Changeset 436 for trunk/kernel/kern/process.h

Timestamp:

Mar 7, 2018, 9:02:03 AM (5 years ago)

Author:

alain

Message:

1) improve the threads and process destruction mechanism.
2) introduce FIFOs in the soclib_tty driver.

File:

• trunk/kernel/kern/process.h (modified) (7 diffs)

trunk/kernel/kern/process.h

@@ -58 +58 @@
 enum process_sigactions
 {
-    BLOCK_ALL_THREADS    = 11,
-    UNBLOCK_ALL_THREADS  = 22,
-    DELETE_ALL_THREADS   = 33, 
+    BLOCK_ALL_THREADS    = 0x11,
+    UNBLOCK_ALL_THREADS  = 0x22,
+    DELETE_ALL_THREADS   = 0x33, 
 };
 
@@ -281 +281 @@
  * This function allows a client thread running in any cluster to block, unblock or delete 
  * all threads of a process identified by the <pid> argument, depending on the 
- * <action_type> argument.  The scenario is the following:
- * - It uses the multicast, non blocking rpc_process_sigaction_client() function to send
- *   parallel requests to all remote clusters containing a process copy. Then it blocks
- $   and deschedule to wait completion of these parrallel requests.
- * - In each remote cluster, the rpc_process_sigaction_server() function, calls directly
- *   the relevant process_block(), process_unblock(), or process_delete() function, and
- *   decrement the responses counter to signal completion. The last server unblock
- *   the client thread.
- * - Finally, the client thread calls directly the process_block(), process_unblock(), or
- *   process_delete() function in the owner cluster.
+ * <action_type> argument.
+ * WARNING : the DELETE action is NOT executed on the target process main thread
+ * (thread 0 in process owner cluster).
+ * It uses the multicast, non blocking rpc_process_sigaction_client() function to send
+ * parallel requests to all remote clusters containing a process copy. 
+ * Then it blocks and deschedule to wait completion of these parallel requests.
+ *
  * It is used by the sys_kill() & sys_exit() functions to handle the "kill" & "exit" syscalls.
  * It is also used by the process_make_exec() function to handle the "exec" syscall.
- * It is also called by the TXT device to execute the ctrl C & ctrl Z commands.
- * WARNING : the DELETE action is NOT executed on the main thread (thread 0 in owner cluster).
+ * It is also called by the TXT device ISR to execute the ctrl C & ctrl Z commands.
+ *
+ * Implementation note:
+ * This function allocates a - shared - RPC descriptor in client thread stack, 
+ * and initializes it. This RPC descriptor can be shared because all parallel,
+ * non-blocking, RPC server threads use the same input arguments, including the
+ * RPC responses counter field.
  *********************************************************************************************
  * @ pid         : target process identifier.
@@ -303 +305 @@
 
 /*********************************************************************************************
- * This function blocks all threads for a given <process> in a given cluster.
- * The calling thread cannot be a target thread.
- * It loops on all local threads of the process, set the THREAD_BLOCKED_GLOBAL bit, 
+ * This function blocks all threads - but the main thread - for a given <process> 
+ * in a given cluster. It sets the THREAD_BLOCKED_GLOBAL bit in the thread descriptor, 
  * and request the relevant schedulers to acknowledge the blocking, using IPI if required. 
  * The threads are not detached from the scheduler, and not detached from the local process.
@@ -322 +323 @@
 
 /*********************************************************************************************
- * This function marks for deletion all threads - but one _ for a given <process>
- * in a given cluster. The main thread in owner cluster is NOT marked.
- * It will be marked for deletion by the parent process sys_wait().
- * The calling thread cannot be a target thread.
- * It loops on all local threads of the process, and set the THREAD_FLAG_REQ_DELETE bit.
- * For each marked thread, the following actions will be done by the scheduler at the next
- * scheduling point: 
+ * This function marks for deletion all threads - but the main thread - for a given <process>
+ * in a given cluster. It sets the THREAD_FLAG_REQ_DELETE bit. For each marked thread,
+ * the following actions will be done by the scheduler at the next scheduling point: 
  * - the thread will be detached from the scheduler.
  * - the thread will be detached from the local process descriptor.
@@ -349 +346 @@
  ********************************************************************************************/
 process_t * process_get_local_copy( pid_t pid );
+
+/*********************************************************************************************
+ * This function returns the parent process identifier for a remote process descriptor
+ * identified by an extended pointer.
+ *********************************************************************************************
+ * @ process_xp   : extended pointer on remote process descriptor.
+ * @ returns parent process dentifier.
+ ********************************************************************************************/
+pid_t process_get_ppid( xptr_t process_xp );
 
 /*********************************************************************************************
@@ -508 +514 @@
 
 /*********************************************************************************************
- * This function attach a reference process descriptor, identified by the <process>
+ * This function attach a process descriptor in owner cluster, identified by the <process>
  * argument to a TXT terminal, identified by its <txt_id> channel index argument.
  * It insert the process descriptor in the xlist rooted in the TXT_RX device.
@@ -520 +526 @@
 
 /*********************************************************************************************
- * This function detach a reference process descriptor, identified by the <process_xp>
- * argument, from the list of process attached to a given TXT terminal.
- * It is called when the process is killed.
- *********************************************************************************************
- * @ process  : local pointer on process descriptor.
- ********************************************************************************************/
-void process_txt_detach( process_t * process );                     
-
-/*********************************************************************************************
- * This function gives to a process identified by the <process_xp> argument, and attached
+ * This function detach a process, identified by the <process_xp> argument,
+ * from the list of process attached to a given TXT terminal.
+ * The target process descriptor must be in the owner cluster, but the calling thread can
+ * be running in any cluster. 
+ *********************************************************************************************
+ * @ process_xp  : extended pointer on process descriptor.
+ ********************************************************************************************/
+void process_txt_detach( xptr_t  process_xp );                     
+
+/*********************************************************************************************
+ * This function gives to a process identified by the <owner_xp> argument, and attached
  * to terminal TXT[i] the exclusive ownership of the TXT_RX[i] terminal.
- *********************************************************************************************
- * @ process_xp  : extended pointer on reference process descriptor.
- ********************************************************************************************/
-void process_txt_set_ownership( xptr_t process_xp );
-
-/*********************************************************************************************
- * When the process identified by the <process_xp> argument has the exclusive ownership
- * of the TXT_RX[i] terminal, this function gives this ownership to the KSH[i] process.
- * It does nothing if the process is not the owner.
- *********************************************************************************************
- * @ process_xp  : extended pointer on reference process descriptor.
- ********************************************************************************************/
-void process_txt_reset_ownership( xptr_t process_xp );
-
-/*********************************************************************************************
- * This function returns the terminal owner process (foreground process)
+ * The process descriptor must be in the process owner cluster.
+ *********************************************************************************************
+ * @ owner_xp  : extended pointer on process descriptor in owner cluster.
+ ********************************************************************************************/
+void process_txt_set_ownership( xptr_t owner_xp );
+
+/*********************************************************************************************
+ * When the process dentified by the <owner_xp> argument has the exclusive ownership of
+ * the TXT_RX terminal, this function transfer this ownership to another attached process.
+ * The process descriptor must be in the process owner cluster.
+ * This function does nothing if the <pid> process is not the owner.
+ * - If the current owner is not the KSH process, the new owner is the KSH process.
+ * - If the <pid> process is the the KSH process, the new owner is another attached process.
+ * - If there is no other attached process, the TXT has no more defined owner. 
+ *********************************************************************************************
+ * @ owner_xp  : extended pointer on process descriptor in owner cluster.
+ ********************************************************************************************/
+void process_txt_transfer_ownership( xptr_t owner_xp );
+
+/*********************************************************************************************
+ * This function returns the TXT owner process (foreground process)
  * for a given TXT terminal identified by its <channel> index.
  *********************************************************************************************
  * @ channel  : TXT terminal channel.
- * @ return owner process identifier.
- ********************************************************************************************/
-pid_t process_get_txt_owner( uint32_t channel );
+ * @ return extentded pointer on TXT owner process in owner cluster.
+ ********************************************************************************************/
+xptr_t process_txt_get_owner( uint32_t channel );
 
 /*********************************************************************************************