patch-2.2.0-pre8 linux/include/linux/poll.h

• Lines: 109
• Date: Mon Jan 18 17:35:44 1999
• Orig file: v2.2.0-pre7/linux/include/linux/poll.h
• Orig date: Sun Nov 8 14:03:11 1998

diff -u --recursive --new-file v2.2.0-pre7/linux/include/linux/poll.h linux/include/linux/poll.h
@@ -7,6 +7,7 @@
 
 #include <linux/wait.h>
 #include <linux/string.h>
+#include <linux/mm.h>
 #include <asm/uaccess.h>
 
 
@@ -17,11 +18,12 @@
 };
 
 typedef struct poll_table_struct {
+	struct poll_table_struct * next;
 	unsigned int nr;
 	struct poll_table_entry * entry;
 } poll_table;
 
-#define __MAX_POLL_TABLE_ENTRIES (PAGE_SIZE / sizeof (struct poll_table_entry))
+#define __MAX_POLL_TABLE_ENTRIES ((PAGE_SIZE - sizeof (poll_table)) / sizeof (struct poll_table_entry))
 
 extern inline void poll_wait(struct file * filp, struct wait_queue ** wait_address, poll_table *p)
 {
@@ -29,8 +31,18 @@
 
 	if (!p || !wait_address)
 		return;
-	if (p->nr >= __MAX_POLL_TABLE_ENTRIES)
-		return;
+	while (p->nr >= __MAX_POLL_TABLE_ENTRIES && p->next != NULL)
+		p = p->next;
+	if (p->nr >= __MAX_POLL_TABLE_ENTRIES) {
+		poll_table *tmp = (poll_table *) __get_free_page(GFP_KERNEL);
+		if (!tmp)
+			return;
+		tmp->nr = 0;
+		tmp->entry = (struct poll_table_entry *)(tmp + 1);
+		tmp->next = NULL;
+		p->next = tmp;
+		p = tmp;
+	}
  	entry = p->entry + p->nr;
  	entry->filp = filp;
  	filp->f_count++;
@@ -59,11 +71,30 @@
 #define KFDS_NR (KFDS_64BLOCK*8 > NR_OPEN ? NR_OPEN : KFDS_64BLOCK*8)
 typedef unsigned long kernel_fd_set[KFDS_NR/__NFDBITS];
 
+/*
+ * XXX - still used by alpha osf and sparc32 compatiblity.
+ */
+
 typedef struct {
 	kernel_fd_set in, out, ex;
 	kernel_fd_set res_in, res_out, res_ex;
 } fd_set_buffer;
 
+/*
+ * Scaleable version of the fd_set.
+ */
+
+typedef struct {
+	unsigned long *in, *out, *ex;
+	unsigned long *res_in, *res_out, *res_ex;
+} fd_set_bits;
+
+/*
+ * How many longwords for "nr" bits?
+ */
+#define FDS_BITPERLONG	(8*sizeof(long))
+#define FDS_LONGS(nr)	(((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
+#define FDS_BYTES(nr)	(FDS_LONGS(nr)*sizeof(long))
 
 /*
  * We do a VERIFY_WRITE here even though we are only reading this time:
@@ -74,8 +105,7 @@
 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);
+	nr = FDS_BYTES(nr);
 	if (ufdset) {
 		int error;
 		error = verify_area(VERIFY_WRITE, ufdset, nr);
@@ -90,20 +120,17 @@
 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);
-	}
+	if (ufdset)
+		__copy_to_user(ufdset, fdset, FDS_BYTES(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);
+	memset(fdset, 0, FDS_BYTES(nr));
 }
 
-extern int do_select(int n, fd_set_buffer *fds, long *timeout);
+extern int do_select(int n, fd_set_bits *fds, long *timeout);
 
 #endif /* KERNEL */