Java Threads: Difference between revisions
| Line 14: | Line 14: | ||
==Java Threads and Linux Processes== | ==Java Threads and Linux Processes== | ||
On a Linux system, each JVM thread counts as a "process", in that it is subject to system-wide and user-wide process number limitations | On a Linux system, each JVM thread counts as a "process", in that it is subject to system-wide and user-wide process number limitations - see "[[Linux_Process_Management_Concepts#Maximum_Number_of_Processes_Allowed_on_the_System|maximum number of processes allowed on a system]]" and "[[Linux_Process_Management_Concepts#Maximum_Number_of_Processes_Available_to_a_Single_User|maximum number of processes available to a single user]]". When a JVM instance adjust its number of threads, the change is reflected by <tt>/proc/stat</tt> "[[Linux_Process_Information#.2Fproc.2Fstat|processes]]" count. | ||
For an example of what happens when the number of Linux processes allowed to an user is reached, see {{Internal|Max_User_Processes_and_Java_OutOfMemoryError_%22unable_to_create_new_native_thread%22|OutOfMemoryError "unable to create new native thread"}} | For an example of what happens when the number of Linux processes allowed to an user is reached, see {{Internal|Max_User_Processes_and_Java_OutOfMemoryError_%22unable_to_create_new_native_thread%22|OutOfMemoryError "unable to create new native thread"}} | ||
Revision as of 02:27, 22 April 2017
Internal
Subjects
Concepts
Daemon Thread
Java Threads and Linux Processes
On a Linux system, each JVM thread counts as a "process", in that it is subject to system-wide and user-wide process number limitations - see "maximum number of processes allowed on a system" and "maximum number of processes available to a single user". When a JVM instance adjust its number of threads, the change is reflected by /proc/stat "processes" count.
For an example of what happens when the number of Linux processes allowed to an user is reached, see
A simple Java program that allows experimenting with threads:
Java Thread Stack Memory Management
The default thread stack size on 64-bit systems is 1024K. 64k is the least amount of stack space allowed per thread.
It can be modified with with the -Xss option:
java ... -Xss<size> ...
where "<size>" represents the amount of memory and the measure unit (ex "2048k").
More about Java memory management can be found here