SysV semaphores
E701316
SysV semaphores are a classic UNIX System V inter-process communication mechanism that provides counting semaphores for synchronizing access to shared resources among multiple processes.
All labels observed (2)
| Label | Occurrences |
|---|---|
| SysV semaphores canonical | 1 |
| System V semaphores | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T7894692 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: SysV semaphores Context triple: [UNIX System V, influenced, SysV semaphores]
-
A.
System V derivatives
System V derivatives are a family of Unix operating systems that evolved from AT&T’s UNIX System V, shaping many commercial Unix variants and standards.
-
B.
POSIX
POSIX is a family of standardized operating system interfaces and utilities that ensure compatibility and portability among Unix-like systems and applications.
-
C.
Serial Management Protocol (SMP)
Serial Management Protocol (SMP) is a protocol used in Serial Attached SCSI (SAS) environments to manage and configure SAS expanders and devices over the SAS fabric.
-
D.
CSP (Communicating Sequential Processes)
CSP (Communicating Sequential Processes) is a formal model for describing and analyzing concurrent systems based on independent processes that interact solely through message-passing communication.
-
E.
System Use Sharing Protocol
The System Use Sharing Protocol (SUSP) is an extension mechanism for ISO 9660 filesystems that allows additional metadata—such as that used by Rock Ridge—to be stored in a standardized, interoperable way.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: SysV semaphores Target entity description: SysV semaphores are a classic UNIX System V inter-process communication mechanism that provides counting semaphores for synchronizing access to shared resources among multiple processes.
-
A.
SpinLock
SpinLock is a lightweight synchronization primitive in .NET used to protect shared data by repeatedly checking for lock availability instead of blocking threads.
-
B.
System V derivatives
System V derivatives are a family of Unix operating systems that evolved from AT&T’s UNIX System V, shaping many commercial Unix variants and standards.
-
C.
POSIX
POSIX is a family of standardized operating system interfaces and utilities that ensure compatibility and portability among Unix-like systems and applications.
-
D.
Serial Management Protocol (SMP)
Serial Management Protocol (SMP) is a protocol used in Serial Attached SCSI (SAS) environments to manage and configure SAS expanders and devices over the SAS fabric.
-
E.
CSP (Communicating Sequential Processes)
CSP (Communicating Sequential Processes) is a formal model for describing and analyzing concurrent systems based on independent processes that interact solely through message-passing communication.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
UNIX System V IPC primitive
ⓘ
counting semaphore mechanism ⓘ inter-process communication mechanism ⓘ |
| advantage | support for sets of semaphores under one identifier ⓘ |
| availableOn |
BSD-derived systems with System V IPC support
ⓘ
Linux ⓘ UNIX System V ⓘ |
| canBe | persistent until explicitly removed ⓘ |
| configuredVia | kernel parameters ⓘ |
| contrastedWith |
POSIX named semaphores
ⓘ
POSIX unnamed semaphores ⓘ |
| controlledBy | kernel ⓘ |
| definedIn |
<sys/sem.h>
ⓘ
POSIX.1 System Interfaces (XSI) extension ⓘ
linked to:
POSIX
|
| disadvantage |
complex API
ⓘ
system-wide kernel-managed resources ⓘ |
| doesNotSupport | network-transparent synchronization ⓘ |
| hasLimit |
maximum number of semaphore operations per semop call
ⓘ
maximum number of semaphore sets ⓘ maximum number of semaphores per set ⓘ |
| hasMetadata |
creation time
ⓘ
last operation time ⓘ ownership information ⓘ permission bits ⓘ |
| identifiedBy |
IPC key
ⓘ
semaphore set identifier ⓘ |
| introducedIn | UNIX System V ⓘ |
| modeledAs | array of semaphore values ⓘ |
| operatedBy |
semctl
ⓘ
semget ⓘ semop ⓘ |
| relatedTo |
System V message queues
ⓘ
linked to:
SysV message queues
System V shared memory ⓘ
linked to:
System V IPC
|
| removedBy | semctl IPC_RMID ⓘ |
| supports |
counting semaphores
ⓘ
semaphore sets ⓘ |
| supportsOperation |
P operation (decrement / wait)
ⓘ
V operation (increment / signal) ⓘ atomic semaphore operations ⓘ blocking wait ⓘ non-blocking wait ⓘ undo on process exit (SEM_UNDO) ⓘ |
| synchronizes | multiple processes on the same host ⓘ |
| usedFor |
controlling concurrent access to critical sections
ⓘ
inter-process synchronization ⓘ synchronizing access to shared resources ⓘ |
| usedIn |
legacy UNIX applications
ⓘ
multi-process server software ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: SysV semaphores Description of subject: SysV semaphores are a classic UNIX System V inter-process communication mechanism that provides counting semaphores for synchronizing access to shared resources among multiple processes.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: SysV semaphores