers

For additional debug output, the following debug identifiers are available. When building with DUB, you can specify them similar to version identifiers, but using the debugVersions directive instead:

• EventCoreLogDNS: Prints detailed information about DNS lookups
• EventCoreLeakTrace: Gathers stack traces when allocating handles to assist in fixing leaked handles
• EventCoreEpollDebug: Outputs epoll event details
• EventCoreLogFiles: Outputs detailed logging for file operations carried out through the threadedfile implementation

Open questions

• Error code reporting
• Enqueued writes
• Use the type system to prohibit passing thread-local handles to foreign threads