msgsys:msginfo_msgmnb
| Description | Maximum number of bytes
that can be on any one message queue.
| | Data Type | Unsigned long
| | Default | 4096
| | Range | 0 to amount of physical memory
| | Units | Bytes
| | Dynamic? | No. Loaded into msgmnb field of msginfo structure.
| | Validation | None
| | When to Change | When msgsnd() calls block or return with an error of EGAIN,
or at the recommendation of a software vendor.
| | Commitment Level | Unstable
|
msgsys:msginfo_msgmni
| Description | Maximum number of message
queues that can be created.
| | Data Type | Signed integer
| | Default | 50
| | Range | 0 to MAXINT
| | Dynamic? | No. Loaded into msgmni field of msginfo structure.
| | Validation | None
| | When to Change | When msgget(2) calls return with an error
of ENOSPC or at the recommendation of a software vendor.
| | Commitment Level | Unstable
|
msgsys:msginfo_msgtql
| Description | Maximum number of messages
that can be created. If a msgsnd call attempts to exceed
this limit, the request is deferred until a message header is available. Or,
if the request has set the IPC_NOWAIT flag, the request
fails with the error EAGAIN.
| | Data Type | Signed integer
| | Default | 40
| | Range | 0 to MAXINT
| | Dynamic? | No. Loaded into msgtql field of msginfo structure.
| | Validation | None
| | When to Change | When msgsnd() calls block or return with error of EGAIN, or
at the recommendation of a software vendor.
| | Commitment Level | Unstable
|
System V Semaphores
System V semaphores provide counting semaphores in the Solaris environment.
In addition to the standard set and release operations for semaphores, System
V semaphores can have values that are incremented and decremented as needed
(for example, to represent the number of resources available). The ability
is offered to do operations on a group of semaphores simultaneously as well
as to have the system undo the last operation by a process if it dies.
Semaphores are created in sets.
The module is dynamically loaded on first reference. Parameters provided
to the subsystem are validated at that time and all data structures (including
the semaphores) are created. Values for parameters are, accordingly, not changeable
at runtime because increases in values would lead to data corruption. Entries
in the /etc/system
file must contain the semsys: prefix.
This facility is different from the POSIX 1003.1b semaphore facility.
semsys:seminfo_semmni
| Description | Maximum number of semaphore
identifiers.
| | Data Type | Signed integer
| | Default | 10
| | Range | 1 to 65,535
| | Dynamic? | No
| | Validation | Compared to SEMA_INDEX_MAX (currently 65,535) and reset to that value if larger.
A warning message is written to the console and or system messages file.
| | When to Change | When the default
number of sets is not enough. Generally changed at the recommendation of software
vendors. No error messages are displayed when an attempt is made to create
more sets than are currently configured. The application sees a return code
of ENOSPC from a semget(2) call.
| | Commitment Level | Unstable
|
semsys:seminfo_semmns
| Description | Maximum number of System
V semaphores on the system.
| | Data Type | Signed integer
| | Default | 60
| | Range | 1 to MAXINT
| | Dynamic? | No
| | Validation | The amount of space that
could possibly be consumed by the semaphores and their supporting data structures
is compared to 25% of the kernel memory available at the time the module is
first loaded. If the memory threshold is exceeded, the module refuses to load
and the semaphore facility is not available.
| | When to Change | When the default
number of semaphores is not enough. Generally changed at the recommendation
of software vendors. No error messages are displayed when an attempt is made
to create more semaphores than are currently configured. The application sees
a return code of ENOSPC from a semget(2) call.
| | Commitment Level | Unstable
|
semsys:seminfo_semvmx
| Description | Maximum value a semaphore
can be set to.
| | Data Type | Unsigned short
| | Default | 32,767
| | Range | 1 to 65,535
| | Dynamic? | No
| | Validation | None
| | When to Change | When the default
value is not enough. Generally changed at the recommendation of software vendors.
No error messages are displayed when the maximum value is exceeded. The application
sees a return code of ERANGE from a semop(2) call.
| | Commitment Level | Unstable
|
|
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