New discovery of ROS callback function

Look at the code first ：

Publisher

import rospy
from leaning_topic.msg import Person

def personInfoCallback(msg):
    rospy.loginfo("Subcribe Person Info: name:%s  age:%d  sex:%d", 
			 msg.name, msg.age, msg.sex)

def person_subscriber():
	# ROS Node initialization 
    rospy.init_node('person_subscriber', anonymous=True)

	#  Create a Subscriber, The subscription is called /person_info Of topic, Register callback function personInfoCallback
    rospy.Subscriber("/person_info", Person, personInfoCallback)
	#  Loop waiting for callback function 
    rospy.spin()

if __name__ == '__main__':
    person_subscriber()

subscriber ： 

import rospy
from leaning_topic.msg import Person

def personInfoCallback(msg):
    rospy.loginfo("Subcribe Person Info: name:%s  age:%d  sex:%d", 
			 msg.name, msg.age, msg.sex)

    print("huidiaohanshu")
    rospy.sleep(10)

def person_subscriber():
	# ROS Node initialization 
    rospy.init_node('person_subscriber', anonymous=True)

	#  Create a Subscriber, The subscription is called /person_info Of topic, Register callback function personInfoCallback
    #"<class 'rospy.topics.Subscriber'>"
    while 1:
        rospy.sleep(1)
        print("wait 1 sec")
        print("meishoudao")
        rospy.Subscriber("/person_info", Person, personInfoCallback)
        
	#  Loop waiting for callback function 
    # rospy.spin()

if __name__ == '__main__':
    person_subscriber()

  result ：

Publisher

subscriber

  When the publisher has been sending messages , After receiving the message, the subscriber enters the callback function

I thought it would be Wait in the callback function 10 Seconds before exiting , Actually, I don't wait

It is similar to multithreading , The outer circle continues to run , Wait until the ten seconds of the callback function are completed before entering the callback function .

Is there any boss who can explain , The following code and results

New code ：

Publisher

import rospy
from leaning_topic.msg import Person

def velocity_publisher():
	# ROS Node initialization 
	rospy.init_node('person_publisher', anonymous=True)

	#  Create a Publisher, The release is called /person_info Of topic, The message type is learning_topic::Person, The queue length 10
	person_info_pub = rospy.Publisher('/person_info', Person, queue_size=10)

	# Set the frequency of the cycle 
	rate = rospy.Rate(1)
	aage  = 18
    #  initialization learning_topic::Person Type of message 
		
	while not rospy.is_shutdown():
		person_msg = Person()
		person_msg.name = "Tom"
		person_msg.age  = aage
		aage+=1
		person_msg.sex  = Person.male

		#  Release the news 
		person_info_pub.publish(person_msg)
		rospy.loginfo("Publsh person message[%s, %d, %d]", 
				person_msg.name, person_msg.age, person_msg.sex)

		#  Delay according to the cycle frequency 
		rate.sleep()

if __name__ == '__main__':
    try:
        velocity_publisher()
    except rospy.ROSInterruptException:
        pass

subscriber

import rospy
from leaning_topic.msg import Person

def personInfoCallback(msg):
    rospy.loginfo("Subcribe Person Info: name:%s  age:%d  sex:%d", 
			 msg.name, msg.age, msg.sex)
    print("h")
    print("he")
    print("hel")
    print("hell")
    print("hello")
    rospy.sleep( 5)
    print("w")
    print("wo")
    print("wor")
    print("worl")
    print("world")
    

def person_subscriber():
	# ROS Node initialization 
    rospy.init_node('person_subscriber', anonymous=True)

	#  Create a Subscriber, The subscription is called /person_info Of topic, Register callback function personInfoCallback
    #"<class 'rospy.topics.Subscriber'>"
    timee = 0
    while 1:
        timee+=1
        rospy.sleep(1)
        print("wait ",timee," sec")
        rospy.Subscriber("/person_info", Person, personInfoCallback)
        
	#  Loop waiting for callback function 
    # rospy.spin()

if __name__ == '__main__':
    person_subscriber()

[email protected]:~/test_ws/src/leaning_topic/scripts$ python person_subscriber_mytest.py 
('wait ', 1, ' sec')
[INFO] [1658066660.928361]: Subcribe Person Info: name:Tom  age:21  sex:1
h
he
hel
hell
hello
('wait ', 2, ' sec')
('wait ', 3, ' sec')
('wait ', 4, ' sec')
('wait ', 5, ' sec')
('wait ', 6, ' sec')
w
wo
wor
worl
world
[INFO] [1658066665.934645]: Subcribe Person Info: name:Tom  age:22  sex:1
h
he
hel
hell
hello
('wait ', 7, ' sec')
('wait ', 8, ' sec')
('wait ', 9, ' sec')
('wait ', 10, ' sec')
('wait ', 11, ' sec')
w
wo
wor
worl
world
[INFO] [1658066670.942621]: Subcribe Person Info: name:Tom  age:22  sex:1
h
he
hel
hell
hello
('wait ', 12, ' sec')
('wait ', 13, ' sec')
('wait ', 14, ' sec')
('wait ', 15, ' sec')
('wait ', 16, ' sec')
w
wo
wor
worl
world
[INFO] [1658066675.950627]: Subcribe Person Info: name:Tom  age:22  sex:1
h
he
hel
hell
hello
('wait ', 17, ' sec')
('wait ', 18, ' sec')
('wait ', 19, ' sec')
('wait ', 20, ' sec')
('wait ', 21, ' sec')
w
wo
wor
worl
world
[INFO] [1658066680.958480]: Subcribe Person Info: name:Tom  age:22  sex:1
h
he
hel
hell
hello
('wait ', 22, ' sec')
('wait ', 23, ' sec')
('wait ', 24, ' sec')
('wait ', 25, ' sec')
('wait ', 26, ' sec')
w
wo
wor
worl
world
[INFO] [1658066685.966115]: Subcribe Person Info: name:Tom  age:22  sex:1
h
he
hel
hell
hello
('wait ', 27, ' sec')
('wait ', 28, ' sec')
('wait ', 29, ' sec')
('wait ', 30, ' sec')
('wait ', 31, ' sec')
w
wo
wor
worl
world
[INFO] [1658066690.976371]: Subcribe Person Info: name:Tom  age:22  sex:1
h
he
hel
hell
hello
('wait ', 32, ' sec')
('wait ', 33, ' sec')
('wait ', 34, ' sec')
('wait ', 35, ' sec')
('wait ', 36, ' sec')
w
wo
wor
worl
world
[INFO] [1658066695.987310]: Subcribe Person Info: name:Tom  age:23  sex:1
h
he
hel
hell
hello
('wait ', 37, ' sec')
('wait ', 38, ' sec')
('wait ', 39, ' sec')
('wait ', 40, ' sec')
('wait ', 41, ' sec')
w
wo
wor
worl
world
[INFO] [1658066700.995400]: Subcribe Person Info: name:Tom  age:23  sex:1
h
he
hel
hell
hello
('wait ', 42, ' sec')
('wait ', 43, ' sec')
('wait ', 44, ' sec')
('wait ', 45, ' sec')
('wait ', 46, ' sec')
w
wo
wor
worl
world
[INFO] [1658066706.002292]: Subcribe Person Info: name:Tom  age:23  sex:1
h
he
hel
hell
hello
('wait ', 47, ' sec')
('wait ', 48, ' sec')
('wait ', 49, ' sec')
('wait ', 50, ' sec')
('wait ', 51, ' sec')
w
wo
wor
worl
world
[INFO] [1658066711.008724]: Subcribe Person Info: name:Tom  age:23  sex:1
h
he
hel
hell
hello
('wait ', 52, ' sec')
('wait ', 53, ' sec')
('wait ', 54, ' sec')
('wait ', 55, ' sec')
('wait ', 56, ' sec')
w
wo
wor
worl
world
[INFO] [1658066716.016592]: Subcribe Person Info: name:Tom  age:23  sex:1
h
he
hel
hell
hello
('wait ', 57, ' sec')
('wait ', 58, ' sec')
('wait ', 59, ' sec')
('wait ', 60, ' sec')
('wait ', 61, ' sec')
w
wo
wor
worl
world
[INFO] [1658066721.027559]: Subcribe Person Info: name:Tom  age:23  sex:1
h
he
hel
hell
hello
('wait ', 62, ' sec')
('wait ', 63, ' sec')
('wait ', 64, ' sec')
('wait ', 65, ' sec')
('wait ', 66, ' sec')
w
wo
wor
worl
world
[INFO] [1658066726.038374]: Subcribe Person Info: name:Tom  age:24  sex:1
h
he
hel
hell
hello
('wait ', 67, ' sec')
('wait ', 68, ' sec')
('wait ', 69, ' sec')
('wait ', 70, ' sec')
('wait ', 71, ' sec')
w
wo
wor
worl
world
[INFO] [1658066731.049110]: Subcribe Person Info: name:Tom  age:24  sex:1
h
he
hel
hell
hello
('wait ', 72, ' sec')
('wait ', 73, ' sec')
('wait ', 74, ' sec')
('wait ', 75, ' sec')
('wait ', 76, ' sec')
w
wo
wor
worl
world
[INFO] [1658066736.057305]: Subcribe Person Info: name:Tom  age:24  sex:1
h
he
hel
hell
hello
('wait ', 77, ' sec')
('wait ', 78, ' sec')
('wait ', 79, ' sec')
('wait ', 80, ' sec')
('wait ', 81, ' sec')
w
wo
wor
worl
world
[INFO] [1658066741.068204]: Subcribe Person Info: name:Tom  age:24  sex:1
h
he
hel
hell
hello
('wait ', 82, ' sec')
('wait ', 83, ' sec')
('wait ', 84, ' sec')
('wait ', 85, ' sec')
('wait ', 86, ' sec')
w
wo
wor
worl
world
[INFO] [1658066746.074492]: Subcribe Person Info: name:Tom  age:24  sex:1
h
he
hel
hell
hello
('wait ', 87, ' sec')
('wait ', 88, ' sec')
('wait ', 89, ' sec')
('wait ', 90, ' sec')
('wait ', 91, ' sec')
w
wo
wor
worl
world
[INFO] [1658066751.082524]: Subcribe Person Info: name:Tom  age:24  sex:1
h
he
hel
hell
hello
('wait ', 92, ' sec')
('wait ', 93, ' sec')
('wait ', 94, ' sec')
('wait ', 95, ' sec')
('wait ', 96, ' sec')
w
wo
wor
worl
world
[INFO] [1658066756.090489]: Subcribe Person Info: name:Tom  age:25  sex:1
h
he
hel
hell
hello
('wait ', 97, ' sec')
('wait ', 98, ' sec')
('wait ', 99, ' sec')
('wait ', 100, ' sec')
('wait ', 101, ' sec')
w
wo
wor
worl
world
[INFO] [1658066761.098334]: Subcribe Person Info: name:Tom  age:25  sex:1
h
he
hel
hell
hello
('wait ', 102, ' sec')
('wait ', 103, ' sec')
('wait ', 104, ' sec')
('wait ', 105, ' sec')
('wait ', 106, ' sec')
w
wo
wor
worl
world
[INFO] [1658066766.104921]: Subcribe Person Info: name:Tom  age:25  sex:1
h
he
hel
hell
hello
('wait ', 107, ' sec')
('wait ', 108, ' sec')
('wait ', 109, ' sec')
('wait ', 110, ' sec')
('wait ', 111, ' sec')
w
wo
wor
worl
world
[INFO] [1658066771.110689]: Subcribe Person Info: name:Tom  age:25  sex:1
h
he
hel
hell
hello
('wait ', 112, ' sec')
('wait ', 113, ' sec')
('wait ', 114, ' sec')
('wait ', 115, ' sec')
('wait ', 116, ' sec')
w
wo
wor
worl
world
[INFO] [1658066776.117056]: Subcribe Person Info: name:Tom  age:25  sex:1
h
he
hel
hell
hello
('wait ', 117, ' sec')
('wait ', 118, ' sec')
('wait ', 119, ' sec')
('wait ', 120, ' sec')
('wait ', 121, ' sec')
w
wo
wor
worl
world
[INFO] [1658066781.122387]: Subcribe Person Info: name:Tom  age:25  sex:1
h
he
hel
hell
hello
('wait ', 122, ' sec')
('wait ', 123, ' sec')
('wait ', 124, ' sec')
('wait ', 125, ' sec')
('wait ', 126, ' sec')
w
wo
wor
worl
world
[INFO] [1658066786.129833]: Subcribe Person Info: name:Tom  age:26  sex:1
h
he
hel
hell
hello
('wait ', 127, ' sec')
('wait ', 128, ' sec')
('wait ', 129, ' sec')
('wait ', 130, ' sec')
('wait ', 131, ' sec')
w
wo
wor
worl
world
[INFO] [1658066791.137488]: Subcribe Person Info: name:Tom  age:26  sex:1
h
he
hel
hell
hello
('wait ', 132, ' sec')
('wait ', 133, ' sec')
('wait ', 134, ' sec')
('wait ', 135, ' sec')
('wait ', 136, ' sec')
w
wo
wor
worl
world
[INFO] [1658066796.144930]: Subcribe Person Info: name:Tom  age:26  sex:1
h
he
hel
hell
hello
('wait ', 137, ' sec')
('wait ', 138, ' sec')
('wait ', 139, ' sec')
('wait ', 140, ' sec')
('wait ', 141, ' sec')
w
wo
wor
worl
world
[INFO] [1658066801.154495]: Subcribe Person Info: name:Tom  age:26  sex:1
h
he
hel
hell
hello
('wait ', 142, ' sec')
('wait ', 143, ' sec')
('wait ', 144, ' sec')
('wait ', 145, ' sec')
('wait ', 146, ' sec')
w
wo
wor
worl
world
[INFO] [1658066806.162257]: Subcribe Person Info: name:Tom  age:26  sex:1
h
he
hel
hell
hello
('wait ', 147, ' sec')
('wait ', 148, ' sec')
('wait ', 149, ' sec')
('wait ', 150, ' sec')
('wait ', 151, ' sec')
w
wo
wor
worl
world
[INFO] [1658066811.167280]: Subcribe Person Info: name:Tom  age:26  sex:1
h
he
hel
hell
hello
('wait ', 152, ' sec')
('wait ', 153, ' sec')
('wait ', 154, ' sec')
('wait ', 155, ' sec')
('wait ', 156, ' sec')
w
wo
wor
worl
world
[INFO] [1658066816.175524]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 157, ' sec')
('wait ', 158, ' sec')
('wait ', 159, ' sec')
('wait ', 160, ' sec')
('wait ', 161, ' sec')
w
wo
wor
worl
world
[INFO] [1658066821.182114]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 162, ' sec')
('wait ', 163, ' sec')
('wait ', 164, ' sec')
('wait ', 165, ' sec')
('wait ', 166, ' sec')
w
wo
wor
worl
world
[INFO] [1658066826.193277]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 167, ' sec')
('wait ', 168, ' sec')
('wait ', 169, ' sec')
('wait ', 170, ' sec')
('wait ', 171, ' sec')
w
wo
wor
worl
world
[INFO] [1658066831.202561]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 172, ' sec')
('wait ', 173, ' sec')
('wait ', 174, ' sec')
('wait ', 175, ' sec')
('wait ', 176, ' sec')
w
wo
wor
worl
world
[INFO] [1658066836.207695]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 177, ' sec')
('wait ', 178, ' sec')
('wait ', 179, ' sec')
('wait ', 180, ' sec')
('wait ', 181, ' sec')
w
wo
wor
worl
world
[INFO] [1658066841.214497]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 182, ' sec')
('wait ', 183, ' sec')
('wait ', 184, ' sec')
('wait ', 185, ' sec')
('wait ', 186, ' sec')
w
wo
wor
worl
world
[INFO] [1658066846.222484]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 187, ' sec')
('wait ', 188, ' sec')
('wait ', 189, ' sec')
('wait ', 190, ' sec')
('wait ', 191, ' sec')
w
wo
wor
worl
world
[INFO] [1658066851.230717]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 192, ' sec')
('wait ', 193, ' sec')
('wait ', 194, ' sec')
('wait ', 195, ' sec')
('wait ', 196, ' sec')
w
wo
wor
worl
world
[INFO] [1658066856.241519]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 197, ' sec')
('wait ', 198, ' sec')
('wait ', 199, ' sec')
('wait ', 200, ' sec')
('wait ', 201, ' sec')
w
wo
wor
worl
world
[INFO] [1658066861.251622]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 202, ' sec')
('wait ', 203, ' sec')
('wait ', 204, ' sec')
('wait ', 205, ' sec')
('wait ', 206, ' sec')
w
wo
wor
worl
world
[INFO] [1658066866.259658]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 207, ' sec')
('wait ', 208, ' sec')
('wait ', 209, ' sec')
('wait ', 210, ' sec')
('wait ', 211, ' sec')
w
wo
wor
worl
world
[INFO] [1658066871.270496]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 212, ' sec')
('wait ', 213, ' sec')
('wait ', 214, ' sec')
('wait ', 215, ' sec')
('wait ', 216, ' sec')
w
wo
wor
worl
world
[INFO] [1658066876.278537]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 217, ' sec')
('wait ', 218, ' sec')
('wait ', 219, ' sec')
('wait ', 220, ' sec')
('wait ', 221, ' sec')
w
wo
wor
worl
world
[INFO] [1658066881.286493]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 222, ' sec')
('wait ', 223, ' sec')
('wait ', 224, ' sec')
('wait ', 225, ' sec')
('wait ', 226, ' sec')
w
wo
wor
worl
world
[INFO] [1658066886.292880]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 227, ' sec')
('wait ', 228, ' sec')
('wait ', 229, ' sec')
('wait ', 230, ' sec')
('wait ', 231, ' sec')
w
wo
wor
worl
world
[INFO] [1658066891.300657]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 232, ' sec')
('wait ', 233, ' sec')
('wait ', 234, ' sec')
('wait ', 235, ' sec')
('wait ', 236, ' sec')
w
wo
wor
worl
world
[INFO] [1658066896.307402]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 237, ' sec')
('wait ', 238, ' sec')
('wait ', 239, ' sec')
('wait ', 240, ' sec')
('wait ', 241, ' sec')
w
wo
wor
worl
world
[INFO] [1658066901.310330]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 242, ' sec')
('wait ', 243, ' sec')
('wait ', 244, ' sec')
('wait ', 245, ' sec')
('wait ', 246, ' sec')
w
wo
wor
worl
world
[INFO] [1658066906.316772]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 247, ' sec')
('wait ', 248, ' sec')
('wait ', 249, ' sec')
('wait ', 250, ' sec')
('wait ', 251, ' sec')
w
wo
wor
worl
world
[INFO] [1658066911.323292]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 252, ' sec')
('wait ', 253, ' sec')
('wait ', 254, ' sec')
('wait ', 255, ' sec')
('wait ', 256, ' sec')
w
wo
wor
worl
world
[INFO] [1658066916.326533]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 257, ' sec')
('wait ', 258, ' sec')
('wait ', 259, ' sec')
('wait ', 260, ' sec')
('wait ', 261, ' sec')
w
wo
wor
worl
world
[INFO] [1658066921.334591]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 262, ' sec')
('wait ', 263, ' sec')
('wait ', 264, ' sec')
('wait ', 265, ' sec')
('wait ', 266, ' sec')
w
wo
wor
worl
world
[INFO] [1658066926.338224]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 267, ' sec')
('wait ', 268, ' sec')
('wait ', 269, ' sec')
('wait ', 270, ' sec')
('wait ', 271, ' sec')
w
wo
wor
worl
world
[INFO] [1658066931.342251]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 272, ' sec')
('wait ', 273, ' sec')
('wait ', 274, ' sec')
('wait ', 275, ' sec')
('wait ', 276, ' sec')
w
wo
wor
worl
world
[INFO] [1658066936.348688]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 277, ' sec')
('wait ', 278, ' sec')
('wait ', 279, ' sec')
('wait ', 280, ' sec')
('wait ', 281, ' sec')
w
wo
wor
worl
world
[INFO] [1658066941.358506]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 282, ' sec')
('wait ', 283, ' sec')
('wait ', 284, ' sec')
('wait ', 285, ' sec')
('wait ', 286, ' sec')
w
wo
wor
worl
world
[INFO] [1658066946.369562]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 287, ' sec')
('wait ', 288, ' sec')
('wait ', 289, ' sec')
('wait ', 290, ' sec')
('wait ', 291, ' sec')
w
wo
wor
worl
world
[INFO] [1658066951.380609]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 292, ' sec')
('wait ', 293, ' sec')
('wait ', 294, ' sec')
('wait ', 295, ' sec')
('wait ', 296, ' sec')
w
wo
wor
worl
world
[INFO] [1658066956.387533]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 297, ' sec')
('wait ', 298, ' sec')
('wait ', 299, ' sec')
('wait ', 300, ' sec')
('wait ', 301, ' sec')
w
wo
wor
worl
world
[INFO] [1658066961.394490]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 302, ' sec')
('wait ', 303, ' sec')
('wait ', 304, ' sec')
('wait ', 305, ' sec')
('wait ', 306, ' sec')
w
wo
wor
worl
world
[INFO] [1658066966.402521]: Subcribe Person Info: name:Tom  age:27  sex:1
h
he
hel
hell
hello
('wait ', 307, ' sec')