BSD syscall#275
svc · unix #275
sem_init
POSIX entry point for unnamed semaphores; explicitly unsupported on Darwin.
Prototype
int sem_init(sem_t *sem, int phsared, u_int value);Returns: int
Arguments
| Name | Type | Dir | Description |
|---|---|---|---|
| sem | sem_t | - | |
| phsared | int | - | |
| value | u_int | - |
Version history
| XNU tag | macOS | # |
|---|---|---|
| xnu-1456.1.26 | macOS 10.6 Snow Leopard | 275 |
| xnu-1699.24.8 | macOS 10.7 Lion | 275 |
| xnu-2050.18.24 | macOS 10.8 Mountain Lion | 275 |
| xnu-2422.115.4 | macOS 10.9 Mavericks | 275 |
| xnu-1486.2.11 | — | 275 |
| xnu-1504.15.3 | — | 275 |
| xnu-1504.3.12 | — | 275 |
| xnu-1504.7.4 | — | 275 |
| xnu-1504.9.17 | — | 275 |
| xnu-1504.9.26 | — | 275 |
| xnu-1504.9.37 | — | 275 |
| xnu-1699.22.73 | — | 275 |
| xnu-1699.22.81 | — | 275 |
| xnu-1699.24.23 | — | 275 |
| xnu-1699.26.8 | — | 275 |
| xnu-1699.32.7 | — | 275 |
| xnu-2050.22.13 | — | 275 |
| xnu-2050.24.15 | — | 275 |
| xnu-2050.48.11 | — | 275 |
| xnu-2050.7.9 | — | 275 |
| xnu-2050.9.2 | — | 275 |
| xnu-2422.1.72 | — | 275 |
| xnu-2422.100.13 | — | 275 |
| xnu-2422.110.17 | — | 275 |
| xnu-2422.90.20 | — | 275 |
Notes
sem_init(3) is present in <semaphore.h> for source compatibility but the implementation immediately sets errno to ENOSYS and returns -1. Cross-platform code must fall back to sem_open(3) (named), dispatch_semaphore_create() or a pthread_cond_t-based primitive on macOS.
Related APIs
sem_opensem_destroydispatch_semaphore_createpthread_cond_init