category

amqp_pool

AMQP connection pool category. Import this category into an object to create a named connection pool with automatic connection management.

Availability:
logtalk_load(amqp(loader))
Author: Paulo Moura
Version: 1:0:0
Date: 2026-02-19
Compilation flags:
static
Uses:
amqp
list
os
Remarks:
(none)
Inherited public predicates:
(none)

Public predicates

initialize/1

Initializes the connection pool with the given configuration options. Must be called before using other pool predicates.

Compilation flags:
static
Template:
initialize(Options)
Mode and number of proofs:
initialize(+list) - one_or_error
Remarks:

  • Option host(Host): AMQP server hostname. Default is localhost.

  • Option port(Port): AMQP server port. Default is 5672.

  • Option min_size(N): Minimum number of connections to maintain. Default is 1.

  • Option max_size(N): Maximum number of connections allowed. Default is 10.

  • Option connection_options(Options): Options passed to amqp::connect/4. Default is [].

destroy/0

Destroys the pool, closing all connections and clearing state.

Compilation flags:
static
Mode and number of proofs:
destroy - one

acquire/1

Acquires a connection from the pool. Returns an available connection or creates a new one if the pool is not at maximum capacity.

Compilation flags:
static
Template:
acquire(Connection)
Mode and number of proofs:
acquire(--compound) - one_or_error
Exceptions:
Pool not initialized:
pool_error(not_initialized)
Pool exhausted (at max capacity):
pool_error(exhausted)

release/1

Releases a connection back to the pool, making it available for reuse.

Compilation flags:
static
Template:
release(Connection)
Mode and number of proofs:
release(+compound) - one

with_connection/1

Acquires a connection, calls Goal with the connection as argument, and releases the connection. The connection is released even if Goal fails or throws an exception.

Compilation flags:
static
Template:
with_connection(Goal)
Meta-predicate template:
with_connection(1)
Mode and number of proofs:
with_connection(+callable) - zero_or_more

stats/1

Returns pool statistics as a compound term stats(Available, InUse, Total, MinSize, MaxSize).

Compilation flags:
static
Template:
stats(Stats)
Mode and number of proofs:
stats(-compound) - one

resize/2

Resizes the pool by setting new minimum and maximum sizes.

Compilation flags:
static
Template:
resize(MinSize,MaxSize)
Mode and number of proofs:
resize(+integer,+integer) - one_or_error

Protected predicates

(no local declarations; see entity ancestors if any)

Private predicates

pool_config/5

Stores the pool configuration parameters.

Compilation flags:
dynamic
Template:
pool_config(Host,Port,MinSize,MaxSize,ConnectionOptions)
Mode and number of proofs:
pool_config(?atom,?integer,?integer,?integer,?list) - zero_or_one

available/1

Tracks connections that are available for use.

Compilation flags:
dynamic
Template:
available(Connection)
Mode and number of proofs:
available(?compound) - zero_or_more

in_use/2

Tracks connections currently in use along with their acquisition timestamp.

Compilation flags:
dynamic
Template:
in_use(Connection,AcquireTimestamp)
Mode and number of proofs:
in_use(?compound,?compound) - zero_or_more

Operators

(none)