BSD syscall#252
svc · unix #252
msgsys
Multiplexed entry point dispatching the System V message-queue family.
Prototype
int msgsys(u_int which, int a2, int a3, int a4, int a5);Returns: int
Arguments
| Name | Type | Dir | Description |
|---|---|---|---|
| which | u_int | - | |
| a2 | int | - | |
| a3 | int | - | |
| a4 | int | - | |
| a5 | int | - |
Version history
| XNU tag | macOS | # |
|---|---|---|
| xnu-1456.1.26 | macOS 10.6 Snow Leopard | 252 |
| xnu-1699.24.8 | macOS 10.7 Lion | 252 |
| xnu-2050.18.24 | macOS 10.8 Mountain Lion | 252 |
| xnu-1486.2.11 | — | 252 |
| xnu-1504.15.3 | — | 252 |
| xnu-1504.3.12 | — | 252 |
| xnu-1504.7.4 | — | 252 |
| xnu-1504.9.17 | — | 252 |
| xnu-1504.9.26 | — | 252 |
| xnu-1504.9.37 | — | 252 |
| xnu-1699.22.73 | — | 252 |
| xnu-1699.22.81 | — | 252 |
| xnu-1699.24.23 | — | 252 |
| xnu-1699.26.8 | — | 252 |
| xnu-1699.32.7 | — | 252 |
| xnu-2050.22.13 | — | 252 |
| xnu-2050.24.15 | — | 252 |
| xnu-2050.48.11 | — | 252 |
| xnu-2050.7.9 | — | 252 |
| xnu-2050.9.2 | — | 252 |
Notes
msgsys(2) is the historical 4.3BSD-style demultiplexer that takes a subcall number and forwards to msgctl / msgget / msgrcv / msgsnd. macOS keeps it for source compatibility but libSystem always calls the specific syscalls directly; the kernel routes both forms through the same handlers.
Related APIs
msgctlmsggetmsgrcvmsgsnd