particularly in the SBThread & SBFrame interfaces. Instead of filling the whole context & then getting
the API mutex, we now get only the target, acquire the API mutex from it, then fill out the rest of the
context. This removes a race condition where you get a ThreadSP, then wait on the API mutex while another
command Destroy's the Thread you've just gotten.
Also fixed the ExecutionContextRef::Get*SP calls so they don't return invalid objects.
Also fixed the ExecutionContext::Has*Scope calls so they don't claim to have a scope if the object representing
that scope has been destroyed.
Also fixed a think-o in Thread::IsValid which was causing it to return the opposite of the desired value.
<rdar://problem/11995490>
llvm-svn: 162401
information if we're not stopped. This could try to read registers
etc when the process is still running and debug builds of lldb would
assert down in GDBRemoteRegisterContext.cpp ReadRegisterBytes because
we couldn't get the sequence mutex for talking to the remote system.
Non-debug builds would just silently fail when doing this.
<rdar://problem/11941758>
llvm-svn: 160829
This abstracts read/write locks on the current host system. It is currently backed by pthread_rwlock_t objects so it should work on all unix systems.
We also need a way to control multi-threaded access to the process through the public API when it is running. For example it isn't a good idea to try and get stack frames while the process is running. To implement this, the lldb_private::Process class now contains a ReadWriteLock member variable named m_run_lock which is used to control the public process state. The public process state represents the state of the process as the client knows it. The private is used to control the actual current process state. So the public state of the process can be stopped, yet the private state can be running when evaluating an expression for example.
Adding the read/write lock where readers are clients that want the process to stay stopped, and writers are clients that run the process, allows us to accurately control multi-threaded access to the process.
Switched the SBThread and SBFrame over to us shared pointers to the ExecutionContextRef class instead of making their own class to track this. This fixed an issue with assigning on SBFrame to another and will also centralize the code that tracks weak references to execution context objects into one location.
llvm-svn: 154099
Found an issue where we might still have shared pointer references to lldb_private::Thread objects where the object itself is not valid and has been removed from the Process. When a thread is removed from a process, it will call Thread::DestroyThread() which well set a boolean member variable which is exposed now via:
bool
Thread::IsValid() const;
We then check the thread validity before handing out a shared pointer.
llvm-svn: 154048
objects for the backlink to the lldb_private::Process. The issues we were
running into before was someone was holding onto a shared pointer to a
lldb_private::Thread for too long, and the lldb_private::Process parent object
would get destroyed and the lldb_private::Thread had a "Process &m_process"
member which would just treat whatever memory that used to be a Process as a
valid Process. This was mostly happening for lldb_private::StackFrame objects
that had a member like "Thread &m_thread". So this completes the internal
strong/weak changes.
Documented the ExecutionContext and ExecutionContextRef classes so that our
LLDB developers can understand when and where to use ExecutionContext and
ExecutionContextRef objects.
llvm-svn: 151009
the lldb_private::StackFrame objects hold onto a weak pointer to the thread
object. The lldb_private::StackFrame objects the the most volatile objects
we have as when we are doing single stepping, frames can often get lost or
thrown away, only to be re-created as another object that still refers to the
same frame. We have another bug tracking that. But we need to be able to
have frames no longer be able to get the thread when they are not part of
a thread anymore, and this is the first step (this fix makes that possible
but doesn't implement it yet).
Also changed lldb_private::ExecutionContextScope to return shared pointers to
all objects in the execution context to further thread harden the internals.
llvm-svn: 150871
internals. The first part of this is to use a new class:
lldb_private::ExecutionContextRef
This class holds onto weak pointers to the target, process, thread and frame
and it also contains the thread ID and frame Stack ID in case the thread and
frame objects go away and come back as new objects that represent the same
logical thread/frame.
ExecutionContextRef objcets have accessors to access shared pointers for
the target, process, thread and frame which might return NULL if the backing
object is no longer available. This allows for references to persistent program
state without needing to hold a shared pointer to each object and potentially
keeping that object around for longer than it needs to be.
You can also "Lock" and ExecutionContextRef (which contains weak pointers)
object into an ExecutionContext (which contains strong, or shared pointers)
with code like
ExecutionContext exe_ctx (my_obj->GetExectionContextRef().Lock());
llvm-svn: 150801
due to RTTI worries since llvm and clang don't use RTTI, but I was able to
switch back with no issues as far as I can tell. Once the RTTI issue wasn't
an issue, we were looking for a way to properly track weak pointers to objects
to solve some of the threading issues we have been running into which naturally
led us back to std::tr1::weak_ptr. We also wanted the ability to make a shared
pointer from just a pointer, which is also easily solved using the
std::tr1::enable_shared_from_this class.
The main reason for this move back is so we can start properly having weak
references to objects. Currently a lldb_private::Thread class has a refrence
to its parent lldb_private::Process. This doesn't work well when we now hand
out a SBThread object that contains a shared pointer to a lldb_private::Thread
as this SBThread can be held onto by external clients and if they end up
using one of these objects we can easily crash.
So the next task is to start adopting std::tr1::weak_ptr where ever it makes
sense which we can do with lldb_private::Debugger, lldb_private::Target,
lldb_private::Process, lldb_private::Thread, lldb_private::StackFrame, and
many more objects now that they are no longer using intrusive ref counted
pointer objects (you can't do std::tr1::weak_ptr functionality with intrusive
pointers).
llvm-svn: 149207
shared pointers.
Changed the ExecutionContext over to use shared pointers for
the target, process, thread and frame since these objects can
easily go away at any time and any object that was holding onto
an ExecutionContext was running the risk of using a bad object.
Now that the shared pointers for target, process, thread and
frame are just a single pointer (they all use the instrusive
shared pointers) the execution context is much safer and still
the same size.
Made the shared pointers in the the ExecutionContext class protected
and made accessors for all of the various ways to get at the pointers,
references, and shared pointers.
llvm-svn: 140298
variables prior to running your binary. Zero filled sections now get
section data correctly filled with zeroes when Target::ReadMemory
reads from the object file section data.
Added new option groups and option values for file lists. I still need
to hook up all of the options to "target variable" to allow more complete
introspection by file and shlib.
Added the ability for ValueObjectVariable objects to be created with
only the target as the execution context. This allows them to be read
from the object files through Target::ReadMemory(...).
Added a "virtual Module * GetModule()" function to the ValueObject
class. By default it will look to the parent variable object and
return its module. The module is needed when we have global variables
that have file addresses (virtual addresses that are specific to
module object files) and in turn allows global variables to be displayed
prior to running.
Removed all of the unused proxy object support that bit rotted in
lldb_private::Value.
Replaced a lot of places that used "FileSpec::Compare (lhs, rhs) == 0" code
with the more efficient "FileSpec::Equal (lhs, rhs)".
Improved logging in GDB remote plug-in.
llvm-svn: 134579
are defined as enumerations. Current bits include:
eEmulateInstructionOptionAutoAdvancePC
eEmulateInstructionOptionIgnoreConditions
Modified the EmulateInstruction class to have a few more pure virtuals that
can help clients understand how many instructions the emulator can handle:
virtual bool
SupportsEmulatingIntructionsOfType (InstructionType inst_type) = 0;
Where instruction types are defined as:
//------------------------------------------------------------------
/// Instruction types
//------------------------------------------------------------------
typedef enum InstructionType
{
eInstructionTypeAny, // Support for any instructions at all (at least one)
eInstructionTypePrologueEpilogue, // All prologue and epilogue instructons that push and pop register values and modify sp/fp
eInstructionTypePCModifying, // Any instruction that modifies the program counter/instruction pointer
eInstructionTypeAll // All instructions of any kind
} InstructionType;
This allows use to tell what an emulator can do and also allows us to request
these abilities when we are finding the plug-in interface.
Added the ability for an EmulateInstruction class to get the register names
for any registers that are part of the emulation. This helps with being able
to dump and log effectively.
The UnwindAssembly class now stores the architecture it was created with in
case it is needed later in the unwinding process.
Added a function that can tell us DWARF register names for ARM that goes
along with the source/Utility/ARM_DWARF_Registers.h file:
source/Utility/ARM_DWARF_Registers.c
Took some of plug-ins out of the lldb_private namespace.
llvm-svn: 130189
an issue with the way the UnwindLLDB was handing out RegisterContexts: it
was making shared pointers to register contexts and then handing out just
the pointers (which would get put into shared pointers in the thread and
stack frame classes) and cause double free issues. MallocScribble helped to
find these issues after I did some other cleanup. To help avoid any
RegisterContext issue in the future, all code that deals with them now
returns shared pointers to the register contexts so we don't end up with
multiple deletions. Also now that the RegisterContext class doesn't require
a stack frame, we patched a memory leak where a StackFrame object was being
created and leaked.
Made the RegisterContext class not have a pointer to a StackFrame object as
one register context class can be used for N inlined stack frames so there is
not a 1 - 1 mapping. Updates the ExecutionContextScope part of the
RegisterContext class to never return a stack frame to indicate this when it
is asked to recreate the execution context. Now register contexts point to the
concrete frame using a concrete frame index. Concrete frames are all of the
frames that are actually formed on the stack of a thread. These concrete frames
can be turned into one or more user visible frames due to inlining. Each
inlined stack frame has the exact same register context (shared via shared
pointers) as any parent inlined stack frames all the way up to the concrete
frame itself.
So now the stack frames and the register contexts should behave much better.
llvm-svn: 122976
instance:
settings set frame-format <string>
settings set thread-format <string>
This allows users to control the information that is seen when dumping
threads and frames. The default values are set such that they do what they
used to do prior to changing over the the user defined formats.
This allows users with terminals that can display color to make different
items different colors using the escape control codes. A few alias examples
that will colorize your thread and frame prompts are:
settings set frame-format 'frame #${frame.index}: \033[0;33m${frame.pc}\033[0m{ \033[1;4;36m${module.file.basename}\033[0;36m ${function.name}{${function.pc-offset}}\033[0m}{ \033[0;35mat \033[1;35m${line.file.basename}:${line.number}}\033[0m\n'
settings set thread-format 'thread #${thread.index}: \033[1;33mtid\033[0;33m = ${thread.id}\033[0m{, \033[0;33m${frame.pc}\033[0m}{ \033[1;4;36m${module.file.basename}\033[0;36m ${function.name}{${function.pc-offset}}\033[0m}{, \033[1;35mstop reason\033[0;35m = ${thread.stop-reason}\033[0m}{, \033[1;36mname = \033[0;36m${thread.name}\033[0m}{, \033[1;32mqueue = \033[0;32m${thread.queue}}\033[0m\n'
A quick web search for "colorize terminal output" should allow you to see what
you can do to make your output look like you want it.
The "settings set" commands above can of course be added to your ~/.lldbinit
file for permanent use.
Changed the pure virtual
void ExecutionContextScope::Calculate (ExecutionContext&);
To:
void ExecutionContextScope::CalculateExecutionContext (ExecutionContext&);
I did this because this is a class that anything in the execution context
heirarchy inherits from and "target->Calculate (exe_ctx)" didn't always tell
you what it was really trying to do unless you look at the parameter.
llvm-svn: 115485
Enrico Granata