NAME

ACE_Errno_Guard - Provides a wrapper to improve performance when thread-specific errno must be saved and restored in a block of code.

SYNOPSIS

#include <ace/OS.h>

class ACE_Errno_Guard { public: ACE_Errno_Guard (ACE_ERRNO_TYPE &errno_ref, int error); ACE_Errno_Guard (ACE_ERRNO_TYPE &errno_ref); ~ACE_Errno_Guard (void); int operator= (const ACE_ERRNO_TYPE &errno_ref); int operator= (int error); int operator== (int error); int operator!= (int error); private: ACE_ERRNO_TYPE *errno_ptr_; int error_; };

DESCRIPTION

The typical use-case for this is the following:

int error = errno; call_some_function_that_might_change_errno (); errno = error;

This can be replaced with

{ ACE_Errno_Guard guard (errno); call_some_function_that_might_change_errno (); }

This implementation is more elegant and more efficient since it avoids an unnecessary second access to thread-specific storage by caching a pointer to the value of errno in TSS.

Initialization and termination methods.

ACE_Errno_Guard (ACE_ERRNO_TYPE &errno_ref, int error);

ACE_Errno_Guard (ACE_ERRNO_TYPE &errno_ref);

~ACE_Errno_Guard (void);

int operator= (const ACE_ERRNO_TYPE &errno_ref);

int operator= (int error);

int operator== (int error);

int operator!= (int error);

AUTHOR

Doug Schmidt schmidt@cs.wustl.edu, Jesper S. M|ller stophph@diku.dk, and a cast of thousands...

The ACE_Sched_Priority type should be used for platform-

independent thread and process priorities, by convention. int should be used for OS-specific priorities.

typedef for the _stat data structure

Giving unique ACE scoped names for some important

RTSignal-Related constants. Becuase sometimes, different platforms use different names for these constants.

LIBRARY

ace