.

bigfile/file_zodb.cpp

@@ -61,11 +61,15 @@ static int zfile_remmap_blk_read(VMA *vma, BigFile *file, blk_t blk) {
 
 
 static void zfile_munmap(VMA *vma, BigFile *file) {
+    error err;
+
     // NOTE taking 1 ref back from vma->mmap_overlay_server
     wcfs::Mapping mmap = adoptref(static_cast<wcfs::_Mapping*>(vma->mmap_overlay_server));
     vma->mmap_overlay_server = NULL;
 
-    mmap->unmap();
+    err = mmap->unmap();
+    if (err != nil)
+        panic(v(err));  // XXX
 
     // XXX close mmap->fileh
 }

wcfs/client/_wcfs.pxd

@@ -111,7 +111,7 @@ cdef extern from "wcfs/client/wcfs.h" namespace "wcfs" nogil:
         uint8_t *mem_start
         uint8_t *mem_stop
 
-        void    unmap()
+        error   unmap()
 
     cppclass Mapping (refptr[_Mapping]):
         # Mapping.X = Mapping->X in C++
@@ -121,7 +121,7 @@ cdef extern from "wcfs/client/wcfs.h" namespace "wcfs" nogil:
         uint8_t *mem_start      "_ptr()->mem_start"
         uint8_t *mem_stop       "_ptr()->mem_stop"
 
-        void    unmap           "_ptr()->unmap"         ()
+        error   unmap           "_ptr()->unmap"         ()
 
 
     cxx.dict[int64_t, Tid] _tfileh_pinned(FileH wfileh)

wcfs/client/_wcfs.pyx

@@ -155,7 +155,9 @@ cdef class PyMapping:
 
     def unmap(PyMapping pywmmap):
         with nogil:
-            wmmap_unmap_pyexc(pywmmap.wmmap)    # XXX +err
+            err = wmmap_unmap_pyexc(pywmmap.wmmap)
+        if err != nil:
+            raise pyerr(err)
 
 # ----------------------------------------
 
@@ -291,8 +293,8 @@ cdef nogil:
     pair[Mapping, error] wfileh_mmap_pyexc(FileH wfileh, int64_t blk_start, int64_t blk_len)   except +topyexc:
         return wfileh.mmap(blk_start, blk_len)
 
-    void wmmap_unmap_pyexc(Mapping wmmap)                       except +topyexc:
-        wmmap.unmap()
+    error wmmap_unmap_pyexc(Mapping wmmap)                      except +topyexc:
+        return wmmap.unmap()
 
     error wlink_close_pyexc(WatchLink wlink)                    except +topyexc:
         return wlink.close()

wcfs/client/wcfs.cpp

@@ -606,25 +606,29 @@ void _Mapping::remmap_blk(int64_t blk) {
 
 // unmap removes mapping memory from address space.
 // virtmem calls this when VMA is unmapped.
-void _Mapping::unmap() {
+error _Mapping::unmap() {
     Mapping mmap = newref(this);    // XXX newref for std::remove
+    FileH f = mmap->fileh;
+    xerr::Contextf E("wcfs %s: conn @%s: f<%s>: unmap",
+            v(f->wconn->_wc->mountpoint), v(f->wconn->at), v(f->foid));
 
     // XXX locking
 
     error err = mm::unmap(mmap->mem_start, mmap->mem_stop - mmap->mem_start);
     if (err != nil)
-        panic(v(err));  // XXX
+        return E(err);
     mmap->mem_start = NULL;
     mmap->mem_stop  = NULL;
     // XXX clear other fields?
 
-    FileH f = mmap->fileh;
     //f->_mmaps.remove(mmap);
 
     // FIXME keep mmaps sorted
     f->_mmaps.erase(
         std::remove(f->_mmaps.begin(), f->_mmaps.end(), mmap),
         f->_mmaps.end());
+
+    return nil;
 }
 
 

wcfs/client/wcfs.h

@@ -141,6 +141,7 @@ struct PinReq;
 // XXX raw files?
 //
 // WCFS logically mirrors ZODB.DB .
+// It is safe to use WCFS from multiple threads simultaneously.
 struct WCFS {
     string  mountpoint;
 
@@ -162,10 +163,11 @@ struct WCFS {
 // Use .resync to resync Conn onto different database view.
 //
 // Conn logically mirrors ZODB.Connection .
+// It is safe to use Conn from multiple threads simultaneously.
 typedef refptr<struct _Conn> Conn;
 struct _Conn : object {
     WCFS        *_wc;
-    zodb::Tid   at;
+    zodb::Tid   at;	// XXX -> under mu
     WatchLink   _wlink; // watch/receive pins for mappings created under this conn
 
     // XXX kill downMu? (move under filehmu so that e.g. .open() can check downErr without race)
@@ -205,6 +207,8 @@ private:
 // /head/<file>/data primarily and /@revX/<file>/data pin overrides.
 //
 // Use .mmap to map file view into memory.
+//
+// It is safe to use FileH from multiple threads simultaneously.
 typedef refptr<struct _FileH> FileH;
 struct _FileH : object {
     Conn        wconn;
@@ -232,6 +236,9 @@ public:
 // Mapping represents one memory mapping of FileH.
 //
 // The mapped memory is [.mem_start, .mem_stop)
+// Use .unmap to release virtual memory resources used by mapping.
+//
+// XXX It is safe to use Mapping from multiple threads simultaneously.
 typedef refptr<struct _Mapping> Mapping;
 struct _Mapping : object {
     FileH   fileh;
@@ -247,8 +254,8 @@ struct _Mapping : object {
     }
 
     error _remmapblk(int64_t blk, zodb::Tid at);
-    void  remmap_blk(int64_t blk);
-    void  unmap();
+    void  remmap_blk(int64_t blk); // for virtmem-only
+    error unmap();
 
     // don't new - create via FileH.mmap
 private: