SecureSessionPool

R6 class for a pool of pre-warmed SecureSession instances.

Creates multiple sessions at initialization time so that $execute() calls can run immediately on an idle session without waiting for process startup. Sessions are returned to the pool after each execution completes (or errors).

Value

An R6 object of class SecureSessionPool.

Thread Safety

SecureSessionPool is NOT thread-safe. The acquire/release mechanism uses no locking and assumes single-threaded access. If you need to use pools from multiple processes (e.g., via parallel::mclapply or future), each process should create its own pool instance. Sharing a single pool across threads or forked processes will lead to race conditions in session acquisition.

Methods

Public methods

• SecureSessionPool$new()

• SecureSessionPool$execute()

• SecureSessionPool$size()

• SecureSessionPool$available()

• SecureSessionPool$status()

• SecureSessionPool$format()

• SecureSessionPool$print()

• SecureSessionPool$close()

---

Method new()

Create a new SecureSessionPool

Usage

SecureSessionPool$new(
  size = 4L,
  tools = list(),
  sandbox = TRUE,
  limits = NULL,
  verbose = FALSE,
  reset_between_uses = FALSE
)

Arguments

size

Integer, number of sessions to pre-warm (default 4, minimum 1).

tools

A list of securer_tool() objects passed to each session.

sandbox

Logical, whether to enable OS-level sandboxing.

limits

Optional named list of resource limits.

verbose

Logical, whether to emit diagnostic messages.

reset_between_uses

Logical, whether to restart each session after an execution before returning it to the pool (default FALSE). When TRUE, calls session$restart() after every $execute() to prevent state leaking between executions (e.g., variables, loaded packages, options set by prior code).

---

Method execute()

Execute R code on an available pooled session

Usage

SecureSessionPool$execute(code, timeout = NULL, acquire_timeout = NULL)

Arguments

code

Character string of R code to execute.

timeout

Timeout in seconds, or NULL for no timeout.

acquire_timeout

Optional timeout in seconds to wait for a session to become available. If NULL (default), fails immediately when all sessions are busy. If provided, retries acquisition with a short sleep (0.1s) between retries until the timeout expires.

Returns

The result of evaluating the code.

---

Method size()

Number of sessions in the pool

Usage

SecureSessionPool$size()

Returns

Integer

---

Method available()

Number of idle (non-busy) sessions

Usage

SecureSessionPool$available()

Returns

Integer

---

Method status()

Summary of pool state

Usage

SecureSessionPool$status()

Returns

A named list with total, busy, idle, and dead counts. dead indicates sessions that have crashed and need restart.

---

Method format()

Format method for display

Usage

SecureSessionPool$format(...)

Arguments

...

Ignored.

Returns

A character string describing the pool.

---

Method print()

Print method

Usage

SecureSessionPool$print(...)

Arguments

...

Ignored.

Returns

Invisible self.

---

Method close()

Close all sessions and shut down the pool

Usage

SecureSessionPool$close()

Returns

Invisible self

Examples

# \donttest{
pool <- SecureSessionPool$new(size = 2, sandbox = FALSE)
pool$execute("1 + 1")
#> [1] 2
pool$execute("2 + 2")
#> [1] 4
pool$close()
# }