Return External (RTX)

Instruction Syntax

Operand 1: Signed binary(2) scalar or null.

Description:

The instruction terminates execution of the invocation in which the instruction is specified. The automatic storage frame is deallocated.

A Return External instruction can be specified within an invocation's subinvocation, and no exception is signaled.

If a higher invocation exists in the invocation hierarchy, the instruction causes execution to resume in the preceding invocation in the thread hierarchy at an instruction location indirectly specified by operand 1. If operand 1 is binary 0 or null, the next instruction following the Call External instruction from which control was relinquished in the preceding invocation in the hierarchy is given execution control. If the value of operand 1 is not 0, the value represents an index into the instruction definition list (IDL) specified as the return list operand in the Call External instruction, and the value causes control to be passed to the instruction referenced by the corresponding IDL entry. The first IDL entry is referenced by a value of one. If operand 1 is not 0 and no return list was specified in the Call External instruction, or if the value of operand 1 exceeds the number of entries in the IDL, or if the value is negative, a return point invalid (hex 2C02) exception is signaled.

In the initial thread of a process, if a higher invocation does not exist, the Return External instruction causes termination of the current process state. If operand 1 is not 0 and is not null, the return point invalid (hex 2C02) exception is signaled. Refer to the Terminate Process instruction for the functions performed in process termination.

If the returning invocation has received control to process an event, then control is returned to the point where the event handler was invoked. In this case, if operand 1 is not 0 and is not null, then a return point invalid (hex 2C02) exception is signaled.

If the returning invocation has received control from the machine to process an exception, the return instruction invalid (hex 2C01) exception is signaled.

If the returning invocation has an activation, the invocation count in the activation is decremented by 1.

If the returning invocation currently has an invocation exit set, the invocation exit is not given control and is implicitly cleared.

Authorization Required

• None

Lock Enforcement

• None

Exceptions

• 06 Addressing
  • 0601 Space Addressing Violation
  • 0602 Boundary Alignment
  • 0603 Range
• 08 Argument/Parameter
  • 0801 Parameter Reference Violation
• 10 Damage Encountered
  • 1004 System Object Damage State
  • 1044 Partial System Object Damage
• 1C Machine-Dependent
  • 1C03 Machine Storage Limit Exceeded
• 20 Machine Support
  • 2002 Machine Check
  • 2003 Function Check
• 22 Object Access
  • 2201 Object Not Found
  • 2202 Object Destroyed
  • 2203 Object Suspended
  • 2208 Object Compressed
  • 220B Object Not Available
• 24 Pointer Specification
  • 2401 Pointer Does Not Exist
  • 2402 Pointer Type Invalid
• 2C Program Execution
  • 2C01 Return Instruction Invalid
  • 2C02 Return Point Invalid
• 2E Resource Control Limit
  • 2E01 User Profile Storage Limit Exceeded
• 36 Space Management
  • 3601 Space Extension/Truncation
• 44 Protection Violation
  • 4401 Object Domain or Hardware Storage Protection Violation