Abstract: A system includes a processor configured to: initiate atomic execution of a plurality of instruction units in a thread, starting with a beginning instruction unit in the plurality of instruction units, wherein the plurality of instruction units in the thread are not programmatically specified to be executed atomically, and wherein the plurality of instruction units includes one or more memory modification instructions; in response to executing an instruction to commit inserted into the plurality of instructions units, incrementally commit a portion of the one or more memory modification instructions that have been atomically executed so far; and subsequent to incrementally committing the portion of the memory modification instructions that have been atomically executed so far, continue atomic execution of the plurality of instruction units. The system further includes a memory coupled to the processor, configured to provide the processor with the plurality of instruction units.

Abstract: A system includes a processor configured to: initiate atomic execution of a plurality of instruction units in a thread, starting with a beginning instruction unit in the plurality of instruction units, wherein the plurality of instruction units in the thread are not programmatically specified to be executed atomically, and wherein the plurality of instruction units includes one or more memory modification instructions; in response to executing an instruction to commit inserted into the plurality of instructions units, incrementally commit a portion of the one or more memory modification instructions that have been atomically executed so far; and subsequent to incrementally committing the portion of the memory modification instructions that have been atomically executed so far, continue atomic execution of the plurality of instruction units. The system further includes a memory coupled to the processor, configured to provide the processor with the plurality of instruction units.

Abstract: A system includes a processor configured to: initiate atomic execution of a plurality of instruction units in a thread, starting with a beginning instruction unit in the plurality of instruction units, wherein the plurality of instruction units in the thread are not programmatically specified to be executed atomically; detect an atomicity terminating event during atomic execution of the plurality of instruction units, wherein the atomicity terminating event is triggered by a memory access by another processor; and commit at least some of the one or more memory modification instructions. The system further includes a memory coupled to the processor, configured to provide the processor with the plurality of instruction units.

Abstract: A system includes a processor configured to: initiate atomic execution of a plurality of instruction units in a thread, starting with a beginning instruction unit in the plurality of instruction units, wherein the plurality of instruction units is not programmatically specified to be executed atomically; detect an atomicity terminating event during atomic execution of the plurality of instruction units, wherein the atomicity terminating event is triggered by a memory access by another processor; and establish an incidentally atomic sequence of instruction units based at least in part on detection of the atomicity terminating event, wherein the incidentally atomic sequence of instruction units correspond to a sequence of instruction units in the plurality of instruction units. The system further includes a memory coupled to the processor, configured to provide the processor with the plurality of instruction units.

Abstract: Indicating usage in a system includes implementing a performance counter associated with one or more hardware threads; counting events associated with the one or more hardware threads to determine an event count; deriving an initial measure of usage of a processor core associated with the one or more hardware threads based at least in part on the event count; applying a corrective function to modify the initial measure of usage and determine a modified measure of usage, wherein the modified measure of usage has a value that is different from and not equivalent to the initial measure of usage; and outputting an indication of a processor usage, the indication being based at least in part on the modified measure of usage.

Abstract: Handling a virtual method call includes extracting, from a pointer to an object, an identifier associated with the class of the object, the pointer to the object being associated with the virtual method call, and the identifier being embedded within the pointer; using the identifier to obtain a virtual method table, including locating a first entry in a class identifier table mapping a plurality of class identifiers to a corresponding plurality of class data, the first entry being associated with the identifier and comprising the virtual method table or a pointer used to obtain the virtual method table; locating a second entry in the virtual method table, the second entry being associated with the virtual method call; and jumping to an address associated with the second entry to execute code at the address.

Abstract: Indicating usage in a system includes implementing a performance counter associated with one or more hardware threads; counting events associated with the one or more hardware threads to determine an event count; deriving an initial measure of usage of a processor core associated with the one or more hardware threads based at least in part on the event count; applying a corrective function to modify the initial measure of usage and determine a modified measure of usage, wherein the modified measure of usage has a value that is different from and not equivalent to the initial measure of usage; and outputting an indication of a processor usage, the indication being based at least in part on the modified measure of usage.

Abstract: Handling a virtual method call includes extracting, from a pointer to an object, an identifier associated with the class of the object, the pointer to the object being associated with the virtual method call, and the identifier being embedded within the pointer; using the identifier to obtain a virtual method table, including locating a first entry in a class identifier table mapping a plurality of class identifiers to a corresponding plurality of class data, the first entry being associated with the identifier and comprising the virtual method table or a pointer used to obtain the virtual method table; locating a second entry in the virtual method table, the second entry being associated with the virtual method call; and jumping to an address associated with the second entry to execute code at the address.

Abstract: Indicating usage in a system is disclosed. Indicating includes obtaining active thread information related to a number of hardware threads in a processor core, combining the active thread information with information related to a decreasing ability of the processor core to increase throughput by utilizing additional hardware threads, and indicating the usage in the system based at least in part on both the active thread information and the ability of the processor core to increase throughput by utilizing additional hardware threads.

Abstract: Detecting a race condition is disclosed. An indication of a store operation to a memory address is received. An identifier of the memory address is stored. The identifier is used to detect an occurrence of a memory operation that is not associated with a previous ordering operation.

Abstract: Handling a virtual method call includes extracting, from a pointer to an object, an identifier associated with the class of the object, the pointer to the object being associated with the virtual method call, and the identifier being embedded within the pointer; using the identifier to obtain a virtual method table, including locating a first entry in a class identifier table mapping a plurality of class identifiers to a corresponding plurality of class data, the first entry being associated with the identifier and comprising the virtual method table or a pointer used to obtain the virtual method table; locating a second entry in the virtual method table, the second entry being associated with the virtual method call; and jumping to an address associated with the second entry to execute code at the address.

Abstract: A computer system includes a processor; and a memory coupled to the processor, configured to provide the processor with a plurality of instructions including a set of garbage collection instructions configured to perform one or more garbage collection barrier operations and a subsequent instruction that immediately follows the garbage collection instruction; wherein the processor is configured to execute the set of garbage collection instructions, including by: evaluating a memory reference to determine a condition associated with the set of garbage collection instructions; and in the event that the condition is met, while maintaining the same privilege level, saving information that is based at least in part on the current value of a program counter, and setting the program counter to correspond to a target location that is other than the location of the subsequent instruction.

Abstract: Reaching a determination associated with a class of an object is disclosed. An identifier associated with the class of the object is extracted from a pointer to the object. The extracted identifier is compared to a comparison value. At least in part using a result of the comparison a determination is reached.

Abstract: Detecting a race condition is disclosed. An indication of a store operation to a memory address is received. An identifier of the memory address is stored. The identifier is used to detect an occurrence of a memory operation that is not associated with a previous ordering operation.

Abstract: Detecting a race condition is disclosed. An indication of a store operation to a memory address is received. An identifier of the memory address is stored. The identifier is used to detect an occurrence of a memory operation that is not associated with a previous ordering operation.

Abstract: A computer system includes a processor; and a memory coupled to the processor, configured to provide the processor with a plurality of instructions including a set of garbage collection instructions configured to perform one or more garbage collection barrier operations and a subsequent instruction that immediately follows the garbage collection instruction; wherein the processor is configured to execute the set of garbage collection instructions, including by: evaluating a memory reference to determine a condition associated with the set of garbage collection instructions; and in the event that the condition is met, while maintaining the same privilege level, saving information that is based at least in part on the current value of a program counter, and setting the program counter to correspond to a target location that is other than the location of the subsequent instruction.

Abstract: A computer system includes a processor; and a memory coupled to the processor, configured to provide the processor with a plurality of instructions including a garbage collection barrier instruction and a subsequent instruction that immediately follows the garbage collection barrier instruction; wherein the processor is configured to execute the garbage collection barrier instruction, including by: evaluating a memory reference to determine a condition associated with the garbage collection barrier instruction; and in the event that the condition is met, while maintaining the same privilege level, saving information that is based at least in part on the current value of a program counter, and setting the program counter to correspond to a target location that is other than the location of the subsequent instruction.

Abstract: Accessing memory in an array includes performing a first instruction, including by determining whether an index used by the first instruction is within a valid range and in the event that the index is within a valid range, determining a memory address related to an array element that corresponds to the index. Accessing memory in the array further includes, in the event that the index is within a valid range, performing a second instruction to access the array element, the access being based at least in part on the memory address determined by the first instruction.

Abstract: Executing an ordering operation is disclosed. A store operation associated with storing a value into a portion of a memory is initiated. An ordering operation to ensure that the store operation, but not necessarily all store operations, are completed is executed.

Abstract: Addressing memory includes receiving a first operand to a memory addressing operator, receiving a second operand to the memory addressing operator, performing sign extension on the first operand to provide a sign-extended operand, shifting the sign-extended operand to provide a shifted, sign-extended operand, and adding the shifted, sign-extended operand to the second operand. The second operand has a different bit length than the first operand.