pthreads getting you down? libdispatch, aka Grand Central Dispatch (GCD) is Apple's high-performance event-handling library, introduced in OS X Snow Leopard. It provides asynchronous task queues, monitoring of file descriptor read and write-ability, asynchronous I/O (for sockets and regular files), readers-writer locks, parallel for-loops, sane signal handling, periodic timers, semaphores and more. You'll want to read over Apple's API reference.
I've added the ability to integrate libdispatch's main queue with third-party
run-loops, e.g. GLib's GMainLoop. Call
dispatch_get_main_queue_handle_np() to get a file descriptor your run-loop
can monitor for reading; when it becomes readable call
dispatch_main_queue_drain_np() to execute the pending tasks.
I've also added missing _f variants for several functions in data.h and
io.h that took Objective-C blocks
only: look for the functions with _np appended to them. Although you can make
full use of libdispatch with compilers like GCC that don't support blocks, it
is not advisable to build libdispatch itself with anything other than Clang, as
the dispatch i/o portion cannot be built without compiler support for blocks.
On Ubuntu 14.04, the required dependencies are available via apt-get.
sudo apt-get install libblocksruntime-dev libkqueue-dev libpthread-workqueue-dev cmake
git clone git://github.com/nickhutchinson/libdispatch.git && cd libdispatch
mkdir libdispatch-build && cd libdispatch-build
../configure
make
sudo make install
- 2014-10-01 - Dispatch Sources of type
DISPATCH_SOURCE_TYPE_VNODEare unreliable, and should be avoided for now.
ctest -j $(nproc) --output-on-failure
#include <dispatch/dispatch.h>
#include <stdio.h>
static void timer_did_fire(void *context) {
printf("Strawberry fields...\n");
}
int main(int argc, const char *argv[]) {
dispatch_source_t timer = dispatch_source_create(
DISPATCH_SOURCE_TYPE_TIMER, 0, 0, dispatch_get_main_queue());
dispatch_source_set_event_handler_f(timer, timer_did_fire);
dispatch_source_set_timer(timer, DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC,
0.5 * NSEC_PER_SEC);
dispatch_resume(timer);
dispatch_main();
}> clang forever.c -I/usr/local/include -L/usr/local/lib -ldispatch -o forever
> ./forever
Strawberry fields...
Strawberry fields...
Strawberry fields...
Strawberry fields...
[...]
This port was made possible by Mark Heily and others who contributed the
libpthread_workqueue and libkqueue libraries that libdispatch depends on, as
well as numerous portability patches floating around the official libdispatch
mailing list, notably http://lists.macosforge.org/pipermail/libdispatch-dev/2012-August/000676.html.