DbEnv::memp_trickle()
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## DbEnv::memp_trickle()

    #include <db_cxx.h>

    int
    DbEnv::memp_trickle(int percent, int *nwrotep);

The `DbEnv::memp_trickle()` method ensures that a specified percent of the pages in the cache are clean, by writing dirty pages to their backing files.

The purpose of the `DbEnv::memp_trickle()` function is to enable a memory pool manager to ensure that a page is always available for reading in new information without having to wait for a write.

The `DbEnv::memp_trickle()` method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success.

### Parameters

#### nwrotep

The nwrotep parameter references memory into which the number of pages written to reach the specified percentage is copied.

#### percent

The percent parameter is the percent of the pages in the cache that should be clean.

### Errors

The `DbEnv::memp_trickle()` method may fail and throw a DbException exception, encapsulating one of the following non-zero errors, or return one of the following non-zero errors: following non-zero errors:

#### EINVAL

An invalid flag value or parameter was specified.

### Class

DbEnv, DbMpoolFile

### See Also

Memory Pools and Related Methods

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