star-sp

commit 3cb7c4260413a32c9337212e1268e34461e684ca
parent 1851af0ae984e2748191538ba4ea227275f848dc
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Sat, 22 Mar 2025 16:23:43 +0100

Correct the way read status cache is disabled

Do not free its memory space or close its stream, as it could be
reactivated when a proxy sequence is flushed.

Diffstat:
M
src/ssp_rng_proxy.c
 | 
8
++------
M
src/test_ssp_rng_proxy.c
 | 
21
++++++++++++++++++++-

2 files changed, 22 insertions(+), 7 deletions(-)
diff --git a/src/ssp_rng_proxy.c b/src/ssp_rng_proxy.c
@@ -325,12 +325,8 @@ rng_state_cache_read
   && cache->no_wstream
   && cache->read == cache->write
   && cache->nstates == 1/* A state is saved in 'cache->state' */) {
-    /* There is no more data cached into the stream. Close the stream and do
-     * not rely anymore on the proxy RNG to generate the RNG states */
-    fclose(cache->stream);
-    MEM_RM(cache->allocator, cache->buffer);
-    cache->stream = NULL;
-    cache->buffer = NULL;
+    /* There is no more data cached into the stream. Do not rely anymore on the
+     * proxy RNG to generate the RNG states */
     cache->no_rstream = 1;
   }
 
diff --git a/src/test_ssp_rng_proxy.c b/src/test_ssp_rng_proxy.c
@@ -628,6 +628,7 @@ test_cache(void)
     CHK(ssp_rng_get(rng1) == ssp_rng_get(rng));
     if(i % 2) CHK(ssp_rng_discard(rng, 2) == RES_OK);
   }
+
   CHK(ssp_rng_ref_put(rng) == RES_OK);
 
   CHK(ssp_rng_proxy_ref_put(proxy) == RES_OK);
@@ -806,7 +807,7 @@ test_flush_sequence()
   /* Fill the cache of the rng1 */
   CHK(ssp_rng_discard(rng0, 1013) == RES_OK);
   CHK(ssp_rng_proxy_get_sequence_id(proxy, &id) == RES_OK);
-  CHK(id == 63 + 203/*ceil(1023/(args.sequence_size*0.5))*/);
+  CHK(id == 63 + 203/*ceil(1013/(args.sequence_size*0.5))*/);
 
   /* Discard several sequences */
   CHK(ssp_rng_proxy_flush_sequences(proxy, 314) == RES_OK);
@@ -825,6 +826,24 @@ test_flush_sequence()
     CHK(id == 63 + 203 + 314);
   }
 
+  /* Generate several RNs for the first RNG only to make under pressure the
+   * cache stream of 'rng1'. The cache stream limit is set to 32 MB and the
+   * size of a Mersenne Twister RNG state is greater than 6 KB. Consquently,
+   * ~5500 RNG states will exceed the cache stream, i.e. 5500*5 = 27500
+   * random generations (since there is 5 RNs per bucket). Above this limit,
+   * 'rng1' will not rely anymore on the proxy RNG to manage its state. */
+  CHK(ssp_rng_discard(rng0, 30000) == RES_OK);
+
+  /* Discard enough random numbers from rng1 to consume all cached RNG states,
+   * and thus disable read cache usage */
+  CHK(ssp_rng_discard(rng1, 30000) == RES_OK);
+
+  CHK(ssp_rng_proxy_get_sequence_id(proxy, &id) == RES_OK);
+  CHK(id == 63+203+314+(30000*2)/args.sequence_size);
+
+  /* Try to flush a sequence on a proxy whose a generator don't use cache */
+  CHK(ssp_rng_proxy_flush_sequences(proxy, 1) == RES_OK);
+
   CHK(ssp_rng_proxy_ref_put(proxy) == RES_OK);
   CHK(ssp_rng_ref_put(rng1) == RES_OK);
   CHK(ssp_rng_ref_put(rng0) == RES_OK);