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   pmWebTimerSetMetricRegistry    ( 3 )

поточно-безопасное управление списком таймеров (thread-safe timer list management)

Имя (Name)

pmWebTimerRegister, pmWebTimerRelease,
       pmWebTimerSetMetricRegistry - thread-safe timer list management

Синопсис C (C Synopsis)

#include <pcp/pmwebapi.h>

typedef void (*pmWebTimerCallBack)(void *data); int pmWebTimerRegister(pmWebTimerCallBack callback, void *data);

int pmWebTimerRelease(int seq); int pmWebTimerSetMetricRegistry(struct mmv_registry *registry); cc ... -lpcp_web


Описание (Description)

The pmWebTimerRegister and related API functions provide a
       convenient thread-safe API for applications to manage a list of
       timer driven callbacks.  On the first call to pmWebTimerRegister
       or pmWebTimerSetMetricRegistry, an internal timer is set up and
       initialized to fire every 1.0 seconds.  Each time the timer
       fires, all currently registered callback functions will be called
       serially with the opaque data pointer that was supplied when each
       function was registered.  The pmWebTimerCallBack typedef provides
       a suitable callback function prototype.

All registered callback functions should be non-blocking and execute quickly and synchronously. Typical callback functions include refreshing instrumentation, calculating and updating performance metric values, periodic garbage collection and any other local function that requires regular execution.

The pmWebTimerSetMetricRegistry function provides a convenient way for an application to pass in a pointer to an libpcp_mmv(3) registry that has been suitably initialized by the calling application. This registry will be used to dynamically create six server resource metrics named NAME.mem.datasz, NAME.mem.maxrss, NAME.cpu.total, NAME.cpu.sys, NAME.cpu.user and NAME.pid, where NAME is the root PCP PMNS(5) name set up by the calling application. These metrics should be reasonably self explanatory; they provide resource usage metrics from the calling application / server and use getrusage(2), times(2) and getpid(2).


Возвращаемое значение (Return value)

The pmWebTimerRegister function returns a positive integer handle
       that may be subsequently used in a call to pmWebTimerRelease to
       remove a timer from the internal timer list.  When a timer is
       removed with a call to pmWebTimerRelease, the internal data
       structures are freed.  The caller however, is responsible for
       freeing the associated data (since it may or may not be
       dynamically allocated).

Диагностика (Diagnostic)

On failure a negative PMAPI error code is returned in all cases.

Смотри также (See also)

pmproxy(1), mmv_stats_registry(3), PMAPI(3) and PMWEBAPI(3).