9os

commit 876558ef0200bc66ec6271c929e8cb6857137e35
parent fe66fae763439a8da67237ac99803cab03bc0f74
Author: Roberto E. Vargas Caballero <roberto.vargas@midokura.com>
Date:   Fri, 18 Nov 2022 14:43:52 +0100

os9: Add freespace()

We add a pool of objects that can be reused if they are freed.

Diffstat:
M
include/os9/os9.h
 | 
1
+
M
src/os9/proc.c
 | 
21
++++++++++++++++++---

2 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/include/os9/os9.h b/include/os9/os9.h
@@ -162,6 +162,7 @@ struct nspace {
 	Ref ref;
 	mutex_t m;
 	struct mpoint mpoints[NR_MPOINTS];
+	Nspace *next;
 };
 
 struct fdset {
diff --git a/src/os9/proc.c b/src/os9/proc.c
@@ -8,6 +8,11 @@
 static Task tasktab[NR_TASKS];
 static mutex_t procm;
 
+static struct {
+	Nspace *list;
+	mutex_t m;
+} nspool;
+
 /* per cpu globals */
 Task *proc;
 long long now;
@@ -246,8 +251,15 @@ newspace(Nspace *from)
 {
 	Nspace *ns;
 
-	if ((ns = alloc(sizeof(*ns))) == NULL)
-		return NULL;
+	lock(&nspool.m);
+	if (nspool.list) {
+		ns = nspool.list;
+		nspool.list = ns->next;
+	} else {
+		if ((ns = alloc(sizeof(*ns))) == NULL)
+			return NULL;
+	}
+	unlock(&nspool.m);
 
 	*ns = (from) ? *from : (Nspace) {0};
 	initref(&ns->ref);
@@ -287,7 +299,10 @@ newmap(Map *from)
 static void
 freespace(Nspace *ns)
 {
-	/* TODO */
+	lock(&nspool.m);
+	ns->next = nspool.list;
+	nspool.list = ns;
+	unlock(&nspool.m);
 }
 
 static void