From 7f7d415fa3ee369e88ec1c292110ee7d44f074af Mon Sep 17 00:00:00 2001
From: Baptiste Wicht <baptiste.wicht@gmail.com>
Date: Sun, 7 Aug 2016 12:41:48 +0200
Subject: [PATCH] Fix terrible scheduling bug

A process could enter ready state and continue running with it
---
 kernel/include/scheduler.hpp |  1 +
 kernel/src/scheduler.cpp     | 16 +++++++++++-----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/kernel/include/scheduler.hpp b/kernel/include/scheduler.hpp
index ad5bb54b..7d96bb69 100644
--- a/kernel/include/scheduler.hpp
+++ b/kernel/include/scheduler.hpp
@@ -19,6 +19,7 @@ constexpr const size_t MAX_PROCESS = 128;
 
 pid_t get_pid();
 scheduler::process_t& get_process(pid_t pid);
+scheduler::process_state get_process_state(pid_t pid);
 
 void block_process(pid_t pid);
 void unblock_process(pid_t pid);
diff --git a/kernel/src/scheduler.cpp b/kernel/src/scheduler.cpp
index 427617c9..4ae9a6e5 100644
--- a/kernel/src/scheduler.cpp
+++ b/kernel/src/scheduler.cpp
@@ -280,7 +280,8 @@ void switch_to_process(size_t pid){
     auto old_pid = current_pid;
     current_pid = pid;
 
-    auto& process = pcb[current_pid];
+    auto& process = pcb[pid];
+    process.state = scheduler::process_state::RUNNING;
 
     if(process.process.system){
         logging::logf(logging::log_level::DEBUG, "Switch from %u to %u (rip:%u)\n", old_pid, current_pid, process.process.context->rip);
@@ -288,8 +289,6 @@ void switch_to_process(size_t pid){
         logging::logf(logging::log_level::DEBUG, "Switch from %u to %u\n", old_pid, current_pid);
     }
 
-    process.state = scheduler::process_state::RUNNING;
-
     gdt::tss().rsp0_low = process.process.kernel_rsp & 0xFFFFFFFF;
     gdt::tss().rsp0_high = process.process.kernel_rsp >> 32;
 
@@ -762,6 +761,7 @@ void scheduler::tick(){
             --process.sleep_timeout;
 
             if(process.sleep_timeout == 0){
+                logging::logf(logging::log_level::DEBUG, "Process %u finished sleeping, is ready\n", process.process.pid);
                 process.state = process_state::READY;
             }
         }
@@ -779,6 +779,7 @@ void scheduler::tick(){
 
             //If it is the same, no need to go to the switching process
             if(pid == current_pid){
+                process.state = process_state::RUNNING;
                 return;
             }
 
@@ -818,6 +819,12 @@ scheduler::process_t& scheduler::get_process(pid_t pid){
     return pcb[pid].process;
 }
 
+scheduler::process_state scheduler::get_process_state(pid_t pid){
+    thor_assert(pid < scheduler::MAX_PROCESS, "pid out of bounds");
+
+    return pcb[pid].state;
+}
+
 void scheduler::block_process_light(pid_t pid){
     thor_assert(pid < scheduler::MAX_PROCESS, "pid out of bounds");
 
@@ -850,8 +857,7 @@ void scheduler::unblock_process(pid_t pid){
 }
 
 void scheduler::sleep_ms(size_t time){
-    auto pid = get_pid();
-    sleep_ms(pid, time);
+    sleep_ms(current_pid, time);
 }
 
 void scheduler::sleep_ms(pid_t pid, size_t time){