Process and Threads

Threading and Mutual Exclusion. More...

Collaboration diagram for Process and Threads:

Modules
	Thread
	Thread processing.
	Mutex
	Mutual exclusion.
	Semaphore
	Semaphore.

Data Structures
struct	GF_SystemRTInfo
	run-time system info object More...

Enumerations
enum	GF_LockStatus { GF_LOCKFILE_FAILED =0 , GF_LOCKFILE_NEW , GF_LOCKFILE_REUSE }
enum	{ GF_RTI_ALL_PROCESSES_TIMES = 1 , GF_RTI_PROCESS_MEMORY = 1<<1 , GF_RTI_SYSTEM_MEMORY_ONLY = 1<<2 }

Functions
u32	gf_sys_get_process_id ()
	Gets process ID. More...
GF_LockStatus	gs_sys_create_lockfile (const char *lockfile)
	Creates a lock file. More...
Bool	gf_sys_check_process_id (u32 process_id)
	Checks a process is valid. More...
Bool	gf_sys_get_rti (u32 refresh_time_ms, GF_SystemRTInfo *rti, u32 flags)
	Gets Run-Time info. More...

Detailed Description

Time manipulation tools.

This section documents the threading of the GPAC framework. These provide an easy way to implement safe multithreaded tools.

Available tools are thread, mutex and semaphore

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Data Structure Documentation

GF_SystemRTInfo

struct GF_SystemRTInfo

The Run-Time Info object is used to get CPU and memory occupation of the calling process. All time values are expressed in milliseconds (accuracy is not guaranteed).

Data Fields
u32	sampling_instant	start of the sampling period
u32	sampling_period_duration	duration of the sampling period
u32	total_cpu_time	total amount of time (User+kernel) spent in CPU for all processes as evaluated at the end of the sampling period
u32	process_cpu_time	total amount of time (User+kernel) spent in CPU for the calling process as evaluated at the end of the sampling period
u32	total_cpu_time_diff	amount of time (User+kernel) spent in CPU for all processes during the sampling period
u32	process_cpu_time_diff	total amount of time (User+kernel) spent in CPU for the calling process during the sampling period
u32	cpu_idle_time	total amount of idle time during the sampling period.
u32	total_cpu_usage	percentage (from 0 to 100) of CPU usage during the sampling period.
u32	process_cpu_usage	percentage (from 0 to 100) of the CPU usage by the calling process during the sampling period.
u32	pid	calling process ID
u32	thread_count	calling process thread count if known
u64	process_memory	size of calling process allocated heaps
u64	physical_memory	total physical memory in system
u64	physical_memory_avail	available physical memory in system
u64	gpac_memory	total memory currently allocated by gpac
u32	nb_cores	total number of cores on the system

Enumeration Type Documentation

GF_LockStatus

enum GF_LockStatus

lockfile status

Enumerator
GF_LOCKFILE_FAILED	lockfile creation failed
GF_LOCKFILE_NEW	lockfile creation succeeded, creating a new lock file
GF_LOCKFILE_REUSE	lockfile creation succeeded, lock file was already present and created by this process

anonymous enum

anonymous enum

Selection flags for run-time info retrieval

Enumerator
GF_RTI_ALL_PROCESSES_TIMES	Indicates all processes' times must be fetched. If not set, only the current process times will be retrieved, and the thread count and total times won't be available
GF_RTI_PROCESS_MEMORY	Indicates the process allocated heap size must be fetch. If not set, only the system physical memory is fetched. Fetching the entire ocess allocated memory can have a large impact on performances
GF_RTI_SYSTEM_MEMORY_ONLY	Indicates that only system memory should be fetched. When set, all refreshing info is ignored

Function Documentation

gf_sys_get_process_id()

u32 gf_sys_get_process_id

(

)

Gets ID of the process running this gpac instance.

Returns

the ID of the main process

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gs_sys_create_lockfile()

GF_LockStatus gs_sys_create_lockfile

(

const char *

lockfile

)

Creates a lock file for the current process. A lockfile contains a single string giving the creator process ID If a lock file exists with a process ID no longer running, the lock file will be granted to the caller. Lock files are removed using gf_file_delete

Parameters

lockfile

name of the lockfile

Returns

return status

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gf_sys_check_process_id()

Bool gf_sys_check_process_id

(

u32

process_id

)

Checks if a process is running by its ID

Parameters

process_id

process ID

Returns

GF_TRUE if process is running, GF_FALSE otherwise

gf_sys_get_rti()

Bool gf_sys_get_rti	(	u32	refresh_time_ms,
		GF_SystemRTInfo *	rti,
		u32	flags
	)

Gets CPU and memory usage info for the calling process and the system. Information gathering is controled through timeout values.

Parameters

refresh_time_ms	refresh time period in milliseconds. If the last sampling was done less than this period ago, the run-time info is not refreshed.
rti	holder to the run-time info structure to update.
flags	specify which info is to be retrieved.

Returns

1 if info has been updated, 0 otherwise.

Note

You should not try to use a too small refresh time. Typical values are 500 ms or one second.

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