[kernel] Add syscall helpers

Added the syscalls/helpers.h file to templatize common kobject syscall
operations. Also moved most syscall implementations to using
process::current() and thread::current() instead of asking the
scheduler.

src/kernel/syscalls/channel.cpp

@@ -2,60 +2,39 @@
 #include "j6/types.h"
 
 #include "objects/channel.h"
-#include "objects/process.h"
+#include "syscalls/helpers.h"
 
 namespace syscalls {
 
 j6_status_t
 channel_create(j6_handle_t *handle)
 {
-	process &p = process::current();
-
-	channel *c = new channel;
-	*handle = p.add_handle(c);
-
+	construct_handle<channel>(handle);
 	return j6_status_ok;
 }
 
 j6_status_t
 channel_close(j6_handle_t handle)
 {
-	process &p = process::current();
-
-	kobject *o = p.lookup_handle(handle);
-	if (!o || o->get_type() != kobject::type::channel)
-		return j6_err_invalid_arg;
-
-	p.remove_handle(handle);
-	channel *c = static_cast<channel*>(o);
+	channel *c = remove_handle<channel>(handle);
+	if (!c) return j6_err_invalid_arg;
 	c->close();
-
 	return j6_status_ok;
 }
 
 j6_status_t
 channel_send(j6_handle_t handle, size_t *len, void *data)
 {
-	process &p = process::current();
-
-	kobject *o = p.lookup_handle(handle);
-	if (!o || o->get_type() != kobject::type::channel)
-		return j6_err_invalid_arg;
-
-	channel *c = static_cast<channel*>(o);
+	channel *c = get_handle<channel>(handle);
+	if (!c) return j6_err_invalid_arg;
 	return c->enqueue(len, data);
 }
 
 j6_status_t
 channel_receive(j6_handle_t handle, size_t *len, void *data)
 {
-	process &p = process::current();
-
-	kobject *o = p.lookup_handle(handle);
-	if (!o || o->get_type() != kobject::type::channel)
-		return j6_err_invalid_arg;
-
-	channel *c = static_cast<channel*>(o);
+	channel *c = get_handle<channel>(handle);
+	if (!c) return j6_err_invalid_arg;
 	return c->dequeue(len, data);
 }
 

src/kernel/syscalls/endpoint.cpp

@@ -3,97 +3,53 @@
 
 #include "log.h"
 #include "objects/endpoint.h"
-#include "objects/process.h"
-#include "scheduler.h"
+#include "syscalls/helpers.h"
 
 namespace syscalls {
 
 j6_status_t
 endpoint_create(j6_handle_t *handle)
 {
-	scheduler &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *parent = thread::from_tcb(tcb);
-	process &p = parent->parent();
-
-	endpoint *e = new endpoint;
-	*handle = p.add_handle(e);
-
+	construct_handle<endpoint>(handle);
 	return j6_status_ok;
 }
 
 j6_status_t
 endpoint_close(j6_handle_t handle)
 {
-	scheduler &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *parent = thread::from_tcb(tcb);
-	process &p = parent->parent();
-
-	kobject *o = p.lookup_handle(handle);
-	if (!o || o->get_type() != kobject::type::endpoint)
-		return j6_err_invalid_arg;
-
-	p.remove_handle(handle);
-	endpoint *e = static_cast<endpoint*>(o);
+	endpoint *e = remove_handle<endpoint>(handle);
+	if (!e) return j6_err_invalid_arg;
 	e->close();
-
 	return j6_status_ok;
 }
 
 j6_status_t
 endpoint_send(j6_handle_t handle, size_t len, void *data)
 {
-	scheduler &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *parent = thread::from_tcb(tcb);
-	process &p = parent->parent();
-
-	kobject *o = p.lookup_handle(handle);
-	if (!o || o->get_type() != kobject::type::endpoint)
-		return j6_err_invalid_arg;
-
-	endpoint *e = static_cast<endpoint*>(o);
-	j6_status_t status = e->send(len, data);
-	return status;
+	endpoint *e = get_handle<endpoint>(handle);
+	if (!e) return j6_err_invalid_arg;
+	return e->send(len, data);
 }
 
 j6_status_t
 endpoint_receive(j6_handle_t handle, size_t *len, void *data)
 {
-	scheduler &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *parent = thread::from_tcb(tcb);
-	process &p = parent->parent();
-
-	kobject *o = p.lookup_handle(handle);
-	if (!o || o->get_type() != kobject::type::endpoint)
-		return j6_err_invalid_arg;
-
-	endpoint *e = static_cast<endpoint*>(o);
-	j6_status_t status = e->receive(len, data);
-	return status;
+	endpoint *e = get_handle<endpoint>(handle);
+	if (!e) return j6_err_invalid_arg;
+	return e->receive(len, data);
 }
 
 j6_status_t
 endpoint_sendrecv(j6_handle_t handle, size_t *len, void *data)
 {
-	scheduler &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *parent = thread::from_tcb(tcb);
-	process &p = parent->parent();
+	endpoint *e = get_handle<endpoint>(handle);
+	if (!e) return j6_err_invalid_arg;
 
-	kobject *o = p.lookup_handle(handle);
-	if (!o || o->get_type() != kobject::type::endpoint)
-		return j6_err_invalid_arg;
-
-	endpoint *e = static_cast<endpoint*>(o);
 	j6_status_t status = e->send(*len, data);
 	if (status != j6_status_ok)
 		return status;
 
-	status = e->receive(len, data);
-	return status;
+	return e->receive(len, data);
 }
 
 } // namespace syscalls

src/kernel/syscalls/helpers.h

@@ -0,0 +1,40 @@
+#pragma once
+/// \file syscalls/helpers.h
+/// Utility functions for use in syscall handler implementations
+
+#include "j6/types.h"
+#include "objects/process.h"
+
+namespace syscalls {
+
+template <typename T, typename... Args>
+T * construct_handle(j6_handle_t *handle, Args... args)
+{
+	process &p = process::current();
+	T *o = new T {args...};
+	*handle = p.add_handle(o);
+	return o;
+}
+
+template <typename T>
+T * get_handle(j6_handle_t handle)
+{
+	process &p = process::current();
+	kobject *o = p.lookup_handle(handle);
+	if (!o || o->get_type() != T::type)
+		return nullptr;
+	return static_cast<T*>(o);
+}
+
+template <typename T>
+T * remove_handle(j6_handle_t handle)
+{
+	T *o = get_handle<T>(handle);
+	if (o) {
+		process &p = process::current();
+		p.remove_handle(handle);
+	}
+	return o;
+}
+
+}

src/kernel/syscalls/process.cpp

@@ -3,7 +3,6 @@
 
 #include "log.h"
 #include "objects/process.h"
-#include "objects/thread.h"
 #include "scheduler.h"
 
 namespace syscalls {
@@ -11,14 +10,10 @@ namespace syscalls {
 j6_status_t
 process_koid(j6_koid_t *koid)
 {
-	if (koid == nullptr) {
+	if (koid == nullptr)
 		return j6_err_invalid_arg;
-	}
 
-	TCB *tcb = scheduler::get().current();
-	process &p = thread::from_tcb(tcb)->parent();
-
-	*koid = p.koid();
+	*koid = process::current().koid();
 	return j6_status_ok;
 }
 
@@ -26,8 +21,7 @@ j6_status_t
 process_exit(int64_t status)
 {
 	auto &s = scheduler::get();
-	TCB *tcb = s.current();
-	process &p = thread::from_tcb(tcb)->parent();
+	process &p = process::current();
 
 	log::debug(logs::syscall, "Process %llx exiting with code %d", p.koid(), status);
 

src/kernel/syscalls/system.cpp

@@ -2,31 +2,26 @@
 #include "j6/types.h"
 
 #include "log.h"
-#include "scheduler.h"
+#include "objects/thread.h"
 
 namespace syscalls {
 
 j6_status_t
 system_log(const char *message)
 {
-	if (message == nullptr) {
+	if (message == nullptr)
 		return j6_err_invalid_arg;
-	}
 
-	auto &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *th = thread::from_tcb(tcb);
-	log::info(logs::syscall, "Message[%llx]: %s", th->koid(), message);
+	thread &th = thread::current();
+	log::info(logs::syscall, "Message[%llx]: %s", th.koid(), message);
 	return j6_status_ok;
 }
 
 j6_status_t
 system_noop()
 {
-	auto &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *th = thread::from_tcb(tcb);
-	log::debug(logs::syscall, "Thread %llx called noop syscall.", th->koid());
+	thread &th = thread::current();
+	log::debug(logs::syscall, "Thread %llx called noop syscall.", th.koid());
 	return j6_status_ok;
 }
 

src/kernel/syscalls/thread.cpp

@@ -3,6 +3,7 @@
 
 #include "log.h"
 #include "objects/process.h"
+#include "objects/thread.h"
 #include "scheduler.h"
 
 namespace syscalls {
@@ -10,12 +11,10 @@ namespace syscalls {
 j6_status_t
 thread_koid(j6_koid_t *koid)
 {
-	if (koid == nullptr) {
+	if (koid == nullptr)
 		return j6_err_invalid_arg;
-	}
 
-	TCB *tcb = scheduler::get().current();
-	*koid =  thread::from_tcb(tcb)->koid();
+	*koid =  thread::current().koid();
 	return j6_status_ok;
 }
 
@@ -23,9 +22,8 @@ j6_status_t
 thread_create(void *rip, j6_handle_t *handle)
 {
 	scheduler &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *parent = thread::from_tcb(tcb);
-	process &p = parent->parent();
+	thread &parent = thread::current();
+	process &p = parent.parent();
 
 	thread *child = p.create_thread(scheduler::default_priority);
 	child->add_thunk_user(reinterpret_cast<uintptr_t>(rip));
@@ -33,7 +31,7 @@ thread_create(void *rip, j6_handle_t *handle)
 	s.add_thread(child->tcb());
 
 	log::debug(logs::syscall, "Thread %llx spawned new thread %llx, handle %d",
-		parent->koid(), child->koid(), *handle);
+		parent.koid(), child->koid(), *handle);
 
 	return j6_status_ok;
 }
@@ -42,11 +40,9 @@ j6_status_t
 thread_exit(int64_t status)
 {
 	auto &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *th = thread::from_tcb(tcb);
-	log::debug(logs::syscall, "Thread %llx exiting with code %d", th->koid(), status);
-
-	th->exit(status);
+	thread &th = thread::current();
+	log::debug(logs::syscall, "Thread %llx exiting with code %d", th.koid(), status);
+	th.exit(status);
 	s.schedule();
 
 	log::error(logs::syscall, "returned to exit syscall");
@@ -57,9 +53,8 @@ j6_status_t
 thread_pause()
 {
 	auto &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *th = thread::from_tcb(tcb);
-	th->wait_on_signals(th, -1ull);
+	thread &th = thread::current();
+	th.wait_on_signals(&th, -1ull);
 	s.schedule();
 	return j6_status_ok;
 }
@@ -68,11 +63,10 @@ j6_status_t
 thread_sleep(uint64_t til)
 {
 	auto &s = scheduler::get();
-	TCB *tcb = s.current();
-	thread *th = thread::from_tcb(tcb);
-	log::debug(logs::syscall, "Thread %llx sleeping until %llu", th->koid(), til);
+	thread &th = thread::current();
+	log::debug(logs::syscall, "Thread %llx sleeping until %llu", th.koid(), til);
 
-	th->wait_on_time(til);
+	th.wait_on_time(til);
 	s.schedule();
 	return j6_status_ok;
 }