Method and system for maintaining context event logs without locking in virtual machine

1. A system for working with shared memory of a computer, comprising:

a) a plurality of contexts, each having executable processes writing and reading log data;

b) a ring buffer in the shared memory for writing and reading log data by the plurality of contexts;

c) a software primitive for managing access attempts by the contexts to the ring buffer;

d) wherein each context, upon writing to the ring buffer, is allocated an amount of space requested by the context, up to a maximum available amount of space in the ring buffer at any moment in time;

e) wherein the software primitive guarantees consistency of the log data written to the ring buffer, where entries from the same context are grouped together for writing and reading;

f) wherein the software primitive permits simultaneous writing into the ring buffer by multiple contexts;

g) wherein a context that finished writing last opens for reading log data of all other contexts in the ring buffer;

h) wherein a context that finished writing can open its log data for reading by other contexts;

i) wherein, after finishing writing to the ring buffer, the context updates a state of the buffer by decrementing the count of the active writers and/or by shifting the permission pointers for communicating with writers and readers; and

j) wherein a context can read from the buffer only the log data that is marked as valid for reading by the context that wrote that data.

2. The system of claim 1 , wherein the ring buffer is a First In, First Out (FIFO) buffer.

3. The system of claim 1 , wherein ring buffer writes and reads are done without utilizing spinlocks.

4. The system of claim 1 , wherein space in the ring is allocated within a guaranteed write cycle with no more iterations than a number of contexts waiting for their turn to write to the ring buffer.

5. The system of claim 1 , wherein, after registering with the ring buffer and after exiting writing to the buffer, each context reads global variables representing a state of the ring buffer, and updates the global variables based on his local variables,

wherein the global variables include an address of a next write and a number of contexts currently writing to the ring buffer.

6. The system of claim 1 , wherein, after registering with the ring buffer, each context updates global variables of the ring buffer that are also visible to other contexts, the updates including:

incrementing a number of contexts writing to the ring buffer; and

modifying an address of a next write.

7. The system of claim 1 , wherein, after exiting writing from the ring buffer, the context updates a global state of the ring buffer, including:

decrementing a number of contexts writing to the ring buffer; and

modifying an address of a read.

8. The system of claim 1 , further comprising deleting of the log data from the ring buffer after reading it, and modifying an address of a data that have been read already, thereby freeing up this space for writing to it.

9. The system of claim 1 , wherein multiple contexts can write concurrently to the ring buffer with multiple contexts reading from the buffer without conflicts.

10. The system of claim 1 , wherein the log data includes any data of the context.

11. The system of claim 1 , wherein the context is any of:

a virtual machine (VM) process;

a user application;

a user space process;

a Virtual Machine Monitor process; and

a process within a Hypervisor.