From 5b3ceca69d5432f976ac487c63a75f8c6275028b Mon Sep 17 00:00:00 2001 From: Christian Cunningham Date: Tue, 11 Jan 2022 18:05:00 -0700 Subject: Memory freeing is optimized Fixed Uart Bug temporarily --- src/lib/mem.c | 98 ++++++++++++++++++++++++++++++++++------------------------- 1 file changed, 56 insertions(+), 42 deletions(-) (limited to 'src/lib') diff --git a/src/lib/mem.c b/src/lib/mem.c index ed6d23f..fcaea4b 100644 --- a/src/lib/mem.c +++ b/src/lib/mem.c @@ -53,54 +53,63 @@ void* malloc(unsigned char size) unsigned char* mem = (unsigned char*)rpi_heap; unsigned long i = 0; // TODO: Use Null PID - while (((void*)(mem+i) < rpi_heap_top) && !(mem[i] == size && mem[i+1]==0)) { - i += mem[i]+2; + while (((void*)(mem + i) < rpi_heap_top) && !(mem[i + MEM_SIZE_OFFSET] == size && mem[i + MEM_USE_OFFSET]==0)) { + i += mem[i] + MEM_META_SIZE; } // Update top of heap if (mem[i] == 0) - rpi_heap_top = (void*)&mem[i+2+size]; + rpi_heap_top = (void*)&mem[i + MEM_META_SIZE + size]; mem[i] = size; + mem[i + MEM_BASE_SIZE + size] = size; // Use allocator's PID - mem[i+1] = 1; - return (void*)&mem[i+2]; + mem[i + MEM_USE_OFFSET] = 1; + return (void*)&mem[i + MEM_BASE_SIZE]; } void* malloca(unsigned char size, unsigned char amnt) { + // Return malloc if alignment size is 0 or 1 - trivial alignment + if(amnt == 0 || amnt == 1) + return malloc(size); unsigned char* mem = (unsigned char*)rpi_heap; unsigned long i = 0; // TODO: Use Null PID while(1) { - unsigned long diff = (unsigned long)mem + i + 2; + unsigned long diff = (unsigned long)mem + i + MEM_BASE_SIZE; diff %= amnt; diff = amnt - diff; diff %= amnt; - if((mem[i] == size) && mem[i+1]==0) { + if((mem[i + MEM_SIZE_OFFSET] == size) && mem[i + MEM_USE_OFFSET]==0) { if(diff == 0) { - mem[i] = size; - mem[i+1] = 1; - return (void*)&mem[i+2]; + mem[i + MEM_SIZE_OFFSET] = size; + mem[i + MEM_BASE_SIZE + size] = size; + mem[i + MEM_USE_OFFSET] = 1; + return (void*)&mem[i + MEM_BASE_SIZE]; } } else if (mem[i] == 0) { - if(diff == 0 || diff == amnt) { - mem[i] = size; - mem[i+1] = 1; - rpi_heap_top = (void*)&mem[i+2+size]; - return (void*)&mem[i+2]; + if(diff == 0) { + mem[i + MEM_SIZE_OFFSET] = size; + mem[i + MEM_BASE_SIZE + size] = size; + mem[i + MEM_USE_OFFSET] = 1; + rpi_heap_top = (void*)&mem[i + MEM_META_SIZE + size]; + return (void*)&mem[i + MEM_BASE_SIZE]; } else { - if(diff <= 2) { + while (diff <= MEM_BASE_SIZE) { diff += amnt; } - mem[i] = diff-2; + unsigned long empty_size = diff - MEM_META_SIZE; + mem[i + MEM_SIZE_OFFSET] = empty_size; + mem[i + MEM_BASE_SIZE + empty_size] = empty_size; i += diff; - mem[i] = size; - mem[i+1] = 1; - rpi_heap_top = (void*)&mem[i+2+size]; - return (void*)&mem[i+2]; + mem[i + MEM_SIZE_OFFSET] = size; + mem[i + MEM_BASE_SIZE + size] = size; + mem[i + MEM_USE_OFFSET] = 1; + rpi_heap_top = (void*)&mem[i + MEM_META_SIZE + size]; + return (void*)&mem[i + MEM_BASE_SIZE]; } } - i += mem[i]+2; + i += mem[i] + MEM_META_SIZE; } } @@ -109,18 +118,23 @@ void free(void* memloc) // Don't try to free memory outside of heap if(!(((void*)rpi_heap <= memloc) && (memloc < rpi_heap_top))) return; - unsigned char* base = memloc - 2; - unsigned char size = *base; + unsigned char* base = memloc - MEM_BASE_SIZE; + unsigned char size = base[MEM_SIZE_OFFSET]; // TODO: Use Null PID - base[1] = 0; + base[MEM_USE_OFFSET] = 0; // Clear out old memory for(unsigned int i = 0; i < size; i++) { - base[i+2] = 0; + base[i + MEM_BASE_SIZE] = 0; } // If it is the last entry, clear it and move the heap top down - if (base + size + 2 == rpi_heap_top) { - base[0] = 0; - rpi_heap_top = base; + if (base + size + MEM_META_SIZE == rpi_heap_top) { + while(base[MEM_USE_OFFSET] == 0 && base >= rpi_heap) { + base[MEM_SIZE_OFFSET] = 0; + base[MEM_BASE_SIZE + size] = 0; + rpi_heap_top = base; + unsigned long psize = *(base - 1); + base -= psize + MEM_META_SIZE; + } } } @@ -138,24 +152,24 @@ void heap_info(void) { unsigned char* base = rpi_heap; while ((void*)base < rpi_heap_top) { - unsigned char size = *base; - if(base[1] == 0) { + unsigned char size = base[MEM_SIZE_OFFSET]; + if(base[MEM_USE_OFFSET] == 0) { uart_char('F'); uart_char(' '); } - uart_hex((unsigned long)(base+2)); + uart_hex((unsigned long)(base + MEM_BASE_SIZE)); uart_string(" Size: "); uart_10(size); uart_string("\n"); static char* data = "00 \0"; static unsigned char temp = 0; for(unsigned int i = 0; i < size; i++) { - temp = (base[2+i]>>4)&0xF; + temp = (base[MEM_BASE_SIZE + i]>>4)&0xF; if(temp > 9) temp += 7; temp += 0x30; data[0] = temp; - temp = (base[2+i])&0xF; + temp = (base[MEM_BASE_SIZE + i])&0xF; if(temp > 9) temp += 7; temp += 0x30; @@ -163,7 +177,7 @@ void heap_info(void) uart_string(data); } uart_char('\n'); - base += size + 2; + base += size + MEM_META_SIZE; } uart_char('\n'); } @@ -172,24 +186,24 @@ void heap_info_u(void) { unsigned char* base = rpi_heap; while ((void*)base < rpi_heap_top) { - unsigned char size = *base; - if(base[1] == 0) { - base += size + 2; + unsigned char size = base[MEM_SIZE_OFFSET]; + if(base[MEM_USE_OFFSET] == 0) { + base += MEM_META_SIZE; continue; } - uart_hex((unsigned long)(base+2)); + uart_hex((unsigned long)(base + MEM_BASE_SIZE)); uart_string(" Size: "); uart_10(size); uart_string("\n"); static char* data = "00 \0"; static unsigned char temp = 0; for(unsigned int i = 0; i < size; i++) { - temp = (base[2+i]>>4)&0xF; + temp = (base[MEM_BASE_SIZE + i]>>4)&0xF; if(temp > 9) temp += 7; temp += 0x30; data[0] = temp; - temp = (base[2+i])&0xF; + temp = (base[MEM_BASE_SIZE + i])&0xF; if(temp > 9) temp += 7; temp += 0x30; @@ -197,7 +211,7 @@ void heap_info_u(void) uart_string(data); } uart_char('\n'); - base += size + 2; + base += size + MEM_META_SIZE; } uart_char('\n'); } -- cgit v1.2.1