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View Ref-File5.12.26  Psetlimit                                                 TOS

 Name:         »Psetlimit« - Set or obtain allocation limits of the 
               system resources.

 Opcode:       287

 Syntax:       int32_t Psetlimit ( int16_t lim, int32_t value );

 Description:  The function Psetlimit serves for setting or obtaining 
               resource allocation limits for the current process. The 
               parameter lim determines the desired resource type:

                lim  Meaning

                1    Max. CPU-time for the process (milliseconds)
                2    Max. total memory allowed for process in bytes
                3    Max. allocatable memory for the process (in 
                     bytes)

               The difference between 2 and 3 is that the total memory 
               also includes the TEXT, DATA and BSS segments of the 
               process.

               With the help of this function the resource allocation 
               limits are set both for the current process as well as 
               individually for all child processes created later. So 
               if a process sets a CPU limit and later creates several 
               child processes, then this CPU limit applies also for 
               each individual child process, and not, say, for all 
               child processes together.

               The parameter value determines the maximum value that a 
               resource is allowed to take. A value of 0 here means 
               that the resource is unlimited. A negative value here 
               returns the current value, leaving it unaltered.

               Note: There are no restrictions on increasing the 
               limits. Each process may alter any of its limits or 
               even set it to unlimited.

               Memory allocation limits do not apply for Pexec. If, 
               say, a process is limited to 256 kbyte, it can 
               nevertheless use Pexec to launch a child process that 
               uses more memory. Warning: This does not apply in 
               MagiC; here memory limits are inherited at Pexec!

               Memory limitations are not valid retrospectively. If, 
               for instance, a process owns 256 kbyte and then calls 
               Psetlimit to reduce its requirements to 128 kbyte, then 
               though it will not be terminated, it can not allocate 
               any memory any more until its size falls under the 
               specified 128 kbyte.

               Limitations of the CPU-time on the other hand do act 
               retrospectively. If a process reduces its CPU-time 
               below the previously valid value, then it will receive 
               a SIGXCPU signal immediately.

               Warning: Invalid function numbers and those that are 
               not supported by MagiC return EINVFN.

               Note about MagiC: If a program has been modified with 
               the utility program LIMITMEM, then this setting takes 
               precedence over the calling process' memory limit. 
               Psetlimit is supported by the extended shel_write mode; 
               due to this, memory-limited applications may also be 
               started in parallel.

 Return value: The function returns the old limit value.

 Availability: MagiC from Version 4.0 (17.09.1996) onwards and as of 
               the first in MultiTOS integrated MiNT version 1.04.

 Group:        Process functions

 See also:     Binding   Prusage   Signals