feat: add blocking step support to http loop

example/blocking.c

@@ -34,5 +34,5 @@ int main() {
   lnm_log_init_global();
   lnm_log_register_stdout(lnm_log_level_debug);
 
-  printf("res = %i\n", lnm_http_loop_run(hl, 8080, 1, 1));
+  printf("res = %i\n", lnm_http_loop_run(hl, 8080, 1, 32));
 }

include/lnm/loop.h

@@ -47,6 +47,7 @@ typedef struct lnm_loop_queue {
   } buf;
   size_t head;
   size_t tail;
+  bool empty;
   pthread_mutex_t mutex;
   pthread_cond_t cond;
 } lnm_loop_queue;

src/_include/lnm/http/loop_internal.h

@@ -8,6 +8,7 @@
 typedef struct lnm_http_step {
   lnm_http_step_fn fn;
   struct lnm_http_step *next;
+  bool blocking;
 } lnm_http_step;
 
 typedef enum lnm_http_route_type {

src/http/lnm_http_loop_process.c

@@ -133,11 +133,19 @@ void lnm_http_loop_process_steps(lnm_http_conn *conn) {
   while ((ctx->cur_step != NULL) && (step != ctx->cur_step)) {
     step = ctx->cur_step;
 
+    if (step->blocking && (conn->state != lnm_loop_state_req_blocking)) {
+      conn->state = lnm_loop_state_req_blocking;
+
+      break;
+    }
+
     switch (step->fn(conn)) {
     case lnm_http_step_err_done:
       ctx->cur_step = ctx->cur_step->next;
       break;
     case lnm_http_step_err_io_needed:
+      // Ensure steps that require more I/O are executed on the event loop
+      conn->state = lnm_loop_state_req;
       break;
     case lnm_http_step_err_close:
       conn->state = lnm_loop_state_end;
@@ -149,6 +157,7 @@ void lnm_http_loop_process_steps(lnm_http_conn *conn) {
   }
 
   if (ctx->cur_step == NULL) {
+    conn->state = lnm_loop_state_res;
     ctx->state = lnm_http_loop_state_add_headers;
   }
 }

src/loop/lnm_loop_worker.c

@@ -1,9 +1,10 @@
 #include <sys/epoll.h>
 
+#include "lnm/log.h"
 #include "lnm/loop.h"
 
 lnm_err lnm_loop_queue_init(lnm_loop_queue **out, size_t cap) {
-  lnm_loop_conn **arr = malloc(cap * sizeof(lnm_loop_conn *));
+  lnm_loop_conn **arr = calloc(cap, sizeof(lnm_loop_conn *));
 
   if (arr == NULL) {
     return lnm_err_failed_alloc;
@@ -20,6 +21,10 @@ lnm_err lnm_loop_queue_init(lnm_loop_queue **out, size_t cap) {
   q->buf.arr = arr;
   q->buf.len = cap;
 
+  q->tail = 0;
+  q->head = 0;
+  q->empty = true;
+
   pthread_mutex_init(&q->mutex, NULL);
   pthread_cond_init(&q->cond, NULL);
 
@@ -31,14 +36,15 @@ lnm_err lnm_loop_queue_init(lnm_loop_queue **out, size_t cap) {
 void lnm_loop_queue_push(lnm_loop_queue *q, lnm_loop_conn *conn) {
   pthread_mutex_lock(&q->mutex);
 
-  while (q->tail == q->head) {
+  while (q->head == q->tail && !q->empty) {
     pthread_cond_wait(&q->cond, &q->mutex);
   }
 
-  q->buf.arr[q->tail] = conn;
+  q->buf.arr[q->head] = conn;
 
   // Make sure the index wraps around
-  q->tail = (q->tail + 1) % q->buf.len;
+  q->head = (q->head + 1) % q->buf.len;
+  q->empty = false;
 
   // Unlock mutex and signal to waiting threads
   pthread_mutex_unlock(&q->mutex);
@@ -48,12 +54,14 @@ void lnm_loop_queue_push(lnm_loop_queue *q, lnm_loop_conn *conn) {
 lnm_loop_conn *lnm_loop_queue_pop(lnm_loop_queue *q) {
   pthread_mutex_lock(&q->mutex);
 
-  while (q->tail == q->head) {
+  while (q->empty) {
     pthread_cond_wait(&q->cond, &q->mutex);
   }
 
-  lnm_loop_conn *out = q->buf.arr[q->head];
+  lnm_loop_conn *out = q->buf.arr[q->tail];
-  q->head = (q->head + 1) % q->buf.len;
+
+  q->tail = (q->tail + 1) % q->buf.len;
+  q->empty = q->tail == q->head;
 
   // Unlock mutex and signal to waiting threads
   pthread_mutex_unlock(&q->mutex);
@@ -66,8 +74,17 @@ void lnm_loop_worker_run(void *arg) {
   lnm_loop *l = arg;
   lnm_loop_queue *q = l->wq;
 
+  // Get thread ID by incrementing counter
+  pthread_mutex_lock(&l->threads.mutex);
+
+  int thread_id = l->threads.worker_count;
+  l->threads.worker_count++;
+
+  pthread_mutex_unlock(&l->threads.mutex);
+
   while (1) {
     lnm_loop_conn *conn = lnm_loop_queue_pop(q);
+    lnm_ldebug("loop", "worker %i processing fd %i", thread_id, conn->fd);
 
     switch (conn->state) {
     case lnm_loop_state_req_blocking: