PMQSize

These patches may provide tremendous stability in OS/2 systems that suffer from desktop hangs, no-input in shells, invalid switching between the desktop and Window/DOS applications, and other ailments. These patches are not meant to be a complete OS/2 fix, but may be lots of help.

Theory

Every PM thread that sends PM messages or receives posted messages must have a queue to hold those messages until they are processed. Messages are very frequently put into those messages queues to be processed as the thread is able. If more messages are put into the queue than the queue can hold, then it is reasonable to expect problems in the system, ranging from trivial glitches to system hangs. The default size for these queues in OS/2 is only 10 messages. This seems very small considering the number of message-generating activities going on in a busy OS/2 system.

Many OS/2 users experience problems in running OS/2 that I speculate are caused, or at least exacerbated, by this too-small queue.