Simplify lock context managers.

lib/spack/llnl/util/lock.py

@@ -29,13 +29,15 @@
 import time
 import socket
 
+# Default timeout for locks.
+DEFAULT_TIMEOUT = 60
+
+class _ReadLockContext(object):
+    """Context manager that takes and releases a read lock.
 
-class Read_Lock_Instance(object):
-    """
-    A context manager for getting shared access to the object lock
     Arguments are lock and timeout (default 5 minutes)
     """
-    def __init__(self, lock, timeout=300):
+    def __init__(self, lock, timeout=DEFAULT_TIMEOUT):
         self._lock = lock
         self._timeout = timeout
 
@@ -46,12 +48,12 @@ def __exit__(self,type,value,traceback):
         self._lock.release_read()
 
 
-class Write_Lock_Instance(object):
-    """
-    A context manager for getting exclusive access to the object lock
+class _WriteLockContext(object):
+    """Context manager that takes and releases a write lock.
+
     Arguments are lock and timeout (default 5 minutes)
     """
-    def __init__(self, lock, timeout=300):
+    def __init__(self, lock, timeout=DEFAULT_TIMEOUT):
         self._lock = lock
         self._timeout = timeout
 
@@ -72,7 +74,17 @@ def __init__(self, file_path):
         self._writes = 0
 
 
-    def acquire_read(self,timeout):
+    def write_lock(self, timeout=DEFAULT_TIMEOUT):
+        """Convenience method that returns a write lock context."""
+        return _WriteLockContext(self, timeout)
+
+
+    def read_lock(self, timeout=DEFAULT_TIMEOUT):
+        """Convenience method that returns a read lock context."""
+        return _ReadLockContext(self, timeout)
+
+
+    def acquire_read(self, timeout):
         """
         Implements recursive lock. If held in both read and write mode,
         the write lock will be maintained until all locks are released

lib/spack/spack/cmd/__init__.py

@@ -28,7 +28,6 @@
 
 import llnl.util.tty as tty
 from llnl.util.lang import attr_setdefault
-from llnl.util.lock import *
 
 import spack
 import spack.spec
@@ -125,7 +124,7 @@ def elide_list(line_list, max_num=10):
 
 
 def disambiguate_spec(spec):
-    with Read_Lock_Instance(spack.installed_db.lock,1800):
+    with spack.installed_db.read_lock():
         matching_specs = spack.installed_db.get_installed(spec)
         if not matching_specs:
             tty.die("Spec '%s' matches no installed packages." % spec)

lib/spack/spack/cmd/deactivate.py

@@ -24,7 +24,6 @@
 ##############################################################################
 from external import argparse
 import llnl.util.tty as tty
-from llnl.util.lock import *
 
 import spack
 import spack.cmd
@@ -55,7 +54,7 @@ def deactivate(parser, args):
     if args.all:
         if pkg.extendable:
             tty.msg("Deactivating all extensions of %s" % pkg.spec.short_spec)
-            with Read_Lock_Instance(spack.installed_db.lock,1800):
+            with spack.installed_db.read_lock():
                 ext_pkgs = spack.installed_db.installed_extensions_for(spec)
 
                 for ext_pkg in ext_pkgs:

lib/spack/spack/cmd/diy.py

@@ -27,7 +27,6 @@
 from external import argparse
 
 import llnl.util.tty as tty
-from llnl.util.lock import *
 
 import spack
 import spack.cmd
@@ -55,7 +54,7 @@ def diy(self, args):
     if not args.spec:
         tty.die("spack diy requires a package spec argument.")
 
-    with Write_Lock_Instance(spack.installed_db.lock,1800):
+    with spack.installed_db.write_lock():
         specs = spack.cmd.parse_specs(args.spec)
         if len(specs) > 1:
             tty.die("spack diy only takes one spec.")

lib/spack/spack/cmd/extensions.py

@@ -27,7 +27,6 @@
 
 import llnl.util.tty as tty
 from llnl.util.tty.colify import colify
-from llnl.util.lock import *
 
 import spack
 import spack.cmd
@@ -81,7 +80,7 @@ def extensions(parser, args):
     colify(ext.name for ext in extensions)
 
     # List specs of installed extensions.
-    with Read_Lock_Instance(spack.installed_db.lock,1800):
+    with spack.installed_db.read_lock():
         installed  = [s.spec for s in spack.installed_db.installed_extensions_for(spec)]
     print
     if not installed:

lib/spack/spack/cmd/find.py

@@ -32,7 +32,6 @@
 from llnl.util.tty.colify import *
 from llnl.util.tty.color import *
 from llnl.util.lang import *
-from llnl.util.lock import *
 
 import spack
 import spack.spec
@@ -139,11 +138,11 @@ def find(parser, args):
 
     # Get all the specs the user asked for
     if not query_specs:
-        with Read_Lock_Instance(spack.installed_db.lock, 1800):
+        with spack.installed_db.read_lock():
             specs = set(spack.installed_db.installed_package_specs())
 
     else:
-        with Read_Lock_Instance(spack.installed_db.lock, 1800):
+        with spack.installed_db.read_lock():
             results = [set(spack.installed_db.get_installed(qs)) for qs in query_specs]
         specs = set.union(*results)
 

lib/spack/spack/cmd/fsck.py

@@ -1,5 +1,5 @@
 ##############################################################################
-# Copyright (c) 2013, Lawrence Livermore National Security, LLC.
+# Copyright (c) 2013-2015, Lawrence Livermore National Security, LLC.
 # Produced at the Lawrence Livermore National Laboratory.
 #
 # This file is part of Spack.
@@ -23,21 +23,10 @@
 # Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 from external import argparse
-
-from llnl.util.lock import *
-
 import spack
-import os
 
 description = "Correct database irregularities"
 
-#Very basic version of spack fsck
+# Very basic version of spack fsck
 def fsck(parser, args):
-    with Write_Lock_Instance(spack.installed_db.lock,1800):
-        #remove database file
-        if os.path.exists(spack.installed_db._file_path):
-            os.remove(spack.installed_db._file_path)
-        #read database
-        spack.installed_db.read_database()
-        #write database
-        spack.installed_db.write()
+    spack.installed_db.reindex(spack.install_layout)

lib/spack/spack/cmd/install.py

@@ -25,7 +25,6 @@
 from external import argparse
 
 import llnl.util.tty as tty
-from llnl.util.lock import *
 
 import spack
 import spack.cmd
@@ -69,7 +68,7 @@ def install(parser, args):
     if args.no_checksum:
         spack.do_checksum = False        # TODO: remove this global.
 
-    with Write_Lock_Instance(spack.installed_db.lock,1800):
+    with spack.installed_db.write_lock():
         specs = spack.cmd.parse_specs(args.packages, concretize=True)
         for spec in specs:
             package = spack.db.get(spec)

lib/spack/spack/cmd/uninstall.py

@@ -27,7 +27,6 @@
 
 import llnl.util.tty as tty
 from llnl.util.tty.colify import colify
-from llnl.util.lock import *
 
 import spack
 import spack.cmd
@@ -54,7 +53,7 @@ def uninstall(parser, args):
     if not args.packages:
         tty.die("uninstall requires at least one package argument.")
 
-    with Write_Lock_Instance(spack.installed_db.lock,1800):
+    with spack.installed_db.write_lock():
         specs = spack.cmd.parse_specs(args.packages)
 
         # For each spec provided, make sure it refers to only one package.

lib/spack/spack/database.py

@@ -24,13 +24,14 @@
 ##############################################################################
 import os
 import time
+import socket
 
 from external import yaml
 from external.yaml.error import MarkedYAMLError, YAMLError
 
 import llnl.util.tty as tty
 from llnl.util.filesystem import *
-from llnl.util.lock import *
+from llnl.util.lock import Lock
 
 import spack.spec
 from spack.version import Version
@@ -99,6 +100,16 @@ def __init__(self, root):
         self._last_write_time = 0
 
 
+    def write_lock(self):
+        """Get a write lock context for use in a `with` block."""
+        return self.lock.write_lock()
+
+
+    def read_lock(self):
+        """Get a read lock context for use in a `with` block."""
+        return self.lock.read_lock()
+
+
     def _write_to_yaml(self, stream):
         """Write out the databsae to a YAML file."""
         # map from per-spec hash code to installation record.
@@ -198,13 +209,14 @@ def check(cond, msg):
 
     def reindex(self, directory_layout):
         """Build database index from scratch based from a directory layout."""
-        with Write_Lock_Instance(self.lock, 60):
+        with self.write_lock():
             data = {}
             for spec in directory_layout.all_specs():
                 path = directory_layout.path_for_spec(spec)
                 hash_key = spec.dag_hash()
                 data[hash_key] = InstallRecord(spec, path)
             self._data = data
+
             self.write()
 
 
@@ -264,7 +276,7 @@ def add(self, spec, path):
         Write the database back to memory
         """
         # Should always already be locked
-        with Write_Lock_Instance(self.lock, 60):
+        with self.write_lock():
             self.read()
             self._data[spec.dag_hash()] = InstallRecord(spec, path)
             self.write()
@@ -278,7 +290,7 @@ def remove(self, spec):
         Writes the database back to memory
         """
         # Should always already be locked
-        with Write_Lock_Instance(self.lock, 60):
+        with self.write_lock():
             self.read()
             hash_key = spec.dag_hash()
             if hash_key in self._data:
@@ -314,7 +326,7 @@ def installed_package_specs(self):
         and return their specs
         """
         # Should always already be locked
-        with Read_Lock_Instance(self.lock, 60):
+        with self.read_lock():
             self.read()
         return sorted(rec.spec for rec in self._data.values())