Abstract:
In order to provide a mobile phone terminal which is capable, when changing over between an application program which is implemented as standard and a downloaded program which is not implemented as standard which have been started together, of restarting programs in an order which the user anticipate. An execution unit performs any of the procedures of execution, temporary suspension, and termination of programs by storing, in an execution state storage unit, information for programs which consist of static applets and downloaded applets. A management unit, when the activation of a static applet is requested in a situation that a downloaded applet is stored in the execution state storage unit as a program which is being executed, along with storing the downloaded applet in the execution state storage unit as being in a temporarily suspended state, and generating a dummy applet, also stores the dummy applet in the execution state storage unit as being in a temporarily suspended state, and next starts the static applet with the program execution unit.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a mobile phone terminal which controls the execution of multiple programs, to a program management method and to a computer program which performs it. 
     Priority is claimed on Japanese Patent Application No. 2004-315697, filed Oct. 29, 2004, the content of which is incorporated herein by reference. 
     2. Description of Related Art 
     With prior art technique, in a single task operating system, in order to perform multi task like operation in which multiple programs are processed at the same time, thread history for application programs which are operating is stored in the memory of an OS (Operating System). Whether or not there is an application program which is requesting operation for the next is monitored by the operating system with a timer or the like. If there is an application program which is requesting operation for the next, that application program is added to the application program thread history, and the operating system shifts its operation to that application program. When shifting in order again to operate the application program which was executing before, a system has been practiced in which the processes are shifted one at a time by reading in order from those which have been stored first in the stored thread history (for example refer to Japanese Unexamined Patent Application, First Publication No. H06-44084). 
     The technique described in Japanese Unexamined Patent Application, First Publication No. H06-44084 is an example of operation upon a personal computer, upon which more processing capability is available than a mobile phone terminal, and moreover in which the ratio of occasion of unexpected interruptions of operation, for example due to incoming calls, is low. 
     With a prior art technique for a mobile phone terminal, even though activation requests for multiple application programs are issued by the timer or the like, it has not been possible to start processing the next application program without finishing the processes one at a time. Furthermore, it has also not been possible to maintain multiple states of application programs which were executed before in storage. Due to this, with the mobile phone shown in the prior art technique of references #2 (Japanese Unexamined Patent Application, First Publication No. 2003-319020), operation has been performed by individual monitoring when an event such as incoming calls or the like occurs, referring to the type or the state of the application program. 
     With a mobile phone terminal, for application programs which are implemented by the maker of the mobile phone, operation is performed so as to operate in a multi-tasking manner with a small memory capacity, by implementing a different technique from those disclosed in Patent References #1 and #2, in order to comply with a small memory capacity. 
     Now, with recent mobile phone terminals, apart from the application programs which are implemented as a standard (or originally installed) by the mobile phone terminal maker, there are programs such as games and the like which the user downloads and uses by operating the mobile phone terminal via a network (hereinafter termed “downloaded programs”). Such downloaded programs are almost always built according to a common specification, in order to act on any mobile phone terminal operating system from any maker. 
     However, these downloaded programs are not designed based upon the assumption that they process according to the multi-tasking operation which is implemented by the individual mobile phone maker. Due to this, if a downloaded program and a program which is implemented as a standard are activated together upon the operating system, when shifting between these programs, there is the problem that the program which is implemented as a standard undesirably performs restart operation which is not anticipated by the user. 
     SUMMARY OF THE INVENTION 
     The present invention has been conceived in order to solve the above described problem, and it takes as its objective to provide a mobile phone terminal, a program management method, and a computer program, which are capable, when shifting programs, of restarting programs according to the order which the user anticipates, even in a situation in which an application program according to a standard implementation and a downloaded program which is not implemented in a standard manner have been activated together. 
     According to the present invention as specified below, it becomes possible to provide a mobile phone terminal, a program management method, and a computer program, which, when shifting programs, are capable of restarting programs according to the order which the user anticipates, even in a situation in which an application program according to a standard implementation and a downloaded program which is not implemented in a standard manner have been activated together. 
     A first aspect of the present invention is a mobile phone terminal capable of executing a managed program and an unmanaged program, comprising: a program execution unit which performs any of procedures of activation, suspension, and termination of the managed program and the unmanaged program which are stored in an execution state storage unit; and a program management unit which, when execution of the managed program is requested while the unmanaged program is stored in the execution state storage unit as a program which is being activated, along with storing the unmanaged program in the program execution unit as being in a suspended state in the execution state storage unit, generating a substitutional program which is a dummy program and corresponds to the unmanaged program, and storing the substitutional program in the execution state storage unit as being in a suspended state, after that, activates the managed program in the program execution unit. 
     A second aspect of the present invention is a mobile phone terminal according to the first aspect, further comprising: a restart information storage unit which, in a situation in which activation of another program is requested while the managed program in the execution state storage unit is being activated, when the managed program is terminated and the another program is activated, along with terminating the managed program, stores restart information for subsequently restarting the managed program, and wherein the program management unit, when putting into activated state the substitutional program which has been in suspended state, refers to the restart information storage unit and, if restart information is stored, restarts the managed program in the program execution unit corresponding to the restart information. 
     A third aspect of the present invention is a mobile phone terminal according to the second aspect, wherein the program management unit, when it has referred to the restart information storage unit due to activation of the substitutional program which has been in suspended state, if corresponding restart information is not stored, then terminates the substitutional program in the program execution unit. 
     A fourth aspect of the present invention is a mobile phone terminal according to the first aspect, wherein the managed program is a program which is originally installed and managed by the program management unit, and the unmanaged program is a program which is additionally installed by an operation of a user. 
     A fifth aspect of the present invention is a mobile phone terminal according to the first aspect, wherein the program management unit, if the substitutional program is forcibly terminated by the program execution unit, requests the program execution unit to delete the provisional program which is stored in the execution state storage unit. 
     A sixth aspect of the present invention is a mobile phone terminal according to the second aspect, wherein the mobile phone terminal is further capable of activating an idle screen program which displays an idle screen in a state in which communication is being awaited, and the program management unit, when activating another program in a state in which the idle screen program is stored in the execution state storage unit as a program which is being activated, along with storing in the restart information storage unit restart information for restarting the idle screen program which is being activated, also starts the another program in the program execution unit after terminating the idle screen program. 
     A seventh aspect of the present invention is a program management method which is applied to a mobile phone terminal which includes: an execution state storage unit; and a program execution unit which performs any of procedures of execution, suspension, and termination of programs by storing a managed program and an unmanaged program in the execution state storage unit; the program management method comprising: a step of, when activation of a managed program is requested in a state in which an unmanaged program is stored in the execution state storage unit as a program which is being activated, along with storing the program which is in the program execution unit as being in a suspended state in the execution state storage unit, also generating a substitutional program; a step of storing the substitutional program in the execution state storage unit as being in a suspended state; and a step of, after having put the substitutional program into suspended state, starting the managed program in the program execution unit. 
     An eighth aspect of the present invention is a program management method according to the seventh aspect, further including: a step of, in a situation in which activation of another program is requested while the managed program in the execution state storage unit is being activated, when the managed program is terminated and the another program is activated, along with terminating the managed program, storing restart information for subsequently restarting the managed program; a step of, when putting into activated state the substitutional program which has been in suspended state, judging whether or not the restart information is stored, and restarting the managed program in the program execution unit corresponding to the restart information if the restart information is stored. 
     A ninth aspect of the present invention is a program management method according to the eighth aspect, further including: a step of, when the substitutional program which has been in suspended state is activated, judging whether or not restart information is stored, terminating the substitutional program in the program execution unit if corresponding restart information is not stored. 
     A tenth aspect of the present invention is a program management method according to the seventh aspect, wherein the managed program is a program which is originally installed and managed, and the unmanaged program is a program which is additionally installed by an operation of a user. 
     An eleventh aspect of the present invention is a program management method according to the seventh aspect, further including: a step of, if the substitutional program is forcibly terminated by the program execution unit, requesting the program execution unit to delete the provisional program which is stored in the execution state storage unit. 
     A twelfth aspect of the present invention is a program management method according to the seventh aspect, wherein the mobile phone terminal is further capable of activating an idle screen program which displays an idle screen in a state in which communication is being awaited, further including: a step of, when activating another program in a state in which the idle screen program is stored in the execution state storage unit as a program which is being activated, along with storing restart information for restarting the idle screen program which is being activated, also starting the another program in the program execution unit after terminating the idle screen program. 
     A thirteenth aspect of the present invention is a computer program product in a computer readable medium of a computer included in a mobile phone terminal which has: an execution state storage unit; and a program execution unit which performs any of procedures of execution, suspension, and termination of programs by storing a managed program and an unmanaged program in the execution state storage unit, the computer program including: first instructions for, when the execution of the managed program is requested in a situation in which the unmanaged program is stored in the execution state storage unit as a program which is being activated, along with making the program execution unit to store the program as being in a suspended state in the execution state storage unit, generating a substitutional program; second instructions for storing the substitutional program in the execution state storage unit as being in a suspended state; and third instructions for, after having put the substitutional program into a suspended state, starting the managed program in the program execution unit. 
     A fourteenth aspect of the present invention is a computer program product according to the thirteenth aspect, further including: fourth instructions for, in a situation in which activation of another program is requested while the managed program in the execution state storage unit is being activated, when the managed program is terminated and the another program is activated, along with terminating the managed program, storing restart information for subsequently restarting the managed program; fifth instructions for, when putting into activated state the substitutional program which has been in suspended state, judging whether or not the restart information is stored, and restarting the managed program in the program execution unit corresponding to the restart information if the restart information is stored. 
     A fifteenth aspect of the present invention is a computer program product according to the fourteenth aspect, further including: seventh instructions for, when the substitutional program which has been in suspended state is activated, judging whether or not restart information is stored, terminating the substitutional program in the program execution unit if corresponding restart information is not stored. 
     A sixteenth aspect of the present invention is a computer program product according to the thirteenth aspect, wherein the managed program is a program which is originally installed and managed, and the unmanaged program is a program which is additionally installed by an operation of a user. 
     A seventeenth aspect of the present invention is a computer program product according to the thirteenth aspect, further including: eighth instructions for, if the substitutional program is forcibly terminated by the program execution unit, requesting the program execution unit to delete the provisional program which is stored in the execution state storage unit. 
     An eighteenth aspect of the present invention is a computer program product according to the thirteenth aspect, wherein the mobile phone terminal is further capable of activating an idle screen program which displays an idle screen in a state in which communication is being awaited, further including: ninth instructions for, when activating another program in a state in which the idle screen program is stored in the execution state storage unit as a program which is being activated, along with storing restart information for restarting the idle screen program which is being activated, also starting the another program in the program execution unit after terminating the idle screen program. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing the internal structure of a mobile phone terminal according to an embodiment of the present invention. 
         FIG. 2  is a data structure diagram for an execution state storage unit of this embodiment. 
         FIG. 3  is a data structure diagram for a starting state storage unit of this embodiment. 
         FIG. 4  is a data structure diagram for a restart information storage unit of this embodiment. 
         FIG. 5  is a first figure for explanation of the operation of a prior art APMAN. 
         FIG. 6  is a second figure for explanation of the operation of the prior art APMAN. 
         FIG. 7  is a first figure for explanation of the operation of an APMAN of this embodiment. 
         FIG. 8  is a second figure for explanation of the operation of the APMAN of this embodiment. 
         FIG. 9  is a third figure for explanation of the operation of the APMAN of this embodiment. 
         FIG. 10  is a figure showing changes of an execution state storage unit of this embodiment. 
         FIG. 11  is a figure showing changes of the execution state storage unit when a dummy applet is forcibly terminated, in this embodiment. 
         FIG. 12  is a figure for explanation of the operation of the APMAN when an idle screen applet is temporarily terminated, in this embodiment. 
         FIG. 13  is a figure showing changes of the execution state storage unit when an idle screen applet is temporarily terminated, in this embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following, a mobile phone terminal according to an embodiment of the present invention will be explained with reference to the drawings. 
       FIG. 1  is a schematic block diagram showing a mobile phone terminal  1  according to this embodiment. 
     The mobile phone terminal  1  of  FIG. 1  includes a wireless communication unit  50  which connects to a public communication network by radio communication, a display section  52  which includes a liquid crystal screen, a key operation unit  52  which receives input from the user, and a voice processing unit  53  which inputs and outputs voice, and provides fundamental functions as a portable telephone. 
     Furthermore, this mobile phone terminal  1  includes: an operating system  10  (hereinafter termed an “OS”) which executes applets corresponding to the above described programs; an application manager  20  (hereinafter termed an APMAN: Application Program Manager) which performs activation control of these applets by deciding upon the status of conflicts among them and the like; a static applet storage unit  40  which stores static applets which are software such as mailer software for control of electronic mail, browsing software for browsing web pages on the internet, address book management software for initiating telephone calls, and the like, which are provided in a standard manner, and the activation of them are controlled by the APMAN  20 ; and a downloaded applet storage unit  30  which stores downloaded applets such as game programs or the like, which can be downloaded from the internet or the like via the public communication network using the wireless communication unit  50  by the user&#39;s operation of the key operation unit  52 , or can be read in from a removable recording medium by predetermined operations. 
     In the OS  10 , a send/receive unit  11  sends and receives information such as requests to and from the APMAN  20  for activation of applets and so on, and responses from applets which have been activated and so on. An execution unit  12  reads static applets from the static applet storage unit  40  or downloaded applets from the downloaded applet storage unit  30 , based upon requests from the APMAN  20 , and stores the data of these downloaded applets in an execution state storage unit  13  and executes it. In case of some applets which are executed, for example, showing a pane upon the screen of the display section  51 , or outputting from the voice processing unit  53  are processed. The execution state storage unit  13  stores the data of the applet which is being executed by the execution unit  12  and the data of applets which are temporarily suspended. 
     In the APMAN  20 , a send/receive unit  21  sends and receives information to and from the send/receive unit of the OS  10  such as commands for activation of applets and so on, and responses from applets which have been activated and so on. 
     When activating a static applet, the management unit  22  decides upon the status of conflicts of the static applet and so on, and, if it is possible to activate the static applet, transmits a activation request for the static applet via the send/receive unit  21  to the execution unit  12  of the OS  10 . Furthermore, when activating a downloaded applet, the management unit  22  transmits a activation request for the downloaded applet to the execution unit  12  of the OS  10 . 
     An activation state storage unit  23  stores information related to applets which are being activated by the execution unit  12  of the OS  10  or are temporarily suspended. In order to perform multi-tasking type operation for static applets, restart information storage unit  24  stores information for restarting static applets which are suspended by the APMAN  20 , although they are terminated by the management unit  22  in the OS  10 . Herein, the state in which being terminated by the OS  10 , however, being suspended by the APMAN  20 , will be termed the temporarily terminated state. An event reception unit  25  receives events based upon commands for activating or stopping applets due to operation by the user, and events based upon commands from applets for activating other applets, and the like. 
     It should be understood that, the program execution unit corresponds to the execution unit  12 , and the program management unit corresponds to the management unit  22 . 
       FIG. 2  is a figure showing the data structure of the execution state storage unit  13 . This execution state storage unit  13  is a stack type storage region which is allocated in a heap region when an applet is executing, and in which the data of that applet is stored. As shown in  FIG. 2 , since this execution state storage unit  13  is a stack type storage region, the applet which was activated first is stored at the bottommost level of the stack, and, when a new applet is activated, the applet which was previously activated is temporarily suspended, and the new applet is piled upon the applet which has been temporarily suspended. That is to say, the applet data which is stored in the uppermost layer corresponds to the applet which is currently being activated. Furthermore, when a termination is processed by the execution unit  12 , the applet data at the uppermost layer is deleted, and the suspension of the applet which corresponds to the applet data that is stored one level down is cancelled, and the applet corresponding to that applet data is restarted. 
       FIG. 3  is a figure showing the data structure of the starting state storage unit  23 . This starting state storage unit  23  is also a storage region of the stack type, and in it there is stored information related to the applets which are being executed by the execution unit  12 , such as, for example, the identification information appended to each of the applets and so on. That is to say, the identification information for the applets which correspond to the applet data stored in the execution state storage unit  13  is stored according to the order in which they are stored in the execution state storage unit  13 . By referring to the starting state storage unit  23 , the management unit  22  of the APMAN  20  is able to acquire the information for an applet which is being activated by the execution state storage unit  13  of the OS  10 , or which is temporarily suspended. 
       FIG. 4  is a figure showing the data structure of the restart information storage unit  24 . This restart information storage unit  24  is also a storage region of the stack type. In order to be able to activate multiple static applets at the same time, while reducing the memory amount of the execution storage unit  13 , the APMAN  20  performs activation control in order that there is always one static applet which is being activated by the OS  10 . At this time, restart information for restarting a static applet, which is an applet that has been terminated by the OS  10 , and which is in the above described temporarily terminated state in which it is being suspended by the APMAN  20 , is stored in the restart information storage unit  24 . 
     Next, the activation control for applets by the APMAN  20 , when only handling static applets, will be explained with reference to  FIGS. 5 and 6 . 
       FIG. 5  is a figure showing the procedure, when activating another static applet during the execution of a static applet A, for temporarily terminating the static applet A which is being activated. Referring to  FIG. 5 , while the static applet A is being activated (id est, is in the active state), the event reception unit  25  receives an activation event for a static applet B, and, upon receipt of this activation event, the event reception unit  25  transmits (in step Sa 1 ) the information which indicates that the activation event has been received to the management unit  22 . The management unit  22  reads information from the starting state storage unit  23  for the applet A that is being activated. Since the applet that is being executed and has been read is a static applet that is being managed by the APMAN  20 , accordingly the management unit  22  decides upon the conflict state between the static applet A which is being executed and the static applet B for which the activation request has been made, and, if they do not conflict, a temporal termination request is transmitted to the execution unit  12  of the OS  10  (in step Sa 2 ), in order to put the static applet A into the temporarily terminated state. 
     Upon receipt of this temporal termination request, the execution unit  12  transmits (in step Sa 3 ) a termination command including temporal termination request information to the static applet A, in order, along with terminating the static applet A by the OS  10 , to put it into the suspension state by the APMAN  20 . The static applet A receives this termination command including the temporal termination request information, and transmits a termination response including restart information for restart to the execution unit  12 , and (in step Sa 4 ) deleting from the execution state storage unit  13  is processed by the execution unit  12 . Upon receipt of the termination response, the execution unit  12  transmits restart information for the static applet A to the management unit  22 . Upon receipt of this restart information, the static applet A stores this restart information in the restart information storage unit  24 . Furthermore, it deletes the information for the static applet A from the starting state storage unit  23 . 
     Next, upon receipt of the restart information for the static applet A, in order to start the static applet B, the management unit  22  transmits (in step Sa 6 ) an activation request for the static applet B to the execution unit  12 . Upon receipt of the activation request for the static applet B, the execution unit  12  reads the static applet B from the static applet storage unit  40 , and stores the static applet B in the execution state storage unit  13  (in step Sa 7 ). After being activated, the static applet B transmits (in step Sa 8 ) an activation response to the execution unit  12 . The execution unit  12  transmits activation information for the static applet B to the management unit  22 . Upon receipt of the activation information for the static applet B, the management unit  22  stores (in step Sa 9 ) the information for the static applet B in the starting state storage unit  23 . 
     That is to say, according to the procedure shown in  FIG. 5 , since, when a static applet is being activated, even if another static applet is started, that static applet which is being activated is temporarily terminated, accordingly it is possible to ensure that the data of the static applet which is stored in the execution state storage unit  13  that is being activated, id est, the applet that is being executed by the OS  10  can be only one. When the other static applet has been terminated, the static applet is restarted based upon the restart information which is stored in the restart information storage unit  24 , therefore, it becomes possible to perform multi-tasking type operational control in which execution of the static applet is continued from the state in which the applet has been suspended. 
       FIG. 6  is a figure showing the procedure of starting a static applet during an applet which has been downloaded by the APMAN  20  is currently executing. 
     First, the event reception unit  25  of the APMAN  20  receives the activation event for the static applet A. The event reception unit transmits (in step Sb 1 ) the information about this activation event to the management unit  22 . Upon receipt of the information about this activation event, the management unit  22  reads from the starting state storage unit  23  information about the applet which is being executed. Since the applet which is being executed is a downloaded applet which is not being managed by the APMAN  20 , the above described decision about the state of conflict is not processed, however, the management unit  22  transmits (in step Sb 2 ) a activation request for the static applet A to the execution unit  12  of the OS  10 . 
     Upon receipt of the activation request for the static applet A, in order to temporarily suspend the downloaded applet  1  which is currently being executed, the execution unit  12  transmits (in step Sb 3 ) a temporary suspension command to the downloaded applet  1 . Upon receipt of this temporary suspension command, the downloaded applet  1  goes into the temporarily suspended state, and transmits a temporary suspended response to the execution unit  12 . Here, the data for the downloaded applet  1  is not deleted from the execution state storage unit  13  even though it is temporarily suspended, but continues to be in the stored state (in step Sb 4 ). Next, upon receipt of the temporary suspended response, in order to start the static applet A, the execution unit  12  reads the static applet A from the static applet storage unit  40 , and stores (in step Sb 5 ) the static applet A in the execution state storage unit  13 . After having been activated, the static applet A transmits (in step Sb 6 ) an activation response to the execution unit  12 . The execution unit  12  transmits the activation information for the static applet A to the management unit  22 . Upon receipt of this activation information for the static applet A, the management unit  22  records (in step Sb 7 ) the information for the static applet A in the starting state storage unit  23 . 
     That is to say, according to the procedure shown in  FIG. 6 , even if another applet is activated, the downloaded applet continues to be kept in the state in which the data of this downloaded applet is stored in the execution state storage unit  13 . Due to this, when the applet which is being activated is terminated, the downloaded applet is caused to transit by the execution unit  12  from the state in which it is temporarily suspended state to the activated state; in this regard, it differs from a static applet. That is to say, if the state transition of the downloaded applet is not interrupted, even if there is a static applet which has been temporarily terminated before the downloaded applet is temporarily suspended, a situation is set up in which it cannot be restarted before the downloaded applet. 
     Next, the activation control in this embodiment of applets by the APMAN  20  will be explained with reference to  FIGS. 7 through 10 . 
     The state of the execution state storage unit  13  while a downloaded applet  1  is being executed as shown in  FIG. 7 , is that only the downloaded applet  1  is stored, as shown in  FIG. 10(   a ). In this state, the event reception unit  25  of the APMAN  20  receives (in step Sc 1 ) a activation event for a static applet A. Upon receipt of this event, the management unit  22  reads from the starting state storage unit  23  the information for the applet which is being executed. Since the applet being executed which has thus been read is a downloaded applet which is not managed by the APMAN  20 , the management unit  22  transmits (in step Sc 2 ) a dummy applet activation command to the execution unit  12  of the OS  10 , in order to activate a dummy applet which corresponds to a substitutional program. Here, a substitutional program is a program which does not particularly perform any output via display or via voice, but is assumed only to cooperate with the APMAN  20 . 
     Upon receipt of this dummy applet activation command, the execution unit  12  transmits (in step Sc 3 ) a temporary suspension command to the downloaded applet  1  which is executing. Upon receipt of this temporary suspension command, the downloaded applet  1  goes into the temporarily suspended state, and transmits a temporary suspended response to the execution unit  12 . At this time, even though the downloaded applet  1  has been temporarily suspended, its data is not deleted from the execution state storage unit  13 , but maintained to be in the stored state (in step Sc 4 ). Upon receipt of this temporary suspended response, since the dummy applet has been activated, the execution unit  12  stores (in step Sc 5 ) the data of the dummy applet in the execution state storage unit  13 . The dummy applet which has been activated transmits (in step Sc 6 ) an activation response to the execution unit  12 . At this time, the state of the execution state storage unit  13  becomes that shown in  FIG. 10(   b ). Upon receipt of this activation response from the dummy applet, the execution unit  12  transmits the activation information for the dummy applet to the management unit  22 . Upon receipt of this activation information for the dummy applet, the management unit  22  stores (in step Sc 7 ) the information for the dummy applet in the starting state storage unit  23 . 
     Next, upon receipt of the activation information from the dummy applet, the management unit  22  transmits (in step Sc 8 ) an activation request for the activation of the static applet A to the execution unit  12 . Upon receipt of this activation request, the execution unit  12  transmits (in step Sc 9 ) a temporary suspension command to the dummy applet, in order to put the dummy applet into the temporarily suspended state. Upon receipt of this temporary suspension command, the dummy applet goes into the temporarily suspended state, and transmits a temporary suspended response to the execution unit  12 . Here, the data for the dummy applet is not deleted from the execution state storage unit  13  even though it has been temporarily suspended, however, being kept (in step Sc 10 ) in the state of being stored. Upon receipt of this temporary suspended response, in order to activate the static applet A, the execution unit  12  reads the static applet A from the static applet storage unit  40 , and stores in a step (Sc 11 ) the static applet A in the execution state storage unit  13 . After being activated, an activation response is transmitted to the execution unit  12  (in step Sc 12 ). The execution unit  12  transmits the activation information for this static applet A to the management unit  22 . Upon receipt of this activation information for the static applet A, the management unit  22  stores (in step Sc 13 ) the information for this static applet A in the starting state storage unit  23 . 
     At this time, the execution state storage unit  13  is in the state shown in  FIG. 10(   c ). 
     Following on from  FIG. 7 ,  FIG. 8  is a figure showing the procedure when, further, a static applet B is activated. The event reception unit  25  of the APMAN  20  receives the activation event of the static applet B, and transmits that activation event to the management unit  22  (in step Sd 1 ). Upon receipt of the activation event, the management unit  22  reads from the starting state storage unit  23  the information for the applet which is being executed. 
     Since the applet which has been read and is being executed is a static applet which is managed by the APMAN  20 , a decision is made referring to the state of conflict between the static applet A which is being executed and the static applet B for which the start request has been made, and, if there is no conflict between them, then, in order to put the static applet A into the temporarily terminated state, it transmits (in step Sd 2 ) a substitutional termination request to the execution unit  12  of the OS  10 . 
     Upon receipt of this provisional termination request, the execution unit  12  transmits (in step Sd 3 ) to the static applet A a termination command which includes substitutional termination request information, in order, along with terminating that static applet A in the OS  10 , also to put it into the suspended state in the APMAN  20 . Upon receipt of this termination command which includes the substitutional termination request information, the static applet A transmits to the execution unit  12  a termination response which includes restart information for restart, and it is deleted (in step Sd 4 ) by the execution unit  12  from the execution state storage unit  13 . At this time, the state of the execution state storage unit  13  becomes the state shown in  FIG. 10(   d ). 
     Upon receipt of this termination response from the static applet A, the execution unit  12  transmits the restart information for the static applet A to the APMAN  20 . Upon receipt of this restart information, the static applet A stores the restart information in the restart information storage unit  24 . 
     Furthermore, the management unit  22  deletes (in step Sd 5 ) the information of the static applet A from the starting state storage unit  23 . Furthermore, upon receipt of the termination response from the static applet A, the execution unit  12  stores it in the uppermost layer of the execution state storage unit  13 , and transmits (in step Sd 6 ) an activation command for putting the dummy applet, which is in the temporarily suspended state, into the start state. Upon receipt of the activation command, the dummy applet responds (in step Sd 7 ) to the execution unit  12  with an activation response. Upon receipt of the activation response, the execution unit  12  transmits (in step Sd 8 ) the activation information for the dummy applet to the management unit  22 . 
     Upon receipt of the activation information for the dummy applet, the management unit  22  transmits (in step Sd 9 ) an activation request for the activation of the static applet D to the execution unit  12 . Upon receipt of this activation request for the static applet B, the execution unit  12  transmits (in step Sd 10 ) a temporary suspension command for putting the dummy applet which is currently executing into the temporarily suspended state. Upon receipt of this temporary suspension command, the dummy applet goes into the temporarily suspended state, and transmits a temporary suspended response to the execution unit  12 . At this point, the data of the dummy applet is not deleted from the execution state storage unit  13  even though it is temporarily suspended, but continues (in step Sd 11 ) to be in the state of being stored. Next, upon receipt of this temporary suspended response, the execution unit  12  reads the static applet B from the static applet storage unit  40 , in order to activate this static applet B, and store the static applet B in the execution state storage unit  13  (in step Sd 12 ). After activation, the static applet B transmits (in step Sd 13 ) an activation response to the execution unit  12 . The execution unit  12  transmits the activation information of the static applet B to the management unit  22 . Upon receipt of the activation information of the static applet B, the management unit  22  stores (in step Sd 14 ) the information of the static applet B in the starting state storage unit  23 . At this time, the execution state storage unit  13  goes into the state shown in  FIG. 10(   e ). 
     Following on from  FIG. 8 ,  FIG. 9  is a figure showing the processing when terminating the static applet B. The event reception unit  25  of the APMAN  20  receives a termination event which causes the static applet B to be terminated, and transmits (in step Se 1 ) this activation event to the management unit  22 . Upon receipt of this activation event, the management unit  22  reads the information of the applet which is being executed from the starting state storage unit  23 . Since the applet which has been read and is being executed is a static applet which is being managed by the APMAN  20 , a decision is made as to the state of conflict between the static applet B which is being executed and the static applet A for which an activation has been requested, and, if there is no conflict between them, a substitutional termination request is transmitted (in step Se 2 ) to the execution unit  12  of the OS  10 , in order to put the static applet B into the temporarily terminated state. 
     Upon receipt of this termination request for the static applet B, the execution unit  12  transmits (in step Se 3 ) a termination command to the static applet B. The static applet B transmits a termination response to the execution unit  12 , and is deleted (in step Se 4 ) by the execution unit  12  from the execution state storage unit  13 . At this time, the state of the execution state storage unit  13  becomes the state shown in  FIG. 10(   f ). 
     Upon receipt of this termination response from the static applet B, the execution unit  12  transmits the information that the static applet B has terminated to the management unit  22 . Upon receipt of this information that the static applet B has terminated, the management unit  22  deletes (in step Se 5 ) the information of the static applet B from the starting state storage unit  23 . Furthermore, upon receipt of the termination response from the static applet B, the execution unit  12  transmits (in step Se 6 ) an activation command for putting into the activated state the dummy applet which is stored in the uppermost layer of the execution state storage unit  13 , and which is in the temporarily suspended state. Upon receipt of the activation command, the dummy applet responds (in step Se 7 ) with an activation response to the execution unit  12 . Upon receipt of the activation response, the execution unit  12  transmits (in step Se 8 ) the activation information of the dummy applet to the management unit  22 . 
     Upon receipt of this activation information of the dummy applet, the management unit  22  reads the restart information for the static applet A which is stored in the uppermost layer of the restart information storage unit  24 . In order to restart the static applet A, the management unit  22  transmits (in step Se 9 ) to the execution unit  12  a start request for the static applet A which includes the restart information for the static applet A. Upon receipt of this start request, the execution unit  12  transmits (in step Se 10 ) a temporary suspension command for putting the dummy applet which is being executed into the temporarily suspended state. Upon receipt of this temporary suspension command, the dummy applet goes in to the temporarily suspended state, and transmits a temporary suspended response to the execution unit  12 . At this time, the data of the dummy applet is not deleted from the execution state storage unit  13  even though it is temporarily suspended, but continues (in step Se 11 ) in the state of being stored. 
     Next, upon receipt of this temporary suspended response, in order to activate the static applet A, the execution unit  12  reads the static applet A from the static applet storage unit  40 , and stores (in step Se 12 ) the static applet A in the execution state storage unit  13  in a state including the restart information of this static applet A. After activation, the static applet A transmits (in step Se 13 ) an activation response to the execution unit  12 . The execution unit  12  transmits the activation information for this static applet A to the management unit  22 . Upon receipt of this activation information for the static applet A, the management unit  22  stores (in step Se 14 ) the information of the static applet A in the starting state storage unit  23 . At this time, the execution state storage unit  13  goes into the state shown in  FIG. 10(   g ). 
     According to the procedures shown in the above described  FIG. 7  through  FIG. 9 , when switching applets, it becomes possible to restart the static applet A, so as to prevent the downloaded applet restarting first. Due to this, it becomes possible to restart the applets according to a sequence which can be anticipated by the user. 
     It should be understood that the data of a dummy applet is a small amount of data of a few kilobytes in volume, so that it may be generated by the management unit  22  or the execution unit  12 , and stored in the execution state storage unit  13 . 
     Furthermore in order, when the information for the dummy applets stored in the restart information storage unit  24  is removed, it is designed to terminate the dummy applets, therefore, in order to maintain the order of restart between static applets which have become terminated and downloaded applets, the restart information storage unit  24  needs to be provided with one stack type storage region corresponding to each dummy applet, rather than only one stack type storage region. 
       FIG. 11  is a figure for explanation of a deletion procedure performed by the management unit  22  of the APMAN  20  for the data of an applet which is being stored by the execution state storage unit  13 . 
     The execution state storage unit  13  is of a limited capacity, since, as described above, the storage region is allocated within the heap region. Due to this, if the applet data which is stored in the execution state storage unit  13  exceeds capacity, then, in order to execute the applet which has been started at first, the execution unit  12  forcibly deletes the applet data stored in the uppermost layer.  FIG. 11(   a ) through  FIG. 11(   c ) are figures showing this procedure. 
     In  FIG. 11(   a ), a dummy applet  2  which is being executed is stored in the uppermost layer of the execution state storage unit  13 . At this time, when a downloaded applet  2  is to be activated, and the capacity of the execution state storage unit  13  is exceeded, the execution unit  12  deletes the dummy applet  2  from the execution state storage unit  13 , and activates the downloaded applet  2 . When the dummy applet is thus deleted, restart control of the static applet by the management unit  22  can no longer be issued normally. Due to this, as shown in  FIG. 11(   c ), the management unit  22  deletes all the applet data stored in the execution state storage unit  13 , and processes initialization. 
     As has been explained with reference to  FIG. 11 , if the dummy applet which is stored in the execution state storage unit  13  has been deleted by the OS  10 , it is possible to delete all the data for the applet which is stored in the execution state storage unit  13  and to perform initialization. By doing this, it becomes possible to maintain control of switching the applets by the APMAN  20  in a normal manner. 
     Next, with reference to  FIGS. 12 and 13 , start control will be explained in which an idle screen that is activated when the power is on via the key operation unit  52  of the mobile phone terminal  1 , and is displayed upon the display section  51  to indicate that communication is being awaited. 
     As explained first, with reference to  FIG. 7  through  FIG. 10 , since the structure is such that the static applet is restarted by the activation of the dummy applet as an opportunity after reading the restart information which is stored in the restart information storage unit  24 , accordingly, for the idle screen applet which is activated when the mobile phone terminal  1  is powered on, when it is put into the temporarily suspended state, an event for restart is lost in a case that there is no dummy applet which corresponds to the idle screen applet. Due to this, if the idle screen applet is temporarily suspended by some other applet being activated, it is necessary to activate a dummy applet, in order to make it possible to perform restart. 
       FIG. 12  is a figure showing the processing when the idle screen applet is put into the temporarily suspended state. 
     In this figure, the idle screen applet is being activated, and the state of the execution state storage unit  13  is that only the idle screen applet is stored, as shown in  FIG. 13(   a ). In this state, the event reception unit  25  of the APMAN  20  receives the activation event for a downloaded applet  1 . Upon receipt of the activation event for the downloaded applet  1 , the event reception unit  25  transmits (in step Sf 1 ) the activation event to the management unit  22 . Upon receipt of this activation event, the management unit  22  reads the information for the applet which is being activated from the starting state storage unit  23 . Since the applet which has thus been read and is being activated is the idle screen applet which is managed by the APMAN  20 , a substitutional termination request is transmitted (in step Sf 2 ) to the execution unit  12  of the OS  10 , in order to put the idle screen applet into the temporarily suspended state. 
     Upon receipt of this substitutional termination request, the execution unit  12  transmits (in step Sf 3 ) to the idle screen applet a termination command including substitutional termination request information, in order, along with terminating the idle screen applet in the OS  10 , to set the suspended state in the APMAN  20 . The idle screen applet receives the termination command including the substitutional termination request information, transmits to the execution unit  12  a termination response which includes restart information for restart, and is deleted (in step Sf 4 ) from the execution state storage unit  13  by the execution unit  12 . 
     Upon receipt of this termination response, the execution unit  12  transmits the restart information for the idle screen applet to the management unit  22 . Upon receipt of the restart information, the restart information is stored in the restart information storage unit  24 . Furthermore, the information of the idle screen applet is deleted (in step Sf 5 ) from the starting state storage unit  23 . Next, upon receipt of the termination response of the idle screen applet, the management unit  22  transmits (in step Sf 6 ) to the execution unit  12  a dummy applet activation command, in order to activate a dummy applet. Upon receipt of the dummy applet activation command, the execution unit  12  stores (in step Sf 7 ) the data of the dummy applet in the execution state storage unit  13 , in order to activate the dummy applet. 
     The dummy applet which has been activated transmits (in step Sf 8 ) its start response to the execution unit  12 . At this time, the state of the execution state storage unit  13  comes to be as shown in  FIG. 13(   b ). Upon receipt of the start response from the dummy applet, the execution unit  12  transmits the activation information of the dummy applet to the management unit  22 . Upon receipt of this activation information of the dummy applet, the management unit  22  stores (in step Sf 9 ) the information of the dummy applet in the starting state storage unit  23 . Next, upon receipt of the activation information for the dummy applet, the management unit  22  transmits (in step Sf 10 ) an activation request to the execution unit  12  for the activation of the downloaded applet  1 . Upon receipt of the activation request, the execution unit  12  transmits (in step Sf 11 ) a temporary suspension command to the dummy applet, in order to put into the temporarily suspended state. 
     Upon receipt of this temporary suspension command, the dummy applet goes into the temporarily suspended state, and transmits a temporary suspended response to the execution unit  12 . At this time, the data for the dummy applet is not deleted from the execution state storage unit  13 , but continues (in step Sf 12 ) in the state of being stored. Next, upon receipt of the temporary suspended response, in order to activate the downloaded applet  1 , the execution unit  12  reads the downloaded applet  1  from the download storage unit  30 , and stores (in step Sf 13 ) the downloaded applet  1  in the execution state storage unit  13 . The downloaded applet which has been activated transmits (in step Sf 14 ) an activation response to the execution unit  12 . Upon receipt of the activation response of the downloaded applet  1 , the execution unit  12  transmits the activation information of the downloaded applet  1  to the management unit  22 . Upon receipt of the activation information of the downloaded applet  1 , the management unit  22  stores (in step Sf 15 ) the information of the downloaded applet  1  in the starting state storage unit  23 . At this time, the execution state storage unit  13  comes to be in the state shown in  FIG. 13(   c ). 
     As explained with reference to  FIG. 12  and  FIG. 13 , even in the case of an idle screen applet, it becomes possible to restart the idle screen applet by activating a dummy applet when substitutionaly terminating the idle screen applet. 
     A computer system is provided internally by the above described mobile phone terminal. During the processing performed by the above described mobile phone terminal, the above described procedures are stored in a form of a program upon a storage medium which can be read by a computer, and it can be executed by reading the program with the computer. Here, a storage medium which can be read by a computer, is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory or the like. Moreover, it may be arranged for this computer program to be distributed to the computer via a communication line, and for the computer, upon receipt of this distribution, to execute this program. 
     While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.