boinc/lib/app_ipc.h

// Berkeley Open Infrastructure for Network Computing
// http://boinc.berkeley.edu
// Copyright (C) 2005 University of California
//
// This is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation;
// either version 2.1 of the License, or (at your option) any later version.
//
// This software is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU Lesser General Public License for more details.
//
// To view the GNU Lesser General Public License visit
// http://www.gnu.org/copyleft/lesser.html
// or write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

#ifndef _APP_IPC_
#define _APP_IPC_

#include <vector>
#include <string>
#include <cstdio>

#include "hostinfo.h"
#include "proxy_info.h"
#include "prefs.h"

// Communication between the core client and the BOINC app library.
// This code is linked into both core client and app lib.
//
// Some apps may involve separate "coordinator" and "worker" programs.
// The coordinator runs one or more worker programs in sequence,
// and don't do work themselves.
//
// Includes the following:
// - shared memory (APP_CLIENT_SHM)
// - main init file
// - fd init file
// - graphics init file
// - conversion of symbolic links

// Shared memory is a set of MSG_CHANNELs.
// First byte of a channel is nonzero if
// the channel contains an unread data.
// This is set by the sender and cleared by the receiver.
// The sender doesn't write if the flag is set.
// Remaining 1023 bytes contain data.
//
#define MSG_CHANNEL_SIZE 1024

struct MSG_CHANNEL {
    char buf[MSG_CHANNEL_SIZE];
    bool get_msg(char*);    // returns a message and clears pending flag
    bool has_msg();
    bool send_msg(const char*);   // if there is not a message in the segment,
                            // writes specified message and sets pending flag
    void send_msg_overwrite(const char*);
                            // write message, overwriting any msg already there
};

struct SHARED_MEM {
    MSG_CHANNEL process_control_request;
        // core->app
        // <quit/>
        // <suspend/>
        // <resume/>
    MSG_CHANNEL process_control_reply;
        // app->core
        // same as above
    MSG_CHANNEL graphics_request;
        // core->app
        // request a graphics mode:
        // <mode_hide_graphics/>
        // ...
        // <mode_blankscreen/>
    MSG_CHANNEL graphics_reply;
        // app->core
        // same as above
    MSG_CHANNEL heartbeat;
        // core->app
        // <heartbeat/>             sent every second, even while app is suspended
        // <disable_heartbeat/>     disables heartbeat mechanism
        // <enable_heartbeat/>      enable heartbeat mechanism (default)
    MSG_CHANNEL app_status;
        // app->core
        // status message every second, of the form
        // <current_cpu_time>...
        // <checkpoint_cpu_time>...
        // <working_set_size>...
        // <fraction_done> ...
    MSG_CHANNEL trickle_up;
        // app->core
        // <have_new_trickle_up/>
    MSG_CHANNEL trickle_down;
        // core->app
        // <have_new_trickle_down/>
};

// MSG_QUEUE provides a queuing mechanism for shared-mem messages
// (which don't have one otherwise)
//
struct MSG_QUEUE {
    std::vector<std::string> msgs;
    char name[256];
    void msg_queue_send(const char*, MSG_CHANNEL& channel);
    void msg_queue_poll(MSG_CHANNEL& channel);
};

#define DEFAULT_FRACTION_DONE_UPDATE_PERIOD     1
#define DEFAULT_CHECKPOINT_PERIOD               300

#define SHM_PREFIX          "shm_"
#define QUIT_PREFIX         "quit_"

// graphics messages
//
#define MODE_UNSUPPORTED        0
#define MODE_HIDE_GRAPHICS      1
#define MODE_WINDOW             2
#define MODE_FULLSCREEN         3
#define MODE_BLANKSCREEN        4
#define MODE_REREAD_PREFS       5
#define MODE_QUIT               6

#define NGRAPHICS_MSGS  7

struct GRAPHICS_MSG {
    int mode;
    char window_station[256];
    char desktop[256];
    char display[256];

    GRAPHICS_MSG();
};

class APP_CLIENT_SHM {
public:
    SHARED_MEM *shm;

    int decode_graphics_msg(char*, GRAPHICS_MSG&);
    void reset_msgs();        // resets all messages and clears their flags

    APP_CLIENT_SHM();
};

#ifdef _WIN32
    typedef char SHMEM_SEG_NAME[256];
#else
    typedef int SHMEM_SEG_NAME;
#endif

// parsed version of main init file
//
struct APP_INIT_DATA {
    int core_version;
    char app_name[256];
    char* project_preferences;
    int userid;
    int teamid;
    int hostid;
    char user_name[256];
    char team_name[256];
    char project_dir[256];
    char boinc_dir[256];
    char wu_name[256];
    char authenticator[256];
    int slot;
    double user_total_credit;
    double user_expavg_credit;
    double host_total_credit;
    double host_expavg_credit;
    HOST_INFO host_info;
    PROXY_INFO proxy_info;
    GLOBAL_PREFS global_prefs;

    // Items below here are for implementation only
    // (not used by app developers)
    //
    double checkpoint_period;     // recommended checkpoint period
    SHMEM_SEG_NAME shmem_seg_name;
    double wu_cpu_time;       // cpu time from previous episodes
    double fraction_done_update_period;
        // the following 2 are used for compound apps,
        // where each stage of the computation is a fixed
        // fraction of the total.
    double fraction_done_start;
    double fraction_done_end;

    APP_INIT_DATA();
    ~APP_INIT_DATA();
};

struct GRAPHICS_INFO {
    int xsize;
    int ysize;
    double refresh_period;
};

typedef struct GRAPHICS_INFO GRAPHICS_INFO;

int write_init_data_file(FILE* f, APP_INIT_DATA&);
int parse_init_data_file(FILE* f, APP_INIT_DATA&);
int write_graphics_file(FILE* f, GRAPHICS_INFO* gi);
int parse_graphics_file(FILE* f, GRAPHICS_INFO* gi);

// filenames used in the slot directory
//
#define INIT_DATA_FILE    "init_data.xml"
#define BOINC_FINISH_CALLED_FILE "boinc_finish_called"
#define TRICKLE_UP_FILENAME "trickle_up.xml"
#define STDERR_FILE           "stderr.txt"
#define STDOUT_FILE           "stdout.txt"
#define LOCKFILE               "boinc_lockfile"
#define UPLOAD_FILE_REQ_PREFIX      "boinc_ufr_"
#define UPLOAD_FILE_STATUS_PREFIX   "boinc_ufs_"

extern const char* xml_graphics_modes[NGRAPHICS_MSGS];
extern int boinc_link(const char* phys_name, const char* logical_name);

#endif