mq_timedreceive

Implemented in Antinomie 0.7.0 · Syscall list

Synopsis

long mq_timedreceive(mqd_t mqdes, char *msg_ptr, size_t msg_len, unsigned int *msg_prio, const struct __kernel_timespec *abs_timeout);


Number (x86-64)	243
ABI	common
Kernel entry point	`sys_mq_timedreceive`

This is the raw kernel prototype from the pinned Linux 6.12.94 schema, not the libc wrapper.

Description

Receives a message from a POSIX message queue, with a timeout on an empty queue, and returns its length.

Arguments

Name	Type	Meaning
`mqdes` (arg0)	`mqd_t`	Message queue descriptor.
`msg_ptr` (arg1)	`char *`	Pointer to the message text.
`msg_len` (arg2)	`size_t`	Length of the message in bytes.
`msg_prio` (arg3)	`unsigned int *`	Message priority.
`abs_timeout` (arg4)	`const struct __kernel_timespec *`	Absolute timeout.

Return value

On success: The number of bytes transferred (see the description for what 0 means).

In an Antinomie trace the Return column and the ret filter field show the raw kernel return value. On failure that is the negative errno, for example -2 for ENOENT, not the -1 plus errno that the libc wrapper gives. syscall.errno holds the positive errno and syscall.success is false.

Common errors

Raw return	Name	Meaning
`-11`	`EAGAIN`	The call would block, or a resource is temporarily unavailable.
`-4`	`EINTR`	The call was interrupted by a signal.
`-110`	`ETIMEDOUT`	The operation timed out.

Man page

mq_timedreceive(2) on man7.org

Captured by Antinomie

Coverage mark: Implemented. Every pointer argument has a capture rule in the pinned kernel patch and none of them records a “no decoder”, “address only” or “not observed” gap on any code path. Individual values can still be incomplete on a particular call; see the capture statuses.

Every call is recorded as an Entry record (the six argument words and the pointees copied at entry) and an Exit record (the return value and the pointees copied at exit).

Arguments

Argument	When	How	Recorded field key	Condition
`mqdes` (arg0)	Entry	raw scalar word	`args.0`, `args.mqdes`
`msg_ptr` (arg1)	Entry	the pointer itself, as a raw word	`args.1`, `args.raw[1]`
↳ pointee	Exit	message bytes, length min(`msg_len`, result)	`arg1.message`	result is 0 or greater
`msg_len` (arg2)	Entry	raw scalar word	`args.2`, `args.msg_len`
`msg_prio` (arg3)	Entry	the pointer itself, as a raw word	`args.3`, `args.raw[3]`
↳ pointee	Exit	`u32` priority	`arg3.priority`	result is 0 or greater and the pointer is not NULL
`abs_timeout` (arg4)	Entry	the pointer itself, as a raw word	`args.4`, `args.raw[4]`
↳ pointee	Entry	structure `timespec`	`arg4.timeout`	the pointer is not NULL

Filter fields

Result: ret, syscall.errno, syscall.success, syscall.duration_ns.
Argument words: args.mqdes (arg0), args.msg_ptr (arg1), args.msg_len (arg2), args.msg_prio (arg3), args.abs_timeout (arg4); args.0 to args.5 by position.
Structure wait_status behind msg_prio (arg3): args.msg_prio.<member> for value.
Structure timespec[2] behind abs_timeout (arg4): args.abs_timeout.<member> for tv_nsec, tv_sec.

See Syscall Trace filter for the full syntax.

For what the capture statuses mean, see Capture statuses. For what is never recorded, see Known gaps.