From 9901f95d78a689c2ab347d6bf12de85570ed16dc Mon Sep 17 00:00:00 2001
From: Bananymous <bananymousosq@gmail.com>
Date: Mon, 4 Sep 2023 12:58:25 +0300
Subject: [PATCH] Kernel: Add basic nanosleep, only millisecond percision

---
 kernel/include/kernel/Process.h | 1 +
 kernel/kernel/Process.cpp       | 7 +++++++
 kernel/kernel/Syscall.cpp       | 3 +++
 libc/include/sys/syscall.h      | 1 +
 libc/time.cpp                   | 5 +++++
 5 files changed, 17 insertions(+)

diff --git a/kernel/include/kernel/Process.h b/kernel/include/kernel/Process.h
index 2a808fa409..a77c97594d 100644
--- a/kernel/include/kernel/Process.h
+++ b/kernel/include/kernel/Process.h
@@ -68,6 +68,7 @@ namespace Kernel
 
 		BAN::ErrorOr<long> sys_wait(pid_t pid, int* stat_loc, int options);
 		BAN::ErrorOr<long> sys_sleep(int seconds);
+		BAN::ErrorOr<long> sys_nanosleep(const timespec* rqtp, timespec* rmtp);
 
 		BAN::ErrorOr<long> sys_setenvp(char** envp);
 
diff --git a/kernel/kernel/Process.cpp b/kernel/kernel/Process.cpp
index 9bafe0cfa5..99d4bbebe1 100644
--- a/kernel/kernel/Process.cpp
+++ b/kernel/kernel/Process.cpp
@@ -529,6 +529,13 @@ namespace Kernel
 		return 0;
 	}
 
+	BAN::ErrorOr<long> Process::sys_nanosleep(const timespec* rqtp, timespec* rmtp)
+	{
+		(void)rmtp;
+		SystemTimer::get().sleep(rqtp->tv_sec * 1000 + BAN::Math::div_round_up<uint64_t>(rqtp->tv_nsec, 1'000'000));
+		return 0;
+	}
+
 	BAN::ErrorOr<long> Process::sys_setenvp(char** envp)
 	{
 		LockGuard _(m_lock);
diff --git a/kernel/kernel/Syscall.cpp b/kernel/kernel/Syscall.cpp
index c919c39dfe..a6e147301f 100644
--- a/kernel/kernel/Syscall.cpp
+++ b/kernel/kernel/Syscall.cpp
@@ -182,6 +182,9 @@ namespace Kernel
 		case SYS_FCNTL:
 			ret = Process::current().sys_fcntl((int)arg1, (int)arg2, (int)arg3);
 			break;
+		case SYS_NANOSLEEP:
+			ret = Process::current().sys_nanosleep((const timespec*)arg1, (timespec*)arg2);
+			break;
 		default:
 			dwarnln("Unknown syscall {}", syscall);
 			break;
diff --git a/libc/include/sys/syscall.h b/libc/include/sys/syscall.h
index ae177acdd8..a3f0ba53b0 100644
--- a/libc/include/sys/syscall.h
+++ b/libc/include/sys/syscall.h
@@ -51,6 +51,7 @@ __BEGIN_DECLS
 #define SYS_GET_PGID 44
 #define SYS_SET_PGID 45
 #define SYS_FCNTL 46
+#define SYS_NANOSLEEP 47
 
 __END_DECLS
 
diff --git a/libc/time.cpp b/libc/time.cpp
index e98ff75ee2..9d62dbc160 100644
--- a/libc/time.cpp
+++ b/libc/time.cpp
@@ -5,4 +5,9 @@
 int clock_gettime(clockid_t clock_id, struct timespec* tp)
 {
 	return syscall(SYS_CLOCK_GETTIME, clock_id, tp);
+}
+
+int nanosleep(const struct timespec* rqtp, struct timespec* rmtp)
+{
+	return syscall(SYS_NANOSLEEP, rqtp, rmtp);
 }
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