io: refactor for ref counting

src/dirent.c

@@ -110,14 +110,10 @@ int closedir(Thread *t, DIR *dir) {
     if(!descriptor) return -EBADF;
 
     // destroy the descriptor
-    if(!p->io[dd].clone)
-        free(p->io[dd].data);
-
     p->io[dd].valid = false;
     p->io[dd].type = 0;
     p->io[dd].flags = 0;
     p->io[dd].data = NULL;
-    p->io[dd].clone = false;
     p->iodCount--;
 
     return 0;

src/include/kernel/file.h

@@ -30,6 +30,7 @@ typedef struct {
     char path[MAX_FILE_PATH];       // path relative to device mountpount
     off_t position;
     uint64_t id;                    // unique ID, this is for device files
+    int refCount;
 } FileDescriptor;
 
 /* file system syscalls */

src/include/kernel/io.h

@@ -44,7 +44,7 @@
 // TODO: decide whether to implement named pipes as files or an independent type
 
 typedef struct IODescriptor {
-    bool valid, clone;
+    bool valid;
     int type;
     uint16_t flags;
     void *data;                 // file or socket-specific data

src/io.c

@@ -39,7 +39,6 @@ int openIO(void *pv, void **iodv) {
     if(desc >= MAX_IO_DESCRIPTORS) return -EMFILE;
 
     p->io[desc].valid = true;
-    p->io[desc].clone = false;
     p->io[desc].type = IO_WAITING;
     p->io[desc].data = NULL;
 
@@ -134,16 +133,6 @@ int close(Thread *t, int fd) {
 
     if(!p->io[fd].valid || !p->io[fd].data) return -EBADF;
 
-    if(p->io[fd].clone) {
-        p->io[fd].valid = false;
-        p->io[fd].clone = false;
-        p->io[fd].type = 0;
-        p->io[fd].flags = 0;
-        p->io[fd].data = NULL;
-
-        return 0;
-    }
-
     if(p->io[fd].type == IO_SOCKET) return closeSocket(t, fd);
     else if(p->io[fd].type == IO_FILE) return closeFile(t, fd);
     else return -EBADF;

src/sched/fork.c

@@ -88,9 +88,6 @@ pid_t fork(Thread *t) {
         memcpy(p->io, parent->io, sizeof(IODescriptor) * MAX_IO_DESCRIPTORS);
         p->iodCount = parent->iodCount;
 
-        for(int i = 0; i < MAX_IO_DESCRIPTORS; i++)
-            if(p->io[i].valid) p->io[i].clone = true;
-
         // clone working directory
         strcpy(p->cwd, parent->cwd);