1. Naming

A namespace is 1 to 16 characters from [a-z0-9_-]. The default namespace is default. An implementation SHOULD use the value of the environment variable BLEEP_BUS_NAMESPACE when the plugin does not choose one; this lets users and test hosts separate buses (for example two DAWs running at once).

The segment name is built from the major spec version and the namespace:

macOS limits POSIX shared-memory names to 31 characters, which is why the namespace is limited to 16.

The segment MUST be created with permissions for the current user only (POSIX mode 0600). It is never unlinked during normal operation: plugins come and go, the segment stays. Tools MAY unlink it when no host is running.

Creating and opening

1. Open the object with create permission (O_RDWR | O_CREAT).
2. If its size is 0, set it to the v0.1 total size (17 187 072 bytes). The operating system MAY round the size up to whole pages; a size at least the total size is valid. If two processes race, one resize fails harmlessly; re-read the size.
3. Map the first 17 187 072 bytes read/write.
4. Initialise: compare-and-swap header.init_state from 0 to 1. The winner writes the header (section 2) and then stores 2 with release semantics. Everyone else waits (up to 2 s) until init_state reads 2.
5. Validate the header (magic, version, sizes, offsets). On a mismatch the implementation MUST NOT touch the segment and reports a version error.