syscalls: start trying to add nanosleep syscall

include/task.h

@@ -70,6 +70,7 @@ typedef struct Process
     void* brk;
 
     uint32_t kstack_top;
+    size_t wake_up_time;//wake up time in ticks of the processor, gets set by nanosleep syscall
 } Process;
 
 extern Process* current;

src/kernel/apic.c

@@ -153,7 +153,7 @@ void init_apic_timer()
    lapic_write(APIC_REGISTER_TIMER_DIV, 0x3);
  
    // Prepare the PIT to sleep for 10ms (10000µs)
-   init_pit_timer_apic(1000);
+   init_pit_timer_apic(10000);
 
    __asm__ __volatile__ ("sti");
 

src/tasking/syscalls.c

@@ -7,6 +7,10 @@
 #include "../include/screen.h"
 #include "../include/fat.h"
 #include "../include/vfs.h"
+#include "../include/isr.h"
+#include "../include/task.h"
+
+extern void switchProcess(Process* next);
 
 #define STDIN_FILENO 0
 #define STDOUT_FILENO 1
@@ -299,6 +303,26 @@ uint32_t sys_brk(TrapFrame *tf)
     return (uint32_t)current->brk;
 }
 
+typedef struct timespec {
+    int32_t tv_sec;  // seconds
+    int32_t tv_nsec; // nanoseconds
+} timespec;
+
+uint32_t sys_nanosleep(TrapFrame *tf)
+{
+    timespec* duration = (timespec*)tf->ebx;
+    size_t ms = duration->tv_sec * 1000 + duration->tv_nsec / 1000000;
+    //debug_log("waiting for 0x%X ms\n", ms);
+    size_t start_time = timer_ticks;
+
+    current->wake_up_time = timer_ticks + ms;
+    //debug_log("setting wake up time to %X (current time is %X)\n", current->wake_up_time, timer_ticks);
+    
+    //TODO: find a way to call the scheduler from here without fucking shit up
+    
+    return 0;
+}
+
 void handle_syscall(TrapFrame *tf)
 {
     /*
@@ -347,6 +371,10 @@ void handle_syscall(TrapFrame *tf)
         case 0x2d://brk
             tf->eax = sys_brk(tf);
             break;
+        
+        case 0xa2://nanosleep
+            tf->eax = sys_nanosleep(tf);
+            break;
 
         default:
             debug_log("unknown syscall: %X\n", tf->eax);

src/tasking/task.c

@@ -4,6 +4,7 @@
 #include "../include/string.h"
 #include "../include/liballoc.h"
 #include "../include/gdt.h"
+#include "../include/isr.h"
 
 #include <stddef.h>
 
@@ -67,6 +68,8 @@ Process* task_create(uint32_t func, uint32_t user_esp, uint32_t ring, uint32_t*
     p->context->eip = (uint32_t)trapret;
     p->kesp = (uint32_t)sp;
 
+    p->wake_up_time = 0;
+
     p->next = 0;
 
     if (!queue) {
@@ -133,6 +136,11 @@ void schedule() {
         current = queue; // Start search from the beginning
     }
 
+    if(current->wake_up_time > timer_ticks)
+    {
+        current = queue;
+    }
+
     // Find the next ready process to run
     Process* next = current ? current->next : NULL;
     if (!next) next = queue;