liblog: add log/log_read.h (21de8aca) · Commits · e / os / android_system_core

liblog/include/log/log.h

+1 −247

Original line number	Diff line number	Diff line
		@@ -31,6 +31,7 @@
		#include <log/log_id.h>
		#include <log/log_main.h>
		#include <log/log_radio.h>
		#include <log/log_read.h>
		#include <log/log_system.h>
		#include <log/log_time.h>
		#include <log/uio.h> /* helper to define iovec for portability */
		@@ -145,253 +146,6 @@ typedef enum {
		(void) __android_log_bswrite(_tag, _value);
		#endif

		/* --------------------------------------------------------------------- */

		/*
		* Native log reading interface section. See logcat for sample code.
		*
		* The preferred API is an exec of logcat. Likely uses of this interface
		* are if native code suffers from exec or filtration being too costly,
		* access to raw information, or parsing is an issue.
		*/

		/*
		* The userspace structure for version 1 of the logger_entry ABI.
		*/
		#ifndef __struct_logger_entry_defined
		#define __struct_logger_entry_defined
		struct logger_entry {
		uint16_t len; /* length of the payload */
		uint16_t __pad; /* no matter what, we get 2 bytes of padding */
		int32_t pid; /* generating process's pid */
		int32_t tid; /* generating process's tid */
		int32_t sec; /* seconds since Epoch */
		int32_t nsec; /* nanoseconds */
		#ifndef __cplusplus
		char msg[0]; /* the entry's payload */
		#endif
		};
		#endif

		/*
		* The userspace structure for version 2 of the logger_entry ABI.
		*/
		#ifndef __struct_logger_entry_v2_defined
		#define __struct_logger_entry_v2_defined
		struct logger_entry_v2 {
		uint16_t len; /* length of the payload */
		uint16_t hdr_size; /* sizeof(struct logger_entry_v2) */
		int32_t pid; /* generating process's pid */
		int32_t tid; /* generating process's tid */
		int32_t sec; /* seconds since Epoch */
		int32_t nsec; /* nanoseconds */
		uint32_t euid; /* effective UID of logger */
		#ifndef __cplusplus
		char msg[0]; /* the entry's payload */
		#endif
		} __attribute__((__packed__));
		#endif

		/*
		* The userspace structure for version 3 of the logger_entry ABI.
		*/
		#ifndef __struct_logger_entry_v3_defined
		#define __struct_logger_entry_v3_defined
		struct logger_entry_v3 {
		uint16_t len; /* length of the payload */
		uint16_t hdr_size; /* sizeof(struct logger_entry_v3) */
		int32_t pid; /* generating process's pid */
		int32_t tid; /* generating process's tid */
		int32_t sec; /* seconds since Epoch */
		int32_t nsec; /* nanoseconds */
		uint32_t lid; /* log id of the payload */
		#ifndef __cplusplus
		char msg[0]; /* the entry's payload */
		#endif
		} __attribute__((__packed__));
		#endif

		/*
		* The userspace structure for version 4 of the logger_entry ABI.
		*/
		#ifndef __struct_logger_entry_v4_defined
		#define __struct_logger_entry_v4_defined
		struct logger_entry_v4 {
		uint16_t len; /* length of the payload */
		uint16_t hdr_size; /* sizeof(struct logger_entry_v4) */
		int32_t pid; /* generating process's pid */
		uint32_t tid; /* generating process's tid */
		uint32_t sec; /* seconds since Epoch */
		uint32_t nsec; /* nanoseconds */
		uint32_t lid; /* log id of the payload, bottom 4 bits currently */
		uint32_t uid; /* generating process's uid */
		#ifndef __cplusplus
		char msg[0]; /* the entry's payload */
		#endif
		};
		#endif

		/*
		* The maximum size of the log entry payload that can be
		* written to the logger. An attempt to write more than
		* this amount will result in a truncated log entry.
		*/
		#define LOGGER_ENTRY_MAX_PAYLOAD 4068

		/*
		* The maximum size of a log entry which can be read from the
		* kernel logger driver. An attempt to read less than this amount
		* may result in read() returning EINVAL.
		*/
		#define LOGGER_ENTRY_MAX_LEN (5*1024)

		#ifndef __struct_log_msg_defined
		#define __struct_log_msg_defined
		struct log_msg {
		union {
		unsigned char buf[LOGGER_ENTRY_MAX_LEN + 1];
		struct logger_entry_v4 entry;
		struct logger_entry_v4 entry_v4;
		struct logger_entry_v3 entry_v3;
		struct logger_entry_v2 entry_v2;
		struct logger_entry entry_v1;
		} __attribute__((aligned(4)));
		#ifdef __cplusplus
		/* Matching log_time operators */
		bool operator== (const log_msg& T) const
		{
		return (entry.sec == T.entry.sec) && (entry.nsec == T.entry.nsec);
		}
		bool operator!= (const log_msg& T) const
		{
		return !(*this == T);
		}
		bool operator< (const log_msg& T) const
		{
		return (entry.sec < T.entry.sec)
		\|\| ((entry.sec == T.entry.sec)
		&& (entry.nsec < T.entry.nsec));
		}
		bool operator>= (const log_msg& T) const
		{
		return !(*this < T);
		}
		bool operator> (const log_msg& T) const
		{
		return (entry.sec > T.entry.sec)
		\|\| ((entry.sec == T.entry.sec)
		&& (entry.nsec > T.entry.nsec));
		}
		bool operator<= (const log_msg& T) const
		{
		return !(*this > T);
		}
		uint64_t nsec() const
		{
		return static_cast<uint64_t>(entry.sec) * NS_PER_SEC + entry.nsec;
		}

		/* packet methods */
		log_id_t id()
		{
		return static_cast<log_id_t>(entry.lid);
		}
		char* msg()
		{
		unsigned short hdr_size = entry.hdr_size;
		if (!hdr_size) {
		hdr_size = sizeof(entry_v1);
		}
		if ((hdr_size < sizeof(entry_v1)) \|\| (hdr_size > sizeof(entry))) {
		return NULL;
		}
		return reinterpret_cast<char*>(buf) + hdr_size;
		}
		unsigned int len()
		{
		return (entry.hdr_size ?
		entry.hdr_size :
		static_cast<uint16_t>(sizeof(entry_v1))) +
		entry.len;
		}
		#endif
		};
		#endif

		#ifndef __ANDROID_USE_LIBLOG_READER_INTERFACE
		#ifndef __ANDROID_API__
		#define __ANDROID_USE_LIBLOG_READER_INTERFACE 3
		#elif __ANDROID_API__ > 23 /* > Marshmallow */
		#define __ANDROID_USE_LIBLOG_READER_INTERFACE 3
		#elif __ANDROID_API__ > 22 /* > Lollipop */
		#define __ANDROID_USE_LIBLOG_READER_INTERFACE 2
		#elif __ANDROID_API__ > 19 /* > KitKat */
		#define __ANDROID_USE_LIBLOG_READER_INTERFACE 1
		#else
		#define __ANDROID_USE_LIBLOG_READER_INTERFACE 0
		#endif
		#endif

		#if __ANDROID_USE_LIBLOG_READER_INTERFACE

		struct logger;

		log_id_t android_logger_get_id(struct logger* logger);

		int android_logger_clear(struct logger* logger);
		long android_logger_get_log_size(struct logger* logger);
		int android_logger_set_log_size(struct logger* logger, unsigned long size);
		long android_logger_get_log_readable_size(struct logger* logger);
		int android_logger_get_log_version(struct logger* logger);

		struct logger_list;

		#if __ANDROID_USE_LIBLOG_READER_INTERFACE > 1
		ssize_t android_logger_get_statistics(struct logger_list* logger_list,
		char* buf, size_t len);
		ssize_t android_logger_get_prune_list(struct logger_list* logger_list,
		char* buf, size_t len);
		int android_logger_set_prune_list(struct logger_list* logger_list,
		char* buf, size_t len);
		#endif

		#define ANDROID_LOG_RDONLY O_RDONLY
		#define ANDROID_LOG_WRONLY O_WRONLY
		#define ANDROID_LOG_RDWR O_RDWR
		#define ANDROID_LOG_ACCMODE O_ACCMODE
		#define ANDROID_LOG_NONBLOCK O_NONBLOCK
		#if __ANDROID_USE_LIBLOG_READER_INTERFACE > 2
		#define ANDROID_LOG_WRAP 0x40000000 /* Block until buffer about to wrap */
		#define ANDROID_LOG_WRAP_DEFAULT_TIMEOUT 7200 /* 2 hour default */
		#endif
		#if __ANDROID_USE_LIBLOG_READER_INTERFACE > 1
		#define ANDROID_LOG_PSTORE 0x80000000
		#endif

		struct logger_list* android_logger_list_alloc(int mode,
		unsigned int tail,
		pid_t pid);
		struct logger_list* android_logger_list_alloc_time(int mode,
		log_time start,
		pid_t pid);
		void android_logger_list_free(struct logger_list* logger_list);
		/* In the purest sense, the following two are orthogonal interfaces */
		int android_logger_list_read(struct logger_list* logger_list,
		struct log_msg* log_msg);

		/* Multiple log_id_t opens */
		struct logger* android_logger_open(struct logger_list* logger_list,
		log_id_t id);
		#define android_logger_close android_logger_free
		/* Single log_id_t open */
		struct logger_list* android_logger_list_open(log_id_t id,
		int mode,
		unsigned int tail,
		pid_t pid);
		#define android_logger_list_close android_logger_list_free

		#endif /* __ANDROID_USE_LIBLOG_READER_INTERFACE */

		#ifdef __linux__

		#ifndef __ANDROID_USE_LIBLOG_CLOCK_INTERFACE

liblog/include/log/log_read.h

0 → 100644

+291 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2005-2017 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.
		*/

		#ifndef _LIBS_LOG_LOG_READ_H
		#define _LIBS_LOG_LOG_READ_H

		/* deal with possible sys/cdefs.h conflict with fcntl.h */
		#ifdef __unused
		#define __unused_defined __unused
		#undef __unused
		#endif

		#include <fcntl.h> /* Pick up O_* macros */

		/* restore definitions from above */
		#ifdef __unused_defined
		#define __unused __attribute__((__unused__))
		#endif

		#include <stdint.h>

		#include <log/log_id.h>
		#include <log/log_time.h>

		#ifdef __cplusplus
		extern "C" {
		#endif

		/*
		* Native log reading interface section. See logcat for sample code.
		*
		* The preferred API is an exec of logcat. Likely uses of this interface
		* are if native code suffers from exec or filtration being too costly,
		* access to raw information, or parsing is an issue.
		*/

		/*
		* The userspace structure for version 1 of the logger_entry ABI.
		*/
		#ifndef __struct_logger_entry_defined
		#define __struct_logger_entry_defined
		struct logger_entry {
		uint16_t len; /* length of the payload */
		uint16_t __pad; /* no matter what, we get 2 bytes of padding */
		int32_t pid; /* generating process's pid */
		int32_t tid; /* generating process's tid */
		int32_t sec; /* seconds since Epoch */
		int32_t nsec; /* nanoseconds */
		#ifndef __cplusplus
		char msg[0]; /* the entry's payload */
		#endif
		};
		#endif

		/*
		* The userspace structure for version 2 of the logger_entry ABI.
		*/
		#ifndef __struct_logger_entry_v2_defined
		#define __struct_logger_entry_v2_defined
		struct logger_entry_v2 {
		uint16_t len; /* length of the payload */
		uint16_t hdr_size; /* sizeof(struct logger_entry_v2) */
		int32_t pid; /* generating process's pid */
		int32_t tid; /* generating process's tid */
		int32_t sec; /* seconds since Epoch */
		int32_t nsec; /* nanoseconds */
		uint32_t euid; /* effective UID of logger */
		#ifndef __cplusplus
		char msg[0]; /* the entry's payload */
		#endif
		} __attribute__((__packed__));
		#endif

		/*
		* The userspace structure for version 3 of the logger_entry ABI.
		*/
		#ifndef __struct_logger_entry_v3_defined
		#define __struct_logger_entry_v3_defined
		struct logger_entry_v3 {
		uint16_t len; /* length of the payload */
		uint16_t hdr_size; /* sizeof(struct logger_entry_v3) */
		int32_t pid; /* generating process's pid */
		int32_t tid; /* generating process's tid */
		int32_t sec; /* seconds since Epoch */
		int32_t nsec; /* nanoseconds */
		uint32_t lid; /* log id of the payload */
		#ifndef __cplusplus
		char msg[0]; /* the entry's payload */
		#endif
		} __attribute__((__packed__));
		#endif

		/*
		* The userspace structure for version 4 of the logger_entry ABI.
		*/
		#ifndef __struct_logger_entry_v4_defined
		#define __struct_logger_entry_v4_defined
		struct logger_entry_v4 {
		uint16_t len; /* length of the payload */
		uint16_t hdr_size; /* sizeof(struct logger_entry_v4) */
		int32_t pid; /* generating process's pid */
		uint32_t tid; /* generating process's tid */
		uint32_t sec; /* seconds since Epoch */
		uint32_t nsec; /* nanoseconds */
		uint32_t lid; /* log id of the payload, bottom 4 bits currently */
		uint32_t uid; /* generating process's uid */
		#ifndef __cplusplus
		char msg[0]; /* the entry's payload */
		#endif
		};
		#endif

		/*
		* The maximum size of the log entry payload that can be
		* written to the logger. An attempt to write more than
		* this amount will result in a truncated log entry.
		*/
		#define LOGGER_ENTRY_MAX_PAYLOAD 4068

		/*
		* The maximum size of a log entry which can be read.
		* An attempt to read less than this amount may result
		* in read() returning EINVAL.
		*/
		#define LOGGER_ENTRY_MAX_LEN (5*1024)

		#ifndef __struct_log_msg_defined
		#define __struct_log_msg_defined
		struct log_msg {
		union {
		unsigned char buf[LOGGER_ENTRY_MAX_LEN + 1];
		struct logger_entry_v4 entry;
		struct logger_entry_v4 entry_v4;
		struct logger_entry_v3 entry_v3;
		struct logger_entry_v2 entry_v2;
		struct logger_entry entry_v1;
		} __attribute__((aligned(4)));
		#ifdef __cplusplus
		/* Matching log_time operators */
		bool operator== (const log_msg& T) const
		{
		return (entry.sec == T.entry.sec) && (entry.nsec == T.entry.nsec);
		}
		bool operator!= (const log_msg& T) const
		{
		return !(*this == T);
		}
		bool operator< (const log_msg& T) const
		{
		return (entry.sec < T.entry.sec)
		\|\| ((entry.sec == T.entry.sec)
		&& (entry.nsec < T.entry.nsec));
		}
		bool operator>= (const log_msg& T) const
		{
		return !(*this < T);
		}
		bool operator> (const log_msg& T) const
		{
		return (entry.sec > T.entry.sec)
		\|\| ((entry.sec == T.entry.sec)
		&& (entry.nsec > T.entry.nsec));
		}
		bool operator<= (const log_msg& T) const
		{
		return !(*this > T);
		}
		uint64_t nsec() const
		{
		return static_cast<uint64_t>(entry.sec) * NS_PER_SEC + entry.nsec;
		}

		/* packet methods */
		log_id_t id()
		{
		return static_cast<log_id_t>(entry.lid);
		}
		char* msg()
		{
		unsigned short hdr_size = entry.hdr_size;
		if (!hdr_size) {
		hdr_size = sizeof(entry_v1);
		}
		if ((hdr_size < sizeof(entry_v1)) \|\| (hdr_size > sizeof(entry))) {
		return NULL;
		}
		return reinterpret_cast<char*>(buf) + hdr_size;
		}
		unsigned int len()
		{
		return (entry.hdr_size ?
		entry.hdr_size :
		static_cast<uint16_t>(sizeof(entry_v1))) +
		entry.len;
		}
		#endif
		};
		#endif

		#ifndef __ANDROID_USE_LIBLOG_READER_INTERFACE
		#ifndef __ANDROID_API__
		#define __ANDROID_USE_LIBLOG_READER_INTERFACE 3
		#elif __ANDROID_API__ > 23 /* > Marshmallow */
		#define __ANDROID_USE_LIBLOG_READER_INTERFACE 3
		#elif __ANDROID_API__ > 22 /* > Lollipop */
		#define __ANDROID_USE_LIBLOG_READER_INTERFACE 2
		#elif __ANDROID_API__ > 19 /* > KitKat */
		#define __ANDROID_USE_LIBLOG_READER_INTERFACE 1
		#else
		#define __ANDROID_USE_LIBLOG_READER_INTERFACE 0
		#endif
		#endif

		#if __ANDROID_USE_LIBLOG_READER_INTERFACE

		struct logger;

		log_id_t android_logger_get_id(struct logger* logger);

		int android_logger_clear(struct logger* logger);
		long android_logger_get_log_size(struct logger* logger);
		int android_logger_set_log_size(struct logger* logger, unsigned long size);
		long android_logger_get_log_readable_size(struct logger* logger);
		int android_logger_get_log_version(struct logger* logger);

		struct logger_list;

		#if __ANDROID_USE_LIBLOG_READER_INTERFACE > 1
		ssize_t android_logger_get_statistics(struct logger_list* logger_list,
		char* buf, size_t len);
		ssize_t android_logger_get_prune_list(struct logger_list* logger_list,
		char* buf, size_t len);
		int android_logger_set_prune_list(struct logger_list* logger_list,
		char* buf, size_t len);
		#endif

		#define ANDROID_LOG_RDONLY O_RDONLY
		#define ANDROID_LOG_WRONLY O_WRONLY
		#define ANDROID_LOG_RDWR O_RDWR
		#define ANDROID_LOG_ACCMODE O_ACCMODE
		#define ANDROID_LOG_NONBLOCK O_NONBLOCK
		#if __ANDROID_USE_LIBLOG_READER_INTERFACE > 2
		#define ANDROID_LOG_WRAP 0x40000000 /* Block until buffer about to wrap */
		#define ANDROID_LOG_WRAP_DEFAULT_TIMEOUT 7200 /* 2 hour default */
		#endif
		#if __ANDROID_USE_LIBLOG_READER_INTERFACE > 1
		#define ANDROID_LOG_PSTORE 0x80000000
		#endif

		struct logger_list* android_logger_list_alloc(int mode,
		unsigned int tail,
		pid_t pid);
		struct logger_list* android_logger_list_alloc_time(int mode,
		log_time start,
		pid_t pid);
		void android_logger_list_free(struct logger_list* logger_list);
		/* In the purest sense, the following two are orthogonal interfaces */
		int android_logger_list_read(struct logger_list* logger_list,
		struct log_msg* log_msg);

		/* Multiple log_id_t opens */
		struct logger* android_logger_open(struct logger_list* logger_list,
		log_id_t id);
		#define android_logger_close android_logger_free
		/* Single log_id_t open */
		struct logger_list* android_logger_list_open(log_id_t id,
		int mode,
		unsigned int tail,
		pid_t pid);
		#define android_logger_list_close android_logger_list_free

		#endif /* __ANDROID_USE_LIBLOG_READER_INTERFACE */

		#ifdef __cplusplus
		}
		#endif

		#endif /* _LIBS_LOG_LOG_H */

liblog/tests/Android.mk

+1 −0

Original line number	Diff line number	Diff line
		@@ -58,6 +58,7 @@ test_src_files := \
		liblog_test.cpp \
		log_id_test.cpp \
		log_radio_test.cpp \
		log_read_test.cpp \
		log_system_test.cpp \
		log_time_test.cpp

liblog/tests/liblog_test.cpp

+0 −41

Original line number	Diff line number	Diff line
		@@ -1115,47 +1115,6 @@ TEST(liblog, dual_reader) {
		#endif
		}

		TEST(liblog, android_logger_get_) {
		#ifdef __ANDROID__
		// This test assumes the log buffers are filled with noise from
		// normal operations. It will fail if done immediately after a
		// logcat -c.
		struct logger_list * logger_list = android_logger_list_alloc(ANDROID_LOG_WRONLY, 0, 0);

		for(int i = LOG_ID_MIN; i < LOG_ID_MAX; ++i) {
		log_id_t id = static_cast<log_id_t>(i);
		const char *name = android_log_id_to_name(id);
		if (id != android_name_to_log_id(name)) {
		continue;
		}
		fprintf(stderr, "log buffer %s\r", name);
		struct logger * logger;
		EXPECT_TRUE(NULL != (logger = android_logger_open(logger_list, id)));
		EXPECT_EQ(id, android_logger_get_id(logger));
		ssize_t get_log_size = android_logger_get_log_size(logger);
		/* security buffer is allowed to be denied */
		if (strcmp("security", name)) {
		EXPECT_LT(0, get_log_size);
		/* crash buffer is allowed to be empty, that is actually healthy! */
		EXPECT_LE((strcmp("crash", name)) != 0,
		android_logger_get_log_readable_size(logger));
		} else {
		EXPECT_NE(0, get_log_size);
		if (get_log_size < 0) {
		EXPECT_GT(0, android_logger_get_log_readable_size(logger));
		} else {
		EXPECT_LE(0, android_logger_get_log_readable_size(logger));
		}
		}
		EXPECT_LT(0, android_logger_get_log_version(logger));
		}

		android_logger_list_close(logger_list);
		#else
		GTEST_LOG_(INFO) << "This test does nothing.\n";
		#endif
		}

		#ifdef __ANDROID__
		static bool checkPriForTag(AndroidLogFormat p_format, const char tag, android_LogPriority pri) {
		return android_log_shouldPrintLine(p_format, tag, pri)

liblog/tests/log_read_test.cpp

0 → 100644

+118 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2013-2017 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 <sys/types.h>
		#include <time.h>
		#include <unistd.h>

		#include <string>

		#include <android/log.h> // minimal logging API
		#include <android-base/stringprintf.h>
		#include <gtest/gtest.h>
		// Test the APIs in this standalone include file
		#include <log/log_read.h>
		// Do not use anything in log/log_time.h despite side effects of the above.

		TEST(liblog, __android_log_write__android_logger_list_read) {
		#ifdef __ANDROID__
		pid_t pid = getpid();

		struct logger_list *logger_list;
		ASSERT_TRUE(NULL != (logger_list = android_logger_list_open(
		LOG_ID_MAIN, ANDROID_LOG_RDONLY \| ANDROID_LOG_NONBLOCK, 1000, pid)));

		struct timespec ts;
		clock_gettime(CLOCK_MONOTONIC, &ts);
		std::string buf = android::base::StringPrintf("pid=%u ts=%ld.%09ld",
		pid, ts.tv_sec, ts.tv_nsec);
		static const char tag[] = "liblog.__android_log_write__android_logger_list_read";
		static const char prio = ANDROID_LOG_DEBUG;
		ASSERT_LT(0, __android_log_write(prio, tag, buf.c_str()));
		usleep(1000000);

		buf = std::string(&prio, sizeof(prio)) +
		tag +
		std::string("", 1) +
		buf +
		std::string("", 1);

		int count = 0;

		for (;;) {
		log_msg log_msg;
		if (android_logger_list_read(logger_list, &log_msg) <= 0) break;

		EXPECT_EQ(log_msg.entry.pid, pid);
		// There may be a future where we leak "liblog" tagged LOG_ID_EVENT
		// binary messages through so that logger losses can be correlated?
		EXPECT_EQ(log_msg.id(), LOG_ID_MAIN);

		if (log_msg.entry.len != buf.length()) continue;

		if (buf != std::string(log_msg.msg(), log_msg.entry.len)) continue;

		++count;
		}
		android_logger_list_close(logger_list);

		EXPECT_EQ(1, count);
		#else
		GTEST_LOG_(INFO) << "This test does nothing.\n";
		#endif
		}

		TEST(liblog, android_logger_get_) {
		#ifdef __ANDROID__
		// This test assumes the log buffers are filled with noise from
		// normal operations. It will fail if done immediately after a
		// logcat -c.
		struct logger_list * logger_list = android_logger_list_alloc(ANDROID_LOG_WRONLY, 0, 0);

		for(int i = LOG_ID_MIN; i < LOG_ID_MAX; ++i) {
		log_id_t id = static_cast<log_id_t>(i);
		const char *name = android_log_id_to_name(id);
		if (id != android_name_to_log_id(name)) {
		continue;
		}
		fprintf(stderr, "log buffer %s\r", name);
		struct logger * logger;
		EXPECT_TRUE(NULL != (logger = android_logger_open(logger_list, id)));
		EXPECT_EQ(id, android_logger_get_id(logger));
		ssize_t get_log_size = android_logger_get_log_size(logger);
		/* security buffer is allowed to be denied */
		if (strcmp("security", name)) {
		EXPECT_LT(0, get_log_size);
		/* crash buffer is allowed to be empty, that is actually healthy! */
		EXPECT_LE((strcmp("crash", name)) != 0,
		android_logger_get_log_readable_size(logger));
		} else {
		EXPECT_NE(0, get_log_size);
		if (get_log_size < 0) {
		EXPECT_GT(0, android_logger_get_log_readable_size(logger));
		} else {
		EXPECT_LE(0, android_logger_get_log_readable_size(logger));
		}
		}
		EXPECT_LT(0, android_logger_get_log_version(logger));
		}

		android_logger_list_close(logger_list);
		#else
		GTEST_LOG_(INFO) << "This test does nothing.\n";
		#endif
		}