Move BpfPerfBuffer under src/maps

This commit is contained in:
Pragyansh Chaturvedi
2025-10-19 18:47:35 +05:30
parent 771d8fef0a
commit 874d567825
4 changed files with 4 additions and 4 deletions

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#include "bpf_perf_buffer.h"
#include "core/bpf_exception.h"
BpfPerfBuffer::BpfPerfBuffer(int map_fd, int page_cnt, py::function callback,
py::object lost_callback)
: pb_(nullptr), callback_(std::move(callback)),
lost_callback_(lost_callback) {
if (page_cnt <= 0 || (page_cnt & (page_cnt - 1)) != 0) {
throw BpfException("page_cnt must be a positive power of 2");
}
struct perf_buffer_opts pb_opts = {};
pb_opts.sz = sizeof(pb_opts); // Required for forward compatibility
pb_ = perf_buffer__new(
map_fd, page_cnt,
sample_callback_wrapper, // sample_cb
lost_callback.is_none() ? nullptr : lost_callback_wrapper, // lost_cb
this, // ctx
&pb_opts // opts
);
if (!pb_) {
throw BpfException("Failed to create perf buffer: " +
std::string(std::strerror(errno)));
}
}
BpfPerfBuffer::~BpfPerfBuffer() {
if (pb_) {
perf_buffer__free(pb_);
}
}
void BpfPerfBuffer::sample_callback_wrapper(void *ctx, int cpu, void *data,
unsigned int size) {
auto *self = static_cast<BpfPerfBuffer *>(ctx);
// Acquire GIL for Python calls
py::gil_scoped_acquire acquire;
try {
// Convert data to Python bytes
py::bytes py_data(static_cast<const char *>(data), size);
// Call Python callback: callback(cpu, data, size)
self->callback_(cpu, py_data, size);
} catch (const py::error_already_set &e) {
PyErr_Print();
}
}
void BpfPerfBuffer::lost_callback_wrapper(void *ctx, int cpu,
unsigned long long cnt) {
auto *self = static_cast<BpfPerfBuffer *>(ctx);
if (self->lost_callback_.is_none()) {
return;
}
py::gil_scoped_acquire acquire;
try {
self->lost_callback_(cpu, cnt);
} catch (const py::error_already_set &e) {
PyErr_Print();
}
}
int BpfPerfBuffer::poll(int timeout_ms) {
// Release GIL during blocking poll
py::gil_scoped_release release;
return perf_buffer__poll(pb_, timeout_ms);
}
int BpfPerfBuffer::consume() {
py::gil_scoped_release release;
return perf_buffer__consume(pb_);
}

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#ifndef PYLIBBPF_BPF_PERF_BUFFER_H
#define PYLIBBPF_BPF_PERF_BUFFER_H
#include <libbpf.h>
#include <pybind11/functional.h>
#include <pybind11/pybind11.h>
namespace py = pybind11;
class BpfPerfBuffer {
private:
struct perf_buffer *pb_;
py::function callback_;
py::function lost_callback_;
// Static callback wrappers for C API
static void sample_callback_wrapper(void *ctx, int cpu, void *data,
unsigned int size);
static void lost_callback_wrapper(void *ctx, int cpu, unsigned long long cnt);
public:
BpfPerfBuffer(int map_fd, int page_cnt, py::function callback,
py::object lost_callback = py::none());
~BpfPerfBuffer();
int poll(int timeout_ms);
int consume();
[[nodiscard]] int fd() const;
};
#endif // PYLIBBPF_BPF_PERF_BUFFER_H