Source repositorymisc.h File Reference

Miscellaneous declarations for Linux. More...

#include <chrono>
#include <fcntl.h>
#include <filesystem>
#include <thread>
#include <unistd.h>
#include <vector>
#include "src/utility.h"

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Typedefs
using	dyn::apiproc = void (*)(void)
	Generic GLX procedure pointer returned by the loader.

Enumerations
enum class	window_system_e { NONE , X11 , WAYLAND }
	Enumerates supported window system options. More...

Functions
library_t *	dyn::handle (const std::vector< const char * > &libs)
	Open the first available shared library from a nonempty list.
void	platf::handle_pacing (std::chrono::steady_clock::time_point &next_frame, std::chrono::nanoseconds delay, auto &logger)
	Generic frame pacing logic for Linux capture methods.
int	dyn::load (library_t *handle, const std::vector< std::tuple< apiproc *, const char * > > &funcs, bool strict)
	Load named functions from an open shared library.
int	platf::open_drm_card_fd (const std::filesystem::path &path, int flags)
	Open a DRM card node, dropping implicit DRM master when possible.
bool	platf::sanitize_process_environment ()
	Remove environment variables that can load untrusted GUI modules.

Variables
window_system_e	window_system
	Window system.

Detailed Description

Miscellaneous declarations for Linux.

Enumeration Type Documentation

window_system_e

enum class window_system_e

strong

Enumerates supported window system options.

Enumerator
NONE	No window system.
X11	X11.
WAYLAND	Wayland.

Function Documentation

handle()

void * dyn::handle

(

const std::vector< const char * > &

libs

)

Open the first available shared library from a nonempty list.

Return the native handle owned by the wrapper.

Returns

Open library handle, or null if none could be loaded.

Parameters

libs	List of libraries to probe for the requested symbol.

Returns

Native dynamic-library handle, or nullptr when no library can be opened.

handle_pacing()

void platf::handle_pacing ( std::chrono::steady_clock::time_point & next_frame, std::chrono::nanoseconds delay, auto & logger )

inline

Generic frame pacing logic for Linux capture methods.

Advances the frame pacing timeline and re-anchors it if the capture thread falls behind.

Parameters

next_frame	Time point that the next frame will be targeted against.
delay	Delay interval used to pace next frame.
logger	The sleep_overshoot_logger for tracking discontinuities.

load()

int dyn::load	(	library_t *	handle,
		const std::vector< std::tuple< apiproc *, const char * > > &	funcs,
		bool	strict = true )

Load named functions from an open shared library.

Parameters

handle	Library whose symbols are queried.
funcs	Function pointer destinations and corresponding symbol names.
strict	Whether missing symbols make the operation fail.

Returns

Zero on success or minus one when a required symbol is missing.

open_drm_card_fd()

int platf::open_drm_card_fd	(	const std::filesystem::path &	path,
		int	flags )

Open a DRM card node, dropping implicit DRM master when possible.

Open a DRM card node and drop implicit DRM master, if any.

See misc.h for full documentation. Master check/drop failures are logged as warnings but do not fail the call.

Performs open(path, flags | O_CLOEXEC) and probes the resulting fd with DRM_IOCTL_AUTH_MAGIC. If the kernel implicitly handed us master, calls drmDropMaster and re-verifies before returning. Master check/drop failures are logged as warnings but do not fail the call: the caller still receives a usable fd.

Callers should use this helper for any /dev/dri/cardN open so we never keep implicit master and block compositors from re-acquiring it on VT switches.

Parameters

path	Path to the DRM card node (e.g. /dev/dri/card0).
flags	open() flags. O_CLOEXEC is always OR-ed in.

Returns

A file descriptor on success, or -1 if open() itself fails.

sanitize_process_environment()

bool platf::sanitize_process_environment

(

)

Remove environment variables that can load untrusted GUI modules.

Loader paths and module lists used by Qt, GTK, GIO, and GdkPixbuf are removed before any of those libraries can initialize. The caller determines whether privileged execution requires the policy.

Returns

true when the environment is safe to use; false if a variable could not be removed.