shithub: neoventi

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cache: use atomic counter for initial buffer allocation

--- a/cache.c

+++ b/cache.c

@@ -16,8 +16,8 @@

 static char *data;

 static bucket_t *buckets, *bucketend;

-static u32int freebufs;

-static Lock freelock;

+static long nextbuf = 0;

+static int full = 0;

 enum {

 	BUCKETSIZE = 8,

@@ -71,7 +71,6 @@

 	// alignment

 	assert(((usize)buckets&0b111111) == 0);

 	bucketend = buckets + BUCKETS;

-	freebufs = REQENTRIES;

 }

 // For now: random eviction.

@@ -104,14 +103,13 @@

 grabfree(void)

 {

 	u32int result;

-	lock(&freelock);

-	if(freebufs == 0){

-		result = evict();

-	} else {

-		result = REQENTRIES - freebufs;

-		freebufs -= 1;

+	if(full)

+		return evict();

+	result = ainc(&nextbuf);

+	if(result >= REQENTRIES){

+		full = 1;

+		return evict();

 	}

-	unlock(&freelock);

 	return result;

 }