Bug#259688: libapt-pkg: make it possible to set select () timeout for pkgAcquire::Run

["Peter Rockai (mornfall)" <mornfall@danill.sk>]

Package: apt
Version: 0.5.26
Severity: wishlist


Hello!

I am writing an libapt-pkg based frontend and i have ran into a slight
problem with pkgAcquire class. Because of the way i write it
(single-threaded), i need to get more pulses in my pkgAcquireStatus than
usual (about 5 - 10 a second).

One proposed solution is to add an optional parameter to Run (), with
a timeout to be used for select. An ABI-compatible patch is attached.
I somehow dislike this, as it's not the "right" solution for the given
problem...

The alternative solution would be to use the _config object to specify
the timeout and query it from within Run (), but i don't really like it.
On the other hand, this would allow the pkgAcquireStatus to change this
value instead of the caller of Run... Well, i'm not sure. A patch is
attached as well.

The best solution would be adding this timeout as a member variable, but
this is binary incompatible and thus probably infeasible right now.
(This way the pkgAcquireStatus would be able to set the Pulse interval,
which would be about ideal). I can make a patch if needed.

The preferred order is 3, 2, 1, but considering other factors, i think
#2 will be optimal for now. Other ways of fixing the problem would be
welcome though.

Thank you, yours,
    Peter

-- System Information:
Debian Release: testing/unstable
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: i386 (i686)
Kernel: Linux 2.6.6-1-686
Locale: LANG=sk_SK.UTF-8, LC_CTYPE=sk_SK.UTF-8

Versions of packages apt depends on:
ii  libc6                       2.3.2.ds1-13 GNU C Library: Shared libraries an
ii  libgcc1                     1:3.3.4-2    GCC support library
ii  libstdc++5                  1:3.3.4-2    The GNU Standard C++ Library v3

-- no debconf information

diff -ruN apt-pkg.orig/acquire.cc apt-pkg/acquire.cc
--- apt-pkg.orig/acquire.cc	2004-03-17 06:17:11.000000000 +0100
+++ apt-pkg/acquire.cc	2004-07-16 08:06:50.000000000 +0200
@@ -314,6 +314,10 @@
    manage the actual fetch. */
 pkgAcquire::RunResult pkgAcquire::Run()
 {
+    return Run (500000);
+}
+pkgAcquire::RunResult pkgAcquire::Run(int pulseUsec)
+{
    Running = true;
    
    for (Queue *I = Queues; I != 0; I = I->Next)
@@ -327,7 +331,7 @@
    // Run till all things have been acquired
    struct timeval tv;
    tv.tv_sec = 0;
-   tv.tv_usec = 500000; 
+   tv.tv_usec = pulseUsec;
    while (ToFetch > 0)
    {
       fd_set RFds;
@@ -357,7 +361,7 @@
       // Timeout, notify the log class
       if (Res == 0 || (Log != 0 && Log->Update == true))
       {
-	 tv.tv_usec = 500000;
+	 tv.tv_usec = pulseUsec;
 	 for (Worker *I = Workers; I != 0; I = I->NextAcquire)
 	    I->Pulse();
 	 if (Log != 0 && Log->Pulse(this) == false)
diff -ruN apt-pkg.orig/acquire.h apt-pkg/acquire.h
--- apt-pkg.orig/acquire.h	2001-05-22 06:17:18.000000000 +0200
+++ apt-pkg/acquire.h	2004-07-16 08:04:27.000000000 +0200
@@ -101,6 +101,7 @@
    enum RunResult {Continue,Failed,Cancelled};
 
    RunResult Run();
+   RunResult Run(int PulseUsec);
    void Shutdown();
    
    // Simple iteration mechanism

diff -ruN apt-pkg.orig/acquire.cc apt-pkg/acquire.cc
--- apt-pkg.orig/acquire.cc	2004-03-17 06:17:11.000000000 +0100
+++ apt-pkg/acquire.cc	2004-07-16 08:40:34.000000000 +0200
@@ -22,6 +22,7 @@
 #include <apt-pkg/configuration.h>
 #include <apt-pkg/error.h>
 #include <apt-pkg/strutl.h>
+#include <apt-pkg/configuration.h>
 
 #include <apti18n.h>
 
@@ -327,7 +328,7 @@
    // Run till all things have been acquired
    struct timeval tv;
    tv.tv_sec = 0;
-   tv.tv_usec = 500000; 
+   long tv_usec = tv.tv_usec = _config->FindI("APT::Fetcher::Select-Timeout-Usec", 500000);
    while (ToFetch > 0)
    {
       fd_set RFds;
@@ -357,7 +358,7 @@
       // Timeout, notify the log class
       if (Res == 0 || (Log != 0 && Log->Update == true))
       {
-	 tv.tv_usec = 500000;
+	 tv.tv_usec = tv_usec;
 	 for (Worker *I = Workers; I != 0; I = I->NextAcquire)
 	    I->Pulse();
 	 if (Log != 0 && Log->Pulse(this) == false)