Abstract: Methods, apparatus, systems and articles of manufacture are disclosed to manage concurrent predicate expressions. An example method discloses inserting a first condition hook into a first thread, the first condition hook associated with a first condition, inserting a second condition hook into a second thread, the second condition hook associated with a second condition, preventing the second thread from executing until the first condition is satisfied, and identifying a concurrency violation when the second condition is satisfied.

Abstract: A processor includes a front end including circuitry to receive an instruction to monitor execution of a thread, a decoder including circuitry to decode the instruction, a scheduler including circuitry to schedule the instruction, a retirement unit including circuitry to retire the instruction, and a core. The core includes circuitry to, based on execution of the instruction, monitor execution of the thread, identify an attempted read of an address during execution of the thread, determine whether a value at the address was previously read during monitoring of the execution of the thread, log the attempted read based on a determination that the value at the address was not previously read during monitoring of the execution of the thread, and omit logging of the attempted read based on a determination that the value at the address was previously read during monitoring of the execution of the thread.

Abstract: A system is disclosed that includes a processor and a dynamic random access memory (DRAM). The processor includes a hybrid transactional memory (HyTM) that includes hardware transactional memory (HTM), and a program debugger to replay a program that includes an HTM instruction and that has been executed has been executed using the HyTM. The program debugger includes a software emulator that is to replay the HTM instruction by emulation of the HTM. Other embodiments are disclosed and claimed.

Abstract: A processing device implementing unbounded transactional memory with forward progress guarantees using a hardware global lock is disclosed. A processing device of the disclosure includes a hardware transactional memory (HTM) hardware contention manager to cause a bounded transaction to be translated to an unbounded transaction, the unbounded transaction to acquire a global hardware lock for the unbounded transaction, the global hardware lock read by bounded transactions that abort when the global hardware lock is taken. The processing device further includes an execution unit communicably coupled to the HTM hardware contention manager to execute instructions of the unbounded transaction without speculation, the unbounded transaction to release the global hardware lock upon completion of execution of the instructions.

Abstract: A processor includes a front end to decode an instruction and pass the instruction to execution units with branch suffix information. The processor further includes execution units to execute the instruction and a retirement unit to retire the instruction. The instruction is to specify an operation to be conditionally executed based upon a branch suffix to identify previous execution. The processor further includes logic to, upon retirement of the instruction, determine the result of a series of branch operations preceding execution of the instruction, compare the result to the branch suffix information, allow execution and retirement of the instruction based on a determination that the result matches the branch suffix information, and generate a fault based on a determination that the result does not match the branch suffix information.

Abstract: An apparatus and method for improving the efficiency with which speculative critical sections are executed within a transactional memory architecture. For example, a method in accordance with one embodiment comprises: waiting to execute a speculative critical section of program code until a lock is freed by a current transaction; responsively executing the speculative critical section to completion upon detecting that the lock has been freed, regardless of whether the lock is held by another transaction during the execution of the speculative critical section; once execution of the speculative critical section is complete, determining whether the lock is taken; and if the lock is not taken, then committing the speculative critical section and, if the lock is taken, then aborting the speculative critical section.

Abstract: A mechanism is described for facilitating dynamic and efficient management of instruction atomicity violations in software programs according to one embodiment. A method of embodiments, as described herein, includes receiving, at a replay logic from a recording system, a recording of a first software thread running a first macro instruction, and a second software thread running a second macro instruction. The first software thread and the second software thread are executed by a first core and a second core, respectively, of a processor at a computing device. The recording system may record interleavings between the first and second macro instructions. The method includes correctly replaying the recording of the interleavings of the first and second macro instructions precisely as they occurred. The correctly replaying may include replaying a local memory state of the first and second macro instructions and a global memory state of the first and second software threads.

Abstract: A memory race recorder (MRR) is provided. The MRR includes a multi-core processor having a relaxed memory consistency model, an extension to the multi-core processor, the extension to store chunks, the chunk having a chunk size (CS) and an instruction count (IC), and a plurality of cores to execute instructions. The plurality of cores executes load/store instructions to/from a store buffer (STB) and a simulated memory to store the value when the value is not in the STB. The oldest value in the STB is transferred to the simulated memory when the IC is equal to zero and the CS is greater than zero. The MRR logs a trace entry comprising the CS, the IC, and a global timestamp, the global timestamp proving a total order across all logged chunks.

Abstract: A mechanism is described for facilitating dynamic and efficient management of instruction atomicity violations in software programs according to one embodiment. A method of embodiments, as described herein, includes receiving, at a replay logic from a recording system, a recording of a first software thread running a first macro instruction, and a second software thread running a second macro instruction. The first software thread and the second software thread are executed by a first core and a second core, respectively, of a processor at a computing device. The recording system may record interleavings between the first and second macro instructions. The method includes correctly replaying the recording of the interleavings of the first and second macro instructions precisely as they occurred. The correctly replaying may include replaying a local memory state of the first and second macro instructions and a global memory state of the first and second software threads.

Abstract: One or more embodiments may provide a method for performing a replay. The method includes initiating execution of a program, the program having a plurality of sets of instructions, and each set of instructions has a number of chunks of instructions. The method also includes intercepting, by a virtual machine unit executing on a processor, an instruction of a chunk of the number of chunks before execution. The method further includes determining, by a replay module executing on the processor, whether the chunk is an active chunk, and responsive to the chunk being the active chunk, executing the instruction.

Abstract: Technologies for identification of a potential root cause of a use-after-free memory corruption bug of a program include a computing device to replay execution of the execution of the program based on an execution log of the program. The execution log comprises an ordered set of executed instructions of the program that resulted in the use-after-free memory corruption bug. The computing device compares a use-after-free memory address access of the program to a memory address associated with an occurrence of the use-after-free memory corruption bug in response to detecting the use-after-free memory address access and records the use-after-free memory address access of the program as a candidate for a root cause of the use-after-free memory corruption bug to a candidate list in response to detecting a match between the use-after-free memory address access of the program and the memory address associated with the occurrence of the use-after-free memory corruption bug.

Abstract: Various embodiments are generally directed to detecting race conditions arising from uncoordinated data accesses by different portions of an application routine by detecting occurrences of a selected cache event associated with such accesses. An apparatus includes a processor component; a trigger component for execution by the processor component to configure a monitoring unit of the processor component to detect a cache event associated with a race condition between accesses to a piece of data and to capture an indication of a state of the processor component to generate monitoring data in response to an occurrence of the cache event; and a counter component for execution by the processor component to configure a counter of the monitoring unit to enable capture of the indication of the state of the processor component at a frequency less than every occurrence of the cache event. Other embodiments are described and claimed.

Abstract: Methods and systems to identify and reproduce concurrency violations in multi-threaded programs are disclosed. An example method disclosed herein comprises determining whether a condition is met and serializing an operation of a first thread of a multi-threaded program relative to an operation of a second thread of the multi-threaded program. The serialization of the operations of the first and second threads results in a concurrency violation or bug thereby causing the multi-threaded program to crash. In this way, the operations of the first and second threads of the multi-threaded program that are responsible for the concurrency violation are identified and can be revised to remove the bug.

Abstract: An apparatus and method are described for a hardware transactional memory (HTM) profiler. For example, one embodiment of an apparatus comprises a transactional debugger (TDB) recording module to record data related to the execution of transactional memory program code, including data related to the execution of branches and transactional events in the transactional memory program code; and a profiler to analyze portions of the recorded data using trace-based replay techniques to responsively generate profile data comprising transaction-level events and function-level conflict data usable to optimize the transactional memory program code.

Abstract: Embodiments may provide a method for performing a replay of a previous execution of a program. The method includes generating an order of recorded chunks of instructions across a plurality of recorded threads based, at least in part, on log files generated from the previous execution of the program. The method includes initiating execution of the program, the executing program having a plurality of threads, each thread having a number of chunks of instructions. The method includes intercepting, by a virtual machine unit executing on a processor, an instruction of a chunk before the instruction is executed. The method includes determining, by a replay module executing on the processor, that the chunk is an active chunk if the chunk is currently in line for execution according to the order of recorded chunks, and responsive to a determination that the chunk is the active chunk, executing the instruction.

Abstract: Methods and systems to identify and reproduce concurrency violations in multi-threaded programs are disclosed. An example method disclosed herein comprises determining whether a condition is met and serializing an operation of a first thread of a multi-threaded program relative to an operation of a second thread of the multi-threaded program. The serialization of the operations of the first and second threads results in a concurrency violation or bug thereby causing the multi-threaded program to crash. In this way, the operations of the first and second threads of the multi-threaded program that are responsible for the concurrency violation are identified and can be revised to remove the bug.

Abstract: Methods and systems to identify threads responsible for causing a concurrency bug in a computer program having a plurality of concurrently executing threads are disclosed. An example method disclosed herein includes defining, with a processor, a data type. The data type including a first predicate, the first predicate being invoked using a first program instruction inserted in a first thread of the plurality of threads, a second predicate, the second predicate being invoked using a second program instruction inserted in a second thread of the plurality of threads, and an expression defining a relationship between the first predicate and the second predicate. The method further includes, in response to determining the relationship is satisfied during execution of the computer program, identifying the first thread and the second thread as responsible for the concurrency bug.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed to manage concurrent predicate expressions. An example method discloses inserting a first condition hook into a first thread, the first condition hook associated with a first condition, inserting a second condition hook into a second thread, the second condition hook associated with a second condition, preventing the second thread from executing until the first condition is satisfied, and identifying a concurrency violation when the second condition is satisfied.

Abstract: A system is disclosed that includes a processor and a dynamic random access memory (DRAM). The processor includes a hybrid transactional memory (HyTM) that includes hardware transactional memory (HTM), and a program debugger to replay a program that includes an HTM instruction and that has been executed has been executed using the HyTM. The program debugger includes a software emulator that is to replay the HTM instruction by emulation of the HTM. Other embodiments are disclosed and claimed.

Abstract: In an embodiment of a transactional memory system, an apparatus includes a processor and an execution logic to enable concurrent execution of at least one first software transaction of a first software transaction mode and a second software transaction of a second software transaction mode and at least one hardware transaction of a first hardware transaction mode and at least one second hardware transaction of a second hardware transaction mode. In one example, the execution logic may be implemented within the processor. Other embodiments are described and claimed.