Lacca v0.1.1 Lacca View Source

Link to this section Summary

Functions

Waits for the child process to exit, and returns a result struct which includes the status code (if applicable), and any remaining data from the stdout or stderr buffers for this process

Returns a specification to start this module under a supervisor

Invoked when the server is started. start_link/3 or start/3 will block until it returns

Attempts to terminate the process immediately. Caller should expect that the process will not be gracefully terminated; similarly to calling SIGKILL on a POSIX operating system

Returns {:ok, binary} which includes any data received from the child's stderr file descriptor. Note that the internal buffer is then cleared, such that subsequent reads will not return this same data again.

Returns {:ok, binary} which includes any data received from the child's stdout file descriptor. Note that the internal buffer is then cleared, such that subsequent reads will not return this same data again.

Starts a server which will run the executable located at exec_path with the specified command line arguments. The returned handle, of the form {:ok, pid}, can be used to interact w/ the program

Requests that the resin daemon send SIGTERM or equivalent to forcefully terminate the running child process. This function returns immediately, and the signal is sent asynchronously

Returns :ok if the data has been sent to the underlying resin daemon. Note that this function returns immediately after having sent the packet to the daemon, no guarantees as to the delivery to the child process are afforded. (i.e: the child may have closed its stdin prematurely, the child may have exited in the interim, it may be deadlocked and not processing stdin, etc.)

Link to this section Functions

Waits for the child process to exit, and returns a result struct which includes the status code (if applicable), and any remaining data from the stdout or stderr buffers for this process.

When this function returns pid will have exited.

Returns a specification to start this module under a supervisor.

See Supervisor.

Invoked when the server is started. start_link/3 or start/3 will block until it returns.

init_arg is the argument term (second argument) passed to start_link/3.

Returning {:ok, state} will cause start_link/3 to return {:ok, pid} and the process to enter its loop.

Returning {:ok, state, timeout} is similar to {:ok, state}, except that it also sets a timeout. See the "Timeouts" section in the module documentation for more information.

Returning {:ok, state, :hibernate} is similar to {:ok, state} except the process is hibernated before entering the loop. See c:handle_call/3 for more information on hibernation.

Returning {:ok, state, {:continue, continue}} is similar to {:ok, state} except that immediately after entering the loop the c:handle_continue/2 callback will be invoked with the value continue as first argument.

Returning :ignore will cause start_link/3 to return :ignore and the process will exit normally without entering the loop or calling c:terminate/2. If used when part of a supervision tree the parent supervisor will not fail to start nor immediately try to restart the GenServer. The remainder of the supervision tree will be started and so the GenServer should not be required by other processes. It can be started later with Supervisor.restart_child/2 as the child specification is saved in the parent supervisor. The main use cases for this are:

  • The GenServer is disabled by configuration but might be enabled later.
  • An error occurred and it will be handled by a different mechanism than the Supervisor. Likely this approach involves calling Supervisor.restart_child/2 after a delay to attempt a restart.

Returning {:stop, reason} will cause start_link/3 to return {:error, reason} and the process to exit with reason reason without entering the loop or calling c:terminate/2.

Callback implementation for GenServer.init/1.

Attempts to terminate the process immediately. Caller should expect that the process will not be gracefully terminated; similarly to calling SIGKILL on a POSIX operating system.

Returns {:ok, binary} which includes any data received from the child's stderr file descriptor. Note that the internal buffer is then cleared, such that subsequent reads will not return this same data again.

Returns {:ok, binary} which includes any data received from the child's stdout file descriptor. Note that the internal buffer is then cleared, such that subsequent reads will not return this same data again.

Starts a server which will run the executable located at exec_path with the specified command line arguments. The returned handle, of the form {:ok, pid}, can be used to interact w/ the program.

Note that stdout and stderr from the process are captured inside StringIO buffers internally. This data will remain in-memory until this server is either killed, or the buffers are flushed using the respective API functions.

Errors

This method will raise ArgumentError if the resin daemon cannot be found on your system's executable PATH. The configuration key located at :resin, :daemon_path can be used to force this process to run the daemon from a non-standard location.

Requests that the resin daemon send SIGTERM or equivalent to forcefully terminate the running child process. This function returns immediately, and the signal is sent asynchronously.

Use await/1 if you wish to block on the child process actually terminating.

Returns :ok if the data has been sent to the underlying resin daemon. Note that this function returns immediately after having sent the packet to the daemon, no guarantees as to the delivery to the child process are afforded. (i.e: the child may have closed its stdin prematurely, the child may have exited in the interim, it may be deadlocked and not processing stdin, etc.)