patch-2.1.72 linux/include/linux/poll.h

• Lines: 107
• Date: Tue Dec 9 12:21:55 1997
• Orig file: v2.1.71/linux/include/linux/poll.h
• Orig date: Sat Jan 25 13:46:14 1997

diff -u --recursive --new-file v2.1.71/linux/include/linux/poll.h linux/include/linux/poll.h
@@ -1 +1,106 @@
+#ifndef _LINUX_POLL_H
+
 #include <asm/poll.h>
+
+#ifdef __KERNEL__
+
+#include <linux/wait.h>
+#include <linux/string.h>
+#include <asm/uaccess.h>
+
+
+struct poll_table_entry {
+	struct wait_queue wait;
+	struct wait_queue ** wait_address;
+};
+
+typedef struct poll_table_struct {
+	unsigned int nr;
+	struct poll_table_entry * entry;
+} poll_table;
+
+#define __MAX_POLL_TABLE_ENTRIES (PAGE_SIZE / sizeof (struct poll_table_entry))
+
+extern inline void poll_wait(struct wait_queue ** wait_address, poll_table *p)
+{
+	struct poll_table_entry * entry;
+
+	if (!p || !wait_address)
+		return;
+	if (p->nr >= __MAX_POLL_TABLE_ENTRIES)
+		return;
+ 	entry = p->entry + p->nr;
+	entry->wait_address = wait_address;
+	entry->wait.task = current;
+	entry->wait.next = NULL;
+	add_wait_queue(wait_address,&entry->wait);
+	p->nr++;
+}
+
+
+/*
+ * For the kernel fd_set we use a fixed set-size for allocation purposes.
+ * This set-size doesn't necessarily bear any relation to the size the user
+ * uses, but should preferably obviously be larger than any possible user
+ * size (NR_OPEN bits).
+ *
+ * We need 6 bitmaps (in/out/ex for both incoming and outgoing), and we
+ * allocate one page for all the bitmaps. Thus we have 8*PAGE_SIZE bits,
+ * to be divided by 6. And we'd better make sure we round to a full
+ * long-word (in fact, we'll round to 64 bytes).
+ */
+
+
+#define KFDS_64BLOCK ((PAGE_SIZE/(6*64))*64)
+#define KFDS_NR (KFDS_64BLOCK*8 > NR_OPEN ? NR_OPEN : KFDS_64BLOCK*8)
+typedef unsigned long kernel_fd_set[KFDS_NR/__NFDBITS];
+
+typedef struct {
+	kernel_fd_set in, out, ex;
+	kernel_fd_set res_in, res_out, res_ex;
+} fd_set_buffer;
+
+
+/*
+ * We do a VERIFY_WRITE here even though we are only reading this time:
+ * we'll write to it eventually..
+ *
+ * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
+ */
+static inline
+int get_fd_set(unsigned long nr, void *ufdset, unsigned long *fdset)
+{
+	/* round up nr to nearest "unsigned long" */
+	nr = (nr + 8*sizeof(long) - 1) / (8*sizeof(long)) * sizeof(long);
+	if (ufdset) {
+		int error;
+		error = verify_area(VERIFY_WRITE, ufdset, nr);
+		if (!error)
+			error = __copy_from_user(fdset, ufdset, nr);
+		return error;
+	}
+	memset(fdset, 0, nr);
+	return 0;
+}
+
+static inline
+void set_fd_set(unsigned long nr, void *ufdset, unsigned long *fdset)
+{
+	if (ufdset) {
+		nr = (nr + 8*sizeof(long) - 1) / (8*sizeof(long))*sizeof(long);
+		__copy_to_user(ufdset, fdset, nr);
+	}
+}
+
+static inline
+void zero_fd_set(unsigned long nr, unsigned long *fdset)
+{
+	nr = (nr + 8*sizeof(long) - 1) / (8*sizeof(long)) * sizeof(long);
+	memset(fdset, 0, nr);
+}
+
+extern int do_select(int n, fd_set_buffer *fds, unsigned long timeout);
+
+#endif /* KERNEL */
+
+#endif /* _LINUX_POLL_H */