jif
4e803a017c
## Why Multi-agent v2 treats agents as durable logical agents, not just live entries in `ThreadManager`. After the reload-on-delivery change, a v2 agent can be addressed even if its thread is not currently loaded. This PR adds the next layer: loaded v2 subagents can be paged out of `ThreadManager` when the session has too many resident agents. That keeps residency separate from logical identity and prepares the stack for making v2 concurrency count active execution instead of existing agents. ## What Changed - Add an `AgentControl`-scoped LRU for resident v2 subagents. - Reserve residency before spawning or reloading a v2 subagent. - If resident capacity is full, unload the least-recently-used idle v2 subagent from `ThreadManager`. - Keep `ThreadManager` as a primitive loaded-thread store; it does not own the LRU policy. - Keep unloaded agents registered and durable so they can be reloaded by the delivery path. - Preserve the existing v2 cap semantics by using the derived non-root v2 cap for residency. Eviction is intentionally conservative. A thread is unloadable only when it is a v2 subagent, has completed or errored, has no active turn, and has no pending mailbox work. Before removal, the rollout is materialized and flushed. ## Assumptions And Non-Goals - PR #26623 provides the reload-on-delivery path for unloaded v2 agents. - `ThreadManager` membership means loaded/resident, not logical agent existence. - `AgentRegistry` remains the logical identity/metadata source for v2 agents that may be unloaded. - `list_agents` remains a recent/resident view for now. - This does not change active execution concurrency; that is the next PR. - This does not change `close_agent` semantics. - This does not change or remove `resume_agent`. - This does not add a new residency config knob. ## Stack 1. V2 durable lookup and reload on delivery (#26623) - reload unloaded v2 agents before delivering follow-up/input. 2. V2 residency LRU (this PR) - unload idle resident v2 agents from `ThreadManager` when resident capacity is full. 3. V2 active-execution concurrency - count running non-root v2 turns instead of logical agents. 4. V2 close/interrupt semantics - make v2 close interrupt the current turn without deleting durable identity. 5. V2 resume cleanup - remove the manual resume surface for v2 while keeping internal reload support. ## Validation - Added focused coverage for the residency LRU eviction path. - Local clippy/check/tests were not run; CI will cover them.
codex-core
This crate implements the business logic for Codex. It is designed to be used by the various Codex UIs written in Rust.
Dependencies
Note that codex-core makes some assumptions about certain helper utilities being available in the environment. Currently, this support matrix is:
macOS
Expects /usr/bin/sandbox-exec to be present.
When using the workspace-write sandbox policy, the Seatbelt profile allows
writes under the configured writable roots while keeping .git (directory or
pointer file), the resolved gitdir: target, and .codex read-only.
Network access and filesystem read/write roots are controlled by
SandboxPolicy. Seatbelt consumes the resolved policy and enforces it.
Seatbelt also keeps the legacy default preferences read access
(user-preference-read) needed for cfprefs-backed macOS behavior.
Linux
Expects the binary containing codex-core to run the equivalent of codex sandbox when arg0 is codex-linux-sandbox. See the codex-arg0 crate for details.
Legacy SandboxPolicy / sandbox_mode configs are still supported on Linux.
They can continue to use the legacy Landlock path when the split filesystem
policy is sandbox-equivalent to the legacy model after cwd resolution.
Split filesystem policies that need direct FileSystemSandboxPolicy
enforcement, such as read-only or denied carveouts under a broader writable
root, automatically route through bubblewrap. The legacy Landlock path is used
only when the split filesystem policy round-trips through the legacy
SandboxPolicy model without changing semantics. That includes overlapping
cases like /repo = write, /repo/a = none, /repo/a/b = write, where the
more specific writable child must reopen under a denied parent.
The Linux sandbox helper prefers the first bwrap found on PATH outside the
current working directory whenever it is available. If bwrap is present but
too old to support --argv0, the helper keeps using system bubblewrap and
switches to a no---argv0 compatibility path for the inner re-exec. If
bwrap is missing, it falls back to the bundled codex-resources/bwrap
binary shipped with Codex and Codex surfaces a startup warning through its
normal notification path instead of printing directly from the sandbox helper.
Codex also surfaces a startup warning when bubblewrap cannot create user
namespaces. WSL2 uses the normal Linux bubblewrap path. WSL1 is not supported
for bubblewrap sandboxing because it cannot create the required user
namespaces, so Codex rejects sandboxed shell commands that would enter the
bubblewrap path before invoking bwrap.
Windows
Legacy SandboxPolicy / sandbox_mode configs are still supported on
Windows. Legacy read-only and workspace-write policies imply full
filesystem read access; exact readable roots are represented by split
filesystem policies instead.
The elevated Windows sandbox also supports:
- legacy
ReadOnlyandWorkspaceWritebehavior - split filesystem policies that need exact readable roots, exact writable roots, or extra read-only carveouts under writable roots
- backend-managed system read roots required for basic execution, such as
C:\Windows,C:\Program Files,C:\Program Files (x86), andC:\ProgramData, when a split filesystem policy requests platform defaults
The unelevated restricted-token backend still supports the legacy full-read
Windows model for legacy ReadOnly and WorkspaceWrite behavior. It also
supports a narrow split-filesystem subset: full-read split policies whose
writable roots still match the legacy WorkspaceWrite root set, but add extra
read-only carveouts under those writable roots.
New [permissions] / split filesystem policies remain supported on Windows
only when they can be enforced directly by the selected Windows backend or
round-trip through the legacy SandboxPolicy model without changing semantics.
Policies that would require direct explicit unreadable carveouts (none) or
reopened writable descendants under read-only carveouts still fail closed
instead of running with weaker enforcement.
All Platforms
Expects the binary containing codex-core to simulate the virtual
apply_patch CLI when arg1 is --codex-run-as-apply-patch. See the
codex-arg0 crate for details.