syscall: Add close (destroy a resource descriptor using its handle number)

3 files changed, 15 insertions, 11 deletions

diff --git a/src/lib/interrupts.zig b/src/lib/interrupts.zig
index 8d95294..e11c693 100644
--- a/src/lib/interrupts.zig
+++ b/src/lib/interrupts.zig
@@ -155,7 +155,7 @@ export fn handleTrap(epc: usize, tval: usize, cause_bits: usize, frame: *trap.Fr
             },
             .ecall => {
                 const proc = &process.list.last.?.data;
-                syscall.handle(proc, frame) catch |err| switch (err) {
+                syscall.handler(proc, frame) catch |err| switch (err) {
                     syscall.Error.UnknownSyscall => {
                         const a7 = frame.general_purpose_registers[17];
                         w.print("Hart {d}: Unknown syscall, a7 = 0x{x:0>16}\r\n", .{ frame.hart_id, a7 }) catch unreachable;
diff --git a/src/lib/process.zig b/src/lib/process.zig
index 6f8ffce..fe5e3cf 100644
--- a/src/lib/process.zig
+++ b/src/lib/process.zig
@@ -67,7 +67,7 @@ pub const Info = struct {
         return self.page_table.satp(self.id);
     }
 
-    pub fn makeRdHandle(self: *Info, rd: vfs.ResourceDescriptor) !usize {
+    pub fn createRdHandle(self: *Info, rd: vfs.ResourceDescriptor) !usize {
         if (self.rds.count() == std.math.maxInt(usize)) {
             return ProcessError.TooManyResourceDescriptors;
         }
@@ -78,6 +78,12 @@ pub const Info = struct {
         try self.rds.put(handle, rd);
         return handle;
     }
+
+    pub fn destroyRdHandle(self: *Info, handle: usize) void {
+        if (self.rds.fetchSwapRemove(handle)) |kv| {
+            kv.value.deinit();
+        }
+    }
 };
 
 pub fn next() ?*Info {
diff --git a/src/lib/syscall.zig b/src/lib/syscall.zig
index c2457c6..55a7da3 100644
--- a/src/lib/syscall.zig
+++ b/src/lib/syscall.zig
@@ -13,11 +13,11 @@ pub const Error = error{
     UnknownSyscall,
 };
 
-pub fn handle(proc: *process.Info, trap_frame: *trap.Frame) !void {
+pub fn handler(proc: *process.Info, trap_frame: *trap.Frame) !void {
     switch (trap_frame.general_purpose_registers[17]) {
         100000 => uprint(trap_frame),
         100001 => open(proc, trap_frame),
-        100002 => close(trap_frame),
+        100002 => close(proc, trap_frame),
         100003 => provideStream(trap_frame),
         100004 => provideFile(trap_frame),
         100005 => provideHook(trap_frame),
@@ -52,19 +52,17 @@ fn open(proc: *process.Info, trap_frame: *trap.Frame) void {
     };
     switch (user_info) {
         .rd => |resource_descriptor| {
-            const maybe_handle = proc.makeRdHandle(resource_descriptor);
+            const maybe_handle = proc.createRdHandle(resource_descriptor);
             sysexchange.frameReturn(null, trap_frame, maybe_handle);
         },
         .value => |value| sysexchange.frameReturnResult(usize, trap_frame, value),
     }
 }
 
-// close(rd: usize) void
-fn close(trap_frame: *const trap.Frame) void {
-    const rd = trap_frame.general_purpose_registers[10];
-
-    _ = rd;
-    unreachable;
+// close(handle: usize) void
+fn close(proc: *process.Info, trap_frame: *const trap.Frame) void {
+    const handle = trap_frame.general_purpose_registers[10];
+    proc.destroyRdHandle(handle);
 }
 
 // provideStream(