platform_system_core/logd/SerializedLogChunkTest.cpp
Tom Cherry 59caa7a045 logd: always compress SerializedLogChunk in FinishWriting()
When calculating the space used for pruning, if a log chunk is
compressed, that size is used otherwise the uncompressed size is
used.  This is intended to reach a steady state where 1/4 of the log
buffer is the uncompressed log chunk that is being written to and the
other 3/4 of the log buffer is compressed logs.

If we wait until there are no readers referencing the log chunk before
compressing it, we end up with 2 uncompressed logs (the one that was
just filled, that readers are still referencing, and the new one that
was allocated to fit the most recent log), which take up 1/2 of the
log buffer's allotted size and will thus cause prune to delete more
compressed logs than it should.

Instead, we should always compress the log chunks in FinishWriting()
such that the compressed size will always be used for log chunks other
than the one that is not actively written to.

Decompressed logs due to readers are ephemeral by their nature and
thus don't add to the log buffer size for pruning.

Test: observe that log buffers can be filled in the presence of a reader.
Change-Id: Ie21ccff032e41c4a0e51710cc435c5ab316563cb
2020-07-16 20:46:14 -07:00

283 lines
11 KiB
C++

/*
* Copyright (C) 2020 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 "SerializedLogChunk.h"
#include <limits>
#include <android-base/stringprintf.h>
#include <android/log.h>
#include <gtest/gtest.h>
using android::base::StringPrintf;
TEST(SerializedLogChunk, smoke) {
size_t chunk_size = 10 * 4096;
auto chunk = SerializedLogChunk{chunk_size};
EXPECT_EQ(chunk_size + sizeof(SerializedLogChunk), chunk.PruneSize());
static const char log_message[] = "log message";
size_t expected_total_len = sizeof(SerializedLogEntry) + sizeof(log_message);
ASSERT_TRUE(chunk.CanLog(expected_total_len));
EXPECT_TRUE(chunk.CanLog(chunk_size));
EXPECT_FALSE(chunk.CanLog(chunk_size + 1));
log_time time(CLOCK_REALTIME);
auto* entry = chunk.Log(1234, time, 0, 1, 2, log_message, sizeof(log_message));
ASSERT_NE(nullptr, entry);
EXPECT_EQ(1234U, entry->sequence());
EXPECT_EQ(time, entry->realtime());
EXPECT_EQ(0U, entry->uid());
EXPECT_EQ(1, entry->pid());
EXPECT_EQ(2, entry->tid());
EXPECT_EQ(sizeof(log_message), entry->msg_len());
EXPECT_STREQ(log_message, entry->msg());
EXPECT_EQ(expected_total_len, entry->total_len());
EXPECT_FALSE(chunk.CanLog(chunk_size));
EXPECT_EQ(static_cast<int>(expected_total_len), chunk.write_offset());
EXPECT_EQ(1234U, chunk.highest_sequence_number());
}
TEST(SerializedLogChunk, fill_log_exactly) {
static const char log_message[] = "this is a log message";
size_t individual_message_size = sizeof(SerializedLogEntry) + sizeof(log_message);
size_t chunk_size = individual_message_size * 3;
auto chunk = SerializedLogChunk{chunk_size};
EXPECT_EQ(chunk_size + sizeof(SerializedLogChunk), chunk.PruneSize());
ASSERT_TRUE(chunk.CanLog(individual_message_size));
EXPECT_NE(nullptr, chunk.Log(1, log_time(), 1000, 1, 1, log_message, sizeof(log_message)));
ASSERT_TRUE(chunk.CanLog(individual_message_size));
EXPECT_NE(nullptr, chunk.Log(2, log_time(), 1000, 2, 1, log_message, sizeof(log_message)));
ASSERT_TRUE(chunk.CanLog(individual_message_size));
EXPECT_NE(nullptr, chunk.Log(3, log_time(), 1000, 3, 1, log_message, sizeof(log_message)));
EXPECT_FALSE(chunk.CanLog(1));
}
TEST(SerializedLogChunk, three_logs) {
size_t chunk_size = 10 * 4096;
auto chunk = SerializedLogChunk{chunk_size};
chunk.Log(2, log_time(0x1234, 0x5678), 0x111, 0x222, 0x333, "initial message",
strlen("initial message"));
chunk.Log(3, log_time(0x2345, 0x6789), 0x444, 0x555, 0x666, "second message",
strlen("second message"));
auto uint64_t_max = std::numeric_limits<uint64_t>::max();
auto uint32_t_max = std::numeric_limits<uint32_t>::max();
chunk.Log(uint64_t_max, log_time(uint32_t_max, uint32_t_max), uint32_t_max, uint32_t_max,
uint32_t_max, "last message", strlen("last message"));
static const char expected_buffer_data[] =
"\x11\x01\x00\x00\x22\x02\x00\x00\x33\x03\x00\x00" // UID PID TID
"\x02\x00\x00\x00\x00\x00\x00\x00" // Sequence
"\x34\x12\x00\x00\x78\x56\x00\x00" // Timestamp
"\x0F\x00initial message" // msg_len + message
"\x44\x04\x00\x00\x55\x05\x00\x00\x66\x06\x00\x00" // UID PID TID
"\x03\x00\x00\x00\x00\x00\x00\x00" // Sequence
"\x45\x23\x00\x00\x89\x67\x00\x00" // Timestamp
"\x0E\x00second message" // msg_len + message
"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF" // UID PID TID
"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF" // Sequence
"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF" // Timestamp
"\x0C\x00last message"; // msg_len + message
for (size_t i = 0; i < chunk_size; ++i) {
if (i < sizeof(expected_buffer_data)) {
EXPECT_EQ(static_cast<uint8_t>(expected_buffer_data[i]), chunk.data()[i])
<< "position: " << i;
} else {
EXPECT_EQ(0, chunk.data()[i]) << "position: " << i;
}
}
}
// Check that the CHECK() in DecReaderRefCount() if the ref count goes bad is caught.
TEST(SerializedLogChunk, catch_DecCompressedRef_CHECK) {
size_t chunk_size = 10 * 4096;
auto chunk = SerializedLogChunk{chunk_size};
EXPECT_DEATH({ chunk.DecReaderRefCount(); }, "");
}
// Check that the CHECK() in ClearUidLogs() if the ref count is greater than 0 is caught.
TEST(SerializedLogChunk, catch_ClearUidLogs_CHECK) {
size_t chunk_size = 10 * 4096;
auto chunk = SerializedLogChunk{chunk_size};
chunk.IncReaderRefCount();
EXPECT_DEATH({ chunk.ClearUidLogs(1000, LOG_ID_MAIN, nullptr); }, "");
chunk.DecReaderRefCount();
}
class UidClearTest : public testing::TestWithParam<bool> {
protected:
template <typename Write, typename Check>
void Test(const Write& write, const Check& check, bool expected_result) {
write(chunk_);
bool finish_writing = GetParam();
if (finish_writing) {
chunk_.FinishWriting();
}
EXPECT_EQ(expected_result, chunk_.ClearUidLogs(kUidToClear, LOG_ID_MAIN, nullptr));
if (finish_writing) {
chunk_.IncReaderRefCount();
}
check(chunk_);
if (finish_writing) {
chunk_.DecReaderRefCount();
}
}
static constexpr size_t kChunkSize = 10 * 4096;
static constexpr uid_t kUidToClear = 1000;
static constexpr uid_t kOtherUid = 1234;
SerializedLogChunk chunk_{kChunkSize};
};
// Test that ClearUidLogs() is a no-op if there are no logs of that UID in the buffer.
TEST_P(UidClearTest, no_logs_in_chunk) {
auto write = [](SerializedLogChunk&) {};
auto check = [](SerializedLogChunk&) {};
Test(write, check, true);
}
// Test that ClearUidLogs() is a no-op if there are no logs of that UID in the buffer.
TEST_P(UidClearTest, no_logs_from_uid) {
static const char msg[] = "this is a log message";
auto write = [](SerializedLogChunk& chunk) {
chunk.Log(1, log_time(), kOtherUid, 1, 2, msg, sizeof(msg));
};
auto check = [](SerializedLogChunk& chunk) {
auto* entry = chunk.log_entry(0);
EXPECT_STREQ(msg, entry->msg());
};
Test(write, check, false);
}
// Test that ClearUidLogs() returns true if all logs in a given buffer correspond to the given UID.
TEST_P(UidClearTest, all_single) {
static const char msg[] = "this is a log message";
auto write = [](SerializedLogChunk& chunk) {
chunk.Log(1, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
};
auto check = [](SerializedLogChunk&) {};
Test(write, check, true);
}
// Test that ClearUidLogs() returns true if all logs in a given buffer correspond to the given UID.
TEST_P(UidClearTest, all_multiple) {
static const char msg[] = "this is a log message";
auto write = [](SerializedLogChunk& chunk) {
chunk.Log(2, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
chunk.Log(3, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
chunk.Log(4, log_time(), kUidToClear, 1, 2, msg, sizeof(msg));
};
auto check = [](SerializedLogChunk&) {};
Test(write, check, true);
}
static std::string MakePrintable(const uint8_t* in, size_t length) {
std::string result;
for (size_t i = 0; i < length; ++i) {
uint8_t c = in[i];
if (isprint(c)) {
result.push_back(c);
} else {
result.append(StringPrintf("\\%02x", static_cast<int>(c) & 0xFF));
}
}
return result;
}
// This test clears UID logs at the beginning and end of the buffer, as well as two back to back
// logs in the interior.
TEST_P(UidClearTest, clear_beginning_and_end) {
static const char msg1[] = "this is a log message";
static const char msg2[] = "non-cleared message";
static const char msg3[] = "back to back cleared messages";
static const char msg4[] = "second in a row gone";
static const char msg5[] = "but we save this one";
static const char msg6[] = "and this 1!";
static const char msg7[] = "the last one goes too";
auto write = [](SerializedLogChunk& chunk) {
ASSERT_NE(nullptr, chunk.Log(1, log_time(), kUidToClear, 1, 2, msg1, sizeof(msg1)));
ASSERT_NE(nullptr, chunk.Log(2, log_time(), kOtherUid, 1, 2, msg2, sizeof(msg2)));
ASSERT_NE(nullptr, chunk.Log(3, log_time(), kUidToClear, 1, 2, msg3, sizeof(msg3)));
ASSERT_NE(nullptr, chunk.Log(4, log_time(), kUidToClear, 1, 2, msg4, sizeof(msg4)));
ASSERT_NE(nullptr, chunk.Log(5, log_time(), kOtherUid, 1, 2, msg5, sizeof(msg5)));
ASSERT_NE(nullptr, chunk.Log(6, log_time(), kOtherUid, 1, 2, msg6, sizeof(msg6)));
ASSERT_NE(nullptr, chunk.Log(7, log_time(), kUidToClear, 1, 2, msg7, sizeof(msg7)));
};
auto check = [](SerializedLogChunk& chunk) {
size_t read_offset = 0;
auto* entry = chunk.log_entry(read_offset);
EXPECT_STREQ(msg2, entry->msg());
read_offset += entry->total_len();
entry = chunk.log_entry(read_offset);
EXPECT_STREQ(msg5, entry->msg());
read_offset += entry->total_len();
entry = chunk.log_entry(read_offset);
EXPECT_STREQ(msg6, entry->msg()) << MakePrintable(chunk.data(), chunk.write_offset());
read_offset += entry->total_len();
EXPECT_EQ(static_cast<int>(read_offset), chunk.write_offset());
};
Test(write, check, false);
}
// This tests the opposite case of beginning_and_end, in which we don't clear the beginning or end
// logs. There is a single log pruned in the middle instead of back to back logs.
TEST_P(UidClearTest, save_beginning_and_end) {
static const char msg1[] = "saved first message";
static const char msg2[] = "cleared interior message";
static const char msg3[] = "last message stays";
auto write = [](SerializedLogChunk& chunk) {
ASSERT_NE(nullptr, chunk.Log(1, log_time(), kOtherUid, 1, 2, msg1, sizeof(msg1)));
ASSERT_NE(nullptr, chunk.Log(2, log_time(), kUidToClear, 1, 2, msg2, sizeof(msg2)));
ASSERT_NE(nullptr, chunk.Log(3, log_time(), kOtherUid, 1, 2, msg3, sizeof(msg3)));
};
auto check = [](SerializedLogChunk& chunk) {
size_t read_offset = 0;
auto* entry = chunk.log_entry(read_offset);
EXPECT_STREQ(msg1, entry->msg());
read_offset += entry->total_len();
entry = chunk.log_entry(read_offset);
EXPECT_STREQ(msg3, entry->msg());
read_offset += entry->total_len();
EXPECT_EQ(static_cast<int>(read_offset), chunk.write_offset());
};
Test(write, check, false);
}
INSTANTIATE_TEST_CASE_P(UidClearTests, UidClearTest, testing::Values(true, false));