improvements to shared memory handling

+ Now each shared region is reference counter (technically each region
  is refernce counted, private regions just have a count of 1).
  Also, syscalls that touch the TLB get flushed, but should probably
  look into where else this flushing might be needed.

2 files changed, 38 insertions, 0 deletions

diff --git a/tests/shmem/init.c b/tests/shmem/init.c
new file mode 100644
index 0000000..13e1667
--- /dev/null
+++ b/tests/shmem/init.c
@@ -0,0 +1,36 @@
+#include <common/test.h>
+
+START(pid, tid, d0, d1, d2, d3)
+{
+	UNUSED(pid);
+	UNUSED(tid);
+	UNUSED(d0);
+	UNUSED(d1);
+	UNUSED(d2);
+	UNUSED(d3);
+
+	printf("allocating shared memory\n");
+	volatile char *shmem = sys_req_sharedmem(1, VM_R | VM_W);
+	check(shmem, "no shared memory?\n");
+
+	*shmem = 'p';
+
+	printf("sharing memory to ourselves\n");
+	volatile char *refmem = sys_ref_sharedmem(1, (uintptr_t)shmem, VM_R | VM_W);
+	check(refmem[0] == 'p', "wrong mapping?\n");
+
+	printf("freeing shared memory (should fail)\n");
+	enum sys_status r = sys_free_mem((uintptr_t)shmem);
+	check(r != OK, "illegal freeing succeeded?\n");
+
+	printf("freeing referenced memory\n");
+	r = sys_free_mem((uintptr_t)refmem);
+	check(r == OK, "legal ref freeing failed?\n");
+	check(shmem[0] == 'p', "freeing ref freed owned memory?\n");
+
+	printf("freeing recently nonshared memory\n");
+	r = sys_free_mem((uintptr_t)shmem);
+	check(r == OK, "legal freeing failed?\n");
+
+	ok();
+}
diff --git a/tests/shmem/source.mk b/tests/shmem/source.mk
new file mode 100644
index 0000000..da84808
--- /dev/null
+++ b/tests/shmem/source.mk
@@ -0,0 +1,2 @@
+DO	!= ./scripts/gen-prog -n shmem -p init init.c
+DO	!= ./scripts/gen-simple -n shmem -p init