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Main program for BPF perf buffer example
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| const std = @import("std"); | |
| const bpf = @import("bpf"); | |
| const mem = std.mem; | |
| usingnamespace @import("common.zig"); | |
| const os = std.os; | |
| const assert = std.debug.assert; | |
| const c = @cImport({ | |
| @cInclude("net/if.h"); | |
| }); | |
| // tell the compiler to include multithreaded event loop | |
| pub const io_mode = .evented; | |
| // embed external file into .rodata section | |
| const probe = @embedFile("probe.o"); | |
| comptime { | |
| @setEvalBranchQuota(4000); | |
| assert(bpf.elf.has_section("socket1")); | |
| } | |
| fn consume_events(perf_buffer: *BPF.PerfBuffer) void { | |
| while (perf_buffer.running.get()) { | |
| const payload = perf_buffer.get(); | |
| switch (payload.event) { | |
| .sample => |data| { | |
| defer data.deinit(); | |
| std.debug.print("cpu: {}, sample: {}\n", .{ | |
| payload.cpu, | |
| mem.bytesToValue(usize, data.items[0..8]), | |
| }); | |
| }, | |
| .lost => |cnt| { | |
| std.debug.print("cpu: {}, lost: {}\n", .{ payload.cpu, cnt }); | |
| }, | |
| } | |
| } | |
| } | |
| pub fn main() anyerror!void { | |
| var gpa = std.heap.GeneralPurposeAllocator(.{}){}; | |
| var obj = try bpf.Object.init(&gpa.allocator, probe); | |
| defer obj.deinit(); | |
| try obj.load(); | |
| defer obj.unload(); | |
| const sock_fd = try create_raw_socket("lo"); | |
| defer os.close(sock_fd); | |
| const prog = obj.find_prog("socket1") orelse unreachable; | |
| try os.setsockopt(sock_fd, c.SOL_SOCKET, c.SO_ATTACH_BPF, mem.asBytes(&prog)); | |
| const perf_event_array = try BPF.PerfEventArray.init(BPF.MapInfo{ | |
| .fd = obj.find_map("events") orelse return error.NoEventsMap, | |
| .def = BPF.kern.PerfEventArray.init(256, 0).map.def, | |
| }); | |
| var perf_buffer = try BPF.PerfBuffer.init(&gpa.allocator, perf_event_array, 64); | |
| _ = async perf_buffer.run(); | |
| _ = async consume_events(&perf_buffer); | |
| // suspends current frame in event loop, which ends up running the program indefinitely | |
| suspend; | |
| } |
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