Search results
Results from the WOW.Com Content Network
A stack may be implemented as, for example, a singly linked list with a pointer to the top element. A stack may be implemented to have a bounded capacity. If the stack is full and does not contain enough space to accept another element, the stack is in a state of stack overflow. A stack is needed to implement depth-first search.
An example of information contained within a TCB is: Thread Identifier: Unique id (tid) is assigned to every new thread; Stack pointer: Points to thread's stack in the process; Program counter: Points to the current program instruction of the thread; State of the thread (running, ready, waiting, start, done) Thread's register values
However, such subroutines do not need to return that value to r14—they merely need to load that value into r15, the program counter, to return. The ARM calling convention mandates using a full-descending stack. In addition, the stack pointer must always be 4-byte aligned, and must always be 8-byte aligned at a function call with a public ...
In 8086, the main stack register is called "stack pointer" (SP). The stack segment register (SS) is usually used to store information about the memory segment that stores the call stack of currently executed program. SP points to current stack top. By default, the stack grows downward in memory, so newer values are placed at lower memory addresses.
Register R7 is the program counter (PC). Although any register can be used as a stack pointer, R6 is the stack pointer (SP) used for hardware interrupts and traps. R5 is often used to point to the current procedure call frame. To speed up context switching, some PDP-11 models provide dual R0-R5 register sets.
Suppose a process A is running and a timer interrupt occurs. The user registers — program counter, stack pointer, and status register — of process A are then implicitly saved by the CPU onto the kernel stack of A. Then, the hardware switches to kernel mode and jumps into interrupt handler for the operating system to take over.
Drop the stack pointer to the current base pointer, so room reserved in the prologue for local variables is freed. Pops the base pointer off the stack, so it is restored to its value before the prologue. Returns to the calling function, by popping the previous frame's program counter off the stack and jumping to it.
The program counter (PC), [1] commonly called the instruction pointer (IP) in Intel x86 and Itanium microprocessors, and sometimes called the instruction address register (IAR), [2] [1] the instruction counter, [3] or just part of the instruction sequencer, [4] is a processor register that indicates where a computer is in its program sequence.