/* Allocate a region of memory of al least size bytes, at or above minAddress.
* If the attempt fails, answer null. If the attempt succeeds, answer the
* start of the region and assign its size through allocatedSizePointer.
*/
void *
sqAllocateMemorySegmentOfSizeAboveAllocatedSizeInto(sqInt size, void *minAddress, sqInt *allocatedSizePointer)
{
void *alloc;
long bytes = roundUpToPage(size);
if (!pageSize) {
pageSize = getpagesize();
pageMask = pageSize - 1;
}
*allocatedSizePointer = bytes;
while ((char *)minAddress + bytes > (char *)minAddress) {
alloc = mmap((void *)roundUpToPage((unsigned long)minAddress), bytes,
PROT_READ | PROT_WRITE, MAP_ANON | MAP_SHARED, -1, 0);
if (alloc == MAP_FAILED) {
perror("sqAllocateMemorySegmentOfSizeAboveAllocatedSizeInto mmap");
return 0;
}
if (alloc >= minAddress)
return alloc;
if (munmap(alloc, bytes) != 0)
perror("sqAllocateMemorySegment... munmap");
minAddress = (void *)((char *)minAddress + bytes);
}
return 0;
}
/* Allocate a region of memory of al least size bytes, at or above minAddress.
* If the attempt fails, answer null. If the attempt succeeds, answer the
* start of the region and assign its size through allocatedSizePointer.
*/
void *
sqAllocateMemorySegmentOfSizeAboveAllocatedSizeInto(sqInt size, void *minAddress, sqInt *allocatedSizePointer)
{
void *alloc;
long bytes = roundUpToPage(size);
*allocatedSizePointer = bytes;
#if 0 /* It appears VirtualAlloc answers low memory by default. */
alloc = VirtualAlloc(0, bytes, MEM_COMMIT, PAGE_READWRITE);
if (!alloc) {
sqMessageBox(MB_OK | MB_ICONSTOP, TEXT("VM Error:"),
"Unable to VirtualAlloc committed memory (%d bytes requested)",
bytes);
return NULL;
}
if ((unsigned long)alloc >= (unsigned long)minAddress)
return alloc;
if (!VirtualFree(alloc, bytes, MEM_RELEASE))
sqMessageBox(MB_OK | MB_ICONSTOP, TEXT("VM Warning:"),
"Unable to VirtualFree committed memory (%d bytes requested)",
bytes);
#endif /* 0 */
alloc = VirtualAlloc(0, bytes, MEM_COMMIT+MEM_TOP_DOWN, PAGE_READWRITE);
if ((unsigned long)alloc >= (unsigned long)minAddress)
return alloc;
if (!VirtualFree(alloc, bytes, MEM_RELEASE))
sqMessageBox(MB_OK | MB_ICONSTOP, TEXT("VM Warning:"),
"Unable to VirtualFree committed memory (%d bytes requested)",
bytes);
sqMessageBox(MB_OK | MB_ICONSTOP, TEXT("VM Error:"),
"Unable to VirtualAlloc committed memory at desired address (%d bytes requested at or above %p)",
bytes, minAddress);
return NULL;
}
/* Answer the address of minHeapSize rounded up to page size bytes of memory. */
usqInt
sqAllocateMemory(usqInt minHeapSize, usqInt desiredHeapSize)
{
char *hint, *address, *alloc;
unsigned long alignment, allocBytes;
if (pageSize) {
fprintf(stderr, "sqAllocateMemory: already called\n");
exit(1);
}
pageSize = getpagesize();
pageMask = ~(pageSize - 1);
hint = sbrk(0);
alignment = mmax(pageSize,1024*1024);
address = (char *)(((usqInt)hint + alignment - 1) & ~(alignment - 1));
alloc = sqAllocateMemorySegmentOfSizeAboveAllocatedSizeInto
(roundUpToPage(desiredHeapSize), address, &allocBytes);
if (!alloc) {
fprintf(stderr, "sqAllocateMemory: initial alloc failed!\n");
exit(errno);
}
return (usqInt)alloc;
}
void
sqMakeMemoryNotExecutableFromTo(unsigned long startAddr, unsigned long endAddr)
{
unsigned long firstPage = roundDownToPage(startAddr);
if (mprotect((void *)firstPage,
roundUpToPage(endAddr - firstPage),
PROT_READ | PROT_WRITE) < 0)
perror("mprotect(x,y,PROT_READ | PROT_WRITE)");
}
