From c31c499372a59c9ff602c58ad5a209192a02c16e Mon Sep 17 00:00:00 2001
From: matt335672 <30179339+matt335672@users.noreply.github.com>
Date: Tue, 7 Oct 2025 11:58:35 +0100
Subject: [PATCH] os_calls: Add NULL_WAIT_OBJ

The wait_obj calls (mostly) ignore objects with a value of zero. This
is codified, so that user code can explicitly make use of this.
---
 common/os_calls.c | 14 +++++++-------
 common/os_calls.h |  5 +++++
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/common/os_calls.c b/common/os_calls.c
index 566e9422..350a4136 100644
--- a/common/os_calls.c
+++ b/common/os_calls.c
@@ -1855,7 +1855,7 @@ g_delete_wait_obj_from_socket(tintptr wait_obj)
 {
 #ifdef _WIN32
 
-    if (wait_obj == 0)
+    if (wait_obj == NULL_WAIT_OBJ)
     {
         return;
     }
@@ -1879,7 +1879,7 @@ g_set_wait_obj(tintptr obj)
     int to_write;
     char buf[4] = "sig";
 
-    if (obj == 0)
+    if (obj == NULL_WAIT_OBJ)
     {
         return 0;
     }
@@ -1928,7 +1928,7 @@ int
 g_reset_wait_obj(tintptr obj)
 {
 #ifdef _WIN32
-    if (obj == 0)
+    if (obj == NULL_WAIT_OBJ)
     {
         return 0;
     }
@@ -1939,7 +1939,7 @@ g_reset_wait_obj(tintptr obj)
     int error;
     int fd;
 
-    if (obj == 0)
+    if (obj == NULL_WAIT_OBJ)
     {
         return 0;
     }
@@ -1975,7 +1975,7 @@ int
 g_is_wait_obj_set(tintptr obj)
 {
 #ifdef _WIN32
-    if (obj == 0)
+    if (obj == NULL_WAIT_OBJ)
     {
         return 0;
     }
@@ -1985,7 +1985,7 @@ g_is_wait_obj_set(tintptr obj)
     }
     return 0;
 #else
-    if (obj == 0)
+    if (obj == NULL_WAIT_OBJ)
     {
         return 0;
     }
@@ -1999,7 +1999,7 @@ int
 g_delete_wait_obj(tintptr obj)
 {
 #ifdef _WIN32
-    if (obj == 0)
+    if (obj == NULL_WAIT_OBJ)
     {
         return 0;
     }
diff --git a/common/os_calls.h b/common/os_calls.h
index bb69f9aa..5e536187 100644
--- a/common/os_calls.h
+++ b/common/os_calls.h
@@ -198,6 +198,11 @@ g_sck_get_peer_description(int sck,
 void     g_sleep(int msecs);
 int      g_pipe(int fd[2]);
 
+// Wait objects with this value are ignored by
+// g_set_wait_obj() / g_reset_wait_obj() / g_is_wait_obj_set() /
+// g_delete_wait_obj()
+#define NULL_WAIT_OBJ (tintptr)0
+
 tintptr  g_create_wait_obj(const char *name);
 tintptr  g_create_wait_obj_from_socket(tintptr socket, int write);
 void     g_delete_wait_obj_from_socket(tintptr wait_obj);