IPC: Inform the scheduler the process is waiting for a IPC message

4 files changed, 19 insertions, 1 deletions

diff --git a/kernel/cpu/int_syscall.s b/kernel/cpu/int_syscall.s
index b2c0de9..bda7312 100644
--- a/kernel/cpu/int_syscall.s
+++ b/kernel/cpu/int_syscall.s
@@ -2,6 +2,7 @@
 .global int_syscall
 .extern syscall_functions
 int_syscall:
+sti
 push   ebp
 mov    ebp,esp
 push   edi
diff --git a/kernel/ipc.c b/kernel/ipc.c
index bce346a..eb7c1b7 100644
--- a/kernel/ipc.c
+++ b/kernel/ipc.c
@@ -2,7 +2,6 @@
 #include <interrupts.h>
 #include <ipc.h>
 #include <math.h>
-#include <sched/scheduler.h>
 #include <stdbool.h>
 #include <string.h>
 
@@ -45,6 +44,16 @@ int ipc_get_mailbox(u32 id, struct IpcMailbox **out) {
   return 1;
 }
 
+int ipc_has_data(process_t *p) {
+  if (!p) {
+    p = get_current_task();
+  }
+  struct IpcMailbox *handler = &p->ipc_mailbox;
+  u32 read_ptr = handler->read_ptr;
+  struct IpcMessage *ipc_message = &handler->data[read_ptr];
+  return ipc_message->is_used;
+}
+
 int ipc_read(u8 *buffer, u32 length, u32 *sender_pid) {
   struct IpcMailbox *handler = &get_current_task()->ipc_mailbox;
 
diff --git a/kernel/ipc.h b/kernel/ipc.h
index ae67f71..d8db074 100644
--- a/kernel/ipc.h
+++ b/kernel/ipc.h
@@ -1,3 +1,4 @@
+#include <sched/scheduler.h>
 #ifndef IPC_H
 #define IPC_H
 #include <stdbool.h>
@@ -23,4 +24,5 @@ bool ipc_register_endpoint(u32 endpoint);
 int ipc_write_to_process(int pid, u8 *buffer, u32 length);
 int ipc_write(int ipc_id, u8 *buffer, u32 length);
 int ipc_read(u8 *buffer, u32 length, u32 *sender_pid);
+int ipc_has_data(process_t *p);
 #endif
diff --git a/kernel/sched/scheduler.c b/kernel/sched/scheduler.c
index e34e7a7..949cdf2 100644
--- a/kernel/sched/scheduler.c
+++ b/kernel/sched/scheduler.c
@@ -373,6 +373,12 @@ int is_halted(process_t *process) {
     }
   }
 
+  if (process->is_halted) {
+    if (ipc_has_data(process)) {
+      return 0;
+    }
+  }
+
   if (isset_fdhalt(process)) {
     return 1;
   }