Recovering from device failure

For a computer system comprising a trusted region of computer executable instructions that calls into an untrusted region of computer executable instructions, a method of recovering a resource from the untrusted region that permits execution of computer instructions in the trusted region without encountering any inconsistencies that may be introduced by recovering the resource from the untrusted region, the method comprising steps for:

• calling one or more untrusted region entry points that are wrapped with exception logic for processing one or more exceptions that may be raised within the untrusted region;
• determining whether an exception has been raised within the untrusted region, and if not executing one or more computer executable instructions of the untrusted region that correspond to a specific entry point;
• and
• preventing one or more resources from entering the untrusted region once an exception is raised in the untrusted region.

For a computer system comprising a trusted region of computer executable instructions that calls into an untrusted region of computer executable instructions, a computer program product comprising a computer readable medium carrying computer executable instructions for a method of implementing resource recovery from the untrusted region that permits continued execution of computer instructions in the trusted region without encountering potential inconsistencies introduced by recovering the resource from the untrusted region, the method comprising acts of:

• wrapping one or more untrusted region entry points with exception logic for processing one or more exceptions that may be raised within the untrusted region;
• testing whether an exception has been raised within the untrusted region, and if not executing one or more computer executable instructions of the untrusted region that correspond to a specific entry point;
• and
• blocking one or more resources from entering the untrusted region once an exception is raised in the untrusted region.

For a computer system comprising a trusted region of computer executable instructions that calls into an untrusted region of computer executable instructions, a computer program product comprising a computer readable medium carrying computer executable instructions that implement a method of recovering a resource from the untrusted region that permits execution of computer instructions in the trusted region without encountering any inconsistencies that may be introduced by recovering the resource from the untrusted region, the method comprising steps for:

• calling one or more untrusted region entry points that are wrapped with exception logic for processing one or more exceptions that may be raised within the untrusted region;
• determining whether an exception has been raised within the untrusted region, and if not executing one or more computer executable instructions of the untrusted region that correspond to a specific entry point;
• and
• preventing one or more resources from entering the untrusted region once an exception is raised in the untrusted region.