ganeti.utils.wrapper

module documentation

Utility functions wrapping other functions.

Function	`CloseFdNoError`	Close a file descriptor ignoring errors.
Function	`GetClosedTempfile`	Creates a temporary file and returns its path.
Function	`IgnoreProcessNotFound`	Ignores ESRCH when calling a process-related function.
Function	`IgnoreSignals`	Tries to call a function ignoring failures due to EINTR.
Function	`IsExecutable`	Checks whether a file exists and is executable.
Function	`ResetTempfileModule`	Resets the random name generator of the tempfile module.
Function	`RetryOnSignal`	Calls a function again if it failed due to EINTR.
Function	`SetCloseOnExecFlag`	Sets or unsets the close-on-exec flag on a file descriptor.
Function	`SetNonblockFlag`	Sets or unsets the O_NONBLOCK flag on on a file descriptor.
Function	`TestDelay`	Sleep for a fixed amount of time.

def CloseFdNoError(fd, retries=5): ¶

Close a file descriptor ignoring errors.

Parameters
fd:int	the file descriptor
retries:int	how many retries to make, in case we get any other error than EBADF

def GetClosedTempfile(*args, **kwargs): ¶

Creates a temporary file and returns its path.

def IgnoreProcessNotFound(fn, *args, **kwargs): ¶

Ignores ESRCH when calling a process-related function.

ESRCH is raised when a process is not found.

Returns
bool	Whether process was found

def IgnoreSignals(fn, *args, **kwargs): ¶

Tries to call a function ignoring failures due to EINTR.

def IsExecutable(filename): ¶

Checks whether a file exists and is executable.

Parameters
filename:string	Filename
Returns
bool	Undocumented

def ResetTempfileModule(_time=time.time): ¶

Resets the random name generator of the tempfile module.

This function should be called after os.fork in the child process to ensure it creates a newly seeded random generator. Otherwise it would generate the same random parts as the parent process. If several processes race for the creation of a temporary file, this could lead to one not getting a temporary name.

def RetryOnSignal(fn, *args, **kwargs): ¶

Calls a function again if it failed due to EINTR.

def SetCloseOnExecFlag(fd, enable): ¶

Sets or unsets the close-on-exec flag on a file descriptor.

Parameters
fd:int	File descriptor
enable:bool	Whether to set or unset it.

def SetNonblockFlag(fd, enable): ¶

Sets or unsets the O_NONBLOCK flag on on a file descriptor.

Parameters
fd:int	File descriptor
enable:bool	Whether to set or unset it

def TestDelay(duration): ¶

Sleep for a fixed amount of time.

Parameters
duration:float	the sleep duration, in seconds
Returns
(boolean, str)	False for negative value, and an accompanying error message; True otherwise (and msg is None)