From e5a06859c52530cb2fedd41f3e26b29c1b150cb2 Mon Sep 17 00:00:00 2001
From: jewelcodes <omarmelghoul01@gmail.com>
Date: Sat, 7 Sep 2024 10:52:26 -0400
Subject: [PATCH] syscalls: allow for blocking syscalls

---
 src/include/kernel/syscalls.h |  2 +-
 src/syscalls/dispatch.c       | 10 +++++++++-
 src/syscalls/queue.c          |  2 +-
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/include/kernel/syscalls.h b/src/include/kernel/syscalls.h
index 6cf90a4..2f5d7d6 100644
--- a/src/include/kernel/syscalls.h
+++ b/src/include/kernel/syscalls.h
@@ -14,7 +14,7 @@
 #define MAX_SYSCALL                     12       // for now
 
 typedef struct SyscallRequest {
-    bool busy, queued;
+    bool busy, queued, unblock;
 
     uint64_t function;
     uint64_t params[4];
diff --git a/src/syscalls/dispatch.c b/src/syscalls/dispatch.c
index 32f2811..d680fb2 100644
--- a/src/syscalls/dispatch.c
+++ b/src/syscalls/dispatch.c
@@ -20,18 +20,22 @@ void syscallDispatchExit(SyscallRequest *req) {
 
 void syscallDispatchFork(SyscallRequest *req) {
     req->ret = fork(req->thread);
+    req->unblock = true;
 }
 
 void syscallDispatchYield(SyscallRequest *req) {
     req->ret = yield(req->thread);
+    req->unblock = true;
 }
 
 void syscallDispatchGetPID(SyscallRequest *req) {
     req->ret = req->thread->pid;
+    req->unblock = true;
 }
 
 void syscallDispatchGetTID(SyscallRequest *req) {
     req->ret = req->thread->tid;
+    req->unblock = true;
 }
 
 void syscallDispatchGetUID(SyscallRequest *req) {
@@ -42,6 +46,8 @@ void syscallDispatchGetUID(SyscallRequest *req) {
     } else {
         req->ret = p->user;
     }
+
+    req->unblock = true;
 }
 
 void syscallDispatchGetGID(SyscallRequest *req) {
@@ -52,6 +58,8 @@ void syscallDispatchGetGID(SyscallRequest *req) {
     } else {
         req->ret = p->group;
     }
+
+    req->unblock = true;
 }
 
 void syscallDispatchMSleep(SyscallRequest *req) {
@@ -59,7 +67,7 @@ void syscallDispatchMSleep(SyscallRequest *req) {
 }
 
 void (*syscallDispatchTable[])(SyscallRequest *) = {
-    // group 1: scheduler functions
+    /* group 1: scheduler functions */
     syscallDispatchExit,        // 0 - exit()
     syscallDispatchFork,        // 1 - fork()
     syscallDispatchYield,       // 2 - yield()
diff --git a/src/syscalls/queue.c b/src/syscalls/queue.c
index f6b75e6..e626980 100644
--- a/src/syscalls/queue.c
+++ b/src/syscalls/queue.c
@@ -96,7 +96,7 @@ int syscallProcess() {
         platformSetContextStatus(syscall->thread->context, syscall->ret);
     }
 
-    if(syscall->thread->status == THREAD_BLOCKED) {
+    if((syscall->thread->status == THREAD_BLOCKED) && syscall->unblock) {
         // this way we prevent accidentally running threads that exit()
         syscall->thread->status = THREAD_QUEUED;
         syscall->thread->time = schedTimeslice(syscall->thread, syscall->thread->priority);