tests/system_properties_test2.cpp

/*
 * Copyright (C) 2017 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 <errno.h>
#include <sys/wait.h>
#include <unistd.h>
#include <sstream>
#include <string>

#if defined(__BIONIC__)
#include <sys/system_properties.h>

static uint64_t NanoTime() {
  timespec now;
  clock_gettime(CLOCK_MONOTONIC, &now);
  return static_cast<uint64_t>(now.tv_sec) * UINT64_C(1000000000) + now.tv_nsec;
}
#endif

// Note that this test affects global state of the system
// this tests tries to mitigate this by using utime+pid
// prefix for the property name. It is still results in
// pollution of property service since properties cannot
// be removed.
//
// Note that there is also possibility to run into "out-of-memory"
// if this test if it is executed often enough without reboot.
TEST(properties, smoke) {
#if defined(__BIONIC__)
    char propvalue[PROP_VALUE_MAX];

    std::stringstream ss;
    ss << "debug.test." << getpid() << "." << NanoTime() << ".";
    const std::string property_prefix = ss.str();
    const std::string property_name = property_prefix + "property1";

    // Set brand new property
    ASSERT_EQ(0, __system_property_set(property_name.c_str(), "value1"));
    ASSERT_EQ(6, __system_property_get(property_name.c_str(), propvalue));
    ASSERT_STREQ("value1", propvalue);

    std::string long_value = "property-";
    for (size_t i = 0; i < PROP_VALUE_MAX; i++) {
      long_value += "y";
    }

    // Make sure that attempts to set invalid property value fails and preserves
    // previous value.
    propvalue[0] = '\0';
    ASSERT_EQ(-1, __system_property_set(property_name.c_str(), long_value.c_str()));
    ASSERT_EQ(6, __system_property_get(property_name.c_str(), propvalue));
    ASSERT_STREQ("value1", propvalue);

    // Update property
    ASSERT_EQ(0, __system_property_set(property_name.c_str(), "value1-1"));
    ASSERT_EQ(8, __system_property_get(property_name.c_str(), propvalue));
    ASSERT_STREQ("value1-1", propvalue);


    // check that there is no limit on property name length
    char suffix[1024];
    for (size_t i = 0; i < sizeof(suffix); i++) {
      suffix[i] = 'x';
    }

    suffix[sizeof(suffix)-1] = '\0';
    const std::string long_property_name = property_prefix + suffix;

    ASSERT_EQ(0, __system_property_set(long_property_name.c_str(), "value2"));
    ASSERT_EQ(6, __system_property_get(long_property_name.c_str(), propvalue));
    ASSERT_STREQ("value2", propvalue);

    // test find and read_callback
    const prop_info* pi = __system_property_find(property_name.c_str());
    ASSERT_TRUE(pi != nullptr);

    std::string expected_name = property_name;
    __system_property_read_callback(pi, [](void* cookie, const char *name, const char *value) {
      const std::string* expected_name = static_cast<const std::string*>(cookie);
      ASSERT_EQ(*expected_name, name);
      ASSERT_STREQ("value1-1", value);
    }, &expected_name);

    pi = __system_property_find(long_property_name.c_str());
    ASSERT_TRUE(pi != nullptr);

    expected_name = long_property_name;
    __system_property_read_callback(pi, [](void* cookie, const char *name, const char *value) {
      const std::string* expected_name = static_cast<const std::string*>(cookie);
      ASSERT_EQ(*expected_name, name);
      ASSERT_STREQ("value2", value);
    }, &expected_name);

    // Check that read() for long names still works but returns truncated version of the name
    pi = __system_property_find(property_name.c_str());
    ASSERT_TRUE(pi != nullptr);
    char legacy_name[PROP_NAME_MAX];
    expected_name = std::string(property_name.c_str(), PROP_NAME_MAX-1);
    ASSERT_EQ(8, __system_property_read(pi, &legacy_name[0], propvalue));
    ASSERT_EQ(expected_name, legacy_name);
    ASSERT_STREQ("value1-1", propvalue);

    const prop_info* pi_long = __system_property_find(long_property_name.c_str());
    ASSERT_TRUE(pi != nullptr);
    expected_name = std::string(long_property_name.c_str(), PROP_NAME_MAX-1);
    ASSERT_EQ(6, __system_property_read(pi_long, &legacy_name[0], propvalue));
    ASSERT_EQ(expected_name, legacy_name);
    ASSERT_STREQ("value2", propvalue);
#else // __BIONIC__
    GTEST_LOG_(INFO) << "This test does nothing.\n";
#endif // __BIONIC__
}