1 Visual Leak Detector (VLD) Version 1.9f (beta)
3 Change Log / Release Notes
5 1.9f beta (18 November 2006)
6 ----------------------------
8 + Deadlocks or access violations may occur when loading DLLs into
9 multithreaded processes.
10 + In multithreaded programs, if the main thread terminates before other
11 threads in the process, then Visual Leak Detector may cause an access
12 violation while generating the memory leak report.
14 Known Bugs/Restrictions:
15 + Memory allocations made through calls to functions loaded from a DLL using
16 delayed loading may not be detected.
17 + Support for programs that use MFC 7.0 or MFC 7.1 is not complete yet. Some
18 memory leaks from such MFC-based programs may not be detected.
19 + Visual Leak Detector may report leaks internal to Visual Leak Detector
20 if the main thread of the process terminates while other threads are still
22 + If more than one copy of the same C Runtime DLL is loaded in the process at
23 the same time, then some leaks may go undetected (note that loading more
24 than one copy of the C Runtime DLL into a process at the same time is
25 probably a bad idea to begin with).
27 1.9e beta (16 November 2006)
28 ----------------------------
29 New Features/Enhancements:
30 + Added a master on/off switch configuration option to vld.ini that can be
31 used to completely disable Visual Leak Detector.
34 + Numerous deadlock situations. The multithread synchronization scheme has
35 been completely re-written which should make deadlocks in VLD much less
37 + An access violation will occur in VLD if GetProcAddress is called to obtain
38 an export's address by ordinal, for certain libraries.
39 + Problems may potentially occur when the program being debugged exits due to
40 the Debug Help Library having been detached from the process too early.
41 Symptoms might include access violation exceptions or other erratic behavior
42 just as the program exits and while VLD is generating the leak report.
43 + The copy of vld.ini installed in VLD's installation directory overrides any
44 other copies of vld.ini that are created, even copies placed in the
45 working directory of the program being debugged.
47 Known Bugs/Restrictions:
48 + Memory allocations made through calls to functions loaded from a DLL using
49 delayed loading may not be detected.
50 + Support for programs that use MFC 7.0 or MFC 7.1 is not complete yet. Some
51 memory leaks from such MFC-based programs may not be detected.
52 + If more than one copy of the same C Runtime DLL is loaded in the process at
53 the same time, then some leaks may go undetected (note that loading more
54 than one copy of the C Runtime DLL into a process at the same time is
55 probably a bad idea to begin with).
57 1.9d beta (12 November 2006)
58 ----------------------------
60 + Failed assertion "freed == TRUE" pops up when running a program with VLD
61 without the debugger attached.
62 + Some, but not all, multithreaded programs that dynamically load and unload
63 many DLLs have been known to experience problems, such as deadlocks or
64 exceptions, when used with VLD.
65 + Failed assertion "exportmodule != NULL" pops up when running some programs
67 + VLD fails to show file names or function names in the memory leak report for
68 some programs that are linked with the dynamic CRT library.
69 + Access violation exceptions are thrown, but caught by the operating system,
70 when running some programs with VLD.
72 1.9c beta (6 November 2006)
73 ---------------------------
74 New Features/Enhancments:
75 + New NSIS installer makes setting up and using VLD much easier.
76 + No need to manually copy dbghelp.dll to the right location, VLD will always
77 find the right version.
78 + MFC 8.0 is now fully supported.
79 + The memory leak report is now written to the output window much faster.
80 Support has been added, through a new configuration option, to slow down
81 the report output for older versions of Visual Studio that have trouble
82 when it is written too quickly.
85 + All known compatibilities with Visual Studio 2005 have been eliminated.
86 + Leaks from calloc may go undetected.
87 + Leaks from vector new operator may go undetected.
88 + VLDDisable and VLDEnable do not work as expected; some memory leaks that
89 should be ignored by VLD due to a previous call to VLDDisable are still
91 + Unloading and reloading a previously loaded module may cause leaks that
92 occur in the module after it was reloaded to go undetected.
93 + If vld.h is included in a release build, then the compiler will generate
94 errors if the VLDEnable or VLDDisable APIs have been used.
96 1.9b beta (26 October 2006)
97 ---------------------------
99 + Source compiles under Visual Studio 2005 and the binaries are compatible
100 with applications that link with the Visual Studio 2005 C Runtime Library
103 Known Restrictions in this Release:
104 + Memory allocations made through calls to functions loaded from a DLL using
105 delayed loading may not be detected.
107 + Support for programs that use MFC 7.0, MFC 7.1, or MFC 8.0 is not complete
108 yet. Some memory leaks from such MFC-based programs may not be detected. A
109 workaround for this restriction is to forcefully include the MFC DLLs in
110 memory leak detection, by setting the "ForceIncludeModules" configuration
111 option to: "mfc70d.dll mfc71d.dll mfc80d.dll" and explicitly adding vld.lib
112 as an input file on the linker command line (can be added through project
113 settings by adding it to the list of library modules in the linker options).
114 This restriction does not apply to programs that use MFC 4.2, which is fully
117 1.9a beta (9 March 2006)
118 ------------------------
119 New Features/Enhancments:
120 + All new leak detection engine detects most, if not all, in-process memory
121 leaks, not just leaks from "new" or "malloc", including COM-based leaks.
123 + Packaged as an easier-to-use DLL. There's no longer any need to carefully
124 decide which modules should be linked with the VLD library. Instead, you
125 just include the vld.h header file in at least one source file from each
126 module (DLL or EXE) to be included in memory leak detection.
128 + Configuration is done from an INI file instead of using preprocessor macros.
129 This allows VLD's configuration to be changed without needing to recompile
132 + Many new configuration options have been added. One of the most often
133 requested option that has been added is the option to save the leak report
134 to a file instead of, or in addition to, the debugger.
137 + The improved design of the new leak detection engine has resolved all of the
138 previously known restrictions in version 1.0.
140 Known Restrictions in this Release:
141 + Memory allocations made through calls to functions loaded from a DLL using
142 delayed loading may not be detected.
144 + Support for programs that use MFC 7.0, MFC 7.1, or MFC 8.0 is not complete
145 yet. Some memory leaks from such MFC-based programs may not be detected. A
146 workaround for this restriction is to forcefully include the MFC DLLs in
147 memory leak detection, by setting the "ForceIncludeModules" configuration
148 option to: "mfc70d.dll mfc71d.dll mfc80d.dll" and explicitly adding vld.lib
149 as an input file on the linker command line (can be added through project
150 settings by adding it to the list of library modules in the linker options).
151 This restriction does not apply to programs that use MFC 4.2, which is fully
157 New Features/Enhancements:
158 + Memory leak detection can now be selectively disabled and enabled at
159 runtime, using provided APIs. This provides a straightforward way of
160 allowing VLD to selectively "ignore" certain allocations. It can also be
161 used to disable VLD altogether at runtime, improving application performance
162 without needing to recompile.
164 + If there are multiple identical memory leaks (i.e. leaks that originate from
165 the same call stack and that leak the same size memory block) then VLD can
166 optionally aggregate all of the repeated leaks, showing only the first such
167 leaked block in detail in the memory leak report. A tally of the total
168 number of leaks that match that particular size and call stack accompanies
169 the information for that leak.
171 + When VLD is initialized at program startup, the library type which was
172 linked-in is displayed. This can help verify that the expected VLD library
173 (either single-threaded static, multithreaded static, or multithreaded DLL)
174 is being linked with your program.
176 + The Visual Leak Detector name is displayed on most messages output to the
177 debugger to easily differentiate VLD's output from the output produced by
178 the built-in memory leak detector.
180 + If any of the compile-time configuration options have been changed from
181 their default values, then the current state of the option is displayed in
182 the debugger when VLD is initialized.
184 + VLD's memory leak self-checking capability (checking for leaks in VLD
185 itself) can be verified using a new preprocessor macro that allows VLD to
186 perform a self-test at runtime.
189 + If the MFC libraries are statically linked to the program being debugged,
190 then MFC will erroneously report memory leaks in the Visual Leak Detector
191 code and may cause an access violation while attempting to report the false
192 memory leaks. These bogus leaks are always reported as "client block at
193 <address>, subtype bf42" and are claimed to be "invalid objects".
195 + VLD will leak a fixed-sized block of memory when the program exits if VLD
196 failed to initialize because the Debug Help library (dbghelp.dll) could not
199 + In multithreaded programs, if the program's main thread terminates before
200 other threads in the same process, then VLD may cause an access violation
201 while freeing resources used internally by VLD.
204 0.9i beta (30 April 2005)
205 -------------------------
206 New Features/Enhancements:
207 + Added support in the source code for x64 architecture. The pre-built
208 libraries will continue to support 32-bit only. If you need 64-bit support
209 you'll need to build 64-bit versions of the libraries from source. Note that
210 x64 is the only 64-bit architecture supported at this time. Itanium (aka
211 IA-64) is NOT currently supported.
214 + VLD does not report memory leaks that are the result of a failure to free
215 memory allocated via a call to realloc().
216 + In multithreaded programs, if the program's main thread terminates before
217 other threads in the same process, then VLD may cause an access violation
218 while checking for memory leaks.
219 + If VLD cannot find the source file and line number information for a program
220 address, the last known file and line number will be repeated in the call
221 stack section of the memory leak report. The correct behavior should be for
222 VLD to print "File and line number not available" for that call stack entry.
225 0.9h beta (22 April 2005)
226 -------------------------
228 + Access Violations occur at random places within the VLD code when using
230 + When using VLD version 0.9g, VLD may fail to report some memory leaks.
233 0.9g beta (22 April 2005)
234 -------------------------
235 New Features/Enhancements:
236 + Replaced the temporary internal search algorithm with a permanent search
237 algorithm that is much faster. Programs that dynamically allocate a large
238 number of memory blocks (tens of thousands or more) will see the most
239 significant performance boost from this version of VLD versus the previous
240 version. Overall, this is the fastest version of VLD released to date.
243 0.9f beta (13 April 2005)
244 -------------------------
245 New Features/Enhancements:
246 + Changed the internal search algorithm to a temporary simpler, but
247 more stable algorithm. A permanent algorithm which should be much
248 more efficient will be in a forthcoming release.
251 + Access Violation at line 319 in vldutil.cpp may occur when running a
252 program linked with the VLD library.
255 0.9e beta (12 April 2005)
256 -------------------------
257 New Features/Enhancements:
258 + VLD no longer uses any STL containers or STL strings. This solves all of the
259 compatibility problems with Visual Studio .NET when using the pre-built
262 + The configuration preprocessor macros now work with C programs without the
263 need to call VLDConfigure from within the program being debugged.
264 Because VLDConfigure is now obsolete, it has been removed.
266 + One new source file (vldutil.cpp) and one new header (vldutil.h) have been
267 added. They contain utility functions and utility classes that replace
268 functionality previously performed by STL containers and strings.
270 + The VisualLeakDetector global class object is now constructed at C runtime
271 initialization (i.e. it resides in the "compiler" initialization area).
272 Because VLD no longer uses any STL components, there is no longer the risk
273 that VLD will conflict with any STL libraries that also are constructed at
274 C runtime initialization. The end result is that VLD starts running earlier
275 and is destroyed later, which leads to more accurate leak detection.
278 + Linking to the VLD 0.9d libraries from the VLD distribution under Visual
279 Studio .NET results in a number of linker "unresolved external symbol"
280 errors. Unresolved symbols include "__declspec(dllimport) void __cdecl
281 std::_Xran(void)" and "__declspec(dllimport) private: void __thiscall
282 std::basic_string,class std::allocator >::_Eos(unsigned int)", among others.
284 + Call stacks do not appear in the memory leak report when linking against
285 release VLD libraries built from source with Visual Studio .NET.
287 + If the preprocessor macro VLD_MAX_DATA_DUMP is defined as 0 (zero), then VLD
288 will get stuck in an infinite loop, repeatedly printing the same information
289 while attempting to display the memory leak report in the debugger's output
293 0.9d beta (30 March 2005)
294 -------------------------
295 New Features/Enhancements:
296 + This version of VLD brings with it some major changes to the way VLD
297 interfaces with programs that use it. Instead of requiring that VLD be built
298 from source and then linked with the application, VLD is now packaged as a
299 pre-built static library. For those who just want to use VLD and are not
300 interested in modifying the source, this eliminates the complexities of
301 building VLD from source. A single header file, vld.h, has been added. To
302 link with the static library, this header needs to be included in one of the
303 program's source files. Please see the README.txt file for details on how
304 these changes affect how to use Visual Leak Detector.
306 + The Microsoft Debug Help Library (dbghelp.dll) version 6.3 is now included
307 with the VLD distribution.
310 0.9c beta (17 March 2005)
311 -------------------------
313 + Compile error, "error C2039: 'size' : is not a member of '_CrtMemBlockHeader'"
314 occurs at line 644 of vld.cpp when building VLD with the VLD_MAX_DATA_DUMP
315 preprocessor macro defined.
318 0.9b beta (15 March 2005)
319 -------------------------
321 + VLD fails to detect memory leaks in class constructors if the objects
322 constructed are global objects.
324 + If a debug executable is built with certain compiler optimizations turned on,
325 specifically frame pointer omission optimization or automatic inlining, then
326 theoretically VLD may produce incomplete or inaccurate stack traces or might
327 fail to produce stack traces altogether.
330 0.9a beta (12 March 2005)
331 -------------------------
332 Initial Public Release