Re: [ES40-developers] c++ question

[Camiel V. <iam...@gm...>]

Hi Brian,

I've created our own implementations of Poco::Mutex, Poco::FastMutex
and Poco::RWLock, called CMutex, CFastMutex and CRWMutex, they don't
do anything special, except that they have a name, and that if
DEBUG_LOCKS is defined, it will give you messages like "LOCKED mutex
<name> from thread <thread>." This might help with your debugging.

I've also created macro's to make life easier, and the scoped locks
now use a pointer.

I've put this into cvs, and converted all code to use it.

Camiel.



On Tue, Mar 11, 2008 at 2:36 AM, brian wheeler <bdw...@in...> wrote:
> Nope, no index function...but I did figure it out.
>
>  The constructors require references, and you can't put those into
>  arrays...so I resorted to mt<whatever>A and mt<whatever>B. Then the
>  "address always evalutates to true" warning was because index wasn't
>  declared in the scope (it was 'channel') so it assumed that index was
>  the name of a function.
>
>  You can smack me now.  Since I've got a few days off I'm going to tinker
>  with the locking and see if I can't figure out why its acting funny.
>
>  Brian
>
>
>
>
>
>
>  On Mon, 2008-03-10 at 13:18 +0100, Camiel Vanderhoeven wrote:
>  > Hi Brian,
>  >
>  > It looks like you have a function named "index", could that be true?
>  >
>  > Camiel.
>  >
>  > On Fri, Mar 7, 2008 at 4:52 PM, Brian Wheeler <bdw...@in...> wrote:
>  > > This is driving me slowly insane...
>  > >
>  > >  I've put this into my AliM1543C_ide.h:
>  > >
>  > >   mutable Poco::RWLock mtRegisters[2];
>  > >   mutable Poco::RWLock mtBusmaster[2];
>  > >  #define LOCK_REGS(i,rw) Poco::RWLock::ScopedLock lock_regs(mtRegisters[i],rw);
>  > >  #define LOCK_BM(i,rw) Poco::RWLock::ScopedLock lock_bm(mtBusmaster[i],rw);
>  > >
>  > >  So I can have a read/write lock for each of the register sets on each of
>  > >  the controllers.  From the very limited documentation I could find for
>  > >  the RWLock, it looks like it allows many readers but one writer.  If
>  > >  another writer tries to come in, it blocks until the writing lock is
>  > >  free.  This is what I want.  And since its the ScopeLock'd variant, when
>  > >  I drop out of my scope the lock is released.
>  > >
>  > >  However, it won't compile...sort of :)  When I try to compile it, I get
>  > >  this message:
>  > >
>  > >  g++ -I. -I.. -g -DHIDE_COUNTER -DDEBUG_BACKTRACE -DDEBUG_IDE -O3 -mtune=generic -DHAVE_SDL -DHAVE_X11 -DHAVE_PCAP -I/usr/include/SDL -c AliM1543C_ide.cpp  -o AliM1543C_ide.o
>  > >  AliM1543C_ide.cpp: In member function 'virtual u32 CAliM1543C_ide::ReadMem_Bar(int, int, u32, int)':
>  > >  AliM1543C_ide.cpp:490: error: invalid types 'Poco::RWLock [2][char* ()(const char*, int)throw ()]' for array subscript
>  > >  AliM1543C_ide.cpp:491: error: invalid types 'Poco::RWLock [2][char* ()(const char*, int)throw ()]' for array subscript
>  > >  AliM1543C_ide.cpp: In member function 'virtual void CAliM1543C_ide::WriteMem_Bar(int, int, u32, int, u32)':
>  > >  AliM1543C_ide.cpp:518: error: invalid types 'Poco::RWLock [2][char* ()(const char*, int)throw ()]' for array subscript
>  > >  AliM1543C_ide.cpp:519: error: invalid types 'Poco::RWLock [2][char* ()(const char*, int)throw ()]' for array subscript
>  > >
>  > >  However, those are the _second_ instances of the macro calls with the
>  > >  arguments:
>  > >
>  > >  435:  LOCK_REGS(index,false); // lock control/command registers
>  > >  436:  LOCK_BM(index,false); // lock busmaster registers
>  > >  462:  LOCK_REGS(index,true); // lock control/command registers
>  > >  463:  LOCK_BM(index,true); // lock busmaster registers
>  > >  490:  LOCK_REGS(index,false); // lock control/command registers
>  > >  491:  LOCK_BM(index,false); // lock busmaster registers
>  > >  518:  LOCK_REGS(index,true); // lock control/command registers
>  > >  519:  LOCK_BM(index,true); // lock busmaster registers
>  > >  1023:    LOCK_BM(index,true)
>  > >  2334:  LOCK_BM(index,true); // lock busmaster registers
>  > >  2435:   LOCK_REGS(index,true); // lock control/command registers
>  > >
>  > >  So it was happy on 435, 436 and 462, 463.
>  > >
>  > >  If I take out the array part it compiles just fine.  If I try to fake it
>  > >  out using a conditional in the #define, it gives a warning:
>  > >
>  > >   mutable Poco::RWLock mtRegistersA;
>  > >   mutable Poco::RWLock mtBusmasterA;
>  > >   mutable Poco::RWLock mtRegistersB;
>  > >   mutable Poco::RWLock mtBusmasterB;
>  > >  #define LOCK_REGS(i,rw) Poco::RWLock::ScopedLock lock_regs((i?mtRegistersB:mtRegistersA),rw);
>  > >  #define LOCK_BM(i,rw) Poco::RWLock::ScopedLock lock_bm((i?mtBusmasterA:mtBusmasterB),rw);
>  > >
>  > >  g++ -I. -I.. -g -DHIDE_COUNTER -DDEBUG_BACKTRACE -DDEBUG_IDE -O3 -mtune=generic -DHAVE_SDL -DHAVE_X11 -DHAVE_PCAP -I/usr/include/SDL -c AliM1543C_ide.cpp  -o AliM1543C_ide.o
>  > >  AliM1543C_ide.cpp: In member function 'virtual u32 CAliM1543C_ide::ReadMem_Bar(int, int, u32, int)':
>  > >  AliM1543C_ide.cpp:490: warning: the address of 'char* index(const char*, int)', will always evaluate as 'true'
>  > >  AliM1543C_ide.cpp:491: warning: the address of 'char* index(const char*, int)', will always evaluate as 'true'
>  > >  AliM1543C_ide.cpp: In member function 'virtual void CAliM1543C_ide::WriteMem_Bar(int, int, u32, int, u32)':
>  > >  AliM1543C_ide.cpp:518: warning: the address of 'char* index(const char*, int)', will always evaluate as 'true'
>  > >  AliM1543C_ide.cpp:519: warning: the address of 'char* index(const char*, int)', will always evaluate as 'true'
>  > >
>  > >  Again, its only the 2nd time it sees the macros.  The LOCK_* calls are
>  > >  within different functions, so it shouldn't be a scope thing...
>  > >
>  > >  Also, sometimes the cpu thread shuts down with an exception.  I plugged
>  > >  the segfault backtracer into it, and it looks like the culprit is
>  > >
>  > >   5 ./es40(_Z12segv_handleri+0x1c) [0x43ac9c]
>  > >   4 ./es40(_ZN9CAlphaCPU3runEv+0x69) [0x432ef9]
>  > >   3 /usr/local/lib/libPocoFoundation.so.5(_ZN4Poco10ThreadImpl5entryEPv
>  > >  +0x88) [0x2aaaaabb47e8]
>  > >         ^^^ Here ^^^
>  > >   2 /lib64/libpthread.so.0 [0x3651e06407]
>  > >   1 /lib64/libc.so.6(clone+0x6d) [0x36512d4b0d]
>  > >
>  > >  since frames 4 & 5 are the shutdown.
>  > >
>  > >
>  > >
>
>