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digitalmars.D.learn - String Appender Fails (Memory Allocation Failure)

reply Loopback <elliott.darfink gmail.com> writes:
Hello!

I've been working on a project where I had to do all memory handling
explicitly because no destructors were called. When I got too tired
of the explicit memory handling I decided to trace what was causing
this error. After hours of code stripping I had gotten myself a
small concrete sample which could demonstrate the error.

Now to the point; I create a program using WinMain as entry point. The
program template i use, is identical to the win32 template on the
D-Website. If you have used this template you know that all user code
goes within the function "myWinMain". In this function I declare a class
named Foo. When I create this class an empty constructor is called, and
then the function "myWinMain" returns.

Now the program calls Runtime.terminate, which is supposed to take
care of the memory garbage and etc. This does not work. The terminate
function call throws an Error, "Memory Allocation Failure".
This failure originates in the 'Foo' destructor, which in turn creates
a appender object of type string. My question is; how come this throws
an error?
Jul 13 2011
next sibling parent Loopback <elliott.darfink gmail.com> writes:
On 2011-07-14 01:11, Loopback wrote:
 Hello!

 I've been working on a project where I had to do all memory handling
 explicitly because no destructors were called. When I got too tired
 of the explicit memory handling I decided to trace what was causing
 this error. After hours of code stripping I had gotten myself a
 small concrete sample which could demonstrate the error.

 Now to the point; I create a program using WinMain as entry point. The
 program template i use, is identical to the win32 template on the
 D-Website. If you have used this template you know that all user code
 goes within the function "myWinMain". In this function I declare a class
 named Foo. When I create this class an empty constructor is called, and
 then the function "myWinMain" returns.

 Now the program calls Runtime.terminate, which is supposed to take
 care of the memory garbage and etc. This does not work. The terminate
 function call throws an Error, "Memory Allocation Failure".
 This failure originates in the 'Foo' destructor, which in turn creates
 a appender object of type string. My question is; how come this throws
 an error?

// Import WINAPI import win32.windows; // Core API import core.runtime; // For appender import std.range; extern (Windows) int WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { int result; void exceptionHandler(Throwable e) { throw e; } try { Runtime.initialize(&exceptionHandler); result = myWinMain(hInstance, hPrevInstance, lpCmdLine, nCmdShow); Runtime.terminate(&exceptionHandler); } // If you use "Exception" object instead here, the program fails // silently without any MessageBox of any kind. The program, in this case quits // automatically after about 7-12 seconds, without any destructors called. // If you instead use Error object to catch the error, a message pops // up saying, "Memory Allocation Failure", why? catch (/*Exception*/Error o) // catch any uncaught exceptions { MessageBoxA(null, cast(char *) o.toString(), "Error", MB_OK | MB_ICONEXCLAMATION); result = 0;// failed } return result; } int myWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { Foo foo = new Foo; return (foo !is null); } class Foo { public: this() { } ~this() { // This line causes memory allocation failure auto writer = appender!string(); } }
Jul 13 2011
prev sibling parent reply David Nadlinger <see klickverbot.at> writes:
On 7/14/11 1:11 AM, Loopback wrote:
 Now the program calls Runtime.terminate, which is supposed to take
 care of the memory garbage and etc. This does not work. The terminate
 function call throws an Error, "Memory Allocation Failure".
 This failure originates in the 'Foo' destructor, which in turn creates
 a appender object of type string. My question is; how come this throws
 an error?

Currently, no memory can be allocated at all during garbage collection runs, which is where destructors are usually called. David
Jul 13 2011
parent reply Loopback <elliott.darfink gmail.com> writes:
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On 2011-07-14 01:17, David Nadlinger wrote:
 Currently, no memory can be allocated at all during garbage collection
 runs, which is where destructors are usually called.

 David

That explains it. Do you know when this feature will be available, if at all? Here is another interesting case, where I am using external libraries (FMOD) in this case. I have two different cases here, but they have two notable things in common. Both use WinMain as entry point and they both originate in the class Foo. In the first case, I use the class Foo, which has the "Sound" class as a private member. If foo omits the call to allocate the sound class no "Memory Allocation Failure" occurs. This error is also avoided if the two lines in the static destructor of sound is omitted: FMOD_System_Close(m_system); FMOD_System_Release(m_system); How come these external functions generates a Memory Allocation Failure when they use malloc for their memory allocation? Also worth noticing is that in the non-static destructor FMOD_Sound_Release is called without any problems, if the two function calls are omitted. One other thing; how come no "Memory Allocation Failure" occurs, when I do not allocate the sound class, since the static de-/constructors of the class are still called? In the second case, the exact same functions are called except that everything takes place in-lined in the Foo constructor. Case 1: Memory Allocation Failure and Sound destructor is not called. Case 2: Everything works as expected.
Jul 13 2011
parent Loopback <elliott.darfink gmail.com> writes:
Anybody got an idea?
Jul 14 2011