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using System;
using System.IO;
using System.Threading;
using Pfz.Extensions.DisposeExtensions;
using Pfz.Extensions.StreamExtensions;
namespace Pfz.Threading
{
/// <summary>
/// Class with methods safe from "Thread.Abort()".
/// </summary>
public static class AbortSafe
{
/// <summary>
/// Returns a value indicating if an abort was requested for this thread.
/// </summary>
public static bool WasAbortRequested
{
get
{
return (Thread.CurrentThread.ThreadState & ThreadState.AbortRequested) == ThreadState.AbortRequested;
}
}
/// <summary>
/// This method will make a thread that is running in non-abortable manner
/// (ie, inside a finally block) to skip the rest of the actual finally block
/// if an abort was requested.
/// </summary>
public static void AllowAbort()
{
if (WasAbortRequested)
Thread.CurrentThread.Abort();
}
/// <summary>
/// Allocates a new object using it's default constructor and sets
/// it's result value to the variable passed as out parameter.
/// This will work completelly or fail completelly in case of an
/// Abort call, so there is no risk of stopping in-the-middle of the work.
/// </summary>
public static void New<T>(out T variable)
where
T: new()
{
try
{
}
finally
{
variable = new T();
}
}
/// <summary>
/// Runs a code block in an AbortSafe manner.
/// Be careful when using this, as you must not avoid Aborts of long running
/// code.
/// </summary>
public static void Run(Action code)
{
try
{
}
finally
{
code();
}
}
/// <summary>
/// Runs a block of code, guaranting that:
/// The allocation block will not be aborted.
/// The finally block will be called, independent if the allocation block was
/// run.
/// The code block is the only one that could be aborted.
/// </summary>
public static void Run(Action allocationBlock, Action codeBlock, Action finallyBlock)
{
if (allocationBlock == null)
throw new ArgumentNullException("allocationBlock");
if (codeBlock == null)
throw new ArgumentNullException("codeBlock");
if (finallyBlock == null)
throw new ArgumentNullException("finallyBlock");
try
{
try
{
}
finally
{
allocationBlock();
}
codeBlock();
}
finally
{
finallyBlock();
}
}
/// <summary>
/// Reads all bytes from a file, avoiding errors caused from Thread.Abort().
/// </summary>
public static byte[] ReadAllBytes(string path)
{
FileStream stream = null;
try
{
Run(() => stream = File.OpenRead(path));
int length = (int)stream.Length;
byte[] bytes = new byte[length];
stream.FullRead(bytes);
return bytes;
}
finally
{
stream.CheckedDispose();
}
}
/// <summary>
/// Writes all bytes to a file, avoiding errors caused from Aborts.
/// If an abort happens, the stream is closed and the file is deleted.
/// </summary>
public static void WriteAllBytes(string path, byte[] bytes)
{
FileStream stream = null;
try
{
Run(() => stream = File.Create(path));
stream.Write(bytes);
}
catch
{
if (stream != null)
{
stream.Dispose();
stream = null;
try
{
File.Delete(path);
}
catch
{
}
}
throw;
}
finally
{
stream.CheckedDispose();
}
}
/// <summary>
/// Executes the given blocks as if they where a using clause.
/// The first block must return a disposable object. The second one will be
/// the "body" executed inside the using clause.
///
/// It simulates:
/// using(...allocationBlock...)
/// {
/// ...codeBlock...
/// }
/// </summary>
public static void Using<T>(Func<T> allocationBlock, Action<T> codeBlock)
where
T: IDisposable
{
if (allocationBlock == null)
throw new ArgumentNullException("allocationBlock");
if (codeBlock == null)
throw new ArgumentNullException("codeBlock");
T value = default(T);
try
{
try
{
}
finally
{
value = allocationBlock();
}
codeBlock(value);
}
finally
{
value.CheckedDispose();
}
}
/// <summary>
/// Locks an object and executes the given action.
/// The lock is abort safe, not the executed block.
/// </summary>
public static void Lock(object objectToLock, Action action)
{
if (objectToLock == null)
throw new ArgumentNullException("objectToLock");
if (action == null)
throw new ArgumentNullException("action");
bool lockAcquired = false;
try
{
while(true)
{
try
{
}
finally
{
lockAcquired = Monitor.TryEnter(objectToLock, 1000);
}
if (lockAcquired)
{
action();
return;
}
}
}
finally
{
if (lockAcquired)
Monitor.Exit(objectToLock);
}
}
/// <summary>
/// Locks an object and executes the given action in an unabortable manner.
/// Aborts will happen or before the lock acquisition, or after the full block
/// is executed and the lock is released.
/// </summary>
public static void UnabortableLock(object objectToLock, Action action)
{
if (objectToLock == null)
throw new ArgumentNullException("objectToLock");
if (action == null)
throw new ArgumentNullException("action");
bool mustRun = true;
do
{
try
{
}
finally
{
if (Monitor.TryEnter(objectToLock, 1000))
{
try
{
action();
}
finally
{
Monitor.Exit(objectToLock);
}
mustRun = false;
}
}
} while(mustRun);
}
/// <summary>
/// Acquires a read-lock and then runs the action.
/// The lock is abort safe, not the executed block.
/// </summary>
public static void ReadLock(ReaderWriterLockSlim readerWriterLock, Action action)
{
if (readerWriterLock == null)
throw new ArgumentNullException("readerWriterLock");
if (action == null)
throw new ArgumentNullException("action");
bool lockAcquired = false;
try
{
while(true)
{
try
{
}
finally
{
lockAcquired = readerWriterLock.TryEnterReadLock(1000);
}
if (lockAcquired)
{
action();
return;
}
}
}
finally
{
if (lockAcquired)
readerWriterLock.ExitReadLock();
}
}
/// <summary>
/// Acquires an upgradeable-lock and then runs the action.
/// The lock is abort safe, not the action.
/// </summary>
public static void UpgradeableLock(ReaderWriterLockSlim readerWriterLock, Action action)
{
if (readerWriterLock == null)
throw new ArgumentNullException("readerWriterLock");
if (action == null)
throw new ArgumentNullException("action");
bool lockAcquired = false;
try
{
while (true)
{
try
{
}
finally
{
lockAcquired = readerWriterLock.TryEnterUpgradeableReadLock(1000);
}
if (lockAcquired)
{
action();
return;
}
}
}
finally
{
if (lockAcquired)
readerWriterLock.ExitUpgradeableReadLock();
}
}
/// <summary>
/// Acquires a write-lock and then runs the action.
/// The lock is abort safe, not the action.
/// </summary>
public static void WriteLock(ReaderWriterLockSlim readerWriterLock, Action action)
{
if (readerWriterLock == null)
throw new ArgumentNullException("readerWriterLock");
if (action == null)
throw new ArgumentNullException("action");
bool lockAcquired = false;
try
{
while (true)
{
try
{
}
finally
{
lockAcquired = readerWriterLock.TryEnterWriteLock(1000);
}
if (lockAcquired)
{
action();
return;
}
}
}
finally
{
if (lockAcquired)
readerWriterLock.ExitWriteLock();
}
}
}
}
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I started to program computers when I was 11 years old, as a hobbyist, programming in AMOS Basic and Blitz Basic for Amiga.
At 12 I had my first try with assembler, but it was too difficult at the time. Then, in the same year, I learned C and, after learning C, I was finally able to learn assembler (for Motorola 680x0).
Not sure, but probably between 12 and 13, I started to learn C++. I always programmed "in an object oriented way", but using function pointers instead of virtual methods.
At 15 I started to learn Pascal at school and to use Delphi. At 16 I started my first internship (using Delphi). At 18 I started to work professionally using C++ and since then I've developed my programming skills as a professional developer in C++ and C#, generally creating libraries that help other developers do their work easier, faster and with less errors.
Want more info or simply want to contact me?
Take a look at:
http://paulozemek.azurewebsites.net/
Or e-mail me at: paulozemek@outlook.com
Codeproject MVP 2012, 2015 & 2016
Microsoft MVP 2013-2014 (in October 2014 I started working at Microsoft, so I can't be a Microsoft MVP anymore).