Changeset 3461 for trunk/src

Timestamp:

Sep 15, 2020, 2:55:26 PM (5 years ago)

Author:

bird

Message:

kash: Cache one pstack_block since parsecmd seems to be called for each statement line in a script. Also, mark pstack blocks as 'done' before returning from parsecmd and prevent them from becoming current (curpstack) again upon popping.

Location:

trunk/src/kash

Files:

• memalloc.c (modified) (6 diffs)
• memalloc.h (modified) (1 diff)
• parser.c (modified) (2 diffs)
• shinstance.c (modified) (1 diff)
• shinstance.h (modified) (2 diffs)

trunk/src/kash/memalloc.c

@@ -371 +371 @@
                 TRACE2((NULL, "pstackrelease: %p - %u refs (%s)\n", pst, refs, caller)); K_NOREF(caller);
                 if (refs == 0) {
-                        shinstance * const psh = shthread_get_shell();
                         struct stack_block *top;
                         while ((top = pst->top) != &pst->first)
@@ -382 +381 @@
                         pst->nextbyte = NULL;
                         pst->top = NULL;
-                        /** @todo push into an alloc cache rather than freeing it */
-                        sh_free(psh, pst);
+
+                        if (!psh->freepstack)
+                                psh->freepstack = pst;
+                        else
+                                sh_free(psh, pst);
                 }
         } else
@@ -395 +397 @@
         while (target < psh->pstacksize) {
                 unsigned idx = --psh->pstacksize;
-                pstack_block *psk = psh->pstack[idx];
+                pstack_block *pst = psh->pstack[idx];
                 psh->pstack[idx] = NULL;
-                if (psh->curpstack == psk)
-                    psh->curpstack = idx > 0 ? psh->pstack[idx - 1] : NULL;
-                pstackrelease(psh, psk, "popstackmark");
+                if (psh->curpstack == pst) {
+                        pstack_block *pstnext;
+                        if (idx <= 0 || (pstnext = psh->pstack[idx - 1])->done)
+                                psh->curpstack = NULL;
+                        else
+                                psh->curpstack = pstnext;
+                }
+                pstackrelease(psh, pst, "popstackmark");
         }
 
@@ -454 +461 @@
          * Allocate and initialize it.
          */
-        pst = (pstack_block *)ckmalloc(psh, blocksize);
+        pst = psh->freepstack;
+        if (pst)
+                psh->freepstack = NULL;
+        else
+                pst = (pstack_block *)ckmalloc(psh, blocksize);
         pst->nextbyte          = &pst->first.space[0];
         pst->avail             = blocksize - offsetof(pstack_block, first.space);
         pst->topsize           = blocksize - offsetof(pstack_block, first.space);
+        pst->top               = &pst->first;
         pst->strleft           = 0;
-        pst->top               = &pst->first;
         pst->allocations       = 0;
         pst->bytesalloced      = 0;
@@ -468 +479 @@
         pst->fragmentation     = 0;
         pst->refs              = 1;
-        pst->padding           = 42;
+        pst->done              = K_FALSE;
         pst->first.prev        = NULL;
 
@@ -480 +491 @@
         TRACE2((psh, "pstackallocpush: %p - entry %u\n", pst, psh->pstacksize - 1));
         return pst;
+}
+
+/**
+ * Marks the block as done, preventing it from being marked current again.
+ */
+void pstackmarkdone(pstack_block *pst)
+{
+        pst->done = K_TRUE;
 }
 

trunk/src/kash/memalloc.h

@@ -94 +94 @@
 unsigned pstackretainpush(struct shinstance *, struct pstack_block *);
 struct pstack_block *pstackallocpush(struct shinstance *);
+void pstackmarkdone(struct pstack_block *);
 #endif
 void *pstalloc(struct shinstance *, size_t);

trunk/src/kash/parser.c

@@ -133 +133 @@
         union node *ret;
         int t;
-
+#ifdef KASH_SEPARATE_PARSER_ALLOCATOR
+        pstack_block *pst = pstackallocpush(psh);
+#endif
         TRACE2((psh, "parsecmd(%d)\n", interact));
-#ifdef KASH_SEPARATE_PARSER_ALLOCATOR
-        pstackallocpush(psh);
-#endif
+
         psh->tokpushback = 0;
         psh->doprompt = interact;
@@ -155 +155 @@
         TRACE2((psh, "parsecmd(%d) returns:\n", interact));
         showtree(psh, ret);
+#endif
+#ifdef KASH_SEPARATE_PARSER_ALLOCATOR
+        pstackmarkdone(pst);
 #endif
         return ret;

trunk/src/kash/shinstance.c

@@ -541 +541 @@
         psh->pstack = NULL;
     }
+    sh_free(psh, psh->freepstack);
+    psh->freepstack = NULL;
 #endif
     psh->markp = NULL;
-
 
     /*

trunk/src/kash/shinstance.h

@@ -131 +131 @@
     /** Reference counter. */
     unsigned volatile   refs;
-    unsigned            padding;
+    /** Whether to make it current when is restored to the top of the stack. */
+    KBOOL               done;
     /** The first stack block. */
     struct stack_block  first;
@@ -339 +340 @@
     unsigned            pstacksize;     /**< Number of entries in pstack. */
     unsigned            pstackalloced;  /**< The allocated size of pstack. */
+    pstack_block       *freepstack;     /**< One cached pstack entry (lots of parsecmd calls). */
 #endif