libbase: add host properties support.

Move init and libprocessgroup away from their existing hacks.

Bug: N/A
Test: ran tests
Change-Id: Ifabdd38e0cc4ab2582f1ea59d32159d386f48eb6

base/Android.bp

@@ -48,6 +48,7 @@ cc_defaults {
         "file.cpp",
         "logging.cpp",
         "parsenetaddress.cpp",
+        "properties.cpp",
         "quick_exit.cpp",
         "stringprintf.cpp",
         "strings.cpp",
@@ -58,9 +59,6 @@ cc_defaults {
     shared_libs: ["liblog"],
     target: {
         android: {
-            srcs: [
-                "properties.cpp",
-            ],
             sanitize: {
                 misc_undefined: ["integer"],
             },
@@ -129,6 +127,7 @@ cc_test {
         "parsedouble_test.cpp",
         "parseint_test.cpp",
         "parsenetaddress_test.cpp",
+        "properties_test.cpp",
         "quick_exit_test.cpp",
         "scopeguard_test.cpp",
         "stringprintf_test.cpp",
@@ -138,7 +137,6 @@ cc_test {
     ],
     target: {
         android: {
-            srcs: ["properties_test.cpp"],
             sanitize: {
                 misc_undefined: ["integer"],
             },

base/include/android-base/properties.h

@@ -19,10 +19,6 @@
 
 #include <sys/cdefs.h>
 
-#if !defined(__BIONIC__)
-#error Only bionic supports system properties.
-#endif
-
 #include <chrono>
 #include <limits>
 #include <string>
@@ -62,14 +58,18 @@ bool SetProperty(const std::string& key, const std::string& value);
 // Waits for the system property `key` to have the value `expected_value`.
 // Times out after `relative_timeout`.
 // Returns true on success, false on timeout.
+#if defined(__BIONIC__)
 bool WaitForProperty(const std::string& key, const std::string& expected_value,
                      std::chrono::milliseconds relative_timeout = std::chrono::milliseconds::max());
+#endif
 
 // Waits for the system property `key` to be created.
 // Times out after `relative_timeout`.
 // Returns true on success, false on timeout.
+#if defined(__BIONIC__)
 bool WaitForPropertyCreation(const std::string& key, std::chrono::milliseconds relative_timeout =
                                                          std::chrono::milliseconds::max());
+#endif
 
 } // namespace base
 } // namespace android

base/properties.cpp

@@ -14,16 +14,18 @@
  * limitations under the License.
  */
 
-#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
-
 #include "android-base/properties.h"
 
+#if defined(__BIONIC__)
+#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
 #include <sys/system_properties.h>
 #include <sys/_system_properties.h>
+#endif
 
 #include <algorithm>
 #include <chrono>
 #include <limits>
+#include <map>
 #include <string>
 
 #include <android-base/parseint.h>
@@ -31,24 +33,6 @@
 namespace android {
 namespace base {
 
-std::string GetProperty(const std::string& key, const std::string& default_value) {
-  const prop_info* pi = __system_property_find(key.c_str());
-  if (pi == nullptr) return default_value;
-
-  std::string property_value;
-  __system_property_read_callback(pi,
-                                  [](void* cookie, const char*, const char* value, unsigned) {
-                                    auto property_value = reinterpret_cast<std::string*>(cookie);
-                                    *property_value = value;
-                                  },
-                                  &property_value);
-
-  // If the property exists but is empty, also return the default value.
-  // Since we can't remove system properties, "empty" is traditionally
-  // the same as "missing" (this was true for cutils' property_get).
-  return property_value.empty() ? default_value : property_value;
-}
-
 bool GetBoolProperty(const std::string& key, bool default_value) {
   std::string value = GetProperty(key, "");
   if (value == "1" || value == "y" || value == "yes" || value == "on" || value == "true") {
@@ -85,10 +69,43 @@ template uint16_t GetUintProperty(const std::string&, uint16_t, uint16_t);
 template uint32_t GetUintProperty(const std::string&, uint32_t, uint32_t);
 template uint64_t GetUintProperty(const std::string&, uint64_t, uint64_t);
 
+#if !defined(__BIONIC__)
+static std::map<std::string, std::string>& g_properties = *new std::map<std::string, std::string>;
+static int __system_property_set(const char* key, const char* value) {
+  g_properties[key] = value;
+  return 0;
+}
+#endif
+
+std::string GetProperty(const std::string& key, const std::string& default_value) {
+  std::string property_value;
+#if defined(__BIONIC__)
+  const prop_info* pi = __system_property_find(key.c_str());
+  if (pi == nullptr) return default_value;
+
+  __system_property_read_callback(pi,
+                                  [](void* cookie, const char*, const char* value, unsigned) {
+                                    auto property_value = reinterpret_cast<std::string*>(cookie);
+                                    *property_value = value;
+                                  },
+                                  &property_value);
+#else
+  auto it = g_properties.find(key);
+  if (it == g_properties.end()) return default_value;
+  property_value = it->second;
+#endif
+  // If the property exists but is empty, also return the default value.
+  // Since we can't remove system properties, "empty" is traditionally
+  // the same as "missing" (this was true for cutils' property_get).
+  return property_value.empty() ? default_value : property_value;
+}
+
 bool SetProperty(const std::string& key, const std::string& value) {
   return (__system_property_set(key.c_str(), value.c_str()) == 0);
 }
 
+#if defined(__BIONIC__)
+
 struct WaitForPropertyData {
   bool done;
   const std::string* expected_value;
@@ -175,5 +192,7 @@ bool WaitForPropertyCreation(const std::string& key,
   return (WaitForPropertyCreation(key, relative_timeout, start_time) != nullptr);
 }
 
+#endif
+
 }  // namespace base
 }  // namespace android

base/properties_test.cpp

@@ -23,7 +23,9 @@
 #include <string>
 #include <thread>
 
-using namespace std::chrono_literals;
+#if !defined(_WIN32)
+using namespace std::literals;
+#endif
 
 TEST(properties, smoke) {
   android::base::SetProperty("debug.libbase.property_test", "hello");
@@ -126,6 +128,7 @@ TEST(properties, GetUintProperty_uint32_t) { CheckGetUintProperty<uint32_t>(); }
 TEST(properties, GetUintProperty_uint64_t) { CheckGetUintProperty<uint64_t>(); }
 
 TEST(properties, WaitForProperty) {
+#if defined(__BIONIC__)
   std::atomic<bool> flag{false};
   std::thread thread([&]() {
     std::this_thread::sleep_for(100ms);
@@ -138,9 +141,13 @@ TEST(properties, WaitForProperty) {
   flag = true;
   ASSERT_TRUE(android::base::WaitForProperty("debug.libbase.WaitForProperty_test", "b", 1s));
   thread.join();
+#else
+  GTEST_LOG_(INFO) << "This test does nothing on the host.\n";
+#endif
 }
 
 TEST(properties, WaitForProperty_timeout) {
+#if defined(__BIONIC__)
   auto t0 = std::chrono::steady_clock::now();
   ASSERT_FALSE(android::base::WaitForProperty("debug.libbase.WaitForProperty_timeout_test", "a",
                                               200ms));
@@ -149,9 +156,13 @@ TEST(properties, WaitForProperty_timeout) {
   ASSERT_GE(std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0), 200ms);
   // Upper bounds on timing are inherently flaky, but let's try...
   ASSERT_LT(std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0), 600ms);
+#else
+  GTEST_LOG_(INFO) << "This test does nothing on the host.\n";
+#endif
 }
 
 TEST(properties, WaitForProperty_MaxTimeout) {
+#if defined(__BIONIC__)
   std::atomic<bool> flag{false};
   std::thread thread([&]() {
     android::base::SetProperty("debug.libbase.WaitForProperty_test", "a");
@@ -165,9 +176,13 @@ TEST(properties, WaitForProperty_MaxTimeout) {
   // Test that this does not immediately return false due to overflow issues with the timeout.
   ASSERT_TRUE(android::base::WaitForProperty("debug.libbase.WaitForProperty_test", "b"));
   thread.join();
+#else
+  GTEST_LOG_(INFO) << "This test does nothing on the host.\n";
+#endif
 }
 
 TEST(properties, WaitForProperty_NegativeTimeout) {
+#if defined(__BIONIC__)
   std::atomic<bool> flag{false};
   std::thread thread([&]() {
     android::base::SetProperty("debug.libbase.WaitForProperty_test", "a");
@@ -181,9 +196,13 @@ TEST(properties, WaitForProperty_NegativeTimeout) {
   // Assert that this immediately returns with a negative timeout
   ASSERT_FALSE(android::base::WaitForProperty("debug.libbase.WaitForProperty_test", "b", -100ms));
   thread.join();
+#else
+  GTEST_LOG_(INFO) << "This test does nothing on the host.\n";
+#endif
 }
 
 TEST(properties, WaitForPropertyCreation) {
+#if defined(__BIONIC__)
   std::thread thread([&]() {
     std::this_thread::sleep_for(100ms);
     android::base::SetProperty("debug.libbase.WaitForPropertyCreation_test", "a");
@@ -192,9 +211,13 @@ TEST(properties, WaitForPropertyCreation) {
   ASSERT_TRUE(android::base::WaitForPropertyCreation(
           "debug.libbase.WaitForPropertyCreation_test", 1s));
   thread.join();
+#else
+  GTEST_LOG_(INFO) << "This test does nothing on the host.\n";
+#endif
 }
 
 TEST(properties, WaitForPropertyCreation_timeout) {
+#if defined(__BIONIC__)
   auto t0 = std::chrono::steady_clock::now();
   ASSERT_FALSE(android::base::WaitForPropertyCreation(
           "debug.libbase.WaitForPropertyCreation_timeout_test", 200ms));
@@ -203,4 +226,7 @@ TEST(properties, WaitForPropertyCreation_timeout) {
   ASSERT_GE(std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0), 200ms);
   // Upper bounds on timing are inherently flaky, but let's try...
   ASSERT_LT(std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0), 600ms);
+#else
+  GTEST_LOG_(INFO) << "This test does nothing on the host.\n";
+#endif
 }

init/action.cpp

@@ -18,16 +18,11 @@
 
 #include <android-base/chrono_utils.h>
 #include <android-base/logging.h>
+#include <android-base/properties.h>
 #include <android-base/strings.h>
 
 #include "util.h"
 
-#if defined(__ANDROID__)
-#include <android-base/properties.h>
-#else
-#include "host_init_stubs.h"
-#endif
-
 using android::base::Join;
 
 namespace android {

init/action_parser.cpp

@@ -16,13 +16,12 @@
 
 #include "action_parser.h"
 
+#include <android-base/properties.h>
 #include <android-base/strings.h>
 
 #include "stable_properties.h"
 
-#if defined(__ANDROID__)
-#include <android-base/properties.h>
-#else
+#if !defined(__ANDROID__)
 #include "host_init_stubs.h"
 #endif
 

init/host_init_stubs.cpp

@@ -21,20 +21,6 @@ int setgroups(size_t __size, const gid_t* __list) {
     return 0;
 }
 
-namespace android {
-namespace base {
-
-std::string GetProperty(const std::string&, const std::string& default_value) {
-    return default_value;
-}
-
-bool GetBoolProperty(const std::string&, bool default_value) {
-    return default_value;
-}
-
-}  // namespace base
-}  // namespace android
-
 namespace android {
 namespace init {
 

init/host_init_stubs.h

@@ -29,16 +29,6 @@
 // unistd.h
 int setgroups(size_t __size, const gid_t* __list);
 
-// android-base/properties.h
-namespace android {
-namespace base {
-
-std::string GetProperty(const std::string& key, const std::string& default_value);
-bool GetBoolProperty(const std::string& key, bool default_value);
-
-}  // namespace base
-}  // namespace android
-
 namespace android {
 namespace init {
 

init/service.cpp

@@ -32,6 +32,7 @@
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
+#include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>
@@ -46,8 +47,6 @@
 #if defined(__ANDROID__)
 #include <sys/system_properties.h>
 
-#include <android-base/properties.h>
-
 #include "init.h"
 #include "property_service.h"
 #else

init/util.cpp

@@ -33,6 +33,7 @@
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
+#include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>
@@ -43,8 +44,6 @@
 #include "reboot.h"
 
 #if defined(__ANDROID__)
-#include <android-base/properties.h>
-
 #include "selinux.h"
 #else
 #include "host_init_stubs.h"

libprocessgroup/processgroup.cpp

@@ -39,18 +39,14 @@
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
-#ifdef __ANDROID__
 #include <android-base/properties.h>
-#endif
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <private/android_filesystem_config.h>
 
 #include <processgroup/processgroup.h>
 
-#ifdef __ANDROID__
 using android::base::GetBoolProperty;
-#endif
 using android::base::StartsWith;
 using android::base::StringPrintf;
 using android::base::WriteStringToFile;
@@ -68,15 +64,10 @@ std::once_flag init_path_flag;
 static const std::string& GetCgroupRootPath() {
     static std::string cgroup_root_path;
     std::call_once(init_path_flag, [&]() {
-#ifdef __ANDROID__
         // low-ram devices use per-app memcg by default, unlike high-end ones
         bool low_ram_device = GetBoolProperty("ro.config.low_ram", false);
         bool per_app_memcg =
             GetBoolProperty("ro.config.per_app_memcg", low_ram_device);
-#else
-        // host does not support Android properties
-        bool per_app_memcg = false;
-#endif
         if (per_app_memcg) {
             // Check if mem cgroup is mounted, only then check for
             // write-access to avoid SELinux denials