ladybird/Kernel/Profiling.cpp
Andreas Kling d7a13dbaa7 Kernel: Reset profiling state on exec() (but keep it going)
We now log the new executable on exec() and throw away all the samples
we've accumulated so far. But profiling keeps going.
2020-02-22 10:54:50 +01:00

109 lines
3 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Demangle.h>
#include <AK/StringBuilder.h>
#include <Kernel/FileSystem/Custody.h>
#include <Kernel/KBuffer.h>
#include <Kernel/KSyms.h>
#include <Kernel/Process.h>
#include <Kernel/Profiling.h>
#include <LibELF/ELFLoader.h>
namespace Kernel {
namespace Profiling {
static KBufferImpl* s_profiling_buffer;
static size_t s_slot_count;
static size_t s_next_slot_index;
static Process* s_process;
static u32 s_pid;
String& executable_path()
{
static String* path;
if (!path)
path = new String;
return *path;
}
u32 pid()
{
return s_pid;
}
void start(Process& process)
{
s_process = &process;
executable_path() = process.executable()->absolute_path().impl();
s_pid = process.pid();
if (!s_profiling_buffer) {
s_profiling_buffer = RefPtr<KBufferImpl>(KBuffer::create_with_size(8 * MB).impl()).leak_ref();
s_profiling_buffer->region().commit();
s_slot_count = s_profiling_buffer->size() / sizeof(Sample);
}
s_next_slot_index = 0;
}
static Sample& sample_slot(size_t index)
{
return ((Sample*)s_profiling_buffer->data())[index];
}
Sample& next_sample_slot()
{
auto& slot = sample_slot(s_next_slot_index++);
if (s_next_slot_index >= s_slot_count)
s_next_slot_index = 0;
return slot;
}
void stop()
{
s_process = nullptr;
}
void did_exec(const String& new_executable_path)
{
executable_path() = new_executable_path;
s_next_slot_index = 0;
}
void for_each_sample(Function<void(Sample&)> callback)
{
for (size_t i = 0; i < s_next_slot_index; ++i) {
auto& sample = sample_slot(i);
callback(sample);
}
}
}
}