D.2.2.16 watchdog

Procedure from library general.lib (see general_lib).

Return:

Result of cmd, if the result can be computed in i seconds. Otherwise the computation is interrupted after i seconds, the string "Killed" is returned and the global variable ’watchdog_interrupt’ is defined.

Note:

* the MP package must be enabled
* the current basering should not be watchdog_rneu, since watchdog_rneu will be killed
* if there are variable names of the structure x(i) all polynomials have to be put into eval(...) in order to be interpreted correctly
* a second Singular process is started by this procedure

Example:

LIB "general.lib";
ring r=0,(x,y,z),dp;
poly f=x^30+y^30;
watchdog(1,"factorize(eval("+string(f)+"))");
→ [1]:
→    _[1]=1
→    _[2]=x16+x14y2-x10y6-x8y8-x6y10+x2y14+y16
→    _[3]=x8-x6y2+x4y4-x2y6+y8
→    _[4]=x4-x2y2+y4
→    _[5]=x2+y2
→ [2]:
→    1,1,1,1,1
watchdog(100,"factorize(eval("+string(f)+"))");
→ [1]:
→    _[1]=1
→    _[2]=x16+x14y2-x10y6-x8y8-x6y10+x2y14+y16
→    _[3]=x8-x6y2+x4y4-x2y6+y8
→    _[4]=x4-x2y2+y4
→    _[5]=x2+y2
→ [2]:
→    1,1,1,1,1