From 897c6b5231b76e475959a3e0c5559df5d46fb87c Mon Sep 17 00:00:00 2001 From: Christopher Faylor Date: Fri, 22 Aug 2003 19:25:56 +0000 Subject: * exceptions.cc (sigreturn): Don't clobber ebp in recursive signal calls. --- winsup/cygwin/heap.cc | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) (limited to 'winsup/cygwin/heap.cc') diff --git a/winsup/cygwin/heap.cc b/winsup/cygwin/heap.cc index 8e0a04e23..95fdd12eb 100644 --- a/winsup/cygwin/heap.cc +++ b/winsup/cygwin/heap.cc @@ -56,6 +56,7 @@ heap_init () if (cygheap->user_heap.base == NULL) api_fatal ("unable to allocate heap, heap_chunk_size %d, %E", cygheap->user_heap.chunk); + cygheap->user_heap.max = (char *) cygheap->user_heap.base + cygheap->user_heap.chunk; } else { @@ -101,7 +102,7 @@ sbrk (int n) unsigned commitbytes, newbrksize; if (n == 0) - return cygheap->user_heap.ptr; /* Just wanted to find current cygheap->user_heap.ptr address */ + return cygheap->user_heap.ptr; /* Just wanted to find current cygheap->user_heap.ptr address */ newbrk = (char *) cygheap->user_heap.ptr + n; /* Where new cygheap->user_heap.ptr will be */ newtop = (char *) pround (newbrk); /* Actual top of allocated memory - @@ -122,23 +123,33 @@ sbrk (int n) assert (newtop > cygheap->user_heap.top); - /* Need to grab more pages from the OS. If this fails it may be because - * we have used up previously reserved memory. Or, we're just plumb out - * of memory. */ + /* Find the number of bytes to commit, rounded up to the nearest page. */ commitbytes = pround (newtop - (char *) cygheap->user_heap.top); - if (VirtualAlloc (cygheap->user_heap.top, commitbytes, MEM_COMMIT, PAGE_READWRITE) != NULL) - goto good; + + /* Need to grab more pages from the OS. If this fails it may be because + we have used up previously reserved memory. Or, we're just plumb out + of memory. Only attempt to commit memory that we know we've previously + reserved. */ + if (newtop <= cygheap->user_heap.max) + { + if (VirtualAlloc (cygheap->user_heap.top, commitbytes, MEM_COMMIT, PAGE_READWRITE) != NULL) + goto good; + } /* Couldn't allocate memory. Maybe we can reserve some more. - Reserve either the maximum of the standard cygwin_shared->heap_chunk_size () or the requested - amount. Then attempt to actually allocate it. */ + Reserve either the maximum of the standard cygwin_shared->heap_chunk_size () + or the requested amount. Then attempt to actually allocate it. */ if ((newbrksize = cygheap->user_heap.chunk) < commitbytes) newbrksize = commitbytes; - if ((VirtualAlloc (cygheap->user_heap.top, newbrksize, MEM_RESERVE, PAGE_NOACCESS) != NULL) && - (VirtualAlloc (cygheap->user_heap.top, commitbytes, MEM_COMMIT, PAGE_READWRITE) != NULL)) - goto good; + if ((VirtualAlloc (cygheap->user_heap.top, newbrksize, MEM_RESERVE, PAGE_NOACCESS) + || VirtualAlloc (cygheap->user_heap.top, newbrksize = commitbytes, MEM_RESERVE, PAGE_NOACCESS)) + && VirtualAlloc (cygheap->user_heap.top, commitbytes, MEM_COMMIT, PAGE_READWRITE) != NULL) + { + (char *) cygheap->user_heap.max += newbrksize; + goto good; + } err: set_errno (ENOMEM); -- cgit v1.2.3