Changeset 670 for trunk/kernel/syscalls/sys_pipe.c

Timestamp:

Nov 19, 2020, 11:45:52 PM (3 years ago)

Author:

alain

Message:

1) Introduce up to 4 command lines arguments in the KSH "load" command.
These arguments are transfered to the user process through the
argc/argv mechanism, using the user space "args" vseg.

2) Introduce the named and anonymous "pipes", for inter-process communication
through the pipe() and mkfifo() syscalls.

3) Introduce the "chat" application to validate the two above mechanisms.

4) Improve printk() and assert() fonctions in printk.c.

File:

• trunk/kernel/syscalls/sys_pipe.c (modified) (2 diffs)

trunk/kernel/syscalls/sys_pipe.c

@@ -2 +2 @@
  * sys_pipe.c - open a pipe communication channel
  * 
- * Author    Alain Greiner  (2016,1017)
+ * Author    Alain Greiner  (2016,1017,2018,2019,2020)
  *
  * Copyright (c)  UPMC Sorbonne Universites
@@ -24 +24 @@
 #include <hal_kernel_types.h>
 #include <vfs.h>
+#include <hal_uspace.h>
 #include <process.h>
 #include <thread.h>
 #include <printk.h>
+#include <pipe.h>
 
 #include <syscalls.h>
 
-//////////////////////////////////////
-int sys_pipe ( uint32_t file_fd[2] )
+////////////////////////////
+int sys_pipe ( fdid_t * fd )
 {
-    printk("\n[ERROR] in %d : not implemented yet\n", __FUNCTION__, file_fd );
-    return ENOSYS;
-}
+    vseg_t       * vseg;
+    kmem_req_t     req;
+    pipe_t       * pipe;
+    vfs_file_t   * file_0;
+    vfs_file_t   * file_1;
+    fdid_t         fdid_0;
+    fdid_t         fdid_1;
+    error_t        error;
+
+    thread_t     * this    = CURRENT_THREAD;
+    process_t    * process = this->process;
+
+#if DEBUG_SYS_PIPE || DEBUG_SYSCALLS_ERROR || CONFIG_INSTRUMENTATION_SYSCALLS
+uint64_t   tm_start = hal_get_cycles();
+#endif
+
+#if DEBUG_SYS_PIPE
+if( DEBUG_SYS_PIPE < tm_end )
+printk("\n[%s] thread[%x,%x] enter for <%s> / cycle %d\n",
+__FUNCTION__, process->pid, this->trdid, pathname, (uint32_t)tm_end );
+#endif
+
+    // check user buffer is mapped 
+    if( vmm_get_vseg( process , (intptr_t)fd , &vseg ) )
+    {
+
+#if DEBUG_SYSCALLS_ERROR
+if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
+printk("\n[ERROR] in %s : thread[%x,%x] / output user buffer unmapped %x\n",
+__FUNCTION__ , process->pid, this->trdid, (intptr_t)fd );
+#endif
+                this->errno = EINVAL;
+                return -1;
+    }
+
+    // 1. allocate memory in local cluster for pipe descriptor,
+    //    remote buf_descriptor, and associated data buffer
+    pipe = pipe_create( local_cxy,
+                        CONFIG_PIPE_BUF_SIZE );
+
+    if( pipe == NULL )
+    {
+
+#if DEBUG_SYSCALLS_ERROR
+if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
+printk("\n[ERROR] in %s : thread[%x,%x] / no memory for pipe\n",
+__FUNCTION__ , process->pid, this->trdid );
+#endif
+        goto error_1;
+    }
+
+    // 2. allocate memory for fd[0] file descriptor in local cluster
+    // we don't use the vfs_file_create function because there is no inode.
+        req.type  = KMEM_KCM;
+        req.order = bits_log2( sizeof(vfs_file_t) );
+    req.flags = AF_ZERO;
+        file_0    = kmem_alloc( &req );
+
+    if( file_0 == NULL ) 
+    {
+
+#if DEBUG_SYSCALLS_ERROR
+if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
+printk("\n[ERROR] in %s : thread[%x,%x] / no memory for file descriptor\n",
+__FUNCTION__, process->pid, this->trdid );
+#endif
+        goto error_2;
+    }
+    
+    // 3. get fd[0] fdid value and register it in owner process fd_array[]
+    error = process_fd_register( process->owner_xp,
+                                 XPTR( local_cxy , file_0 ),
+                                 &fdid_0 );
+    if ( error )
+    {
+
+#if DEBUG_SYSCALLS_ERROR
+if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
+printk("\n[ERROR] in %s : thread[%x,%x] / cannot register file descriptor \n",
+__FUNCTION__, process->pid, this->trdid );
+#endif
+        goto error_3;
+    }
+
+    // 4. allocate memory for fd[1] file descriptor in local cluster
+        req.type  = KMEM_KCM;
+        req.order = bits_log2( sizeof(vfs_file_t) );
+    req.flags = AF_ZERO;
+        file_1    = kmem_alloc( &req );
+
+    if( file_1 == NULL ) 
+    {
+
+#if DEBUG_SYSCALLS_ERROR
+if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
+printk("\n[ERROR] in %s : thread[%x,%x] / no memory for file descriptor\n",
+__FUNCTION__, process->pid, this->trdid );
+#endif
+        goto error_4;
+    }
+
+    // 5. get fd[1] fdid value and register it in owner process fd_array[]
+    error = process_fd_register( process->owner_xp,
+                                 XPTR( local_cxy , file_1 ),
+                                 &fdid_1 );
+    if ( error )
+    {
+
+#if DEBUG_SYSCALLS_ERROR
+if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
+printk("\n[ERROR] in %s : thread[%x,%x] / cannot register file descriptor \n",
+__FUNCTION__, process->pid, this->trdid );
+#endif
+        goto error_5;
+    }
+
+    // link the two file descriptors to the pipe
+    file_0->pipe = pipe;
+    file_1->pipe = pipe;
+
+    // copy fdid_0 & fdid_1 values to user buffer
+    hal_copy_to_uspace( &fd[0] , XPTR( local_cxy , &fdid_0 ) , sizeof(fdid_t) );
+    hal_copy_to_uspace( &fd[1] , XPTR( local_cxy , &fdid_1 ) , sizeof(fdid_t) );
+
+#if (DEBUG_SYS_PIPE || CONFIG_INSTRUMENTATION_SYSCALLS)
+uint64_t     tm_end = hal_get_cycles();
+#endif
+
+#if DEBUG_SYS_PIPE
+if( DEBUG_SYS_PIPE < tm_end )
+printk("\n[%s] thread[%x,%x] exit for <%s> / cycle %d\n",
+__FUNCTION__, this->process->pid, this->trdid, pathname, (uint32_t)tm_end );
+#endif
+ 
+#if CONFIG_INSTRUMENTATION_SYSCALLS
+hal_atomic_add( &syscalls_cumul_cost[SYS_PIPE] , tm_end - tm_start );
+hal_atomic_add( &syscalls_occurences[SYS_PIPE] , 1 );
+#endif
+
+    return 0;
+
+error_5:    // release memory allocated for fd[1] file descriptor
+
+    req.ptr = file_1;
+    kmem_free( &req );
+
+error_4:    // release fdid_0 from fd_array[]
+
+    process_fd_remove( process->ref_xp , fdid_0 );
+
+error_3:    // release memory allocated for fd[0] file descriptor
+
+    req.ptr = file_0;
+    kmem_free( &req );
+
+error_2:    // release memory allocated for the pipe 
+
+    pipe_destroy( XPTR( local_cxy , pipe ) );
+
+error_1:   // set errno and return error
+
+    this->errno = ENOMEM;
+    return -1;
+
+}  // end sys_pipe()