mps br/vmem: simple-chunk-return:

zcoll.c:
 How to get rid of all the objects, so full collect really collects all automatic objects:
   - Rootdrop() helps, but we can still retain a 1.2MB object;
   - stackwipe() does not help much -- these unwanted ambig refs are being left on the stack by MPS code that runs between mps_arena_collect and the flip!
   - therefore StackScan(0/1) to destroy stack+reg root before full collect: it's the only way to be sure.

 Reproducibility:
   - give Make() a random? switch, acted on by df() = diversity function, to allow bypass of rnd();
   - ZRndStateSet, to set the seed for rnd()

 Output:
   - print_M: switchable Mebibytes or Megabytes (more useful, to be honest);
   - get(): don't report message times, it messes up diffs.

 testlib.c/h:
 Reproducibility:
   - fix rnd_state so a rnd_state getter is possible;
   - testlib.h += rnd_state_t, rnd_state(), rnd_state_set(), rnd_state_set_v2()

 trace.c: traceFindGrey diag: no newline please

Copied from Perforce
 Change: 170093
 ServerID: perforce.ravenbrook.com

1 files changed, 5 insertions, 1 deletions

diff --git a/mps/code/testlib.h b/mps/code/testlib.h
index cf40053c2d3..2a70fa81f58 100644
--- a/mps/code/testlib.h
+++ b/mps/code/testlib.h
@@ -138,10 +138,14 @@ extern void verror(const char *format, va_list args);
 
 /* rnd -- random number generator
  *
- * rnd() generates a sequence of integers in the range [1, 2^31-1].
+ * rnd() generates a sequence of integers in the range [1, 2^31-2].
  */
 
 extern unsigned long rnd(void);
+typedef unsigned long rnd_state_t;
+extern rnd_state_t rnd_state(void);
+extern void rnd_state_set(rnd_state_t state_v3);
+extern void rnd_state_set_v2(rnd_state_t seed0_v2);  /* legacy */
 
 
 /* rnd_verify() -- checks behaviour of rnd() */