diff options
Diffstat (limited to 'win32')
| -rw-r--r-- | win32/win32.c | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/win32/win32.c b/win32/win32.c index bead78a8a8..2e5db2c94a 100644 --- a/win32/win32.c +++ b/win32/win32.c @@ -4155,7 +4155,6 @@ static char *base = NULL; /* XXX threadead */ static char *reserved = NULL; /* XXX threadead */ static char *brk = NULL; /* XXX threadead */ static DWORD pagesize = 0; /* XXX threadead */ -static DWORD allocsize = 0; /* XXX threadead */ void * sbrk(ptrdiff_t need) @@ -4168,28 +4167,34 @@ sbrk(ptrdiff_t need) * call the OS to commit just one page ... */ pagesize = info.dwPageSize << 3; - allocsize = info.dwAllocationGranularity; } - /* This scheme fails eventually if request for contiguous - * block is denied so reserve big blocks - this is only - * address space not memory ... - */ if (brk+need >= reserved) { - DWORD size = 64*1024*1024; + DWORD size = brk+need-reserved; char *addr; + char *prev_committed = NULL; if (committed && reserved && committed < reserved) { /* Commit last of previous chunk cannot span allocations */ addr = (char *) VirtualAlloc(committed,reserved-committed,MEM_COMMIT,PAGE_READWRITE); if (addr) + { + /* Remember where we committed from in case we want to decommit later */ + prev_committed = committed; committed = reserved; + } } /* Reserve some (more) space + * Contiguous blocks give us greater efficiency, so reserve big blocks - + * this is only address space not memory... * Note this is a little sneaky, 1st call passes NULL as reserved * so lets system choose where we start, subsequent calls pass * the old end address so ask for a contiguous block */ +sbrk_reserve: + if (size < 64*1024*1024) + size = 64*1024*1024; + size = ((size + pagesize - 1) / pagesize) * pagesize; addr = (char *) VirtualAlloc(reserved,size,MEM_RESERVE,PAGE_NOACCESS); if (addr) { @@ -4201,6 +4206,19 @@ sbrk(ptrdiff_t need) if (!brk) brk = committed; } + else if (reserved) + { + /* The existing block could not be extended far enough, so decommit + * anything that was just committed above and start anew */ + if (prev_committed) + { + if (!VirtualFree(prev_committed,reserved-prev_committed,MEM_DECOMMIT)) + return (void *) -1; + } + reserved = base = committed = brk = NULL; + size = need; + goto sbrk_reserve; + } else { return (void *) -1; @@ -4211,11 +4229,12 @@ sbrk(ptrdiff_t need) if (brk > committed) { DWORD size = ((brk-committed + pagesize -1)/pagesize) * pagesize; - char *addr = (char *) VirtualAlloc(committed,size,MEM_COMMIT,PAGE_READWRITE); + char *addr; + if (committed+size > reserved) + size = reserved-committed; + addr = (char *) VirtualAlloc(committed,size,MEM_COMMIT,PAGE_READWRITE); if (addr) - { - committed += size; - } + committed += size; else return (void *) -1; } |