src/HelperChildConfig.h

   1 #ifndef _SQUID_SRC_HELPERCHILDCONFIG_H
   2 #define _SQUID_SRC_HELPERCHILDCONFIG_H
   3
   4 /**
   5  * Contains statistics of a particular type of child helper.
   6  *
   7  * Some derived from a helper children configuration option,
   8  * some from runtime stats on the currently active children.
   9  */
  10 class HelperChildConfig
  11 {
  12 public:
  13     explicit HelperChildConfig(const unsigned int m = 0);
  14
  15     /**
  16      * When new helpers are needed call this to find out how many more
  17      * we are allowed to start.
  18      * \retval 0       No more helpers may be started right now.
  19      * \retval N < 0   Error. No more helpers may be started.
  20      * \retval N       N more helpers may be started immediately.
  21      */
  22     int needNew() const;
  23     void parseConfig();
  24
  25     /**
  26      * Update an existing set of details with new start/max/idle/concurrent limits.
  27      * This is for parsing new child settings into an object incrementally then updating
  28      * the running set without loosing any of the active state or causing races.
  29      */
  30     HelperChildConfig &updateLimits(const HelperChildConfig &rhs);
  31
  32     /* values from squid.conf */
  33 public:
  34
  35     /** maximum child process limits. How many of this helper the system can cope with */
  36     unsigned int n_max;
  37
  38     /**
  39      * Number of children to kick off at startup.
  40      * set via the startup=N option.
  41      *
  42      * By default if undefined 1 will be started immediately for use.
  43      * The minimum/idle amount will be scheduled for starting as soon as possible after startup is completed.
  44      */
  45     unsigned int n_startup;
  46
  47     /**
  48      * Number of helper children to keep available as a buffer against sudden bursts of requests.
  49      * set via the idle=N option. May be zero.
  50      *
  51      * The default value for backward compatibility the default for this is the same as maximum children.
  52      * For now the actual number of idle children is only reduced by a reconfigure operation. This may change.
  53      */
  54     unsigned int n_idle;
  55
  56     /**
  57      * How many concurrent requests each child helper may be capable of handling.
  58      * Default: 0  - no concurrency possible.
  59      */
  60     unsigned int concurrency;
  61
  62     /* derived from active operations */
  63
  64     /**
  65      * Total helper children objects currently existing.
  66      * Produced as a side effect of starting children or their stopping.
  67      */
  68     unsigned int n_running;
  69
  70     /**
  71      * Count of helper children active (not shutting down).
  72      * This includes both idle and in-use children.
  73      */
  74     unsigned int n_active;
  75 };
  76
  77 /* Legacy parser interface */
  78 #define parse_HelperChildConfig(c)     (c)->parseConfig()
  79 #define dump_HelperChildConfig(e,n,c)  storeAppendPrintf((e), "\n%s %d startup=%d idle=%d concurrency=%d\n", (n), (c).n_max, (c).n_startup, (c).n_idle, (c).concurrency)
  80 #define free_HelperChildConfig(dummy)  // NO.
  81
  82 #endif /* _SQUID_SRC_HELPERCHILDCONFIG_H */