/*ident "@(#)cls4:demo/task/regtest.C 1.1" */ /******************************************************************************* C++ source for the C++ Language System, Release 3.0. This product is a new release of the original cfront developed in the computer science research center of AT&T Bell Laboratories. Copyright (c) 1991 AT&T and UNIX System Laboratories, Inc. Copyright (c) 1984, 1989, 1990 AT&T. All Rights Reserved. THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE of AT&T and UNIX System Laboratories, Inc. The copyright notice above does not evidence any actual or intended publication of such source code. *******************************************************************************/ #include #include /* non-trivial task example: Make a set of tasks which pass an object round between themselves. Each task but the last creates the next task. Each task gets an object from the head of one queue, and puts the object on the tail of another queue. Each task quits after getting the object MAX_CYCLES times. Each task uses lots of registers that must be preserved across a switch. */ const int NTASKS = 1; const int MAX_CYCLES = 5; void dirty() { register int i, j, k, l, m, z; i = -1; j = -2; k = -3; l = -4; m = -5; z = -6; } struct pc : task { // derive a class from task pc(char*, qtail*, qhead*); // task is not intended to }; // be used directly pc::pc(char* n, qtail* t, qhead* h) :task(n) { register int i, j, k, l, m, z; i = *n + 11; j = *n + 12; k = *n + 13; l = *n + 14; m = *n + 15; z = *n + 16; printf("new pc(%s)\n",n); if (*n < 'a'+ NTASKS) { char* c = new char[2]; c[0] = *n + 1; c[1] = '\0'; qtail* qt = new qtail; pc* next = new pc(c, t, qt->head()); t = qt; } else { printf("%s: here we go\n", n); t->put(new object); } if (this_task() != this) abort(); if (i != *n + 11 || j != *n + 12 || k != *n + 13 || l != *n + 14 || m != *n + 15 || z != *n + 16) { printf("pc: lost regs! i==%d, j==%d, k==%d, l==%d, m==%d, z==%d\n", i, j, k, l, m, z); printf("vals should be: i: %d, j: %d, k: %d, l: %d, m: %d, z: %d\n", *n + 11, *n + 12, *n + 13, *n + 14, *n + 15, *n + 16); abort(); } for (int cycles = 0; cycles < MAX_CYCLES; cycles++) { object* p = h->get(); dirty(); printf("task %s\n",n); t->put(p); } printf("task %s: done.\n", n); resultis(0); // Always end task constructors with resultis. // Behavior of those using return or running // off the end of the function is undefined. // Alternatively, use an infinite loop in // constructor body. } main() { register int i, j, k, l, m, z; qhead* hh = new qhead; qtail* t = hh->tail(); qhead* h; printf("main\n"); char* n = "a"; // make a one letter task name i = *n + 1; j = *n + 2; k = *n + 3; l = *n + 4; m = *n + 5; z = *n + 6; h = new qhead; new pc(n,t,h); printf("main()'s loop\n"); if (i != *n + 1 || j != *n + 2 || k != *n + 3 || l != *n + 4 || m != *n + 5 || z != *n + 6) { printf("main: lost regs! i==%d, j==%d, k==%d, l==%d, m==%d, z==%d\n", i, j, k, l, m, z); printf("values should be: i: %d, j: %d, k: %d, l: %d, m: %d, z: %d\n", *n + 1, *n + 2, *n + 3, *n + 4, *n + 5, *n + 6); abort(); } t = h->tail(); for (int cycles = 0; cycles < MAX_CYCLES; cycles++) { object* p = hh->get(); if (i != *n + 1 || j != *n + 2 || k != *n + 3 || l != *n + 4 || m != *n + 5 || z != *n + 6) { printf("main (after get): lost regs! i==%d, j==%d, k==%d, l==%d, m==%d, z==%d\n", i, j, k, l, m, z); printf("values should be: i: %d, j: %d, k: %d, l: %d, m: %d, z: %d\n", *n + 1, *n + 2, *n + 3, *n + 4, *n + 5, *n + 6); abort(); } printf("main task\n"); t->put(p); } printf("main task: done.\n", n); thistask->resultis(0); // main is a task too; it must also // end with resultis (to allow any // remaining tasks to run, otherwise // the whole process would exit). }