Example app.

example.c

@@ -0,0 +1,63 @@
+#include <assert.h>
+#include <netdb.h>
+#include <stdlib.h>
+#include <sys/epoll.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include "asyncaddrinfo.h"
+
+int main(int argc, char *argv[]) {
+	asyncaddrinfo_init(2);
+
+	// These will run in parallel. You can still queue more lookups; they'll run 
+	// on the first available thread.
+	int fd1 = asyncaddrinfo_resolve("github.com", "https", NULL);
+	assert(fd1 >= 0);
+	int fd2 = asyncaddrinfo_resolve("google.com", "https", NULL);
+	assert(fd2 >= 0);
+
+	// This thread continues while lookups run in parallel.
+
+	// We use epoll here, but you could use poll, select, or just call
+	// asyncaddrinfo_result() and block. You could also use an event loop library
+	// like libevent.
+	int epoll_fd = epoll_create1(0);
+	assert(epoll_fd >= 0);
+
+	struct epoll_event ev = {
+		.events = EPOLLIN,
+	};
+	
+	// See epoll_ctl(2) for details on how to attach pointers to application data.
+	ev.data.fd = fd1;
+	assert(!epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd1, &ev));
+
+	ev.data.fd = fd2;
+	assert(!epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd2, &ev));
+
+
+	int max_events = 2;
+	while (max_events) {
+		struct epoll_event events[max_events];
+		int num_events = epoll_wait(epoll_fd, events, max_events, -1);
+		assert(num_events > 0);
+		for (int i = 0; i < num_events; i++) {
+			struct addrinfo *addrs;
+			int err = asyncaddrinfo_result(events[i].data.fd, &addrs);
+			if (err) {
+				// Error; see gai_strerror(err)
+			} else {
+				// Success; see addrs
+				freeaddrinfo(addrs);
+			}
+			max_events--;
+		}
+	}
+
+	assert(!close(epoll_fd));
+	// asyncaddrinfo_result() closes the fds opened by asyncaddrinfo_resolve()
+
+	asyncaddrinfo_cleanup();
+}