mach/mach.h

Reports a fatal user-space error. Writes "panic: <s>" to the standard error stream, requests host_reboot(RB_DEBUGGER) on the host port previously registered with panic_init (effective only if that is the privileged host port), and then calls abort(); does not return. Despite the printf-like prototype, the current implementation formats only the format string itself and ignores the variadic arguments.

Historical CMU routine that converts machine slot values to human-readable strings: given a cpu type and subtype, stores pointers to static name strings for the CPU type and subtype through the last two parameters. The prototype survives in mach.h, but slot_name.c in current xnu retains only unrelated legacy stubs; the implementation is no longer present in the xnu sources. See mach_host.h cpu naming interfaces for current alternatives.

Initializes a MIG reply message header from a request message. Sets the reply's msgh_bits from the request's local bits (remote disposition only), msgh_size to sizeof(mig_reply_error_t), msgh_remote_port to the request's msgh_local_port (the reply port), msgh_local_port to MACH_PORT_NULL, and msgh_id to the request id plus 100, following the MIG reply-id convention; also stores the NDR record. Does not set a value in the RetCode field.

Deallocates all port rights and out-of-line memory carried in a message. Useful in two contexts: disposing of a received request a server does not want, and mimicking the side effects of a send when the reply cannot be delivered (the client died), as if the message were sent and destroyed inside the kernel. Releases the msgh_remote_port and msgh_voucher_port rights according to their dispositions and, if MACH_MSGH_BITS_COMPLEX is set, walks the descriptors: port and ool-ports rights are destroyed (guarded ports are unguarded first), and out-of-line memory with the deallocate bit set is released with vm_deallocate. The msgh_local_port field is not touched; the receive operation already consumed the destination port right.

Receives a message. Equivalent to mach_msg with MACH_RCV_MSG, receiving on the port named by msg->msgh_local_port into msg with receive limit msg->msgh_size and no timeout. Interrupted receives are restarted transparently by mach_msg.

Sends a message. Equivalent to mach_msg with MACH_SEND_MSG, send size msg->msgh_size, and no timeout. Interrupted sends are restarted transparently by mach_msg.

A simple generic server function that processes a single request and returns; allows more flexibility than mach_msg_server. Allocates request and reply buffers (max_size plus space for the requested trailer), receives one message on rcv_name with MACH_RCV_VOUCHER (honoring MACH_RCV_LARGE by reallocating a larger buffer), adopts the message's voucher, and invokes the demux routine to build the reply. The reply is sent unless its RetCode is MIG_NO_REPLY or the reply port is null; on any other failing RetCode the request is destroyed first. MACH_SEND_TIMEOUT is added when replying to a send right (a send-once right cannot block). Recoverable send failures (MACH_SEND_INVALID_DEST, MACH_SEND_TIMED_OUT, MACH_SEND_INTERRUPTED) destroy the unsent reply and report MACH_MSG_SUCCESS. Errors from mach_msg are returned; errors from the demux routine are not.

A simple generic server loop. Repeatedly receives requests on rcv_name with MACH_RCV_VOUCHER, adopts each message's voucher, invokes the demux routine to generate a reply, and sends the reply, using a combined send/receive to stay on the kernel's fast RPC path. Replies are suppressed when the demux RetCode is MIG_NO_REPLY or the reply port is null; on any other failing RetCode the request is destroyed. MACH_SEND_TIMEOUT is added when replying to a send right rather than a send-once right, and recoverable send failures (MACH_SEND_INVALID_DEST, MACH_SEND_TIMED_OUT, MACH_SEND_INTERRUPTED) destroy the unsent reply and continue the loop. MACH_RCV_LARGE in options causes the request buffer to be grown as needed. Returns only when a receive fails, with that mach_msg error.

Identical to mach_msg_server; the current implementation simply calls it. Historically a variant that handled importance-promotion assertions for adaptive daemons around each request; that handling is now performed by the voucher adoption done in mach_msg_server itself, and this entry point remains for compatibility.

Obsolete compatibility prototype, declared in mach.h alongside clock_get_res; intended to set the resolution, in nanoseconds (clock_res_t), of the clock named by the port. No implementation exists in current libsyscall, and the underlying privileged clock-attribute interface (clock_set_attributes) has been removed from the kernel, so clock resolution cannot be changed. clock_get_res remains available to read the resolution.