Understand and Prevent Memory Leaks in Delphi

Understand and Prevent Memory Leaks in Delphi Delphis support for object-oriented programming is rich and powerful. Classes and objects allow for modular code programming. Along with more modular and more complex components come more sophisticated and more complex bugs. While developing applications in Delphi is (almost) always fun, there are situations when you feel like the whole world is against you. Whenever you need to use (create) an object in Delphi, you need to free the memory it consumed (once no longer needed). Surely, the try/finally memory guarding blocks can help you prevent memory leaks; its still up to you to safeguard your code. A memory (or resource) leak occurs when the program loses the ability to free the memory it consumes. Repeated memory leaks cause the memory usage of a process to grow without bounds. Memory leaks are a serious problem if you have a code causing memory leak, in an application running 24/7, the application will eat up all the memory available and finally make the machine stop responding. Memory Leaks in Delphi The first step to avoiding memory leaks is to understand how they occur. What follows is a discussion on some common pitfalls and best practices for writing non-leaking Delphi code. In most (simple) Delphi applications, where you use the components (Buttons, Memos, Edits, etc.) you drop on a form (at design time), you do not need to care too much about memory management. Once the component is placed on a form, the form becomes its owner and will free the memory taken by the component once the form is closed (destroyed). Form, as the owner, is responsible for memory deallocation of the components it hosted. In short: components on a form are created and destroyed automatically Examples of Memory Leaks In any non-trivial Delphi application, you will want to instantiate Delphi components at run time. You will, also, have some of your own custom classes. Lets say you have a class TDeveloper that has a method DoProgram. Now, when you need to use the TDeveloper class, you create an instance of the class by calling the Create method (constructor). The Create method allocates memory for a new object and returns a reference to the object. varzarko : TDeveloperbeginzarko : TMyObject.Create;zarko.DoProgram;end; And heres a simple memory leak! Whenever you create an object, you must dispose of the memory it occupied. To free the memory an object allocated, you must call the Free method. To be perfectly sure, you should also use the try / finally block: varzarko : TDeveloperbeginzarko : TMyObject.Create;tryzarko.DoProgram;finallyzarko.Free;end;end; This is an example of safe memory allocation and deallocation code. Some words of warning: If you want to dynamically instantiate a Delphi component and explicitly free it sometime later, always pass nil as the owner. Failure to do so can introduce unnecessary risk, as well as performance and code maintenance problems. Besides creating and destroying objects using the Create and Free methods, you must also be very careful when using external (files, databases, etc) resources.Lets say you need to operate on some text file. In a very simple scenario, where the AssignFile method is used to associate a file on a disk with a file variable when you are finished with the file, you must call CloseFile to free the file handle to begin used. This is where you do not have an explicit call to Free. varF: TextFile;S: string;beginAssignFile(F, c:\somefile.txt) ;tryReadln(F, S) ;finallyCloseFile(F) ;end;end; Another example includes loading external DLLs from your code. Whenever you use LoadLibrary, you must call FreeLibrary: vardllHandle : THandle;begindllHandle : Loadlibrary(MyLibrary.DLL) ;//do something with this DLLif dllHandle 0 then FreeLibrary(dllHandle) ;end; Memory Leaks in .NET? Although with Delphi for .NET the garbage collector (GC) manages most memory tasks, it is possible to have memory leaks in .NET applications. Heres an article discussion GC in Delphi for .NET. How to Fight Against Memory Leaks Besides writing modular memory-safe code, preventing memory leaks can be done by using some of the third-party tools available. Delphi Memory Leak Fix Tools help you catch Delphi application errors such as memory corruption, memory leaks, memory allocation errors, variable initialization errors, variable definition conflicts, pointer errors, and more.

Financial Analysis Term Paper Example | Topics and Well Written Essays - 1250 words

Financial Analysis - Term Paper Example In the case of Competition Bikes Inc., they have been using traditional costing methods and have recently given ABC a try. The following is the data for the overhead costs of six items: From the figure above, we see the difference in production costs due to the cost allocation method. Under the traditional approach, the manufacturing overheads were overpriced for the Titanium model at $239,020 whereas the actual costs is $188,415. Consequently, the total manufacturing cost is also affected. Using the ABC approach would reduce the manufacturing cost of Titanium products, hence, helping the company get better margins. Similarly, for the Carbon DL model, the manufacturing overhead is underpriced at $232,380 whereas using ABC, we found it to be $282,985. Therefore, the product cost is less than the actual cost incurred. Hence, based on the above findings, we can conclude that Activity Based Costing method is the right approach for cost allocation as it allocates costs to individual activ ities making cost identification better. Moreover, it also helps in making operational improvements as with ABC, we have a clear idea of the cost centers. Evaluation of Cost-Volume-Profit Cost-volume-profit analysis also sometimes termed as breakeven analysis is the point at which revenues equal costs (both fixed and variable costs), i.e. a point of no loss or no gain. The analysis assumes that costs and revenue behave in a linearly and both fixed and variable costs have been accurately assigned. It also assumes that all units produced are sold and in the case of more than one type of product, the sales mix remains constant. Cost-Volume-Profit amalysis is the analysis that provides a company a rough understanding of the number of units they can produce to earn a particular amount of profit while incurring certain cost. One of the tools of Cost-Volume-Proft is Breakeven Analysis, which describes the units are which revenue equal cost. Bascially, this means that if Competition Bikes c an sell more than 1415 units of the Titanium model and 786 units of CarbonLite, they would be able to earn profit. Breakeven analysis describes the volume above which a company can earn profits while incurring the same amount of costs. The following figure provides the calculations for the Breakeven Analysis of Competition Bikes Inc. for their plant in San Diego with Titanium model of 900 units and CarbonLite model with 500 units. From the figure above, we can see that if Competition Bikes Inc. sells a total of 2201 units of Titanium and CarbonLite models combined, they would be able to breakeven and if they sell more than 2201 units, they can earn profit. It is also necessary to find the individual breakeven points of both the models. Competition Bikes need to sell 1415 units of Titanium model and 786 units of CarbonLite to be at the point where they suffer no loss and no gain. If we analyze the breakeven point in terms of sales dollars, we know that for Titanium, $1,273,500 are th e breakeven figures whereas for CarbonLite they are $1,175,070 as it is expensive than the Titanium model that is why lesser units and more sales dollars result in the breakeven of CarbonLite. An increase in fixed costs results in increasing both the breakeven units and sales dollars. If the fixed costs of Competition Bikes Inc. increases by an additional $50,000 and the cost of direct materials increase by 10%, then the following breakeven calculations would result: As we can see

Action Plan for Homeland Security Essay Example | Topics and Well Written Essays - 500 words

Action Plan for Homeland Security - Essay Example For a leader who is determined and courageous, his/her prevention strategies on attacks and disasters entail the strengthening of information sharing and collaboration capabilities. This will entail a robust investigative capacity to address all terror-linked issues and enhancing public awareness on reporting terror-related matters. There is need to establish the permanent commission that comprises of fire chiefs, police chiefs, mayors, local public health officials, and local emergency managers by the Department of Homeland Security to restructure the local-federal partnership with an aim of strengthening domestic security and safety. Create a safe and resilient cyber setting and promoting cyber-security innovation and knowledge (Shoemaker, & Conklin, 2011). There is a probability that a weapon of mass destruction will be utilized in a terrorist attack anywhere in the world by the end of 2016 (Graham, 2013). To ensure the safety of American people, the water systems will be protected from natural disasters and terrorist attacks through web-based monitoring of the distribution system water quality and regular water quality sampling combined with the analysis in the distribution system. Reducing vulnerability to terrorist attacks as well as other related disasters by strengthening capabilities that offer protection to public transport systems, ports, high-traffic borders, and other high priority critical infrastructure. The efforts to prevent terrorism will be centered on a layered risk-based approach to the security of the cargo and passenger systems of transportation, borders, and ports of entry. In the event of an electromagnetic pulse, money needs to be provided to the Department of Homeland Security by the federal government in order to offer protection to the electrical grid system. Office of Homeland Security to be given budgetary control over all federal programs associated with the nation’s domestic protection. Besides that, for those leaders who  are visionary and forward-looking, the Office of Homeland Security needs to be structured in a way that it works directly with mayors in support of their leadership responsibilities.

History Essays Sparta Foreign Policy

History Essays Sparta Foreign Policy Sparta Foreign Policy The beginning of Sparta was a city-state which began with the Dorian migration giving rise to the mighty polis. During this time there were endless military actions and invasions and Sparta fortified its locality through military might but also through the development of its agriculture, trade and crafts which transformed it into a self-sufficient and quite well-provided nation. Sparta became one of the strongest Greek city-states during the Hellenic era because of its order and organization. During the first few years the foreign policy of Sparta had two goals which were to succeed Athens as the leader of an Aegean-based naval empire, and to strengthen Spartas hold on the hegemony (leadership) of Greece (Buckley, Aspects of Greek History 750-323 BC, pg. 424). Get help with your essay from our expert essay writers Sparta, like most cities during that time seemed to have an aggressive policy toward there neighbors. Spartan foreign policies were biased many of the people did not like the way the states had been set up so they usually supported by a Spartan garrison. Sparta had an essentially a foreign policy that was cautious which kept Sparta out of the military involvements near the Aegean. With the expansion of Persia you saw a number of Greek colonies being captured and turned into dependent states belong to the Persian Empire. Many cities did try revolting against Persia. During this time they requested help from Sparta but they refused to help these cities which many felt was very wrong but this seemed to reflect how Sparta was during that time frame along with the fact that Sparta had no resources or equipment to help support a war that was being fought on the other side of the Aegean. Part of the policy of Sparta was once they taken control of one of their neighbors and had them under there influence they would not pursue them any further. They felt that they did not need to expand any further into that country. Also part of the policy of Sparta was not to unify Greece. They felt they did not need to have one rule but they had a policy in place to that it would prevent other states from trying to take total control of Sparta. Do we believe this policy to be successful? I believe it was successful for many years but eventually failed when Sparta lost control to the Macedonians. Eventually we would see Sparta depart from they cautious polices to that they could preserve their democracy. In the second half of the 6th century, Sparta won a reputation as the bulwark of democracy against tyranny by repeatedly coming to the assistance of democratic elements in other cities and helping them to depose their tyrants. Plutarch claims, for example, that Sparta was instrumental in deposing the tyrants in Corinth, Naxon, Athens (Hippias) and Sikyon (Sparta Reconsidered Diplomacy). Many people today have a problem with this but knowing how the people of Sparta believed that there might be some truth to this. Why was this statement even questioned by people? They believed that the Spartan foreign policy of intervention in the internal affairs of other cities can be seen as preventive self-defense. Another explanation, of course, is that the tyrants tended to be populist leaders who catered to the mob. As such, they were viewed as more dangerous to the conservative Spartan s than democracies dominated by aristocratic elites. (Sparta Reconsidered Diplomacy). Many historians believe that the Spartan Kings were able to influence the foreign policy by trying to influence the officials. Since the kings were not able to make the foreign policy of Sparta they felt that if they were able to influence those in control they would be able to get what they wanted. On a formal level, foreign policy seems to have been in the hands of the ephors (Mitchell, Greeks Bearing Gifts, pg. 64). Part of the problem was the many did not think that the ephors had as much power as the kings believed they did. We do have to be careful when we consider the effect that the foreign policy of Sparta had on foreign policy. It did seem that the main policy of Sparta was: the main objectives of Spartan policy form 600 to 400 B.C. were to prvent any state in Greece from becoming dangerous and to bar any outsider from entering the Aegean world (Starr, The Ancient Greeks, pg 115) From my readings I found that during the 6th and 5th centuries it was believed that Last but not least, the conservatism of Spartas 6th and 5th century foreign policy is reflected in the fact that Sparta was extremely reluctant to move against Athensdespite rising pressure for support from the city-states chafing under Athens increasingly oppressive and arrogant hegemony.(Sparta Reconsidered Diplomacy) Did Spartan Foreign Policy have an impact on the world today? Yes I do think that we can see common factors between ancient Greece and the contemporary world. This impact has had an impact on many nations spanning over twenty-four centuries. Has it always had a positive impact, probably not but we do see that these policies had a great impact on the course of human events References Buckley, Terry. Aspects Of Greek History 750-323 BC: A Source-Based Approach. New York: Routledge, 1996. 424 [online] books.google. New York: Routledge, 1996., 424. Available from: http://www.questia.com/library/book/aspects-of-greek-history-750-323-bc-a-source-based-approach-by-terry-buckley.jsp Accessed August 30, 2008 Mitchell, Lynette G.. Greeks Bearing Gifts: The Public Use of Private Relationships in the Greek World, 435-323 BC. New York: Cambridge University Press, 2002. 64 Available from: http://books.google.com/books?hl=enid=FbVPFJQtoZgCdq=Mitchell,+Lynette+G..+Greeks+Bearing+Gifts:+The+Public+Use+of+Private+Relationships+in+the+Greek+World,+435-323+BC.printsec=frontcoversource=webots=oL_hF8Vwo7sig=B8C9j7rGsRYYTaA_CK96Jmze6oMsa=Xoi=book_resultresnum=1ct=result Accessed August 30, 2008 Sparta Reconsidered Spartan Diplomacy. Elysium Gates Web Hosting. http://elysiumgates.com/~helena/Diplomacy.html (accessed August 30, 2008). Starr, Chester. The Ancient Greeks. Library of Congress: Oxford University Press, 1971.

Argentina Genocide Essay

There was court investigated crimes against 200 opponents of the military regime in six illegal detention centers in Buenos Aires, One of the crimes was a kidnapping of a man named Jacobo Timerman who was tortured by electric shocks, beatings and solitary confinement in the years he was held illegally. The prosecutor said Jaime Smart was a leading factor in the persecution of opponents in the military. The illegal detention centers were run in police stations under his command. During the seven year military rule, an estimated 30,000 people were kidnapped, tortured, and killed by the junta. http://www.globalsecurity.org/military/world/war/argentina.htm The Dirty War ran for seven years, from 1976 – 1983. It was run by the Argentine government against dissidents (A person who opposes official policy) and subversives (A person seeking or intended to subvert an established system or institution). Many people were â€Å"disappeared† which usually meant being taken in the night to secret government detention centers where they were tortured and killed. These poor humans were known as â€Å"los desaparecidos† or â€Å"the disappeared.† The war started with the death of President Juan Peron in 1974 when his wife gained authority, unfortunately the woman was not a strong political leader and a military junta removed her from office. http://www.telegraph.co.uk/culture/3673470/Argentinas-dirty-war-the-museum-of-horrors.html Miriam Lewin, 49, one of only 150 Esma survivors, was arrested and taken to a detention center for almost a year, Miriam was locked in a tiny dark cell, kept hooded and chained to the wall and tortured with electric shocks. They told her she was being taken to a work camp to be rehabilitated instead they shoved her into a car trunk and took her to Esma. Miriam spent 10 months at Esma, on her release she fled to the US and returned after the w ar as a journalist for a television station. Lewin repeats some of the horrific events passed, ‘It was similar to the Terezin Nazi camp: some prisoners worked and were shown films for entertainment, while others were tortured next door, then drugged and weighted before being taken on â€Å"death flights† over the Atlantic.’ The bodies were dropped into the ocean; others were burnt. As in the case of the Holocaust victims who were forced to write to their families saying that they were being treated  well, Esma prisoners were occasionally allowed contact with the outside world, mostly through calls from a monitored telephone booth in the entrance, which is now a lavatory.’When I was 20 they took me to see my parents,’ Lewin says, ‘to prevent them from looking for me. My mother asked, â€Å"How are you, how are you being treated?† Fine. â€Å"What do you do all day?† Well, we write, watch films, read†¦ â€Å"Are you with other girls of your age?† Yes, yes, Mum. I couldn’t tell her that I was in a concentration camp where they tortured and killed people, that this could be the last time she would see me alive, otherwise they would have been in danger, too.†I will never forget how, purely to humiliate us, they took me and some other female prisoners to have dinner in a restaurant in the centre of town with a group of armed plain-clothes officers. We would be sleeping in the middle of the night and a guard would shake us and say, â€Å"Wake up, you have to go.† We didn’t know if we were going out for a meal or to die. A girlfriend of mine was taken dancing by the guy who had killed her husband two weeks earlier,’ she says with a wry smile.Like most others, she was imprisoned in the casino or officers’ hall of residence, a building clearly visible from the street and overlooked by nearby flats. She was forced to work in the basement, translating into Spanish articles on the military regime that appeared in English and French newspapers; others wrote military biographies, forged documents and filmed propaganda videos. As they worked, inmates in adjacent rooms were tortured with water and electric cattle prods, their shouts sometimes muffled by loud music. http://www.vice.com/read/inside-argentinas-secret-death-camps Inside Argentina Camps In 1977 Nilda â€Å"Munu† Goretta was walking home from work on a busy street in downtown Buenos Aires when members of the Argentinean Military Death Squad blindfolded her from behind and shoved her into a nearby car. She wasn’t seen or heard from for 13 months. During the height of Argentina’s seven-year military dictatorship Munu lived as a political prisoner in the torture center, ESMA. In order to maintain control, the junta organized a system to eliminate any threats to the new government. Anyone who expressed the slightest sympathies for leftist politics would vanish without a trace. The general public was not aware of the concentration camps. ESMA operatedÃ'Ž

Reconstruction Goals Reconstruction And Reconstruction

Reconstruction Goals Reconstruction started in 1865 after the war was coming to an end and completed in 1877. It Is the process by which federal government controlled the former Confederate states and the conditions for their readmission to the union. Abraham Lincoln was our president at the time and could not form a treaty with the defeated government. After the emancipation, thousands of freedmen left their plantation to find a new life without being owned and forced to work. This began the political, social, and economic goals for reconstruction regarding African Americans. There were many different approaches of political goals set for reconstruction. Republicans dealt with the political control. Conservatives within the party†¦show more content†¦Congress then passed the bill in 1864 to which Lincoln vetoed it; this infuriated Radicals. Lincoln, then, accepted some of the Radical demands to stop the disagreements and conflict. Another view of Reconstruction was Johnson ’s â€Å"Restoration† plan. This plan was very similar to to Lincolns and the Wade-Davis Bill. Southerners who took an oath of allegiance were offered forgiveness. The new president appointed a provisional governor in each state and charged him with inviting qualified voters to elect delegates to a constitutional convention. To win readmission to Congress, a state had to revoke its ordinance of secession, abolish slavery and ratify the Thirteenth Amendment, and repudiate Confederate and state war debts. This plan was implemented in 1865 when Congress was in recess. By the end on 1865, all seceded states underwent new governments following either Lincoln’s or Johnson’s plan. The North became irritated with the South’s reluctance to abolishing slavery which resulted with them becoming harsher towards this situation. Although this plan worked for a short amount of time, it ended in December of 1865 hence starting â€Å"congressional† or â€Å" radical† reconstruction. There were many social plans implemented during the period of reconstruction. Some of these plans included Jim Crow Laws, Black Codes, the Fourteenth Amendment, and the Freedmen’s Bureau. Jim Crow Laws created a hierarchy reaching into almost every area of southern life. Blacks and whites could notShow MoreRelatedEssay The Primary Goal of Reconstruction after the Civil War848 Words   |  4 PagesSouth had been devastated both physically and economically. Helping former slaves and making state governments loyal to the Union also presented various problems that would take years to resolve. The primary goal of Reconstruction after the Civil War would have been- in my Reconstruction Plan- mainly based around the integration of freed African Americans into Southern society. Many problems faced by Southerners that led up to the Civil War and followed it were centered around racial hatred andRead MoreWhat Did The Ku Klux Klan Reach Their Goals, Both Social And Political, During The Reconstruction Period2012 Words   |  9 PagesCriterion A: Identification and evaluation of sources: This investigation will evaluate the question: to what extent did the Ku Klux Klan reach their goals, both social and political, during the reconstruction period from its birth in 1866 to 1877? This essay will first determine the social and political goals of the Klan, than analyze how successful they were in attaining them. 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There was controversy, however, on how to go about rebuilding the nation. Abraham Lincoln proposed a lenient plan. After he was assassinated, Andrew Johnson proposed a very similar plan. The Radical Republicans, a group of legislators that were in favor of freedmen’s rights, were opposed

Learn About Petcoke

Petroleum coke, or petcoke, is a byproduct from the refining of crude oil. It consists mostly of carbon, with variable amounts of sulfurs and heavy metals. It has many industrial uses, including the production of batteries, steel, and aluminum. Lower-grade petcoke, which contains higher concentrations of sulfur, is used as fuel in coal-fired power plants and cement kilns. Lower-grade coal is estimated to represent 75% to 80% of all petcoke produced. The production of petcoke in North America has increased in recent years due to the refining of crude oil originating from Canada’s tar sands region. If all the recoverable bitumen (the â€Å"proven reserves†) from tar sands was removed and refined, several billion tons of petcoke could be produced. When operating at capacity, large U.S. refineries can produce 4,000 to over 7,000 tons of petcoke per day. In 2012 the United States exported 184 million barrels (33 million metric tons) of petcoke, predominantly to China. A lot of petcoke is also produced in Canada, in close proximity to the tar sands, where bitumen is upgraded into synthetic crude oil or syncrude.  Ã‚   A Troublesome Source of Atmospheric Carbon Dioxide Bitumen’s high density, or what gives it that semi-solid consistency, is explained by the fact that it contains more carbon than conventional oil. Refining crude oil from tar sands involves the reduction of the number of carbon atoms per hydrocarbon molecule. These discarded carbon atoms eventually form petcoke. Since large volumes of tar sand crude oil are currently refined, large amounts of low-grade petcoke are produced and sold as an inexpensive fuel for coal plants. This burning of petcoke is where tar sand bitumen releases extra carbon dioxide, compared to conventional oil. Petcoke produces more CO2 per pound than almost any other energy source, making it a contributor to greenhouse gases and thus a driver of global climate change. Not Just a Carbon Problem Refining sulfur-rich tar sand bitumen concentrates the sulfur content in the petcoke. Compared to coal, petcoke combustion requires the use of additional pollution controls to capture much of that sulfur. In addition, heavy metals are also concentrated into the petcoke. There are concerned with the release of these metals into the air when petcoke is used as a fuel in a coal power plant. These same concentrated heavy metals can enter the environment at storage sites where large piles of petcoke are staged, uncovered. The epicenter of complaints stemming from petcoke storage seems to be in the Chicago, Illinois, area. Large piles of petcoke, each made of thousands of tons of the dusty material, sit along the Calumet River and come from an oil refinery in nearby Whiting, Indiana. These storage sites are in close proximity to residential areas in Chicago’s Southeast side, where residents complain about dust from the petcoke piles blowing into their neighborhoods.   Indirect Effects: Keeping Coal-Fired Plants Open The recent boom in natural gas production has been a challenge for coal-fired power stations. Many have been closed or converted to natural gas power generators. However, petcoke can be used concurrently with coal in many power plants, a practice known as co-firing. Some technical challenges associated with co-firing exist (from petcoke’s high sulfur content, for example), but the very low price of petcoke could be an important factor to keep coal plants open in an economically competitive energy environment. New life could be breathed into slated-to-close coal power plants, with for a net result elevated CO2 emissions. Sources Chicago Sun-Times. Accessed 11 February 2014. Rahm Emanuel to Propose Ordinance Prohibiting New Petcoke Facilities.OilChange International. Accessed 11 February 2014. Petroleum Coke: The Coal Hiding in the Tar Sands.Oxbow Carbon. Accessed 11 February 2014. Petroleum Coke.Pavone, Anthony. Accessed 11 February 2014. Converting Petroleum Coke to Electricity.US Energy Information Administration. Accessed 11 February 2014. U.S. Exports of Petroleum Coke.US Energy Information Administration. Accessed 11 February 2014. Voluntary Reporting of Greenhouse Gases Program.