libc: Add poolreset() function

This is intended for the secrmem pool in the kernel,
but could also be used for temporary pools to
recover the memory used by the arenas.

2 files changed, 39 insertions, 0 deletions

diff --git a/sys/src/libc/port/mkfile b/sys/src/libc/port/mkfile
index 557f1d7fa..683e6c583 100644
--- a/sys/src/libc/port/mkfile
+++ b/sys/src/libc/port/mkfile
@@ -131,6 +131,8 @@ UPDATE=mkfile\
 
 profile.$O: /sys/include/tos.h
 
+malloc.$O pool.$O: /sys/include/pool.h
+
 runenorm.$O:	runenormdata runenorm.c
 runetotype.$O:	runetotypedata runetotype.c
 runeistype.$O:	runeistypedata runeistype.c
diff --git a/sys/src/libc/port/pool.c b/sys/src/libc/port/pool.c
index 546d5776a..34254f7f5 100644
--- a/sys/src/libc/port/pool.c
+++ b/sys/src/libc/port/pool.c
@@ -1345,6 +1345,43 @@ poolisoverlap(Pool *p, void *v, ulong n)
 	return a != nil;
 }
 
+void
+poolreset(Pool *p)
+{
+	Arena *a;
+
+	if(p == nil)
+		return;
+
+	p->lock(p);
+	paranoia {
+		poolcheckl(p);
+	}
+	verbosity {
+		pooldumpl(p);
+	}
+	p->cursize = 0;
+	p->curfree = 0;
+	p->curalloc = 0;
+	p->lastcompact = p->nfree = 0;
+	p->freeroot = nil;
+	a = p->arenalist;
+	p->arenalist = nil;
+	LOG(p, "poolreset %p\n", p);
+	p->unlock(p);
+
+	while(a != nil){
+		Arena *next = a->down;
+		ulong asize = a->asize;
+		antagonism {
+			memmark(a, 0xFF, asize);
+		}
+		if(p->free)
+			p->free(a, asize);
+		a = next;
+	}
+}
+
 /*
  * Debugging
  */