diff options
Diffstat (limited to 'dostsr.h')
| -rw-r--r-- | dostsr.h | 27 |
1 files changed, 24 insertions, 3 deletions
@@ -96,9 +96,6 @@ static __segment reallocate_to_umb(segment_t cur_seg, unsigned segment_size) // Create a new program instance including PSP at the new_segment copy_program(new_segment_psp, old_segment_psp, segment_size); - // Tell DOS to "switch" to the new program - dos_set_psp(new_segment_psp); - // Return the new segment return new_segment; } else { @@ -111,4 +108,28 @@ static __segment reallocate_to_umb(segment_t cur_seg, unsigned segment_size) } } +/** Called in case there is an error and we should free our HMA segment. */ +static void cancel_reallocation(segment_t new_seg) +{ + segment_t new_segment_psp = new_seg - (DOS_PSP_SIZE/16); + dos_free(new_segment_psp); +} + +/** Called right before doing the TSR call. + * Frees the old code segment. */ +static void finish_reallocation(segment_t old_segment_psp, segment_t new_seg) +{ + segment_t new_segment_psp = new_seg - (DOS_PSP_SIZE/16); + + // Tell DOS that we are "switching" to the new program in the HMA + dos_set_psp(new_segment_psp); + + // We are about to free() the old code segment, + // which is likely where the currently running function code resides. + dos_free(old_segment_psp); + + // Nothing should try to allocate memory between this and the actual TSR call, + // since it could overwrite the currently running code... ! +} + #endif // DOSTSR_H |