text: /* Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /**
   * @file  scoreboard.h
   * @brief Apache scoreboard library
   */
  
  #ifndef APACHE_SCOREBOARD_H
  #define APACHE_SCOREBOARD_H
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  #ifdef HAVE_SYS_TIMES_H
  #include <sys/time.h>
  #include <sys/times.h>
  #elif defined(TPF)
  #include <time.h>
  #endif
  
  #include "ap_config.h"
  #include "apr_hooks.h"
  #include "apr_thread_proc.h"
  #include "apr_portable.h"
  #include "apr_shm.h"
  #include "apr_optional.h"
  
  /* Scoreboard file, if there is one */
  #ifndef DEFAULT_SCOREBOARD
  #define DEFAULT_SCOREBOARD "logs/apache_runtime_status"
  #endif
  
  /* Scoreboard info on a process is, for now, kept very brief --- 
   * just status value and pid (the latter so that the caretaker process
   * can properly update the scoreboard when a process dies).  We may want
   * to eventually add a separate set of long_score structures which would
   * give, for each process, the number of requests serviced, and info on
   * the current, or most recent, request.
   *
   * Status values:
   */
  
  #define SERVER_DEAD 0
  #define SERVER_STARTING 1	/* Server Starting up */
  #define SERVER_READY 2		/* Waiting for connection (or accept() lock) */
  #define SERVER_BUSY_READ 3	/* Reading a client request */
  #define SERVER_BUSY_WRITE 4	/* Processing a client request */
  #define SERVER_BUSY_KEEPALIVE 5	/* Waiting for more requests via keepalive */
  #define SERVER_BUSY_LOG 6	/* Logging the request */
  #define SERVER_BUSY_DNS 7	/* Looking up a hostname */
  #define SERVER_CLOSING 8	/* Closing the connection */
  #define SERVER_GRACEFUL 9	/* server is gracefully finishing request */
  #define SERVER_IDLE_KILL 10     /* Server is cleaning up idle children. */
  #define SERVER_NUM_STATUS 11	/* number of status settings */
  
  /* Type used for generation indicies.  Startup and every restart cause a
   * new generation of children to be spawned.  Children within the same
   * generation share the same configuration information -- pointers to stuff
   * created at config time in the parent are valid across children.  However,
   * this can't work effectively with non-forked architectures.  So while the
   * arrays in the scoreboard never change between the parent and forked
   * children, so they do not require shm storage, the contents of the shm
   * may contain no pointers.
   */
  typedef int ap_generation_t;
  
  /* Is the scoreboard shared between processes or not? 
   * Set by the MPM when the scoreboard is created.
   */
  typedef enum {
      SB_NOT_SHARED = 1,
      SB_SHARED = 2
  } ap_scoreboard_e;
  
  #define SB_WORKING  0  /* The server is busy and the child is useful. */
  #define SB_IDLE_DIE 1  /* The server is idle and the child is superfluous. */
                         /*   The child should check for this and exit gracefully. */
  
  /* stuff which is worker specific */
  /***********************WARNING***************************************/
  /* These are things that are used by mod_status. Do not put anything */
  /*   in here that you cannot live without. This structure will not   */
  /*   be available if mod_status is not loaded.                       */
  /*********************************************************************/
  typedef struct worker_score worker_score;
  
  struct worker_score {
      int thread_num;
  #if APR_HAS_THREADS
      apr_os_thread_t tid;
  #endif
      /* With some MPMs (e.g., worker), a worker_score can represent
       * a thread in a terminating process which is no longer
       * represented by the corresponding process_score.  These MPMs
       * should set pid and generation fields in the worker_score.
       */
      pid_t pid;
      ap_generation_t generation;
      unsigned char status;
      unsigned long access_count;
      apr_off_t     bytes_served;
      unsigned long my_access_count;
      apr_off_t     my_bytes_served;
      apr_off_t     conn_bytes;
      unsigned short conn_count;
      apr_time_t start_time;
      apr_time_t stop_time;
  #ifdef HAVE_TIMES
      struct tms times;
  #endif
      apr_time_t last_used;
      char client[32];		/* Keep 'em small... */
      char request[64];		/* We just want an idea... */
      char vhost[32];	        /* What virtual host is being accessed? */
  };
  
  typedef struct {
      int             server_limit;
      int             thread_limit;
      ap_scoreboard_e sb_type;
      ap_generation_t running_generation; /* the generation of children which
                                           * should still be serving requests.
                                           */
      apr_time_t restart_time;
      int             lb_limit;
  } global_score;
  
  /* stuff which the parent generally writes and the children rarely read */
  typedef struct process_score process_score;
  struct process_score{
      pid_t pid;
      ap_generation_t generation;	/* generation of this child */
      ap_scoreboard_e sb_type;
      int quiescing;          /* the process whose pid is stored above is
                               * going down gracefully
                               */
  };
  
  /* stuff which is lb specific */
  typedef struct lb_score lb_score;
  struct lb_score{
      /* TODO: make a real stuct from this */
      unsigned char data[1024];
  };
  
  /* Scoreboard is now in 'local' memory, since it isn't updated once created,
   * even in forked architectures.  Child created-processes (non-fork) will
   * set up these indicies into the (possibly relocated) shmem records.
   */
  typedef struct {
      global_score *global;
      process_score *parent;
      worker_score **servers;
      lb_score     *balancers;
  } scoreboard;
  
  typedef struct ap_sb_handle_t ap_sb_handle_t;
  
  AP_DECLARE(int) ap_exists_scoreboard_image(void);
  AP_DECLARE(void) ap_increment_counts(ap_sb_handle_t *sbh, request_rec *r);
  
  int ap_create_scoreboard(apr_pool_t *p, ap_scoreboard_e t);
  apr_status_t ap_reopen_scoreboard(apr_pool_t *p, apr_shm_t **shm, int detached);
  void ap_init_scoreboard(void *shared_score);
  AP_DECLARE(int) ap_calc_scoreboard_size(void);
  apr_status_t ap_cleanup_scoreboard(void *d);
  
  AP_DECLARE(void) ap_create_sb_handle(ap_sb_handle_t **new_sbh, apr_pool_t *p,
                                       int child_num, int thread_num);
      
  int find_child_by_pid(apr_proc_t *pid);
  AP_DECLARE(int) ap_update_child_status(ap_sb_handle_t *sbh, int status, request_rec *r);
  AP_DECLARE(int) ap_update_child_status_from_indexes(int child_num, int thread_num,
                                                      int status, request_rec *r);
  void ap_time_process_request(ap_sb_handle_t *sbh, int status);
  
  /** Return a pointer to the worker_score for a given child, thread pair.
   * @param child_num The child number.
   * @param thread_num The thread number.
   * @return A pointer to the worker_score structure.
   * @deprecated This function is deprecated, use ap_copy_scoreboard_worker instead. 
   */
  AP_DECLARE(worker_score *) ap_get_scoreboard_worker(int x, int y);
  
  /** Copy the contents of a worker's scoreboard entry.  The contents of
   * the worker_score structure are copied verbatim into the dest
   * structure.
   * @param dest Output parameter.
   * @param child_num The child number.
   * @param thread_num The thread number.
   */
  AP_DECLARE(void) ap_copy_scoreboard_worker(worker_score *dest,
                                             int child_num, int thread_num);
  
  AP_DECLARE(process_score *) ap_get_scoreboard_process(int x);
  AP_DECLARE(global_score *) ap_get_scoreboard_global(void);
  AP_DECLARE(lb_score *) ap_get_scoreboard_lb(int lb_num);
  
  AP_DECLARE_DATA extern scoreboard *ap_scoreboard_image;
  AP_DECLARE_DATA extern const char *ap_scoreboard_fname;
  AP_DECLARE_DATA extern int ap_extended_status;
  AP_DECLARE_DATA extern int ap_mod_status_reqtail;
  
  AP_DECLARE_DATA extern ap_generation_t volatile ap_my_generation;
  
  /* Hooks */
  /**
    * Hook for post scoreboard creation, pre mpm.
    * @param p       Apache pool to allocate from.
    * @param sb_type 
    * @ingroup hooks
    * @return OK or DECLINE on success; anything else is a error
    */  
  AP_DECLARE_HOOK(int, pre_mpm, (apr_pool_t *p, ap_scoreboard_e sb_type))
  
  /**
    * proxy load balancer
    * @return the number of load balancer workers.
    */  
  APR_DECLARE_OPTIONAL_FN(int, ap_proxy_lb_workers,
                          (void));
  
  /* for time_process_request() in http_main.c */
  #define START_PREQUEST 1
  #define STOP_PREQUEST  2
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif	/* !APACHE_SCOREBOARD_H */
  