Implement try_close_finalizer, fix #1048 (#1049)

* Implement try_close_finalizer, do not wait for liblock, fix #1048

Author: mkitti

src/api/api.jl

@@ -13,8 +13,7 @@ else
     )
 end
 
-const liblock = ReentrantLock()
-
+include("lock.jl")
 include("types.jl")
 include("error.jl")
 include("functions.jl") # core API ccall wrappers

src/api/lock.jl

@@ -0,0 +1,15 @@
+const liblock = ReentrantLock()
+
+# Try to acquire the lock (test-test-set) and close if successful
+# Otherwise, defer finalization
+# https://github.com/JuliaIO/HDF5.jl/issues/1048
+function try_close_finalizer(x)
+    if !islocked(liblock) && trylock(liblock) do
+        close(x)
+        true
+    end
+    else
+        finalizer(try_close_finalizer, x)
+    end
+    return nothing
+end

src/properties.jl

@@ -104,7 +104,7 @@ macro propertyclass(name, classid)
             id::API.hid_t
             function $name(id::API.hid_t)
                 obj = new(id)
-                finalizer(close, obj)
+                finalizer(API.try_close_finalizer, obj)
                 obj
             end
         end

src/types.jl

@@ -41,7 +41,7 @@ mutable struct File <: H5DataStore
     function File(id, filename, toclose::Bool=true)
         f = new(id, filename)
         if toclose
-            finalizer(close, f)
+            finalizer(API.try_close_finalizer, f)
         end
         f
     end
@@ -55,7 +55,7 @@ mutable struct Group <: H5DataStore
 
     function Group(id, file)
         g = new(id, file)
-        finalizer(close, g)
+        finalizer(API.try_close_finalizer, g)
         g
     end
 end
@@ -69,7 +69,7 @@ mutable struct Dataset
 
     function Dataset(id, file, xfer=DatasetTransferProperties())
         dset = new(id, file, xfer)
-        finalizer(close, dset)
+        finalizer(API.try_close_finalizer, dset)
         dset
     end
 end
@@ -84,14 +84,14 @@ mutable struct Datatype
     function Datatype(id, toclose::Bool=true)
         nt = new(id, toclose)
         if toclose
-            finalizer(close, nt)
+            finalizer(API.try_close_finalizer, nt)
         end
         nt
     end
     function Datatype(id, file::File, toclose::Bool=true)
         nt = new(id, toclose, file)
         if toclose
-            finalizer(close, nt)
+            finalizer(API.try_close_finalizer, nt)
         end
         nt
     end
@@ -106,7 +106,7 @@ mutable struct Dataspace
 
     function Dataspace(id)
         dspace = new(id)
-        finalizer(close, dspace)
+        finalizer(API.try_close_finalizer, dspace)
         dspace
     end
 end
@@ -119,7 +119,7 @@ mutable struct Attribute
 
     function Attribute(id, file)
         dset = new(id, file)
-        finalizer(close, dset)
+        finalizer(API.try_close_finalizer, dset)
         dset
     end
 end