platform_system_core/libcutils/trace-dev.cpp
Hridya Valsaraju 6a879b25d9 Check /sys/kernel/tracing for tracefs
When debugfs is not mounted, atrace should look for
tracefs in /sys/kernel/tracing.

Test: CtsAtraceHostTestCases
Bug: 148436518
Change-Id: I45c0e664892bcda277fd9612106ad5216aea0a1b
2020-01-30 17:38:51 -08:00

107 lines
2.9 KiB
C++

/*
* Copyright (C) 2012 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 <cutils/trace.h>
#include "trace-dev.inc"
static pthread_once_t atrace_once_control = PTHREAD_ONCE_INIT;
// Set whether tracing is enabled in this process. This is used to prevent
// the Zygote process from tracing.
void atrace_set_tracing_enabled(bool enabled)
{
atomic_store_explicit(&atrace_is_enabled, enabled, memory_order_release);
atrace_update_tags();
}
static void atrace_init_once()
{
atrace_marker_fd = open("/sys/kernel/debug/tracing/trace_marker", O_WRONLY | O_CLOEXEC);
if (atrace_marker_fd == -1) {
atrace_marker_fd = open("/sys/kernel/tracing/trace_marker", O_WRONLY | O_CLOEXEC);
}
if (atrace_marker_fd == -1) {
ALOGE("Error opening trace file: %s (%d)", strerror(errno), errno);
atrace_enabled_tags = 0;
} else {
atrace_enabled_tags = atrace_get_property();
}
#if !ATRACE_SHMEM
atomic_store_explicit(&atrace_is_ready, true, memory_order_release);
#endif
}
static void atrace_seq_number_changed(uint32_t prev_seq_no, uint32_t seq_no) {
if (!atomic_load_explicit(&atrace_is_enabled, memory_order_acquire)) {
return;
}
// Someone raced us.
if (!atomic_compare_exchange_strong(&last_sequence_number, &prev_seq_no, seq_no)) {
return;
}
if (CC_UNLIKELY(prev_seq_no == kSeqNoNotInit)) {
#if defined(__BIONIC__)
const prop_info* new_pi = __system_property_find("debug.atrace.tags.enableflags");
if (new_pi) atrace_property_info = new_pi;
#endif
pthread_once(&atrace_once_control, atrace_init_once);
}
atrace_update_tags();
}
void atrace_setup()
{
#if ATRACE_SHMEM
atrace_init();
#else
pthread_once(&atrace_once_control, atrace_init_once);
#endif
}
void atrace_begin_body(const char* name)
{
WRITE_MSG("B|%d|", "%s", name, "");
}
void atrace_end_body()
{
WRITE_MSG("E|%d", "%s", "", "");
}
void atrace_async_begin_body(const char* name, int32_t cookie)
{
WRITE_MSG("S|%d|", "|%" PRId32, name, cookie);
}
void atrace_async_end_body(const char* name, int32_t cookie)
{
WRITE_MSG("F|%d|", "|%" PRId32, name, cookie);
}
void atrace_int_body(const char* name, int32_t value)
{
WRITE_MSG("C|%d|", "|%" PRId32, name, value);
}
void atrace_int64_body(const char* name, int64_t value)
{
WRITE_MSG("C|%d|", "|%" PRId64, name, value);
}