JP5845771B2 - Information transmission system and information transmission method - Google Patents

Description

  The present invention relates to an information transmission system and an information transmission method suitable for transmitting specific information about a point in time from one system or apparatus to the other system or apparatus. The present invention relates to an information transmission system that can be suitably used for, for example, a device using a multi-core processor and having a bare metal environment without an OS (Operating System) and acquiring accurate time information from the environment with the OS. Information transmission method.

  The multi-core processor is a microprocessor in which a plurality of processor cores are mounted on one CPU (Central Processing Unit). When there are multiple processor cores, the OS may become overhead if the tasks executed on some of the processor cores are simple or if the performance required for the functions executed on some of the processor cores is high. . An OS is not required for a processor core that executes such a simple task or a function that requires high performance. Therefore, in addition to the OS environment in which the OS exists in the processor core, a bare metal environment without the OS can exist. Here, bare metal refers to a minimum software operating environment (for example, only memory management and device drivers) that does not have a function provided by a general OS.

  FIG. 13 shows an example of a node in a bare metal environment in which a clock function does not exist as a first related technique of the present invention. In a node 100A as one management unit of the computer, a CPU 120 having four cores from the 0th core 110 to the third core 113 is arranged, and a bare metal environment 121 without an OS is realized. doing. Here, the first function 131, the second function 132, and the third function 133 are executed without the clock function.

  According to the first related art, since the watch does not exist in the bare metal environment 121, the first to third functions 131 to 133 cannot perform any control regarding time.

  FIG. 14 shows an example of a node in a bare metal environment provided with an interval timer that constitutes a part of the clock function as the second related technique of the present invention. 14, the same parts as those in FIG. 13 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the bare metal environment 141 of the node 100B illustrated in FIG. 14, an interval timer 142 that periodically adds time after activation is disposed. For this reason, for example, time management such as executing the second function 132 after the time t ₁ from the time when the first function 131 is executed becomes possible. However, since there is no clock that can know the date and time, for example, the process of executing the third function 133 on October 1 is impossible.

  FIG. 15 shows an example of a node provided with a real-time clock in a bare metal environment as a third related technique of the present invention. 15, the same parts as those in FIG. 13 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In the node 100 </ b> C illustrated in FIG. 15, two environments, an environment with an OS 151 and a bare metal environment 152 without an OS, are realized by a multicore processor. In the bare metal environment 152, a real time clock 161 for uniquely measuring the date and time is arranged.

  On the other hand, a clock 162 exists in the environment 151 with OS. The clock 162 is synchronized with the correct date and time by a time synchronization protocol 166 decided between an NTP (Network Time Protocol) server 164 and an NTP client 165 in another node 163. Accordingly, the fourth function 167 executed in the OS environment 151 is controlled by the clock 162 at the correct date and time.

  On the other hand, the real-time clock 161 cannot communicate with the NTP server 164 as indicated by a cross 168 in FIG. For this reason, the real-time clock 161 is likely to have a date / time shift from the clock 162, and this shift is not corrected. As a result, there is a possibility that time-related processing cannot be performed between the OS environment 151 and the bare metal environment 152.

  For example, the procedure in which the fourth function 167 reads and uses the data (data) 171 written in the shared memory 169 by the first function 131 at 1 pm on October 1 exactly at 2:00 pm on October 1 Suppose there was. In this example, the fourth function 167 cannot receive the data 171 via the shared memory 169 when the real-time clock 161 is delayed by more than one hour with respect to the clock 162.

  As described above, in the bare metal environment 152 without an OS, it is not possible to have a clock that indicates the absolute time synchronized with the external date and time of the NTP server 164 or the like. Only the timekeeping function can be realized.

  On the other hand, as a fourth related technique of the present invention, it has been proposed to exchange data using a shared memory in an apparatus environment using a multi-core processor. If this proposal is used, the time information of one environment can be passed as data to the other environment.

  FIG. 16 is for explaining the information transmission system according to the fourth related technique. In the information transmission system of the fourth related technology, the data transmission unit 182 of the transmission device 181 equipped with the OS uses the shared memory 185 to transmit data to the data reception unit 184 of the reception device 183. Yes.

  When time information to be transmitted to the reception device 183 is generated, the transmission device 181 secures a free area in the data storage unit 186 of the shared memory 185 and copies (stores) transmission data there. Further, the transmission device 181 stores (queues) the message block including the information on the storage destination address of the transmission data and the data length information of the transmission data in the unprocessed list storage unit 187. When a predetermined condition is satisfied, the inter-domain interrupt 188 is notified to the receiving device 183.

  When receiving the notification of the inter-domain interrupt 188 from the transmission device 181, the reception device 183 activates an interrupt handler and executes data reception processing by the data reception unit 183. Specifically, the data receiving unit 183 accesses the unprocessed list storage unit 187 and acquires a message block stored therein. Then, the acquired message block is transferred from the data receiving unit 184 to the upper layer processing unit 189.

  The upper layer processing unit 189 acquires data from the data storage unit 186 based on information included in the message block received from the data reception unit 184. Specifically, an area in which time information to be acquired is stored based on transmission data storage destination address information and data length information included in the message block is specified, and this time information is acquired from the specified area. . Then, the message block including the address information of the area where the acquired time information is stored and the data length information of the acquired data is queued to the processed list storage unit 191. Therefore, when the time information stored in the data storage unit 186 is read by the receiving device 183, the storage destination address information and the data length information (message block) corresponding to the read time information are stored in the unprocessed list storage unit. The process moves from 187 to the processed list storage unit 191.

JP 2009-116561 A (paragraphs 0019 to 0021, FIG. 1)

  In the fourth related technique, the message block stored in the unprocessed list storage unit 187 is acquired. This message block is time information before the data transmission unit 182 makes a list, and does not necessarily reflect the current time information of the data transmission unit 182. In some cases, the data transmission unit 182 stores and lists newer time information as a message block in the unprocessed list storage unit 187 than the message block read by the list. May be progressing.

  As described above, in the fourth related technique, there is a possibility that the reception device 183 cannot acquire the time information at the time when the transmission device 181 wrote the shared memory 185 due to the list. Therefore, a failure may occur in the temporal cooperation between the transmission device 181 and the reception device 183.

  As mentioned above, problems related to the transmission of time information between the two systems of the environment with OS and the bare metal environment without OS have been pointed out. However, not only the time information but also the passage of time such as environmental information such as temperature and humidity. A similar problem occurs when changing information is transmitted from one system to the other.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an information transmission system and an information transmission method that use a shared memory and that allows the receiving side to obtain the latest information without having to transmit information that the transmitting side has written to the shared memory to the receiving side. There is to do.

  In the present invention, (b) information that exists in the first system as the transmitting side and whose contents may change over time, and information that may be transmitted to the second system as the receiving side. Specific information input means for repeatedly inputting the specific information at the first system side in the first cycle, and (b) the contents each time the specific information input means inputs the specific information. Change information input means for inputting change information as information that changes at the first system side described above at the input timing of the specific information, and (c) the first system and the second system are common. And (d) the amount of the specific information input by the specific information input means described above on the first system side and written in the shared memory once in a single step To the specific information after division Specific information dividing means to divide, and (e) writing the change information input by the change information input means once, and then, previously storing the plurality of post-division specific information divided by the change information input means in advance Shared memory writing means for writing change information having the same contents as the above-described change information once after writing in a predetermined order, and ending one set of writing to the shared memory, (f) The latest one of the change information and the plurality of post-division specific information described above from the shared memory described above at an arbitrary second cycle that is arranged on the second system side and shorter than the first cycle described above Shared memory reading means for reading out one set, and (g) the contents of the pair of change information described above arranged on the second system side and read by the shared memory reading means Change information matching presence / absence determining means for determining the presence / absence of these matches, and (h) the change information matching presence / absence determining means arranged on the second system side so that the contents of the pair of change information match. Specific information reproducing means for reconstructing the specific information by assembling the plurality of post-division specific information as the remaining information constituting the one set in the predetermined order when it is determined that the specific information is included. Is provided in the information transmission system.

In the present invention, (b) information that exists in the first system as the transmitting side and whose contents may change with time may be transmitted to the second system as the receiving side. A specific information input step in which specific information as information is repeatedly input in the first cycle with time on the first system side, and (b) the specific information is input in the specific information input step. A change information input step in which change information as information whose contents change is input on the first system side at the input timing of the specific information, and (c) the above-mentioned specification on the first system side. plurality first system and a second system in which specific information described above that the input in the information input step is predetermined as the amount to be written separately once the shared memory as a memory that can be accessed in common Special after splitting A specific information dividing step for dividing the information into information, and (d) the plurality of post-division specific information divided by the change information input step after the change information input in the change information input step is written once. Are written in a predetermined order and then the change information having the same content as the change information is written once more, and the writing of one set to the shared memory is completed, ) The latest of the change information described above and the plurality of post-division specific information described above from the shared memory in an arbitrary second period that is arranged on the second system side and shorter than the first period described above A shared memory reading step for reading out one set of memory, and (f) arranged on the second system side as described above, and reading by this shared memory reading step A change information coincidence presence / absence determining step for determining whether or not there is a match between the contents of the pair of change information described above, and (g) the change information match presence / absence determining step arranged on the second system side described above. When it is determined that the contents of the pair of change information match, the above-mentioned identification is performed by assembling the plurality of post-division identification information as the remaining information constituting the one set in the predetermined order. The information transmission method includes a specific information reproduction step of reproducing information.

  As described above, according to the present invention, when the second system requires specific information as information that exists in the first system and whose contents may change over time, the first system Can be obtained from the system. Therefore, for example, when the specific information is time information managed by the first system, the second system side can match the time with the first system without providing a special clock. Further, if the time information of the first system is synchronized with an external clock, the time information can be synchronized with the external clock even if the second system does not have a mechanism for directly synchronizing with the external clock. it can.

  Further, according to the present invention, the specific information such as time information is divided into a plurality of parts by the specific information dividing means or the specific information dividing step and transmitted from the first system to the second system. Therefore, the upper limit of the size of the specific information to be transmitted is not limited to the maximum amount of writing once in the shared memory. For this reason, if the specific information is time information managed by the first system, for example, the number of significant digits representing the time information can be set sufficiently large. If the specific information is information describing the environmental change managed by the first system, various environments can be described extensively.

It is a claim corresponding figure of the information transmission system of the present invention. It is a claim corresponding figure of the information transmission method of the present invention. 1 is a system configuration diagram showing an information transmission system according to an embodiment of the present invention. It is the block diagram which expressed the principal part of the information transmission system in this Embodiment concretely centering around the synchronous mechanism. It is explanatory drawing which showed an example of the time-dependent change of the output data output from the sequential writing part of this Embodiment. It is explanatory drawing which showed an example of the count value of the counter in a certain time, and time information of this Embodiment. It is explanatory drawing which showed an example when time information was correctly assembled in the time information assembly part of the information transmission system of this Embodiment. It is explanatory drawing which showed an example when time information was not correctly assembled in the time information assembly part of the information transmission system of this Embodiment. It is a flowchart showing the mode of processing in the environment with OS in the present embodiment. It is a flowchart showing the mode of the process in the bare metal environment without OS in this Embodiment. It is a system configuration figure showing the information transmission system by the 1st modification of the present invention. It is a system block diagram showing the information transmission system by the 2nd modification of this invention. It is a schematic block diagram showing an example of the node of the bare metal environment where a clock function does not exist as the 1st related technology of this invention. It is a schematic block diagram showing an example of the node of the bare metal environment provided with the interval timer which makes a part of timepiece function as the 2nd related technique of this invention. It is a schematic block diagram showing an example of the node with which the real-time clock was provided in the bare metal environment as the 3rd related technique of this invention. It is a system configuration | structure figure showing the information transmission system of the 4th related technique of this invention.

  FIG. 1 shows a claim correspondence diagram of the information transmission system of the present invention. The information transmission system 10 of the present invention includes a specific information input means 11, a change information input means 12, a shared memory 13, a specific information dividing means 14, a shared memory writing means 15, a shared memory reading means 16, A change information coincidence determination unit 17 and a specific information reproduction unit 18 are provided. Here, the specific information input means 11 is information that exists in the first system as the transmitting side and whose contents may change over time, and may be transmitted to the second system as the receiving side. Specific information as certain information is repeatedly input at a first period with time on the first system side. The change information input means 12 inputs change information as information whose contents change each time the specific information input means 11 inputs the specific information on the first system side at the input timing of the specific information. To do. The shared memory 13 is a memory that can be accessed in common by the first system and the second system. The specific information dividing unit 14 divides the specific information input by the specific information input unit 11 on the first system side into a plurality of post-division specific information predetermined as an amount to be written into the shared memory 13 once. . The shared memory writing means 15 writes the change information input by the change information input means 12 once, and then follows the predetermined order of the plurality of post-division specific information divided by the change information input means 12. Then, the change information having the same contents as the above-described change information is written once more, and writing for one set to the shared memory 13 is completed. The shared memory reading means 16 is arranged on the second system side described above, and the change information described above from the shared memory 13 and the plurality of post-divided identifications in any second cycle shorter than the first cycle described above. Read one set of the latest information. The change information coincidence presence / absence discriminating means 17 is arranged on the second system side, and discriminates whether or not there is a match between the contents of the change information pair read by the shared memory reading means 16. The specific information reproducing means 18 is arranged on the second system side, and constitutes the one set described above when the change information matching presence / absence judging means 17 determines that the contents of the change information pair match. The above-described specific information is reproduced by assembling the plurality of post-division specific information as remaining information to be performed in the predetermined order.

  FIG. 2 is a diagram corresponding to claims of the information transmission method of the present invention. The information transmission method 20 of the present invention includes a specific information input step 21, a change information input step 22, a specific information division step 23, a shared memory write step 24, a shared memory read step 25, and a change information coincidence determination. Step 26 and specific information reproduction step 27 are provided. Here, in the specific information input step 21, information that exists in the first system as the transmission side and whose contents may change with time may be transmitted to the second system as the reception side. Specific information as certain information is repeatedly input at a first period with time on the first system side. In the change information input step 22, change information as information whose contents change each time the specific information is input in the specific information input step 21 is input on the first system side at the input timing of the specific information. To do. In the specific information dividing step 23, the above-described specific information input in the specific information input step 21 on the first system side is a memory that can be accessed in common by the first system and the second system. Are divided into a plurality of post-division specific information predetermined as an amount to be written once in the shared memory. In the shared memory writing step 24, the change information input in the change information input step 22 is written once, and the plurality of post-division specific information divided in the change information input step 22 is followed in a predetermined order. Then, the change information having the same content as the change information described above is written once more, and the writing for one set to the shared memory is completed. In the shared memory read step 25, the change information described above and the plurality of divisions described above from the above-mentioned shared memory in an arbitrary second cycle shorter than the above-described first cycle are arranged on the above-mentioned second system side. Read the latest set of specific information for one set. In the change information coincidence determination step 26, it is determined whether or not there is a match between the contents of the change information pair arranged on the second system side and read out by the shared memory read step 25. The specific information reproducing step 27 is arranged on the second system side, and when the change information matching / non-identifying step 26 determines that the contents of the change information pair match, the one set is configured. The above-described specific information is reproduced by assembling the plurality of post-division specific information as remaining information to be performed in the predetermined order.

  <Embodiment of the Invention>

  Next, an embodiment of the present invention will be described.

  FIG. 3 shows an information transmission system according to an embodiment of the present invention. The information transmission system 200 includes a first node 201 composed of a computer using a multi-core processor, and a second node provided with an NTP server 211 for synchronizing the first node 201 with a time such as the correct date and time. The node 202 is configured. In the first node 201, a CPU 230 having four cores from the zeroth core 220 to the third core 223 is arranged, and there are two environments, an environment 241 with an OS and a bare metal environment 242 without an OS. Realized. In the bare metal environment 242, the first function 251, the second function 252 and the third function 253 are executed. In the OS presence environment 241, the fourth function 254 is executed.

  A clock 261 and an NTP client 262 exist in the OS environment 241. The clock 261 is synchronized with the correct date and time by the time synchronization protocol 263 negotiated between the NTP server 211 and the NTP client 262 in the second node 202. Therefore, the fourth function 254 executed in the OS environment 241 is controlled in a state corrected by the clock 261 with the correct date and time.

  Between the OS presence environment 241 and the bare metal environment 242, a shared memory 271 that is accessible in common from both environments is provided. In addition, the OS presence environment 241 and the bare metal environment 242 include a synchronization mechanism 274 for transmitting time information 273 from the OS presence environment 241 to the bare metal environment 242 using the shared memory 271. As a result, for example, the first function 251 and the second function 252 can perform processing using the clock information 273 synchronized with the OS presence environment 241 under the bare metal environment 242.

  FIG. 4 specifically shows the main part of the information transmission system according to the present embodiment, centering on the synchronization mechanism. 4, the same parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The synchronization mechanism 274 includes an OS presence environment side synchronization mechanism 274A existing on the OS presence environment 241 side, and a bare metal environment side synchronization mechanism 274B existing on the bare metal environment 242 side. Among these, the OS-side environment-side synchronization mechanism 274A includes a time information reading unit 282 that reads the time information 281 from the clock 261. The time information reading unit 282 reads the time information 281 from the clock 261 at a cycle of once per second, for example, according to the reading cycle 284 given from the reading cycle setting unit 283.

  The reading cycle set by the reading cycle setting unit 283 is set in advance in response to a request from the bare metal environment 242 side. Therefore, in order to realize the first function 251 and the second function 252 shown in FIG. 3, even if the synchronization of the time information 281 is required at a cycle of once per second, When the synchronization of the time information 281 is required at a cycle of once every 0.1 second in order to newly realize the function, the reading cycle is changed accordingly.

  The OS-side environment-side synchronization mechanism 274A is provided with a first time information buffer 286 and a second time information buffer 287 on the output side of the time information reading unit 282. The time information reading unit 282 stores, in the first time information buffer 286, first time information 288 constituting the first half portion of the bit string constituting the read time information 281. Further, the time information reading unit 282 stores the second time information 289 constituting the second half part of the bit string constituting the read time information 281 in the second time information buffer 287.

  On the output side of the first time information buffer 286 and the second time information buffer 287, there is arranged a sequential writing unit 291 that writes each data with four steps as one set and periodically repeats this. . The sequential writing unit 291 is also connected to a counter 293 that outputs a count value 292 with these four steps as one cycle. Of these, two steps are the count value 292 output from the counter 293, and the remaining two steps are the first time information 288 and the second time information 289.

  Note that the count value 292 of the counter 293 may change in a time shorter than the time required for four steps. That is, a device other than the counter 293 can be used as long as a different value is output for each set.

The output data 295 output from the sequential writing unit 291 is written into the ring buffer 296 that constitutes the shared memory 271. The ring buffer 296 is composed of a first area R ₁ to a fourth area R ₄ , and writes the output data 295 to corresponding locations in order one step at a time. Output data 295 (WRITE ₁ ) output from the sequential writing unit 291 in the first step is written in the first region R ₁ , and the sequential writing unit in the second step is written in the second region R _2. Output data 295 (WRITE ₂ ) output from 291 is written. Similarly, output data 295 (WRITE ₃ ) output from the sequential writing unit 291 in the third step is written in the third region R ₃ , and sequential writing is performed in the fourth region R ₄ in the fourth step. Output data 295 (WRITE ₄ ) output from the loading unit 291 is written. The next step returns to the first step again, and the output data 295 (WRITE ₁ ) output from the sequential writing unit 291 is overwritten in the first region R ₁ . Similarly, the count value 292 for two steps and the first time information 288 and the second time information 289 are cyclically written in the ring buffer 296 sequentially for one step.

  FIG. 5 shows an example of a change with time of output data output from the sequential writing unit of the present embodiment. Here, each step of the output data 295, the type of the output data 295 at each step, and the contents of the output data 295 are shown along with changes in time. This will be described with reference to FIG.

In the first step, which is the earliest in time shown in this figure, the output data 295 is “WRITE ₁ ”, and the content is “count value 0001” as the count value 292 output from the counter 293. is there. In the next second step, the output data 295 is “WRITE ₂ ”, and the content is “1234 seconds” as the first time information 288 output from the first time information buffer 286. This “1234 seconds” is the first time information 288 constituting the first half of the bit string read by the time information reading unit 282 from the clock 261 as the time information 281. “1234 seconds” means the hour, minute, and second at the moment of reading from the clock 261.

In the next third step, the output data 295 is “WRITE ₃ ”, and the content is “5678 micro (μ) seconds” as the second time information 289 output from the second time information buffer 287. This “5678 microseconds” is the second time information 289 that constitutes the second half of the bit string read by the time information reading unit 282 from the clock 261 as the time information 281. “5678 microseconds” represents a fraction of a second from the clock 261 as a microsecond.

In the next fourth step, the output data 295 is “WRITE ₄ ”, and the content is “count value 0001” as the count value 292 output by the counter 293. This is a value output by the counter 293 as the count value 292 as a common value in the first step and the fourth step, and the time information reading unit 282 reads the time information from the timepiece 261. This coincides with the timing of reading 281.

  FIG. 6 shows an example of the count value of the counter and time information at the time point according to the present embodiment. This will be described with reference to FIGS.

The example shown in FIG. 6 shows the content of the output data 295 output from the sequential writing unit 291 in the first to fourth steps described immediately before in FIG. That is, the count value of the counter 293 at that time when the time information reading unit 282 reads the time information 281 from the clock 261 indicates “count value 0001”, and the time information 281 at this time is “1234 seconds 5678 microseconds”. It is. The reason why “1234 seconds 5678 microseconds” is divided into “1234 seconds” and “5678 microseconds” in the second step and the third step is because the number of bits written to the ring buffer 296 at a time is limited. is there.

  Therefore, for example, there is time information of “09:09:08, 09/25/2011, 10:09:08, 7654432 microseconds”, and the information is transmitted to the shared memory 271 four times from the OS presence environment 241 to the bare metal environment 242. Suppose that it is necessary to write time information divided into two. In this case, instead of the output data 295 output as one cycle from the sequential writing unit 291 in the first step to the fourth step, which is currently described, 1 in the first step to the sixth step. The output data 295 of the cycle is output.

  In the example shown in FIG. 5, the count value 292 of the counter 293 changes as “count value 0001”, “count value 0002”,... For each cycle of the first step to the fourth step. When the first to sixth steps constitute one cycle, the count value 292 sequentially changes in this cycle. In addition, when the first step to the fourth step constitute one cycle, the count values of the first step and the fourth step among them indicate “count value 0001”. When the first step to the sixth step constitute one cycle, the count values of the first step and the sixth step indicate “count value 0001”, and the second step between the first step and the sixth step In the fifth step, the time information is divided and output.

  In the bare metal environment side synchronization mechanism 274 </ b> B constituting the synchronization mechanism 274 on the bare metal environment 242 side, the sequential reading unit 301 reads data from the ring buffer 296. However, the bare metal environment 242 is not the same environment as the OS presence environment 241 and does not have a unified clock. The sequential reading unit 301 generates time information based on a request for processing by a functional unit such as the first function 251 shown in FIG. The data is read out with. However, the reading cycle for the ring buffer 296 of the sequential reading unit 301 is read at a cycle shorter than the reading cycle for the time information 281 of the time information reading unit 282 according to the setting of the reading cycle setting unit 283. Yes.

The sequential reading unit 301 first reads the first count information 303 from the first region R ₁ of the ring buffer 296 according to the instruction of the first count information acquisition unit 302. Next, the sequential reading unit 301 reads the first time information 305 from the _second region R ₂ of the ring buffer 296 according to the instruction of the first time information acquisition unit 304. Next, the sequential reading unit 301 reads the second time information 307 from the _third region R ₃ of the ring buffer 296 according to the instruction of the second time information acquisition unit 306. Finally, the sequential reading unit 301 reads the second count information 309 from the _fourth region R ₄ of the ring buffer 296 according to the instruction of the second count information acquisition unit 308.

Sequential reading unit 301, or more After performing the reading of data from the first region R ₁ ~ fourth region R ₄ described similarly from the first region R ₁ ~ fourth region R ₄ also thereafter Data reading is repeated.

  The first count information 303 acquired by the first count information acquisition unit 302 and the second count information 309 acquired by the second count information acquisition unit 308 are input to the comparison unit 311 and are used as their values. The “count value XXX” and the “count value XXX” are compared. When the “count value xxx” is equal to the “count value XXX”, an enable signal 312 is supplied to the time information assembling unit 313.

  The time information assembly unit 313 receives the first time information 305 from the first time information acquisition unit 304 and receives the second time information 307 from the second time information acquisition unit 306. When the enable signal 312 is supplied from the comparison unit 311, the time information assembling unit 313 connects the first time information 305 and the second time information 307 at the timing to obtain the time information 314. This time information 314 is used as information representing the current time in the bare metal environment 242.

  When the enable signal 312 is not supplied from the comparison unit 311, that is, in a disabled state, the time information assembling unit 313 discards the input first time information 305 and second time information 307, and time information It is not output as 314. The reason for this will be described next.

FIG. 7 shows an example when the time information is correctly assembled by the time information assembling unit of the information transmission system. In the case of this example, as described above, the count value written in the _first area R ₁ of the ring buffer 296 and the count value written in the fourth area R ₄ are both “count value 0001”. ,Match. Therefore, “1234 seconds 5678 μs” which is time information assembled from the first time information 305 and the second time information 307 read from the second region R ₂ and the third region R ₃ of the ring buffer 296. "Is time information that matches in both the OS presence environment 241 and the bare metal environment 242 without OS.

FIG. 8 shows an example when the time information is not correctly assembled by the time information assembling unit of the information transmission system, that is, when the time information is discarded. In this example, the count value written in the _first area R ₁ of the ring buffer 296 is “count value 0002”, which is one cycle later than in the case of FIG. Similarly, the first time information written in ₂ is “1235 seconds”, which is one cycle later than the case of FIG. 7 (see FIG. 5). Other than this, the state is one cycle before as in FIG.

As a result, in the example shown in FIG. 8, the count value written in the _first area R ₁ and the count value written in the fourth area R ₄ are inconsistent. Therefore, the time information assembling unit 313 shown in FIG. 4 discards the time information “1235 seconds 5678 μsec” that would have been assembled by the first time information 305 and the second time information 307 as incorrect time information. In this case, the bare metal environment side synchronization mechanism 274B shown in FIG. 4 repeats the comparison processing by the comparison unit 311. When the comparison result matches and the enable signal 312 is supplied to the time information assembly unit 313, the time of the bare metal environment 242 is obtained. Information 314 is obtained.

  As described above, the OS-side environment-side synchronization mechanism 274A in FIG. 4 uses the various function units such as the time information reading unit 282 to read the time information 281 from the clock 261 and write it to the shared memory 271, and the bare metal environment side of the bare metal environment 242 It has been described that the synchronization mechanism 274B obtains the time information 314 by reading it. The above processing is performed on the OS presence environment 241 side and the bare metal environment 242 side by, for example, a virtual machine using a corresponding CPU core among the 0th core 220 to the third core 223 shown in FIG. Can also be realized.

  FIG. 9 shows the state of processing in an environment with an OS according to the present embodiment. This will be described with reference to FIGS. 3 and 4.

  On the OS presence environment 241 side, a time information reading device is set with time accuracy required by the bare metal environment 242 side. For example, a control unit (not shown) realized by the 0th core 220 monitors whether or not the time reading time comes (step S401). When the time reading time arrives (Y), the control unit reads the time information 281 from the clock 261 and acquires and holds the count value at that time from the counter 293 (step S402).

Next, the control unit overwrites the held count value in the first area R ₁ of the shared memory 271 (step S403). Next, the control unit overwrites the first time information of the time information read in step S402 in the second region R ₂ of the shared memory 271 (step S404). The further control unit overwrites the second time information among the time information read in step S402 in the third region R ₃ in the shared memory 271 (step S405). Finally the control unit to overwrite the count value of the counter 293 which is held in step S402 to the fourth region R ₄ (step S406).

  Thereafter, the control unit returns to the process of step S401 (return). That is, on the OS presence environment 241 side, at least the data writing operation to the shared memory 271 is repeated in the time zone in which the bare metal environment 242 side requires time information.

  FIG. 10 shows a state of processing in a bare metal environment without an OS in the present embodiment. This will be described with reference to FIGS. 3 and 4.

On the bare metal environment 242 side, as an example, when the first function 251 requires the same time information as the OS presence environment 241 side (step S421: Y), for example, a control unit (not shown) realized by the first core 221 is Then, the count value as the first count information is read from the first area R ₁ of the shared memory 271 (step S422). Subsequently, the control unit reads the first time information from the _second area R ₂ of the shared memory 271 (step S423), and reads the second time information from the _third area R ₃ of the shared memory 271 (step S424). ).

Thereafter, the control unit reads the count value as the second count information from the _fourth area R ₄ of the shared memory 271 (step S425), and does this match the first count information read in step S422? (Step S426). If both count values match (Y), current time information is created from the first time information and the second time information (step S427). And it returns to step S421 (return) and prepares for the process of the next time information.

  On the other hand, if the contents of the first count information and the second count information do not match in step S426 (N), assembling the first time information and the second time information as they are, The contents of the time will be mixed. Therefore, the process returns to step S422, and the process up to step S425 is performed again on the shared memory 271. In this way, the access to the shared memory 271 is repeated after a while until the contents of the first count information and the second count information match at step S426. The bare metal environment 242 side acquires it.

  According to the present embodiment described above, the time information of the OS-provided environment 241 can be obtained with high accuracy only by the existence of the shared memory 271 that can be accessed from the two operating environments 241 and the bare metal environment 242. A bare metal environment 242 can be obtained. Therefore, it is possible to eliminate the occurrence of a problem between the OS presence environment 241 and the bare metal environment 242 due to time information mismatch.

  Moreover, in this embodiment, the clock 261 arranged on the OS environment 241 side can correct the time by the NTP server 211. Therefore, even on the side of the bare metal environment 242 where a clock cannot be arranged, an accurate time that matches the external time can be obtained via the OS presence environment 241. That is, when the first function 251 and the second function 252 shown in FIG. 3 require time, the time synchronized with the outside can be used. Moreover, since the time information is divided into a plurality of pieces and stored in the shared memory 271, the number of bits of data constituting the time information is not limited.

  Furthermore, in this embodiment, the reading cycle setting unit 283 shown in FIG. 4 can set the cycle for writing the time information 281 of the clock 261 in the shared memory 271. As a result, the OS presence environment 241 side can access the shared memory 271 in accordance with the accuracy required by various functions such as the first function 251 on the bare metal environment 242 side, which is unnecessary due to excessive accuracy. It is possible to prevent a load from being applied.

  Furthermore, in the present embodiment, the synchronization process between the OS presence environment 241 and the bare metal environment 242 is performed by a periodic process. Therefore, unlike the first modification in which the OS environment kernel described below is modified, time information synchronized with an OS-free environment can be provided without modifying the kernel.

  <First deformability of invention>

  FIG. 11 shows an information transmission system according to a first modification of the present invention. 11, the same parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In the information transmission system 200A of the first modified example, the synchronization accuracy of the timepiece 261 is improved compared to the previous embodiment. That is, in the information transmission system 200A, the relationship between the clock 261 and the NTP server 211 is the same as that of the information transmission system 200, but the processing for synchronizing the time information of the clock 261 with the shared memory 271 is different.

  In this modified example, the synchronization mechanism 274 by the process used in FIG. 3 is not adopted, and the clock synchronization processing 501 is implemented in the OS (kernel) of the OS environment 241. The OS can take the shortest periodic processing interval in units of ticks.

  Here, the unit of tick will be briefly explained. The kernel as software periodically receives an interrupt (timer interrupt) from the hardware. A relative timer as software is realized with this timer interrupt as the shortest cycle. For example, taking Linux (registered trademark) as an example, the relative timer is incremented in 10 milliseconds or 1 millisecond depending on the version. This is a unit called ticks. Depending on the increment of the relative timer, the time to be measured is not accurately determined. Therefore, correction is performed by an external clock such as the NTP server 211.

  In the information transmission system 200A of the first modified example as described above, the clock synchronization process 501 is performed in which the OS clock 261 is read in the kernel at the same timing as the OS tick process and the time information 502 is written in the shared memory 271. To do. As a result, the clock on the shared memory 271 used in both the OS clock 261 and the bare metal environment 242 where the OS does not exist can be synchronized at the shortest synchronization interval, and the accuracy of synchronization can be improved in the information transmission system of the previous embodiment. 200 can be improved.

  As described above, according to the information transmission system 200A of the first modified example, by performing synchronization processing in units of ticks inside the kernel, the accuracy is synchronized with the shortest synchronization interval that cannot be realized by implementation in the process. High time can be provided in an environment without an OS.

  <Second deformability of invention>

  FIG. 12 shows an information transmission system according to a second modification of the present invention. In FIG. 12, the same parts as those in FIG.

  In the information transmission system 200B according to the second modification, the clock 261 existing in the OS presence environment 241 is mounted on the shared memory 271B that can be directly referred to from the bare metal environment 242 without the OS. For this purpose, it is necessary to modify the clock function of the existing kernel in the OS presence environment 241.

  However, by realizing the clock 601 realized in the OS environment on the shared memory 271B, the time information of the clock in the environment in which the OS exists can be referred to and used from the bare metal environment 242 without the OS. Moreover, in the OS presence environment 241, the NTP client 262 can synchronize the clock 601 on the shared memory 271B with the NTP server 211.

  Further, the information transmission system 200B according to the second modification does not require the synchronization mechanism 274 for transmitting the time information 273 from the OS presence environment 241 to the bare metal environment 242 shown in FIG. For this reason, for example, the first function 251 and the second function 252 can be used by referring to the clock information with the same accuracy as the OS presence environment 241 under the bare metal environment 242.

  In the embodiment and each modification described above, the case where the bare metal environment 242 obtains the time information of the OS presence environment 241 has been described. However, other information is matched with the OS presence environment 241 in the bare metal environment 242. The present invention can be similarly applied to the acquisition.

  Further, in the embodiment and each modified example, the case where one system acquires information of the same content from the other system has been described using the OS presence environment 241 and the bare metal environment 242 as examples, but the present invention is not limited thereto. is not. For example, it is also possible to acquire data with the technical idea described above via a shared memory that can be commonly accessed by one of two systems having an OS.

  Further, in the embodiment, information is transmitted from the OS presence environment 241 to the bare metal environment 242 via the ring buffer 296 constituting the shared memory 271. However, the address may be controlled using a memory having a normal configuration. Is possible.

  Furthermore, in the embodiment, when the time information 273 is written to the shared memory 271, the count value 292 of the counter 293 is read and written to the shared memory 271, so that the bare metal environment 242 side compares the count value 293 and compares the time information 273. Although it was checked whether was transmitted correctly, it is not restricted to this. Instead of the count value 292 of the counter 293, change information whose contents change each time information is transmitted can be used. For example, change information that sequentially changes into four, A, B, C, and D, may be prepared, and these may be cyclically transmitted from the OS presence environment 241 to the bare metal environment 242.

  In the embodiment and the modification, the clock 261 is synchronized with an external clock using the NTP server 211. However, the same correction of the time may be performed using an external clock other than the NTP server 211. Of course.

  Some or all of the embodiments described above are described as in the following supplementary notes, but are not limited to the following descriptions.

(Appendix 1)
Specific information as information that exists in the first system as the transmitting side and whose contents may change over time, and that may be transmitted to the second system as the receiving side. Specific information input means for repeatedly inputting in a first period with time on the system side of 1;
Change information input means for inputting change information as information whose contents change each time the specific information input means inputs the specific information on the first system side at the input timing of the specific information;
A shared memory that can be accessed in common by the first system and the second system;
Specific information dividing means for dividing the specific information input by the specific information input means on the first system side into a plurality of divided specific information predetermined as an amount to be written once in the shared memory;
The change information input by the change information input means is written once, and then the plurality of post-division specific information divided by the change information input means is written in a predetermined order, and then the same content as the change information Writing the change information once more, and the shared memory writing means for ending the writing for one set to the shared memory;
One set of the latest information of the change information and the plurality of post-division specific information from the shared memory in an arbitrary second cycle that is arranged on the second system side and shorter than the first cycle. A shared memory reading means for reading;
Change information matching presence / absence determining means that is arranged on the second system side and that determines the presence or absence of matching between the contents of the pair of change information read by the shared memory reading means;
After the plurality of divisions as the remaining information constituting the one set when it is determined that the contents of the pair of change information are matched by the change information match presence / absence discriminating means arranged on the second system side An information transmission system comprising: specific information reproducing means for assembling specific information in the predetermined order and reproducing the specific information.

(Appendix 2)
Arranged on the second system side, and when the change information matching presence / absence determining means determines that the contents of the pair of change information do not match, the shared memory reading means determines the change information and The information transmission system according to claim 1, further comprising: a reading repetition unit that repeats an operation of reading one set of the latest pieces of the plurality of divided specific information.

(Appendix 3)
The first system is a system with an OS environment in an apparatus using a multi-core processor, the second system is a system with a bare metal environment without an OS, and the specific information is arranged in the first system. The information transmission system according to appendix 1 or appendix 2, wherein the information is time information output by a timepiece.

(Appendix 4)
The information transmission system according to appendix 3, wherein the OS in the environment with OS manages time information in units of ticks with a timer interrupt as the shortest cycle.

(Appendix 5)
The information transmission system according to claim 3, wherein the clock is mounted on the shared memory, and the second system can be used with reference to time information of the clock.

(Appendix 6)
2. The information transmission system according to claim 1, wherein the change information is a counter that is arranged in the first system and outputs a change of a count value as time elapses.

(Appendix 7)
The information transmission system according to supplementary note 3, wherein the specific information dividing unit divides the time information constituting the specific information into two pieces of post-division specific information.

(Appendix 8)
6. The information transmission system according to appendix 3 or appendix 5, wherein the clock arranged in the first system has the time information corrected by an NTP client that communicates with an NTP (Network Time Protocol) server.

(Appendix 9)
Specific information as information that exists in the first system as the transmitting side and whose contents may change over time, and that may be transmitted to the second system as the receiving side. A specific information input step in which time is repeatedly input in the first cycle with time on the system side of 1;
A change information input step of inputting change information as information whose contents change each time the specific information is input in the specific information input step on the first system side at the input timing of the specific information;
The specific information input in the specific information input step on the first system side is divided once into the shared memory as a memory that can be accessed in common by the first system and the second system. A specific information dividing step of dividing into a plurality of post-division specific information predetermined as a writing amount;
The change information input in the change information input step is written once, and then the plurality of post-division specific information divided in the change information input step is written in a predetermined order, and then the same content as the change information Writing the change information once more, and writing to the shared memory for one set is completed.
One set of the latest information of the change information and the plurality of post-division specific information from the shared memory in an arbitrary second cycle that is arranged on the second system side and shorter than the first cycle. A shared memory read step for reading; and
A change information matching presence / absence determination step that is arranged on the second system side and determines whether or not there is a match between the contents of the pair of change information read by the shared memory reading step;
After the plurality of divisions as the remaining information that constitutes the one set when it is determined that the contents of the pair of change information match in the change information match presence / absence determining step disposed on the second system side And a specific information reproducing step for reproducing the specific information by assembling the specific information in the predetermined order.

(Appendix 10)
When it is determined that the content of the pair of change information is not matched by the change information match presence / absence determining step, the shared memory reading step is used until the match is determined to be determined. 10. The information transmission method according to claim 9, further comprising a read repetition step of repeating an operation of reading one set of change information and the plurality of pieces of specific information after division.

(Appendix 11)
The first system is a system with an OS environment in an apparatus using a multi-core processor, the second system is a system with a bare metal environment without an OS, and the specific information is arranged in the first system. The information transmission method according to appendix 10 or appendix 11, wherein the information is time information output by a clock.

  As described above, the present invention is not limited to a device that simply uses a multi-core processor, but information that exists in the first system as the transmission side and whose contents may change over time. The present invention can be widely applied to various devices and systems that transmit to the second system as the receiving side.

10, 200, 200A, 200B Information transmission system 11 Specific information input means 12 Change information input means 13, 271, 271B Shared memory 14 Specific information dividing means 15 Shared memory writing means 16 Shared memory reading means 17 Change information matching presence / absence determining means 18 specific information reproduction means 20 information transmission method 21 specific information input step 22 change information input step 23 specific information division step 24 shared memory write step 25 shared memory read step 26 change information match presence / absence determination step 27 specific information reproduction step 201, 201A 201B 1st node 202 2nd node 220 0th core 221 1st core 222 2nd core 223 3rd core 230 CPU
211 NTP server 241 OS presence environment 242 Bare metal environment (no OS) 261, 601 Clock 262 NTP client 273 Clock information 274 Synchronization mechanism 281, 314, 502 Time information 282 Time information reading unit 283 Reading cycle setting unit 286 First time Information buffer 287 Second time information buffer 291 Sequential writing unit 293 Counter 296 Ring buffer 301 Sequential reading unit 302 First count information acquisition unit 304 First time information acquisition unit 306 Second time information acquisition unit 308 Second Count information acquisition unit 311 comparison unit 313 time information assembly unit 501 clock synchronization processing

Claims (9)

Specific information as information that exists in the first system as the transmitting side and whose contents may change over time, and that may be transmitted to the second system as the receiving side. Specific information input means for repeatedly inputting in a first period with time on the system side of 1;
Change information input means for inputting change information as information whose contents change each time the specific information input means inputs the specific information on the first system side at the input timing of the specific information;
A shared memory that can be accessed in common by the first system and the second system;
Specific information dividing means for dividing the specific information input by the specific information input means on the first system side into a plurality of divided specific information predetermined as an amount to be written once in the shared memory;
The change information input by the change information input means is written once, and then the plurality of post-division specific information divided by the change information input means is written in a predetermined order, and then the same content as the change information Writing the change information once more, and the shared memory writing means for ending the writing for one set to the shared memory;
One set of the latest information of the change information and the plurality of post-division specific information from the shared memory in an arbitrary second cycle that is arranged on the second system side and shorter than the first cycle. A shared memory reading means for reading;
Change information matching presence / absence determining means that is arranged on the second system side and that determines the presence or absence of matching between the contents of the pair of change information read by the shared memory reading means;
After the plurality of divisions as the remaining information constituting the one set when it is determined that the contents of the pair of change information are matched by the change information match presence / absence discriminating means arranged on the second system side An information transmission system comprising: specific information reproducing means for assembling specific information in the predetermined order and reproducing the specific information.   Arranged on the second system side, and when the change information matching presence / absence determining means determines that the contents of the pair of change information do not match, the shared memory reading means determines the change information and The information transmission system according to claim 1, further comprising a reading repetition unit that repeats an operation of reading one set of the latest pieces of the plurality of divided specific information.   The first system is a system with an OS environment in an apparatus using a multi-core processor, the second system is a system with a bare metal environment without an OS, and the specific information is arranged in the first system. 3. The information transmission system according to claim 1, wherein the information is time information output from a clock.   4. The information transmission system according to claim 3, wherein the OS in the environment with the OS manages time information in units of ticks with a timer interrupt as the shortest cycle. 2. The information transmission system according to claim 1, wherein the change information is a counter that is arranged in the first system and outputs a change of a count value as time elapses. The information transmission system according to claim 3, wherein the specific information dividing unit divides the time information constituting the specific information into two pieces of divided specific information. 4. The information transmission system according to claim 3, wherein the time information of the timepiece arranged in the first system is corrected by an NTP client communicating with an NTP (Network Time Protocol) server. Specific information as information that exists in the first system as the transmitting side and whose contents may change over time, and that may be transmitted to the second system as the receiving side. A specific information input step in which time is repeatedly input in the first cycle with time on the system side of 1;
  A change information input step of inputting change information as information whose contents change each time the specific information is input in the specific information input step on the first system side at the input timing of the specific information;
  The specific information input in the specific information input step on the first system side is written once in a shared memory as a memory that can be accessed in common by the first system and the second system. A specific information dividing step for dividing the information into a plurality of pieces of post-division specific information determined in advance,
  The change information input in the change information input step is written once, and then the plurality of post-division specific information divided in the change information input step is written in a predetermined order, and then the same content as the change information Writing the change information once more, and writing to the shared memory for one set is completed.
  One set of the latest information of the change information and the plurality of post-division specific information from the shared memory in an arbitrary second cycle that is arranged on the second system side and shorter than the first cycle. A shared memory read step for reading; and
  A change information matching presence / absence determination step that is arranged on the second system side and determines whether or not there is a match between the contents of the pair of change information read by the shared memory reading step;
  After the plurality of divisions as the remaining information that constitutes the one set when it is determined that the contents of the pair of change information match in the change information match presence / absence determining step disposed on the second system side A specific information reproducing step of assembling specific information in the predetermined order and reproducing the specific information
An information transmission method comprising: When it is determined that the content of the pair of change information is not matched by the change information match presence / absence determining step, the shared memory reading step is used until the match is determined to be determined. 9. The information transmission method according to claim 8, further comprising a reading repetition step of repeating an operation of reading one set of change information and the plurality of pieces of specific information after division.

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