8fea5ab8bd
The set of processes to which a SIGKMESS signal is sent whenever new diagnostics messages are added to the kernel's message buffer, is now no longer hardcoded. Instead, processes can (un)register themselves to receive such notifications, by means of sys_diagctl(). Change-Id: I9d6ac006a5d9bbfad2757587a068fc1ec3cc083e
32 lines
1.1 KiB
C
32 lines
1.1 KiB
C
/* A server must occasionally print some message. It uses a simple version of
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* printf() found in the system lib that calls kputc() to output characters.
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* Printing is done with a call to the kernel, and not by going through FS.
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*
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* This routine can only be used by servers and device drivers. The kernel
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* must define its own kputc(). Note that the log driver also defines its own
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* kputc() to directly call the TTY instead of going through this library.
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*/
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#include "sysutil.h"
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static char print_buf[DIAG_BUFSIZE]; /* output is buffered here */
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/*===========================================================================*
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* kputc *
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*===========================================================================*/
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void kputc(int c)
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{
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/* Accumulate another character. If 0 or buffer full, print it. */
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static int buf_count; /* # characters in the buffer */
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if ((c == 0 && buf_count > 0) || buf_count == sizeof(print_buf)) {
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sys_diagctl_diag(print_buf, buf_count);
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buf_count = 0;
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}
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if (c != 0) {
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/* Append a single character to the output buffer. */
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print_buf[buf_count] = c;
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buf_count++;
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}
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}
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