feat(sys): reimplement ngx_event_t macros and inline methods

Bindgen does not support functional macros or inline functions, so we
have to maintain a copy of the implementation for any such item we need
to use.

Author: bavshin-f5

examples/async.rs

@@ -8,7 +8,7 @@ use ngx::core;
 use ngx::ffi::{
     ngx_array_push, ngx_command_t, ngx_conf_t, ngx_cycle, ngx_event_t, ngx_http_core_module, ngx_http_core_run_phases,
     ngx_http_handler_pt, ngx_http_module_t, ngx_http_phases_NGX_HTTP_ACCESS_PHASE, ngx_http_request_t, ngx_int_t,
-    ngx_module_t, ngx_posted_events, ngx_queue_s, ngx_str_t, ngx_uint_t, NGX_CONF_TAKE1, NGX_HTTP_LOC_CONF,
+    ngx_module_t, ngx_post_event, ngx_posted_events, ngx_str_t, ngx_uint_t, NGX_CONF_TAKE1, NGX_HTTP_LOC_CONF,
     NGX_HTTP_LOC_CONF_OFFSET, NGX_HTTP_MODULE,
 };
 use ngx::http::{self, HTTPModule, MergeConfigError};
@@ -112,7 +112,7 @@ unsafe extern "C" fn check_async_work_done(event: *mut ngx_event_t) {
         // this doesn't have have good performance but works as a simple thread-safe example and doesn't causes
         // segfault. The best method that provides both thread-safety and performance requires
         // an nginx patch.
-        post_event(event, addr_of_mut!(ngx_posted_events));
+        ngx_post_event(event, addr_of_mut!(ngx_posted_events));
     }
 }
 
@@ -128,20 +128,6 @@ struct EventData {
 unsafe impl Send for EventData {}
 unsafe impl Sync for EventData {}
 
-// same as ngx_post_event
-// source: https://github.com/nginx/ngx-rust/pull/31/files#diff-132330bb775bed17fb9990ec2b56e6c52e6a9e56d62f2114fade95e4decdba08R80-R90
-unsafe fn post_event(event: *mut ngx_event_t, queue: *mut ngx_queue_s) {
-    let event = &mut (*event);
-    if event.posted() == 0 {
-        event.set_posted(1);
-        // translated from ngx_queue_insert_tail macro
-        event.queue.prev = (*queue).prev;
-        (*event.queue.prev).next = &event.queue as *const _ as *mut _;
-        event.queue.next = queue;
-        (*queue).prev = &event.queue as *const _ as *mut _;
-    }
-}
-
 http_request_handler!(async_access_handler, |request: &mut http::Request| {
     let co = unsafe { request.get_module_loc_conf::<ModuleConfig>(&*addr_of!(ngx_http_async_module)) };
     let co = co.expect("module config is none");
@@ -184,7 +170,7 @@ http_request_handler!(async_access_handler, |request: &mut http::Request| {
         event.data = Arc::into_raw(event_data.clone()) as _;
         event.log = (*ngx_cycle).log;
 
-        post_event(event, addr_of_mut!(ngx_posted_events));
+        ngx_post_event(event, addr_of_mut!(ngx_posted_events));
     }
 
     ngx_log_debug_http!(request, "async module enabled: {}", co.enable);

nginx-sys/src/event.rs

@@ -0,0 +1,83 @@
+use core::ptr;
+
+use crate::{
+    ngx_current_msec, ngx_event_t, ngx_event_timer_rbtree, ngx_msec_t, ngx_queue_insert_before, ngx_queue_remove,
+    ngx_queue_t, ngx_rbtree_delete, ngx_rbtree_insert, NGX_TIMER_LAZY_DELAY,
+};
+
+/// Sets a timeout for an event.
+///
+/// # Safety
+///
+///`ev` must be a valid pointer to an `ngx_event_t`.
+#[inline]
+pub unsafe fn ngx_add_timer(ev: *mut ngx_event_t, timer: ngx_msec_t) {
+    let key: ngx_msec_t = ngx_current_msec.wrapping_add(timer);
+
+    if (*ev).timer_set() != 0 {
+        /*
+         * Use a previous timer value if difference between it and a new
+         * value is less than NGX_TIMER_LAZY_DELAY milliseconds: this allows
+         * to minimize the rbtree operations for fast connections.
+         */
+        if key.abs_diff((*ev).timer.key) < NGX_TIMER_LAZY_DELAY as _ {
+            return;
+        }
+
+        ngx_del_timer(ev);
+    }
+
+    (*ev).timer.key = key;
+
+    ngx_rbtree_insert(
+        ptr::addr_of_mut!(ngx_event_timer_rbtree),
+        ptr::addr_of_mut!((*ev).timer),
+    );
+
+    (*ev).set_timer_set(1);
+}
+
+/// Deletes a previously set timeout.
+///
+/// # Safety
+///
+/// `ev` must be a valid pointer to an `ngx_event_t`, previously armed with [ngx_add_timer].
+#[inline]
+pub unsafe fn ngx_del_timer(ev: *mut ngx_event_t) {
+    ngx_rbtree_delete(
+        ptr::addr_of_mut!(ngx_event_timer_rbtree),
+        ptr::addr_of_mut!((*ev).timer),
+    );
+
+    (*ev).timer.left = ptr::null_mut();
+    (*ev).timer.right = ptr::null_mut();
+    (*ev).timer.parent = ptr::null_mut();
+
+    (*ev).set_timer_set(0);
+}
+
+/// Post the event `ev` to the post queue `q`.
+///
+/// # Safety
+///
+/// `ev` must be a valid pointer to an `ngx_event_t`.
+/// `q` is a valid pointer to a queue head.
+#[inline]
+pub unsafe fn ngx_post_event(ev: *mut ngx_event_t, q: *mut ngx_queue_t) {
+    if (*ev).posted() == 0 {
+        (*ev).set_posted(1);
+        ngx_queue_insert_before(q, ptr::addr_of_mut!((*ev).queue));
+    }
+}
+
+/// Deletes the event `ev` from the queue it's currently posted in.
+///
+/// # Safety
+///
+/// `ev` must be a valid pointer to an `ngx_event_t`.
+/// `ev.queue` is initialized with `ngx_queue_init`.
+#[inline]
+pub unsafe fn ngx_delete_posted_event(ev: *mut ngx_event_t) {
+    (*ev).set_posted(0);
+    ngx_queue_remove(ptr::addr_of_mut!((*ev).queue));
+}

nginx-sys/src/lib.rs

@@ -2,6 +2,7 @@
 #![warn(missing_docs)]
 #![no_std]
 
+mod event;
 mod queue;
 
 use core::fmt;
@@ -24,6 +25,7 @@ mod bindings {
 #[doc(no_inline)]
 pub use bindings::*;
 
+pub use event::*;
 pub use queue::*;
 
 /// The offset of the `main_conf` field in the `ngx_http_conf_ctx_t` struct.