diff options
Diffstat (limited to 'freelist.go')
| -rw-r--r-- | freelist.go | 46 |
1 files changed, 20 insertions, 26 deletions
diff --git a/freelist.go b/freelist.go index 149e595..a236079 100644 --- a/freelist.go +++ b/freelist.go @@ -1,6 +1,7 @@ package bolt import ( + "fmt" "sort" "unsafe" ) @@ -67,15 +68,31 @@ func (f *freelist) allocate(n int) pgid { } // free releases a page and its overflow for a given transaction id. +// If the page is already free then a panic will occur. func (f *freelist) free(txid txid, p *page) { - var ids = f.pending[txid] _assert(p.id > 1, "cannot free page 0 or 1: %d", p.id) + + // Verify that page is not already free. + minid, maxid := p.id, p.id+pgid(p.overflow) + for _, id := range f.ids { + if id >= minid && id <= maxid { + panic(fmt.Sprintf("page %d already freed in tx", id)) + } + } + for ptxid, m := range f.pending { + for _, id := range m { + if id >= minid && id <= maxid { + panic(fmt.Sprintf("tx %d: page %d already freed in tx %d", txid, id, ptxid)) + } + } + } + + // Free page and all its overflow pages. + var ids = f.pending[txid] for i := 0; i < int(p.overflow+1); i++ { ids = append(ids, p.id+pgid(i)) } f.pending[txid] = ids - - // DEBUG ONLY: f.check() } // release moves all page ids for a transaction id (or older) to the freelist. @@ -123,26 +140,3 @@ func (f *freelist) write(p *page) { p.count = uint16(len(ids)) copy(((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[:], ids) } - -// check verifies there are no double free pages. -// This is slow so it should only be used while debugging. -// If errors are found then a panic invoked. -/* -func (f *freelist) check() { - var lookup = make(map[pgid]txid) - for _, id := range f.ids { - if _, ok := lookup[id]; ok { - panic(fmt.Sprintf("page %d already freed", id)) - } - lookup[id] = 0 - } - for txid, m := range f.pending { - for _, id := range m { - if _, ok := lookup[id]; ok { - panic(fmt.Sprintf("tx %d: page %d already freed in tx %d", txid, id, lookup[id])) - } - lookup[id] = txid - } - } -} -*/ |