Git Source Code Mirror - This is a publish-only repository and all pull requests are ignored. Please follow Documentation/SubmittingPatches procedure for any of your improvements. https://git-scm.com/
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

234 lines
6.7 KiB

#ifndef GIT_SIMPLE_IPC_H
#define GIT_SIMPLE_IPC_H
/*
* See Documentation/technical/api-simple-ipc.txt
*/
enum ipc_active_state {
/*
* The pipe/socket exists and the daemon is waiting for connections.
*/
IPC_STATE__LISTENING = 0,
/*
* The pipe/socket exists, but the daemon is not listening.
* Perhaps it is very busy.
* Perhaps the daemon died without deleting the path.
* Perhaps it is shutting down and draining existing clients.
* Perhaps it is dead, but other clients are lingering and
* still holding a reference to the pathname.
*/
IPC_STATE__NOT_LISTENING,
/*
* The requested pathname is bogus and no amount of retries
* will fix that.
*/
IPC_STATE__INVALID_PATH,
/*
* The requested pathname is not found. This usually means
* that there is no daemon present.
*/
IPC_STATE__PATH_NOT_FOUND,
IPC_STATE__OTHER_ERROR,
};
#ifdef SUPPORTS_SIMPLE_IPC
#include "pkt-line.h"
/*
* Simple IPC Client Side API.
*/
struct ipc_client_connect_options {
/*
* Spin under timeout if the server is running but can't
* accept our connection yet. This should always be set
* unless you just want to poke the server and see if it
* is alive.
*/
unsigned int wait_if_busy:1;
/*
* Spin under timeout if the pipe/socket is not yet present
* on the file system. This is useful if we just started
* the service and need to wait for it to become ready.
*/
unsigned int wait_if_not_found:1;
/*
* Disallow chdir() when creating a Unix domain socket.
*/
unsigned int uds_disallow_chdir:1;
};
#define IPC_CLIENT_CONNECT_OPTIONS_INIT { 0 }
/*
* Determine if a server is listening on this named pipe or socket using
* platform-specific logic. This might just probe the filesystem or it
* might make a trivial connection to the server using this pathname.
*/
enum ipc_active_state ipc_get_active_state(const char *path);
struct ipc_client_connection {
int fd;
};
/*
* Try to connect to the daemon on the named pipe or socket.
*
* Returns IPC_STATE__LISTENING and a connection handle.
*
* Otherwise, returns info to help decide whether to retry or to
* spawn/respawn the server.
*/
enum ipc_active_state ipc_client_try_connect(
const char *path,
const struct ipc_client_connect_options *options,
struct ipc_client_connection **p_connection);
void ipc_client_close_connection(struct ipc_client_connection *connection);
/*
* Used by the client to synchronously send and receive a message with
* the server on the provided client connection.
*
* Returns 0 when successful.
*
* Calls error() and returns non-zero otherwise.
*/
int ipc_client_send_command_to_connection(
struct ipc_client_connection *connection,
const char *message, size_t message_len,
struct strbuf *answer);
/*
* Used by the client to synchronously connect and send and receive a
* message to the server listening at the given path.
*
* Returns 0 when successful.
*
* Calls error() and returns non-zero otherwise.
*/
int ipc_client_send_command(const char *path,
const struct ipc_client_connect_options *options,
const char *message, size_t message_len,
struct strbuf *answer);
/*
* Simple IPC Server Side API.
*/
struct ipc_server_reply_data;
typedef int (ipc_server_reply_cb)(struct ipc_server_reply_data *,
const char *response,
size_t response_len);
/*
* Prototype for an application-supplied callback to process incoming
* client IPC messages and compose a reply. The `application_cb` should
* use the provided `reply_cb` and `reply_data` to send an IPC response
* back to the client. The `reply_cb` callback can be called multiple
* times for chunking purposes. A reply message is optional and may be
* omitted if not necessary for the application.
*
* The return value from the application callback is ignored.
* The value `SIMPLE_IPC_QUIT` can be used to shutdown the server.
*/
typedef int (ipc_server_application_cb)(void *application_data,
const char *request,
size_t request_len,
ipc_server_reply_cb *reply_cb,
struct ipc_server_reply_data *reply_data);
#define SIMPLE_IPC_QUIT -2
/*
* Opaque instance data to represent an IPC server instance.
*/
struct ipc_server_data;
/*
* Control parameters for the IPC server instance.
* Use this to hide platform-specific settings.
*/
struct ipc_server_opts
{
int nr_threads;
/*
* Disallow chdir() when creating a Unix domain socket.
*/
unsigned int uds_disallow_chdir:1;
};
/*
* Start an IPC server instance in one or more background threads
* and return a handle to the pool.
*
* Returns 0 if the asynchronous server pool was started successfully.
* Returns -1 if not.
* Returns -2 if we could not startup because another server is using
* the socket or named pipe.
*
* When a client IPC message is received, the `application_cb` will be
* called (possibly on a random thread) to handle the message and
* optionally compose a reply message.
*/
int ipc_server_run_async(struct ipc_server_data **returned_server_data,
const char *path, const struct ipc_server_opts *opts,
ipc_server_application_cb *application_cb,
void *application_data);
/*
* Gently signal the IPC server pool to shutdown. No new client
* connections will be accepted, but existing connections will be
* allowed to complete.
*/
int ipc_server_stop_async(struct ipc_server_data *server_data);
/*
* Block the calling thread until all threads in the IPC server pool
* have completed and been joined.
*/
int ipc_server_await(struct ipc_server_data *server_data);
/*
* Close and free all resource handles associated with the IPC server
* pool.
*/
void ipc_server_free(struct ipc_server_data *server_data);
/*
* Run an IPC server instance and block the calling thread of the
* current process. It does not return until the IPC server has
* either shutdown or had an unrecoverable error.
*
* The IPC server handles incoming IPC messages from client processes
* and may use one or more background threads as necessary.
*
* Returns 0 after the server has completed successfully.
* Returns -1 if the server cannot be started.
* Returns -2 if we could not startup because another server is using
* the socket or named pipe.
*
* When a client IPC message is received, the `application_cb` will be
* called (possibly on a random thread) to handle the message and
* optionally compose a reply message.
*
* Note that `ipc_server_run()` is a synchronous wrapper around the
* above asynchronous routines. It effectively hides all of the
* server state and thread details from the caller and presents a
* simple synchronous interface.
*/
int ipc_server_run(const char *path, const struct ipc_server_opts *opts,
ipc_server_application_cb *application_cb,
void *application_data);
#endif /* SUPPORTS_SIMPLE_IPC */
#endif /* GIT_SIMPLE_IPC_H */