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diff --git a/third_party/rust/ashmem/src/lib.rs b/third_party/rust/ashmem/src/lib.rs
new file mode 100755
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+++ b/third_party/rust/ashmem/src/lib.rs
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+#![cfg(target_os = "android")]
+//! Provides a wrapper around Android's ASharedMemory API.
+//!
+//! ashmem has existed in Android as a non-public API for some time.
+//! Originally accessed via ioctl, it was later available via libcutils as ashmem_create_region etc.
+//! ASharedMemory is the new public API, but it isn't available until API 26 (Android 8).
+//! Builds targeting Android 10 (API 29) are no longer permitted to access ashmem via the ioctl interface.
+//! This makes life for a portable program difficult - you can't reliably use the old or new interface during this transition period.
+//! We try to dynamically load the new API first, then fall back to the ioctl interface.
+//!
+//! References:
+//!   - [ASharedMemory documentation](https://developer.android.com/ndk/reference/group/memory)
+//!   - [Linux ashmem.h definitions](https://elixir.bootlin.com/linux/v5.11.8/source/drivers/staging/android/uapi/ashmem.h)
+
+#[macro_use]
+extern crate ioctl_sys;
+
+const __ASHMEMIOC: u32 = 0x77;
+
+static mut LIBANDROID_ASHAREDMEMORY_CREATE: Option<
+    extern "C" fn(*const libc::c_char, libc::size_t) -> libc::c_int,
+> = None;
+static mut LIBANDROID_ASHAREDMEMORY_GETSIZE: Option<extern "C" fn(libc::c_int) -> libc::size_t> =
+    None;
+static mut LIBANDROID_ASHAREDMEMORY_SETPROT: Option<
+    extern "C" fn(libc::c_int, libc::c_int) -> libc::c_int,
+> = None;
+
+unsafe fn maybe_init() {
+    const LIBANDROID_NAME: *const libc::c_char = "libandroid.so\0".as_ptr() as *const libc::c_char;
+    const LIBANDROID_ASHAREDMEMORY_CREATE_NAME: *const libc::c_char =
+        "ASharedMemory_create\0".as_ptr() as _;
+    const LIBANDROID_ASHAREDMEMORY_GETSIZE_NAME: *const libc::c_char =
+        "ASharedMemory_getSize\0".as_ptr() as _;
+    const LIBANDROID_ASHAREDMEMORY_SETPROT_NAME: *const libc::c_char =
+        "ASharedMemory_setProt\0".as_ptr() as _;
+    static ONCE: std::sync::Once = std::sync::Once::new();
+    ONCE.call_once(|| {
+        // Leak the handle, there's no safe time to close it.
+        let handle = libc::dlopen(LIBANDROID_NAME, libc::RTLD_LAZY | libc::RTLD_LOCAL);
+        if handle.is_null() {
+            return;
+        }
+        // Transmute guarantee for `fn -> Option<fn>`: https://doc.rust-lang.org/std/option/#representation
+        LIBANDROID_ASHAREDMEMORY_CREATE =
+            std::mem::transmute(libc::dlsym(handle, LIBANDROID_ASHAREDMEMORY_CREATE_NAME));
+        LIBANDROID_ASHAREDMEMORY_GETSIZE =
+            std::mem::transmute(libc::dlsym(handle, LIBANDROID_ASHAREDMEMORY_GETSIZE_NAME));
+        LIBANDROID_ASHAREDMEMORY_SETPROT =
+            std::mem::transmute(libc::dlsym(handle, LIBANDROID_ASHAREDMEMORY_SETPROT_NAME));
+    });
+}
+
+/// See [ASharedMemory_create NDK documentation](https://developer.android.com/ndk/reference/group/memory#asharedmemory_create)
+///
+/// # Safety
+///
+/// Directly calls C or kernel APIs.
+#[allow(non_snake_case)]
+pub unsafe fn ASharedMemory_create(name: *const libc::c_char, size: libc::size_t) -> libc::c_int {
+    const ASHMEM_NAME_DEF: *const libc::c_char = "/dev/ashmem\0".as_ptr() as _;
+    const ASHMEM_NAME_LEN: usize = 256;
+    const ASHMEM_SET_NAME: libc::c_int = iow!(
+        __ASHMEMIOC,
+        1,
+        std::mem::size_of::<[libc::c_char; ASHMEM_NAME_LEN]>()
+    ) as _;
+    const ASHMEM_SET_SIZE: libc::c_int =
+        iow!(__ASHMEMIOC, 3, std::mem::size_of::<libc::size_t>()) as _;
+
+    maybe_init();
+    if let Some(fun) = LIBANDROID_ASHAREDMEMORY_CREATE {
+        return fun(name, size);
+    }
+
+    let fd = libc::open(ASHMEM_NAME_DEF, libc::O_RDWR, 0o600);
+    if fd < 0 {
+        return fd;
+    }
+
+    if !name.is_null() {
+        // NOTE: libcutils uses a local stack copy of `name`.
+        let r = libc::ioctl(fd, ASHMEM_SET_NAME, name);
+        if r != 0 {
+            libc::close(fd);
+            return -1;
+        }
+    }
+
+    let r = libc::ioctl(fd, ASHMEM_SET_SIZE, size);
+    if r != 0 {
+        libc::close(fd);
+        return -1;
+    }
+
+    fd
+}
+
+/// See [ASharedMemory_getSize NDK documentation](https://developer.android.com/ndk/reference/group/memory#asharedmemory_getsize)
+///
+/// # Safety
+///
+/// Directly calls C or kernel APIs.
+#[allow(non_snake_case)]
+pub unsafe fn ASharedMemory_getSize(fd: libc::c_int) -> libc::size_t {
+    const ASHMEM_GET_SIZE: libc::c_int = io!(__ASHMEMIOC, 4) as _;
+
+    maybe_init();
+    if let Some(fun) = LIBANDROID_ASHAREDMEMORY_GETSIZE {
+        return fun(fd);
+    }
+
+    libc::ioctl(fd, ASHMEM_GET_SIZE) as libc::size_t
+}
+
+/// See [ASharedMemory_setProt NDK documentation](https://developer.android.com/ndk/reference/group/memory#asharedmemory_setprot)
+///
+/// # Safety
+///
+/// Directly calls C or kernel APIs.
+#[allow(non_snake_case)]
+pub unsafe fn ASharedMemory_setProt(fd: libc::c_int, prot: libc::c_int) -> libc::c_int {
+    const ASHMEM_SET_PROT_MASK: libc::c_int =
+        iow!(__ASHMEMIOC, 5, std::mem::size_of::<libc::c_ulong>()) as _;
+
+    maybe_init();
+    if let Some(fun) = LIBANDROID_ASHAREDMEMORY_SETPROT {
+        return fun(fd, prot);
+    }
+
+    let r = libc::ioctl(fd, ASHMEM_SET_PROT_MASK, prot);
+    if r != 0 {
+        return -1;
+    }
+    r
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn basic() {
+        unsafe {
+            let name = std::ffi::CString::new("/test-ashmem").unwrap();
+            let fd = super::ASharedMemory_create(name.as_ptr(), 128);
+            assert!(fd >= 0);
+            assert_eq!(super::ASharedMemory_getSize(fd), 128);
+            assert_eq!(super::ASharedMemory_setProt(fd, 0), 0);
+            libc::close(fd);
+        }
+    }
+
+    #[test]
+    fn anonymous() {
+        unsafe {
+            let fd = super::ASharedMemory_create(std::ptr::null(), 128);
+            assert!(fd >= 0);
+            libc::close(fd);
+        }
+    }
+}