Async working (in concept)

src/async.c

@@ -1,12 +1,18 @@
+/**
+ * Sesimos - secure, simple, modern web server
+ * @brief Async handler
+ * @file src/async.c
+ * @author Lorenz Stechauner
+ * @date 2022-12-28
+ */
 
-
+#include "async.h"
 #include "logger.h"
 
-#include <stdio.h>
 #include <poll.h>
 #include <signal.h>
 #include <errno.h>
-
+#include <memory.h>
 
 typedef struct {
     int fd;
@@ -23,21 +29,31 @@ typedef struct {
     evt_listen_t q[256];
 } listen_queue_t;
 
+static listen_queue_t listen1, listen2, *listen = &listen1;
+static volatile sig_atomic_t alive = 1;
 
-static listen_queue_t listen1;
-static listen_queue_t listen2;
-listen_queue_t *listen = &listen1;
+static int async_add_to_queue(evt_listen_t *evt) {
+    // TODO locking
+    memcpy(&listen->q[listen->n++], evt, sizeof(*evt));
+    return 0;
+}
 
-volatile sig_atomic_t alive = 1;
-
-int async(int fd, int events, int flags, void (*cb)(void *), void *arg, void (*err_cb)(void *), void *err_arg) {
-    return -1;
+int async(int fd, short events, int flags, void cb(void *), void *arg, void err_cb(void *), void *err_arg) {
+    evt_listen_t evt = {
+            .fd = fd,
+            .events = events,
+            .flags = flags,
+            .cb = cb,
+            .arg = arg,
+            .err_cb = err_cb,
+            .err_arg = err_arg,
+    };
+    return async_add_to_queue(&evt);
 }
 
 void async_thread(void) {
-
-    int num_fds = 0;
-    struct pollfd fds[256];
+    int num_fds;
+    struct pollfd fds[256];  // TODO dynamic
 
     // main event loop
     while (alive) {
@@ -45,17 +61,15 @@ void async_thread(void) {
         listen_queue_t *l = listen;
         listen = (listen == &listen1) ? &listen2 : &listen1;
 
-        // fill fds with newly added
-        for (int i = 0; i < l->n; i++, num_fds++) {
-            fds[num_fds].fd = l->q[i].fd;
-            fds[num_fds].events = l->q[i].events;
+        // fill fds with newly added queue entries
+        for (num_fds = 0; num_fds < l->n; num_fds++) {
+            fds[num_fds].fd = l->q[num_fds].fd;
+            fds[num_fds].events = l->q[num_fds].events;
         }
 
-        int ready_fds = poll(fds, num_fds, -1);
-        if (ready_fds < 0) {
+        if (poll(fds, num_fds, -1) < 0) {
             if (errno == EINTR) {
                 // interrupt
-                continue;
             } else {
                 // other error
                 critical("Unable to poll for events");
@@ -64,7 +78,26 @@ void async_thread(void) {
         }
 
         for (int i = 0; i < num_fds; i++) {
-            // TODO
+            evt_listen_t *e = &l->q[i];
+            if (fds[i].revents & e->events) {
+                // specified event(s) occurred
+                e->cb(e->arg);
+
+                if (e->flags & ASYNC_KEEP)
+                    async_add_to_queue(e);
+            } else if (fds[i].revents & (POLLERR | POLLHUP | POLLNVAL)) {
+                // error occurred
+                e->err_cb(e->err_arg);
+            } else {
+                // no event occurred
+                async_add_to_queue(e);
+            }
+
+            // reset errno to prevent strange behaviour
+            errno = 0;
         }
+
+        // reset size of queue
+        l->n = 0;
     }
 }