increment (order of the Mark), by leader to each log to vote to reach the majority, if the Midway leader switch, for the new leader "empty", need to re-vote, confirm the validity of the log.Can the 4.multi-paxos non-leader node provide service?Only leader in the Multi-paxos protocol ensures that all already persisted logs are included, although the locally persisted log does not necessarily have a majority, so for a log that does not have confirm, an
the order. For each log, through a logid mark, Logid strict increment (order of the Mark), by leader to each log to vote to reach the majority, if the Midway leader switch, for the new leader "empty", need to re-vote, confirm the validity of the log.Can the 4.multi-paxos non-leader node provide service?Only leader in the Multi-paxos protocol ensures that all already persisted logs are included, although the locally persisted log does not necessarily
Win95 and thread
Win95 loses about 200 bytes of memory for each thread creation. Therefore, if you have many connections, you should not run them in Win95.
mysqldFor a long time, because
MySQLCreates a new thread for each connection! WinNT and Win98 cannot tolerate this bug.
Blocked readBlocking read)
MySQLUse a blocking read for each connection, which means:
A connection will be automatically disconnected after 8 hours, just likeMySQL.
If a connection is suspend
PrincipleConsistency of the database1. Transaction and Agent Checklist tricks (pre-write logging)1. Action list trick: write the log to write the operation to the hardware first. Even if the database operation is wrong, it can be corrected according to the log. The operation of the log has the same power, that is, each operation in the log, whether executed once or multiple times, will have the same effect.2. Transaction: The transaction as a whole, either complete, or
Android ROM developers, as described herehttps://wiki.ubuntu.com/Touch/AndroidDevelAlternately, all the Android code can be downloaded using the phablet-dev-bootstrap tool provided by the phablet-tools package installed in the previous step. This tool is a Python wrapper around repo and used to also check out bzr repositories before all code was managed by repo and git. For the purposes of getting the source code for development it is no longer needed.To get the code setup run:
phablet-dev-
\ getter method is generated simultaneously.
Readonly: generate only simple getter without setter.
Assign: the default type. The setter method directly assigns values without retain operations.
Retain: the setter method performs the release old value on the parameter, and then retain the new value.
Copy: the setter Method for Copy operations, the same as retain
Atomic: atomicity. If you do not declare atomicity (atomic or nonatomic), the system selects atomic by default.
Atomicity means that
are correct and which ones are not changed at all. For example, you need a script to add users. Add_to_passwd $ usercp-a/etc/skel/home/$ userchown $ user/home/$ user-R when the disk space is insufficient or the process is killed midway through, this script will cause problems. In this case, you may wish that the user account does not exist and that his/her files should also be deleted. Rollback () {del_from_passwd $ userif [-e/home/$ user]; thenrm-rf
, while the finish method is In the end, it will determine whether the doInBackground is properly executed or canceled midway through, so as to determine whether to call onCancelled or onPostExecute, finally, set the execution status of AsyncTask to FINISH to complete the interaction process between the entire asynchronous thread and the UI thread. Note that the done method in mFeture is mainly used to process the execution of the AsyncTask. Note th
screen is tapped in a short time. Therefore, you can click, double-click, or click more based on tapCount.Timestamp: the timestamp records the time when a touch event is generated or changed. The unit is seconds.Phase: a touch event has a cycle on the screen, that is, touch start, touch point movement, touch end, and Midway cancel. Phase allows you to view the status of the current touch event in a cycle. Phase is of the UITouchPhase type, which is a
What is a transaction?In the MySQL environment, a transaction is composed of one or more SQL statements as a separate unit. Each SQL statement in this unit is mutually dependent, and the unit as a whole is inseparable. If a statement in a unit cannot be completed successfully, the entire unit will be rolled back, and all affected data will be returned to the status before the start of the transaction. Therefore, the transaction is successfully executed only when all statements in the transaction
download a brush machine tools, sweet pepper Brush Machine Assistant, which has a "utility" can be directly into the Hboot mode, simple and convenient
Mobile Phone Enter Hboot mode, waiting to appear as shown in the following figure:
The diagram above shows that already s-off, if your machine is s-on the suggestion gets the merchant to carry on the hard solution into S-off.
2. A card reader and a form of FAT32 storage card Micro
copied!"chmod0755modules/modules/*# Create Modules.mk(Cat # modules.mk Generate by extract-files.sh, does not edit it.Product_copy_files + = \ \$ (call find-copy-subdir-files,*,\$ (Local_path)/modules,system/vendor/modules) EOFCD $CURDIR}Can see from the Linux directory copy kernel and some modules, need the main is the Get_lichee_out_dir () function, Linux directory must be placed in the upper directory of the Android directory, you can view the source code. Next, we can execute our make comma
;Switch (box) {//switch (box) box is the variable to compareCase 1://case1: Equivalent to the IF statement (box = = 1), if box is 1Alert (' one ');Break Exit the switch statement midway through the break to prevent penetrationCase 2:Alert (' both ');BreakCase 3:Alert (' three ');BreakDefault://equivalent to the else in the IF statementAlert (' Error ');}---------------------------------------------------------------------------------------------------
)". So the proof. 2. Each time the value of a[1] is removed, place the value of a[n] into a[1] (n is the size of the current heap, that is, the number of tree nodes ), and then the a[1] is down . Prove:Root node a[1] can always reach a point through a certain path A[s], set midway through point d1,d2,... , DK, then a[1]a[1] is guaranteed to be the minimum value in a two-fork tree. Then the a[1] down operation, according to i "Each point I down the op
Android source code, The maximum number of worker threads I can set is 4 * 2 = 8. When executing the make command, we should set a reasonable value for the working thread based on our CPU parameters.After the completion of the above steps, is a very long wait, I start from 12 o'clock Noon to compile, until the end of the night to nine o'clock more compiled, the entire compilation process took nine hours, fortunately, my luck is good, the compilation process did not appear any errors, just
Number: Positive, negative, 0, decimal, NaNNan:not A number is not a valid digit but he is a numeric data type ofvar num = 12;12==12 comparisonvar a= 12 Assignment;IsNaN (); detects whether a value is a valid number if the proposition is true, is a valid number that returns FALSE, is not a valid number to return;If the detected value is not of type number, the browser will default to convert it to type # and then determine if it is a valid digitConsole.log (IsNaN ("123")) returns the result is F
(), execute: {print ("Group Done")}) //2, wait forever until all tasks are completed, midway cannot be canceled, blocking the current threadgroup.wait () print ("Complete Task Execution")9,concurrentperform the specified number of blocks to the queueThe Dispatchqueue.concurrentperform function is an associated API for the Sync function and dispatch group. Appends the specified block to the specified dispatch queue for a specified number of times and w
is encrypted with K1, the data is decrypted with K2, and the data is encrypted with K3.The decryption formula is as follows:plaintext = DK1 (EK2 (DK3 (ciphertext)))ThatPingwen = DK1 (EK2 (DK3 (ciphertext)))The data is decrypted with K3J, the data is encrypted with K2, and the data is encrypted with K1. Each encryption processes 64 bits of data and forms a piece.3DES encryption OptionsThree key options are defined.(1) Three keys are independent of each other.(2) K1 and K2 keys are independent, b
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