Add support for ashmem-host for host Windows
Migrate to tmpfile and fileno for temp file operations. These calls are
supported on MinGW, and the temp files are automatically cleaned up.
A Windows variant of ashmem-host is needed to support CursorWindows on
host Windows.
In Windows, it is not possible to unlink an open file, so the nlink
check in ashmem_validate_stat must be made Unix-only.
Test: SQLiteDatabaseTest in Google3
Test: libcutils_test_static on Windows
Bug: 317884162
Change-Id: I7fc0f1f49406b01549b7f4d7e138cb3e4d79be72
diff --git a/libcutils/Android.bp b/libcutils/Android.bp
index b7752d9..862af84 100644
--- a/libcutils/Android.bp
+++ b/libcutils/Android.bp
@@ -156,23 +156,18 @@
"fs_config.cpp",
],
},
- not_windows: {
- srcs: libcutils_nonwindows_sources + [
- "ashmem-host.cpp",
- "trace-host.cpp",
- ],
- },
- windows: {
- host_ldlibs: ["-lws2_32"],
-
+ host: {
srcs: [
"trace-host.cpp",
+ "ashmem-host.cpp",
],
-
+ },
+ not_windows: {
+ srcs: libcutils_nonwindows_sources,
+ },
+ windows: {
enabled: true,
- cflags: [
- "-D_GNU_SOURCE",
- ],
+ host_ldlibs: ["-lws2_32"],
},
android: {
sanitize: {
@@ -241,6 +236,7 @@
cc_defaults {
name: "libcutils_test_default",
srcs: [
+ "ashmem_base_test.cpp",
"native_handle_test.cpp",
"properties_test.cpp",
"sockets_test.cpp",
@@ -299,20 +295,26 @@
cc_defaults {
name: "libcutils_test_static_defaults",
defaults: ["libcutils_test_default"],
- static_libs: [
- "libc",
- "libcgrouprc_format",
- ] + test_libraries + always_static_test_libraries,
stl: "libc++_static",
require_root: true,
target: {
android: {
static_executable: true,
+ static_libs: [
+ "libcgrouprc_format",
+ ] + test_libraries + always_static_test_libraries,
+ },
+ not_windows: {
+ static_libs: test_libraries + always_static_test_libraries,
},
windows: {
+ static_libs: [
+ "libbase",
+ "libcutils",
+ "libcutils_sockets",
+ ],
host_ldlibs: ["-lws2_32"],
-
enabled: true,
},
},
@@ -320,6 +322,7 @@
cc_test {
name: "libcutils_test_static",
+ host_supported: true,
test_suites: ["device-tests"],
defaults: ["libcutils_test_static_defaults"],
}
diff --git a/libcutils/ashmem-host.cpp b/libcutils/ashmem-host.cpp
index 2ba1eb0..9003b76 100644
--- a/libcutils/ashmem-host.cpp
+++ b/libcutils/ashmem-host.cpp
@@ -17,10 +17,13 @@
#include <cutils/ashmem.h>
/*
- * Implementation of the user-space ashmem API for the simulator, which lacks
- * an ashmem-enabled kernel. See ashmem-dev.c for the real ashmem-based version.
+ * Implementation of the user-space ashmem API for the simulator, which lacks an
+ * ashmem-enabled kernel. See ashmem-dev.c for the real ashmem-based version. A
+ * disk-backed temp file is the best option that is consistently supported
+ * across all host platforms.
*/
+#include <android-base/unique_fd.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
@@ -31,8 +34,10 @@
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
-
#include <utils/Compat.h>
+#include <memory>
+
+using android::base::unique_fd;
static bool ashmem_validate_stat(int fd, struct stat* buf) {
int result = fstat(fd, buf);
@@ -40,15 +45,20 @@
return false;
}
- /*
- * Check if this is an "ashmem" region.
- * TODO: This is very hacky, and can easily break.
- * We need some reliable indicator.
- */
- if (!(buf->st_nlink == 0 && S_ISREG(buf->st_mode))) {
+ // Check if this is an ashmem region. Since there's no such thing on the host,
+ // we can't actually implement that. Check that it's at least a regular file.
+ if (!S_ISREG(buf->st_mode)) {
errno = ENOTTY;
return false;
}
+ // In Win32, unlike Unix, the temp file is not unlinked immediately after
+ // creation.
+#if !defined(_WIN32)
+ if (buf->st_nlink != 0) {
+ errno = ENOTTY;
+ return false;
+ }
+#endif
return true;
}
@@ -58,19 +68,24 @@
}
int ashmem_create_region(const char* /*ignored*/, size_t size) {
- char pattern[PATH_MAX];
- snprintf(pattern, sizeof(pattern), "/tmp/android-ashmem-%d-XXXXXXXXX", getpid());
- int fd = mkstemp(pattern);
- if (fd == -1) return -1;
+ // Files returned by tmpfile are automatically removed.
+ std::unique_ptr<FILE, decltype(&fclose)> tmp(tmpfile(), &fclose);
- unlink(pattern);
-
- if (TEMP_FAILURE_RETRY(ftruncate(fd, size)) == -1) {
- close(fd);
- return -1;
+ if (!tmp) {
+ return -1;
}
-
- return fd;
+ int fd = fileno(tmp.get());
+ if (fd == -1) {
+ return -1;
+ }
+ unique_fd dupfd = unique_fd(dup(fd));
+ if (dupfd == -1) {
+ return -1;
+ }
+ if (TEMP_FAILURE_RETRY(ftruncate(dupfd, size)) == -1) {
+ return -1;
+ }
+ return dupfd.release();
}
int ashmem_set_prot_region(int /*fd*/, int /*prot*/) {
diff --git a/libcutils/ashmem_base_test.cpp b/libcutils/ashmem_base_test.cpp
new file mode 100644
index 0000000..c9b14e5
--- /dev/null
+++ b/libcutils/ashmem_base_test.cpp
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+
+#include <unistd.h>
+
+#include <android-base/mapped_file.h>
+#include <android-base/unique_fd.h>
+#include <cutils/ashmem.h>
+
+/*
+ * Tests in AshmemBaseTest are designed to run on Android as well as host
+ * platforms (Linux, Mac, Windows).
+ */
+
+#if defined(_WIN32)
+static inline size_t getpagesize() {
+ return 4096;
+}
+#endif
+
+using android::base::unique_fd;
+
+TEST(AshmemBaseTest, BasicTest) {
+ const size_t size = getpagesize();
+ std::vector<uint8_t> data(size);
+ std::generate(data.begin(), data.end(), [n = 0]() mutable { return n++ & 0xFF; });
+
+ unique_fd fd = unique_fd(ashmem_create_region(nullptr, size));
+ ASSERT_TRUE(fd >= 0);
+ ASSERT_TRUE(ashmem_valid(fd));
+ ASSERT_EQ(size, static_cast<size_t>(ashmem_get_size_region(fd)));
+
+ std::unique_ptr<android::base::MappedFile> mapped =
+ android::base::MappedFile::FromFd(fd, 0, size, PROT_READ | PROT_WRITE);
+ EXPECT_TRUE(mapped.get() != nullptr);
+ void* region1 = mapped->data();
+ EXPECT_TRUE(region1 != nullptr);
+
+ memcpy(region1, data.data(), size);
+ ASSERT_EQ(0, memcmp(region1, data.data(), size));
+
+ std::unique_ptr<android::base::MappedFile> mapped2 =
+ android::base::MappedFile::FromFd(fd, 0, size, PROT_READ | PROT_WRITE);
+ EXPECT_TRUE(mapped2.get() != nullptr);
+ void* region2 = mapped2->data();
+ EXPECT_TRUE(region2 != nullptr);
+ ASSERT_EQ(0, memcmp(region2, data.data(), size));
+}
diff --git a/libcutils/ashmem_test.cpp b/libcutils/ashmem_test.cpp
index 571b410..ccbb8c9 100644
--- a/libcutils/ashmem_test.cpp
+++ b/libcutils/ashmem_test.cpp
@@ -69,28 +69,6 @@
}
}
-TEST(AshmemTest, BasicTest) {
- const size_t size = getpagesize();
- std::vector<uint8_t> data(size);
- FillData(data);
-
- unique_fd fd;
- ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE));
-
- void* region1 = nullptr;
- ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_READ | PROT_WRITE, ®ion1));
-
- memcpy(region1, data.data(), size);
- ASSERT_EQ(0, memcmp(region1, data.data(), size));
-
- EXPECT_EQ(0, munmap(region1, size));
-
- void *region2;
- ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_READ, ®ion2));
- ASSERT_EQ(0, memcmp(region2, data.data(), size));
- EXPECT_EQ(0, munmap(region2, size));
-}
-
TEST(AshmemTest, ForkTest) {
const size_t size = getpagesize();
std::vector<uint8_t> data(size);
diff --git a/libcutils/sockets_test.cpp b/libcutils/sockets_test.cpp
index 1fa40bc..f6f9c36 100644
--- a/libcutils/sockets_test.cpp
+++ b/libcutils/sockets_test.cpp
@@ -19,8 +19,6 @@
// should be the case for loopback communication, but is not guaranteed.
#include <string.h>
-#include <sys/socket.h>
-#include <sys/types.h>
#include <time.h>
#include <cutils/sockets.h>