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Q47933: Effective Limit of 52 Threads Per Process with DosCreateThread |
/pubs/pc/reference/microsoft/kb/Q47933/ |
Article: Q47933
Version(s): 5.10
Operating System: OS/2
Flags: ENDUSER | docerr OpSys PMWin
Last Modified: 16-JAN-1990
A single process running under OS/2 Version 1.10 or 1.00 is limited to
creating 52 threads with DosCreateThread.
Attempting to create additional threads results in a return value
from DosCreateThread of 155, which is defined as ERROR_TOO_MANY_TCBS
(Thread Control BlockS) in BSEERR.H.
The "Microsoft OS/2 Programmer's Reference," Volume 3, Page 34,
incorrectly states "DosCreateThread can create up to 255 threads per
process." The Reference also fails to note that DosCreateThread could
return ERROR_TOO_MANY_TCBS.
The only way to work around the current OS/2 1.x limitation with
DosCreateThread is by starting additional processes, with each process
being limited to 52 threads. OS/2 1.10 and 1.00 can support up to 255
threads total for all processes in the entire system.
An increase in the limit will be considered for inclusion in a future
release.
Note that threads that will be calling C run-time library functions
should be created with _beginthread, which performs essential library
initializations that DosCreateThread does not perform. The library
function _beginthread is limited to creating 31 threads in C 5.10, for
a total of 32 threads. The next version of C will support the creation
of substantially more threads with its _beginthread.