Function memfd_createZ [src]

Prototype

pub fn memfd_createZ(name: [*:0]const u8, flags: u32) MemFdCreateError!fd_t

Parameters

name: [*:0]const u8flags: u32

Possible Errors

NameTooLong

Either the name provided exceeded NAME_MAX, or invalid flags were passed.

OutOfMemory

ProcessFdQuotaExceeded

SystemFdQuotaExceeded

SystemOutdated

Unexpected UnexpectedError

The Operating System returned an undocumented error code.

This error is in theory not possible, but it would be better to handle this error than to invoke undefined behavior.

When this error code is observed, it usually means the Zig Standard Library needs a small patch to add the error code to the error set for the respective function.

Source

  pub fn memfd_createZ(name: [*:0]const u8, flags: u32) MemFdCreateError!fd_t {
    switch (native_os) {
        .linux => {
            // memfd_create is available only in glibc versions starting with 2.27.
            const use_c = std.c.versionCheck(.{ .major = 2, .minor = 27, .patch = 0 });
            const sys = if (use_c) std.c else linux;
            const rc = sys.memfd_create(name, flags);
            switch (errno(rc)) {
                .SUCCESS => return @intCast(rc),
                .FAULT => unreachable, // name has invalid memory
                .INVAL => return error.NameTooLong, // or, program has a bug and flags are faulty
                .NFILE => return error.SystemFdQuotaExceeded,
                .MFILE => return error.ProcessFdQuotaExceeded,
                .NOMEM => return error.OutOfMemory,
                else => |err| return unexpectedErrno(err),
            }
        },
        .freebsd => {
            if (comptime builtin.os.version_range.semver.max.order(.{ .major = 13, .minor = 0, .patch = 0 }) == .lt)
                @compileError("memfd_create is unavailable on FreeBSD < 13.0");
            const rc = system.memfd_create(name, flags);
            switch (errno(rc)) {
                .SUCCESS => return rc,
                .BADF => unreachable, // name argument NULL
                .INVAL => unreachable, // name too long or invalid/unsupported flags.
                .MFILE => return error.ProcessFdQuotaExceeded,
                .NFILE => return error.SystemFdQuotaExceeded,
                .NOSYS => return error.SystemOutdated,
                else => |err| return unexpectedErrno(err),
            }
        },
        else => @compileError("target OS does not support memfd_create()"),
    }
}  