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22_Signals_Advanced_Features

README.md

Chapter 22: Signals: Advanced Features

Table of Contents

Exercise 22-1

To build the solution, run:

make Ex_22_1

To experiment without masking, run:

./Ex_22_1.sh

Sample output is:

./Ex_22_1 2023-08-27 12:33:33: Signal handler added
./Ex_22_1 2023-08-27 12:33:33: Idling started
./Ex_22_1 2023-08-27 12:33:38: Signal caught
./Ex_22_1 2023-08-27 12:35:14: Idling ended

To experiment with masking, run:

./Ex_22_1.sh --mask

Sample output is:

./Ex_22_1 2023-08-27 12:35:15: Signal blocked
./Ex_22_1 2023-08-27 12:35:15: Signal handler added
./Ex_22_1 2023-08-27 12:35:15: Idling started
./Ex_22_1 2023-08-27 12:36:56: Idling ended
./Ex_22_1 2023-08-27 12:36:56: Signal unblocked
./Ex_22_1 2023-08-27 12:36:56: Signal caught

Log Files

  • logs/test1/Ex_22_1_main.log contains the above output.
  • logs/test1/Ex_22_1_stdout.log contains any output sent to STDOUT from Ex_22_1.
  • logs/test1/Ex_22_1.log contains any error messages, and verbose messages if the --verbose option is chosen.

Exercise 22-2

To build and test the solution, run:

make test_2

Sample output can be found in the file Ex_22_2_sample_solution.

The answer to the question is that real time signals are presented first.

Exercise 22-3

To build and test the solution, run:

make test_3

Sample output is:

test using sigsuspend completed  1000000 3.98 1.14 2.83
test using sigwaitinfo completed 1000000 0.68 0.35 0.32

Using sigwaitinfo() results in an 83% reduction in run time.

Exercise 22-4

To build and test the solution, run:

make test_4

Sample output is:

gcc -o Ex_22_4 Ex_22_4.c
./Ex_22_4.sh  --log-dir=logs/Ex_22_4

The contents of the stdout log is:

my_sigset passed
my_sighold passed
my_sigignore passed
my_sigrelse passed
my_sigpause passed
*** All tests done ***