platform_system_core/liblog/logger.h

201 lines
7.6 KiB
C

/*
* Copyright (C) 2016 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 _LIBLOG_LOGGER_H__
#define _LIBLOG_LOGGER_H__
#include <stdatomic.h>
#include <stdbool.h>
#include <cutils/list.h>
#include <log/log.h>
#include <log/uio.h>
#include "log_portability.h"
__BEGIN_DECLS
/* Union, sock or fd of zero is not allowed unless static initialized */
union android_log_context {
void* priv;
atomic_int sock;
atomic_int fd;
struct listnode* node;
atomic_uintptr_t atomic_pointer;
};
struct android_log_transport_write {
struct listnode node;
const char* name; /* human name to describe the transport */
unsigned logMask; /* mask cache of available() success */
union android_log_context context; /* Initialized by static allocation */
int (*available)(log_id_t logId); /* Does not cause resources to be taken */
int (*open)(); /* can be called multiple times, reusing current resources */
void (*close)(); /* free up resources */
/* write log to transport, returns number of bytes propagated, or -errno */
int (*write)(log_id_t logId, struct timespec* ts, struct iovec* vec,
size_t nr);
};
struct android_log_logger_list;
struct android_log_transport_context;
struct android_log_logger;
struct android_log_transport_read {
struct listnode node;
const char* name; /* human name to describe the transport */
/* Does not cause resources to be taken */
int (*available)(log_id_t logId);
int (*version)(struct android_log_logger* logger,
struct android_log_transport_context* transp);
/* Release resources taken by the following interfaces */
void (*close)(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp);
/*
* Expect all to instantiate open automagically on any call,
* so we do not have an explicit open call.
*/
int (*read)(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp,
struct log_msg* log_msg);
/* Must only be called if not ANDROID_LOG_NONBLOCK (blocking) */
int (*poll)(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp);
int (*clear)(struct android_log_logger* logger,
struct android_log_transport_context* transp);
ssize_t (*setSize)(struct android_log_logger* logger,
struct android_log_transport_context* transp, size_t size);
ssize_t (*getSize)(struct android_log_logger* logger,
struct android_log_transport_context* transp);
ssize_t (*getReadableSize)(struct android_log_logger* logger,
struct android_log_transport_context* transp);
ssize_t (*getPrune)(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp, char* buf,
size_t len);
ssize_t (*setPrune)(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp, char* buf,
size_t len);
ssize_t (*getStats)(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp, char* buf,
size_t len);
};
struct android_log_logger_list {
struct listnode node;
struct listnode logger;
struct listnode transport;
int mode;
unsigned int tail;
log_time start;
pid_t pid;
};
struct android_log_logger {
struct listnode node;
struct android_log_logger_list* parent;
log_id_t logId;
};
struct android_log_transport_context {
struct listnode node;
union android_log_context context; /* zero init per-transport context */
struct android_log_logger_list* parent;
struct android_log_transport_read* transport;
unsigned logMask; /* mask of requested log buffers */
int ret; /* return value associated with following data */
struct log_msg logMsg; /* peek at upcoming data, valid if logMsg.len != 0 */
};
/* assumes caller has structures read-locked, single threaded, or fenced */
#define transport_context_for_each(transp, logger_list) \
for ((transp) = node_to_item((logger_list)->transport.next, \
struct android_log_transport_context, node); \
((transp) != node_to_item(&(logger_list)->transport, \
struct android_log_transport_context, node)) && \
((transp)->parent == (logger_list)); \
(transp) = node_to_item((transp)->node.next, \
struct android_log_transport_context, node))
#define logger_for_each(logp, logger_list) \
for ((logp) = node_to_item((logger_list)->logger.next, \
struct android_log_logger, node); \
((logp) != node_to_item(&(logger_list)->logger, \
struct android_log_logger, node)) && \
((logp)->parent == (logger_list)); \
(logp) = \
node_to_item((logp)->node.next, struct android_log_logger, node))
/*
* Global list of log readers.
*
* Usage case: search out transport contexts for all readers
*/
LIBLOG_HIDDEN struct listnode __android_log_readers;
#if defined(_WIN32)
#define logger_list_rdlock()
#define logger_list_wrlock()
#define logger_list_unlock()
#else
LIBLOG_HIDDEN pthread_rwlock_t __android_log_readers_lock;
#define logger_list_rdlock() pthread_rwlock_rdlock(&__android_log_readers_lock)
#define logger_list_wrlock() pthread_rwlock_wrlock(&__android_log_readers_lock)
#define logger_list_unlock() pthread_rwlock_unlock(&__android_log_readers_lock)
#endif
/* Must be called with logger_list_rdlock() or logger_list_wrlock() held */
#define logger_list_for_each(logger_list) \
for ((logger_list) = node_to_item(&__android_log_readers, \
struct android_log_logger_list, node); \
(logger_list) != node_to_item(&__android_log_readers, \
struct android_log_logger_list, node) && \
(logger_list) != node_to_item((logger_list)->node.next, \
struct android_log_logger_list, node); \
(logger_list) = node_to_item((logger_list)->node.next, \
struct android_log_logger_list, node))
/* OS specific dribs and drabs */
#if defined(_WIN32)
#include <private/android_filesystem_config.h>
typedef uint32_t uid_t;
static inline uid_t __android_log_uid() {
return AID_SYSTEM;
}
#else
static inline uid_t __android_log_uid() {
return getuid();
}
#endif
LIBLOG_HIDDEN void __android_log_lock();
LIBLOG_HIDDEN int __android_log_trylock();
LIBLOG_HIDDEN void __android_log_unlock();
LIBLOG_HIDDEN int __android_log_transport;
__END_DECLS
#endif /* _LIBLOG_LOGGER_H__ */