From 44ec7317a134e84c948f439903c83ada3857ffc4 Mon Sep 17 00:00:00 2001
From: Abdelrahman Said <said.abdelrahman89@gmail.com>
Date: Sun, 26 Jan 2025 18:13:36 +0000
Subject: [PATCH] Calculate internal system id to be stored in events

---
 src/event_system.c | 21 +++++++++++++++++----
 src/event_system.h |  1 +
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/event_system.c b/src/event_system.c
index 00ea014..07ef10a 100644
--- a/src/event_system.c
+++ b/src/event_system.c
@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdbool.h>
+#include <time.h>
 #include <sys/mman.h>
 
 #define MAGIC 0x4556535953
@@ -23,6 +24,7 @@
 typedef struct es_internal ESInternal;
 struct es_internal {
   u64  magic;
+  u64  id;
   u64  alloc_size;
   u64  event_capacity;
   u64  event_count;
@@ -57,7 +59,14 @@ internal EventInternal *get_event(const ESInternal *es, Event event);
 internal EventInternal *get_event_from_offset(const ESInternal *es, u64 offset);
 internal u64           get_largest_capacity(const ESInternal *es);
 
+internal bool seeded = false;
+
 EventSystem es_init(u64 initial_event_capacity, u64 initial_listeners_capacity) {
+  if (!seeded) {
+    srand(time(0));
+    seeded = true;
+  }
+
   // Double event capacity to reduce chances of reallocation
   u64 event_capacity     = initial_event_capacity * 2;
   // Double listener capacity to reduce chances of reallocation
@@ -92,6 +101,7 @@ EventSystem es_init(u64 initial_event_capacity, u64 initial_listeners_capacity)
   ESInternal *event_system = (ESInternal *)buffer;
 
   event_system->magic                     = MAGIC;
+  event_system->id                        = (u64)time(0) + (u64)rand();
   event_system->alloc_size                = alloc_size;
   event_system->event_capacity            = event_capacity;
   event_system->event_count               = 0;
@@ -166,6 +176,7 @@ Event es_register_event(EventSystem *event_system) {
     EventSystem event_system_new = es_init(es->event_capacity, new_callback_capacity);
     ESInternal  *es_new          = get_event_system_internal(event_system_new);
 
+    es_new->id          = es->id;
     es_new->event_count = es->event_count;
 
     copy_event_data(es, es_new);
@@ -175,7 +186,9 @@ Event es_register_event(EventSystem *event_system) {
     es = es_new;
   }
 
-  event.id = ++(es->event_count);
+  event.id     = ++(es->event_count);
+  event.system = es->id;
+
   event_slots_array[event.id].registered = true;
 
 RETURN_EVENT:
@@ -188,7 +201,7 @@ void es_deregister_event(EventSystem event_system, Event *event) {
   }
 
   ESInternal *es = get_event_system_internal(event_system);
-  if (!VALID_MAGIC(es) || event->id > es->event_count) {
+  if (!VALID_MAGIC(es) || event->system != es->id || event->id > es->event_count) {
     return;
   }
 
@@ -213,7 +226,7 @@ EventListener es_add_event_listener(EventSystem *event_system, Event event, Even
   }
 
   ESInternal *es = get_event_system_internal(*event_system);
-  if (!VALID_MAGIC(es)) {
+  if (!VALID_MAGIC(es) || event.system != es->id) {
     goto RETURN_LISTENER;
   }
 
@@ -281,7 +294,7 @@ void es_emit_event(EventSystem event_system, Event event, void *data) {
   }
 
   ESInternal *es = get_event_system_internal(event_system);
-  if (!VALID_MAGIC(es) || event.id > es->event_count) {
+  if (!VALID_MAGIC(es) || event.system != es->id || event.id > es->event_count) {
     return;
   }
 
diff --git a/src/event_system.h b/src/event_system.h
index adebbdc..6c18be4 100644
--- a/src/event_system.h
+++ b/src/event_system.h
@@ -10,6 +10,7 @@ struct event_system {
 typedef struct event Event;
 struct event {
   u64 id;
+  u64 system;
 };
 
 typedef struct event_listener EventListener;