Changeset 416 for trunk/libs/malloc.h

Timestamp:

Jan 4, 2018, 10:05:47 AM (6 years ago)

Author:

alain

Message:

Improve sys_exec.

File:

• trunk/libs/malloc.h (modified) (4 diffs)

trunk/libs/malloc.h

@@ -24 +24 @@
 ////////////////////////////////////////////////////////////////////////////////
 // General principles:
-// - In user space this HEAP zone has a fixed size, that spread between the
-//   ELF zone and the STACK zone.
+// - In user space the HEAP zone spread between the ELF zone and the STACK zone,
+//   as defined in the kernel_config.h file.
 // - The malloc library uses the mmap() syscall to create - on demand -
-//   up to one vseg per cluster. The size of these vsegs is defined by the
-//   MALLOC_LOCAL_STORAGE_SIZE parameter.
-// - For a standard malloc(), the target cluster is the cluster of the client
-//   thread. For a remote_malloc(), the target cluster is explicitely defined
-//   by the arguments.
+//   one vseg in a given cluster. The size of this vseg is defined below
+//   by the MALLOC_LOCAL_STORE_SIZE parameter.
+// - For a standard malloc(), the target cluster is the cluster containing
+//   the core running the client thread.
+// - For a remote_malloc(), the target cluster is explicitely defined
+//   by the argument.
 // - In each cluster, the available storage in virtual space is handled by a
 //   local allocator using the buddy algorithm.
-// TODO : introduce the possibility to use a list of vsegs in each cluster...  
+//
+// TODO : In this first implementation one single - fixed size - vseg 
+//        is allocated on demand in each cluster.
+//        We should introduce the possibility to dynamically allocate
+//        several vsegs in each cluster, using several mmap when required. 
 ////////////////////////////////////////////////////////////////////////////////
 // Free blocks organisation in each cluster :
@@ -43 +48 @@
 //   given list have the same size. 
 // - The NEXT pointer implementing those linked lists is written 
-//   in the 4 first bytes of the block itself, using the unsigned int type.
+//   in the first bytes of the block itself, using the unsigned int type.
 // - The pointers on the first free block for each size are stored in an
-//   array of pointers free[32] in the stotrage(x,y) descriptor.
+//   array of pointers free[32] in the storage(x,y) descriptor.
 ////////////////////////////////////////////////////////////////////////////////
 // Allocation policy:
@@ -56 +61 @@
 //   and returns the block B if the list[actual_size] is not empty.
 // - If the list[actual_size] is empty, it pop the list[actual_size * 2].
-//   If a block B' is found, it break this block in 2 B/2 blocks, returns 
+//   If a block B' is found, it breaks this block in 2 B/2 blocks, returns 
 //   the first B/2 block and push the other B/2 block into list[actual_size].
 // - If the list[actual_size * 2] is empty, it pop the list[actual_size * 4].
@@ -73 +78 @@
 //   of the allocated block must be obtained from the base address of the block.  
 // - The number of entries in this array is equal to the max number
-//   of allocated block : MALLOC_LOCAL_STORAGE_SIZE / MALLOC_MIN_BLOCK_SIZE.
+//   of allocated block : MALLOC_LOCAL_STORE_SIZE / MALLOC_MIN_BLOCK_SIZE.
 // - For each allocated block, the value registered in the alloc[] array
 //   is log2( size_of_allocated_block ).