perf_event_open

pub fn perf_event_open(
    attr: *system.perf_event_attr,
    pid: pid_t,
    cpu: i32,
    group_fd: fd_t,
    flags: usize,
) PerfEventOpenError!fd_t {
    if (native_os == .linux) {
        // There is no syscall wrapper for this function exposed by libcs
        const rc = linux.perf_event_open(attr, pid, cpu, group_fd, flags);
        switch (linux.errno(rc)) {
            .SUCCESS => return @intCast(rc),
            .@"2BIG" => return error.TooBig,
            .ACCES => return error.PermissionDenied,
            .BADF => unreachable, // group_fd file descriptor is not valid.
            .BUSY => return error.DeviceBusy,
            .FAULT => unreachable, // Segmentation fault.
            .INVAL => unreachable, // Bad attr settings.
            .INTR => unreachable, // Mixed perf and ftrace handling for a uprobe.
            .MFILE => return error.ProcessResources,
            .NODEV => return error.EventRequiresUnsupportedCpuFeature,
            .NOENT => unreachable, // Invalid type setting.
            .NOSPC => return error.TooManyBreakpoints,
            .NOSYS => return error.SampleStackNotSupported,
            .OPNOTSUPP => return error.EventNotSupported,
            .OVERFLOW => return error.SampleMaxStackOverflow,
            .PERM => return error.PermissionDenied,
            .SRCH => return error.ProcessNotFound,
            else => |err| return unexpectedErrno(err),
        }
    }
}