9os

commit 1b514694b7db293fee61cd36828ddf1e41a4f358
parent 9009cda6c00522e802a5266d1544f58183fd7c2e
Author: Roberto E. Vargas Caballero <roberto.vargas@midokura.com>
Date:   Fri, 18 Nov 2022 16:59:02 +0100

os9: Implement freeb()

We add a pool to reuse pages.

Diffstat:
M
include/os9/os9.h
 | 
1
+
M
src/os9/alloc.c
 | 
48
++++++++++++++++++++++++++++++++++++------------
M
src/os9/sys.c
 | 
1
+

3 files changed, 38 insertions(+), 12 deletions(-)
diff --git a/include/os9/os9.h b/include/os9/os9.h
@@ -257,6 +257,7 @@ extern void unlocktask(Task *);
 extern void *alloc(size_t);
 extern void *allocb(int);
 extern void freeb(void *);
+extern void ialloc(void);
 
 /* sys.c */
 extern void isys(void);
diff --git a/src/os9/alloc.c b/src/os9/alloc.c
@@ -6,35 +6,44 @@
 union bucket {
 	long long ll;
 	uintptr_t up;
+	union bucket *next;
 };
 
+struct {
+	union bucket *list;
+	mutex_t m;
+} bufpool;
 
 void
 freeb(void *bp)
 {
+	union bucket *p;
+
 	if (!bp)
 		return;
-	/* TODO */
+
+	lock(&bufpool.m);
+	p = bp;
+	p->next = bufpool.list;
+	bufpool.list = p;
+	unlock(&bufpool.m);
 }
 
 void *
 allocb(int n)
 {
-	void *addr = NULL;
-	static unsigned long npages;
-	static mutex_t m;
+	union bucket *bp = NULL;
 
-	lock(&m);
-	if (n >= NR_BUFFERS - npages) {
+	lock(&bufpool.m);
+	if (!bufpool.list) {
 		errno = ENOMEM;
-		goto end;
+	} else {
+		bp = bufpool.list;
+		bufpool.list = bp->next;
 	}
-	addr= buffertab[npages];
-	npages += n;
-end:
-	unlock(&m);
+	unlock(&bufpool.m);
 
-	return addr;
+	return bp;
 }
 
 void *
@@ -74,3 +83,18 @@ end:
 
 	return bp;
 }
+
+void
+ialloc(void)
+{
+	int i;
+	union bucket *bp, *prev;
+
+	prev = NULL;
+	for (i = 0; i < NR_BUFFERS; i++) {
+		bp = (union bucket *) buffertab[i];
+		bp->next = prev;
+		prev = bp;
+	}
+	bufpool.list = bp;
+}
diff --git a/src/os9/sys.c b/src/os9/sys.c
@@ -114,6 +114,7 @@ info(void)
 void
 isys(void)
 {
+	ialloc();
 	iproc();
 	idev();
 	iconf();