ref: 75bca30647aff6589c348a8b7f00d1218da09843
parent: 8417787f994891759273865919b34b5a2e6e8735
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Tue Mar 14 19:21:38 EDT 2017
upas/fs: remove unused segbrk memory allocator
--- a/sys/src/cmd/upas/fs/seg.c
+++ /dev/null
@@ -1,164 +1,0 @@
-#include "common.h"
-#include <libsec.h>
-#include "dat.h"
-
-/*
- * unnatural acts with virtual memory
- */
-
-typedef struct{- int ref;
- char *va;
- long sz;
-}S;
-
-static S s[15]; /* 386 only gives 4 */
-static int nstab = nelem(s);
-static long ssem = 1;
-//static ulong thresh = 10*1024*1024;
-static ulong thresh = 1024;
-
-void*
-segmalloc(ulong sz)
-{- int i, j;
- void *va;
-
- if(sz < thresh)
- return emalloc(sz);
- semacquire(&ssem, 1);
- for(i = 0; i < nstab; i++)
- if(s[i].ref == 0)
- goto found;
-notfound:
- /* errstr not informative; assume we hit seg limit */
- for(j = nstab - 1; j >= i; j--)
- if(s[j].ref)
- break;
- nstab = j;
- semrelease(&ssem, 1);
- return emalloc(sz);
-found:
- /*
- * the system doesn't leave any room for expansion
- */
- va = segattach(SG_CEXEC, "memory", 0, sz + sz/10 + 4096);
- if(va == 0)
- goto notfound;
- s[i].ref++;
- s[i].va = va;
- s[i].sz = sz;
- semrelease(&ssem, 1);
- memset(va, 0, sz);
- return va;
-}
-
-void
-segmfree(void *va)
-{- char *a;
- int i;
-
- a = va;
- for(i = 0; i < nstab; i++)
- if(s[i].va == a)
- goto found;
- free(va);
- return;
-found:
- semacquire(&ssem, 1);
- s[i].ref--;
- s[i].va = 0;
- s[i].sz = 0;
- semrelease(&ssem, 1);
-}
-
-void*
-segreallocfixup(int i, ulong sz)
-{- char buf[ERRMAX];
- void *va, *ova;
-
- rerrstr(buf, sizeof buf);
- if(strstr(buf, "segments overlap") == 0)
- sysfatal("segibrk: %r");- va = segattach(SG_CEXEC, "memory", 0, sz);
- if(va == 0)
- sysfatal("segattach: %r");- ova = s[i].va;
-fprint(2, "fix memcpy(%p, %p, %lud)\n", va, ova, s[i].sz);
- memcpy(va, ova, s[i].sz);
- s[i].va = va;
- s[i].sz = sz;
- segdetach(ova);
- return va;
-}
-
-void*
-segrealloc(void *va, ulong sz)
-{- char *a;
- int i;
- ulong sz0;
-
-fprint(2, "segrealloc %p %lud\n", va, sz);
- if(va == 0)
- return segmalloc(sz);
- a = va;
- for(i = 0; i < nstab; i++)
- if(s[i].va == a)
- goto found;
- if(sz >= thresh)
- if(a = segmalloc(sz)){- sz0 = msize(va);
- memcpy(a, va, sz0);
-fprint(2, "memset(%p, 0, %lud)\n", a + sz0, sz - sz0);
- memset(a + sz0, 0, sz - sz0);
- return a;
- }
- return realloc(va, sz);
-found:
- sz0 = s[i].sz;
-fprint(2, "segbrk(%p, %p)\n", s[i].va, s[i].va + sz);
- va = segbrk(s[i].va, s[i].va + sz);
- if(va == (void*)-1 || va < end)
- return segreallocfixup(i, sz);
- a = va;
- if(sz > sz0)
-{-fprint(2, "memset(%p, 0, %lud)\n", a + sz0, sz - sz0);
- memset(a + sz0, 0, sz - sz0);
-}
- s[i].va = va;
- s[i].sz = sz;
- return va;
-}
-
-void*
-emalloc(ulong n)
-{- void *p;
-fprint(2, "emalloc %lud\n", n);
- p = mallocz(n, 1);
- if(!p)
- sysfatal("malloc %lud: %r", n);- setmalloctag(p, getcallerpc(&n));
- return p;
-}
-
-void
-main(void)
-{- char *p;
- int i;
- ulong sz;
-
- p = 0;
- for(i = 0; i < 6; i++){- sz = i*512;
- p = segrealloc(p, sz);
- memset(p, 0, sz);
- }
- segmfree(p);
- exits("");-}