From 3922adcdec5bd003b4106ffce79c28553bc40c15 Mon Sep 17 00:00:00 2001
From: Anton Kling <anton@kling.gg>
Date: Wed, 14 Feb 2024 17:40:06 +0100
Subject: Kernel: Update signal handling and IPC

---
 kernel/sched/scheduler.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/sched/scheduler.h | 17 ++++++++++++++
 2 files changed, 77 insertions(+)

(limited to 'kernel/sched')

diff --git a/kernel/sched/scheduler.c b/kernel/sched/scheduler.c
index 8019e5a..505dbd8 100644
--- a/kernel/sched/scheduler.c
+++ b/kernel/sched/scheduler.c
@@ -26,6 +26,66 @@ process_t *get_current_task(void) {
   return current_task;
 }
 
+void process_push_restore_context(process_t *p, reg_t r) {
+  if (!p) {
+    p = current_task;
+  }
+  reg_t *new_r = kmalloc(sizeof(reg_t));
+  memcpy(new_r, &r, sizeof(reg_t));
+  stack_push(&p->restore_context_stack, new_r);
+  return;
+}
+
+void process_pop_restore_context(process_t *p, reg_t *out_r) {
+  if (!p) {
+    p = current_task;
+  }
+  reg_t *r = stack_pop(&p->restore_context_stack);
+  if (NULL == r) {
+    assert(NULL);
+  }
+  memcpy(out_r, r, sizeof(reg_t));
+  kfree(r);
+}
+
+void process_push_signal(process_t *p, signal_t s) {
+  if (!p) {
+    p = current_task;
+  }
+
+  int index = -1;
+  for (int i = 0; i < 100; i++) {
+    const signal_t *s = p->active_signals[i];
+    if (!s) {
+      index = i;
+      break;
+    }
+  }
+  if (-1 == index) {
+    assert(0);
+    return;
+  }
+  signal_t *new_signal_entry = kmalloc(sizeof(signal_t));
+  memcpy(new_signal_entry, &s, sizeof(signal_t));
+  p->active_signals[index] = new_signal_entry;
+}
+
+const signal_t *process_pop_signal(process_t *p) {
+  if (!p) {
+    p = current_task;
+  }
+
+  for (int i = 0; i < 100; i++) {
+    const signal_t *s = p->active_signals[i];
+    if (!s) {
+      continue;
+    }
+    p->active_signals[i] = NULL;
+    return s;
+  }
+  return NULL;
+}
+
 bool get_task_from_pid(u32 pid, process_t **out) {
   for (process_t *tmp = ready_queue; tmp; tmp = tmp->next) {
     if (tmp->pid == pid) {
diff --git a/kernel/sched/scheduler.h b/kernel/sched/scheduler.h
index 01276dc..f73d8ef 100644
--- a/kernel/sched/scheduler.h
+++ b/kernel/sched/scheduler.h
@@ -4,6 +4,7 @@
 #include <fs/vfs.h>
 #include <halts.h>
 #include <ipc.h>
+#include <lib/stack.h>
 #include <mmu.h>
 #include <signal.h>
 #include <stdbool.h>
@@ -32,6 +33,10 @@ typedef struct {
   int fd;
 } MemoryMap;
 
+typedef struct {
+  uintptr_t handler_ip;
+} signal_t;
+
 typedef struct Process process_t;
 
 typedef struct TCB {
@@ -40,6 +45,11 @@ typedef struct TCB {
   uint32_t ESP0;
 } __attribute__((packed)) TCB;
 
+void process_push_restore_context(process_t *p, reg_t r);
+void process_pop_restore_context(process_t *p, reg_t *out_r);
+void process_push_signal(process_t *p, signal_t s);
+const signal_t *process_pop_signal(process_t *p);
+
 struct Process {
   u32 pid;
   char program_name[100];
@@ -57,6 +67,13 @@ struct Process {
   vfs_inode_t *read_halt_inode[100];
   vfs_inode_t *write_halt_inode[100];
   vfs_inode_t *disconnect_halt_inode[100];
+
+  //  // FIXME: Make this a array or circular buffer
+  //  reg_t restore_context;
+  struct stack restore_context_stack;
+
+  signal_t *active_signals[100];
+
   u32 halts[2];
   struct Halt *halt_list;
   void *data_segment_end;
-- 
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