PureBasic

Thread Pool Size

See more Async Examples

Demonstrates how to set the maximum number of threads in Chilkat's thread pool manager. Also demonstrates how to set a thread pool log file for help in diagnosing unexpected problems. PureBasic

IncludeFile "CkTask.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkGlobal.pb"

Procedure ChilkatExample()

    success.i = 0

    ; This example assumes the Chilkat API to have been previously unlocked.
    ; See Global Unlock Sample for sample code.

    success = 0

    ; Set the maximum number of threads in the Chilkat thread pool to 12.
    ; This means that no more than 12 background worker threads will exist simultaneously.
    ; If more than 12 tasks are queued then some must wait for a worker thread to become free.
    ; Note: The Chilkat thread pool manager thread is a thread distinct from the
    ; worker threads.  It starts when the 1st asynchronous task is Run. 
    glob.i = CkGlobal::ckCreate()
    If glob.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkGlobal::setCkMaxThreads(glob, 12)

    ; Also, the ThreadPoolLogPath can be set to cause the thread pool manager thread to
    ; keep a log file. This is for the purpose of debugging if unexpected problems occur.
    CkGlobal::setCkThreadPoolLogPath(glob, "/home/users/chilkat/logs/threadPoolLog.txt")

    http1.i = CkHttp::ckCreate()
    If http1.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    http2.i = CkHttp::ckCreate()
    If http2.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    http3.i = CkHttp::ckCreate()
    If http3.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    url1.s = "http://www.marcusmiller.com/"
    url2.s = "http://www.tromboneshorty.com/"
    url3.s = "http://www.jamesmorrison.com/"

    ; Call the async version of the QuickGetStr method to return a task object.
    ; The task object is loaded, but is in the Inert state -- meaning it is
    ; not yet scheduled to run on Chilkat's background thread pool.
    task1.i = CkHttp::ckQuickGetStrAsync(http1,url1)
    If CkHttp::ckLastMethodSuccess(http1) = 0
        Debug CkHttp::ckLastErrorText(http1)
        CkGlobal::ckDispose(glob)
        CkHttp::ckDispose(http1)
        CkHttp::ckDispose(http2)
        CkHttp::ckDispose(http3)
        ProcedureReturn
    EndIf

    task2.i = CkHttp::ckQuickGetStrAsync(http2,url2)
    If CkHttp::ckLastMethodSuccess(http2) = 0
        Debug CkHttp::ckLastErrorText(http2)
        CkTask::ckDispose(task1)

        CkGlobal::ckDispose(glob)
        CkHttp::ckDispose(http1)
        CkHttp::ckDispose(http2)
        CkHttp::ckDispose(http3)
        ProcedureReturn
    EndIf

    task3.i = CkHttp::ckQuickGetStrAsync(http3,url3)
    If CkHttp::ckLastMethodSuccess(http3) = 0
        Debug CkHttp::ckLastErrorText(http3)
        CkTask::ckDispose(task1)

        CkTask::ckDispose(task2)

        CkGlobal::ckDispose(glob)
        CkHttp::ckDispose(http1)
        CkHttp::ckDispose(http2)
        CkHttp::ckDispose(http3)
        ProcedureReturn
    EndIf

    ; At this point we have 3 task objects, each loaded with a Chilkat method call.
    ; Note: At this point no background threads are running.  The thread pool manager
    ; thread is not started -- it will start when the very first task is Run.

    ; Schedule each task for running on the thread pool.  This changes each task's state
    ; from Inert to Live. The thread pool manager thread starts with the 1st task queued.
    ; If the Global.ThreadPoolLogPath property was set, then
    ; the log file would be created (or appended) at this point.
    success = CkTask::ckRun(task1)
    ; Assuming success for brevity...
    success = CkTask::ckRun(task2)
    success = CkTask::ckRun(task3)

    ; The application is now free to do anything else
    ; while the HTML at the URL's are being downloaded in background threads.

    ; In this case, we'll just wait for all three tasks to finish.
    ; All three tasks are running simultaneously in separate background threads.
    ; We can wait for each in any order.  If Wait is called and the task has already
    ; finished (or been canceled), then the Wait method returns immediately.
    maxWaitMs.i = 20000
    success = CkTask::ckWait(task1,maxWaitMs)
    success = CkTask::ckWait(task2,maxWaitMs)
    success = CkTask::ckWait(task3,maxWaitMs)
    ; Assuming success for brevity...

    err.s = "Task failed or canceled"
    html1.s = err
    html2.s = err
    html3.s = err

    ; Now get the HTML downloaded in each task:
    If (CkTask::ckStatusInt(task1) = 7) AND (CkTask::ckTaskSuccess(task1) = 1)
        html1 = CkTask::ckGetResultString(task1)
    EndIf

    If (CkTask::ckStatusInt(task2) = 7) AND (CkTask::ckTaskSuccess(task2) = 1)
        html2 = CkTask::ckGetResultString(task2)
    EndIf

    If (CkTask::ckStatusInt(task3) = 7) AND (CkTask::ckTaskSuccess(task3) = 1)
        html3 = CkTask::ckGetResultString(task3)
    EndIf

    Debug html1
    Debug "----"
    Debug html2
    Debug "----"
    Debug html3
    Debug "----"

    CkTask::ckDispose(task1)

    CkTask::ckDispose(task2)

    CkTask::ckDispose(task3)



    CkGlobal::ckDispose(glob)
    CkHttp::ckDispose(http1)
    CkHttp::ckDispose(http2)
    CkHttp::ckDispose(http3)


    ProcedureReturn
EndProcedure