Add wrapper for mremap

1 files changed, 80 insertions, 0 deletions

diff --git a/test/sys/test_mman.rs b/test/sys/test_mman.rs
new file mode 100644
index 00000000..152fff69
--- /dev/null
+++ b/test/sys/test_mman.rs
@@ -0,0 +1,80 @@
+use nix::Error;
+use nix::libc::{c_void, size_t};
+use nix::sys::mman::{mmap, MapFlags, ProtFlags};
+
+#[cfg(target_os = "linux")]
+use nix::sys::mman::{mremap, MRemapFlags};
+
+#[test]
+fn test_mmap_anonymous() {
+    let ref mut byte = unsafe {
+        let ptr = mmap(std::ptr::null_mut(), 1,
+                       ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
+                       MapFlags::MAP_PRIVATE | MapFlags::MAP_ANONYMOUS, -1, 0)
+                      .unwrap();
+        *(ptr as * mut u8)
+    };
+    assert_eq !(*byte, 0x00u8);
+    *byte = 0xffu8;
+    assert_eq !(*byte, 0xffu8);
+}
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_mremap_grow() {
+    const ONE_K : size_t = 1024;
+    let slice : &mut[u8] = unsafe {
+        let mem = mmap(std::ptr::null_mut(), ONE_K,
+                       ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
+                       MapFlags::MAP_ANONYMOUS | MapFlags::MAP_PRIVATE, -1, 0)
+                      .unwrap();
+        std::slice::from_raw_parts_mut(mem as * mut u8, ONE_K)
+    };
+    assert_eq !(slice[ONE_K - 1], 0x00);
+    slice[ONE_K - 1] = 0xFF;
+    assert_eq !(slice[ONE_K - 1], 0xFF);
+
+    let slice : &mut[u8] = unsafe {
+        let mem = mremap(slice.as_mut_ptr() as * mut c_void, ONE_K, 10 * ONE_K,
+                         MRemapFlags::MREMAP_MAYMOVE, None)
+                      .unwrap();
+        std::slice::from_raw_parts_mut(mem as * mut u8, 10 * ONE_K)
+    };
+
+    // The first KB should still have the old data in it.
+    assert_eq !(slice[ONE_K - 1], 0xFF);
+
+    // The additional range should be zero-init'd and accessible.
+    assert_eq !(slice[10 * ONE_K - 1], 0x00);
+    slice[10 * ONE_K - 1] = 0xFF;
+    assert_eq !(slice[10 * ONE_K - 1], 0xFF);
+}
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_mremap_shrink() {
+    const ONE_K : size_t = 1024;
+    let slice : &mut[u8] = unsafe {
+        let mem = mmap(std::ptr::null_mut(), 10 * ONE_K,
+                       ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
+                       MapFlags::MAP_ANONYMOUS | MapFlags::MAP_PRIVATE, -1, 0)
+                      .unwrap();
+        std::slice::from_raw_parts_mut(mem as * mut u8, ONE_K)
+    };
+    assert_eq !(slice[ONE_K - 1], 0x00);
+    slice[ONE_K - 1] = 0xFF;
+    assert_eq !(slice[ONE_K - 1], 0xFF);
+
+    let slice : &mut[u8] = unsafe {
+        let mem = mremap(slice.as_mut_ptr() as * mut c_void, 10 * ONE_K, ONE_K,
+                         MRemapFlags::empty(), None)
+                      .unwrap();
+        // Since we didn't supply MREMAP_MAYMOVE, the address should be the
+        // same.
+        assert_eq !(mem, slice.as_mut_ptr() as * mut c_void);
+        std::slice::from_raw_parts_mut(mem as * mut u8, ONE_K)
+    };
+
+    // The first KB should still be accessible and have the old data in it.
+    assert_eq !(slice[ONE_K - 1], 0xFF);
+}