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authorScott MacVicar <scottmac@php.net>2008-03-07 10:55:14 +0000
committerScott MacVicar <scottmac@php.net>2008-03-07 10:55:14 +0000
commit31dade5280849135b00fd1c5e53d057732a72776 (patch)
tree564b9f0f9d8cf89d7df9a9c12147ba8a5da6506f /ext/pdo_sqlite/sqlite/src/fault.c
parent7abf0787ad9fd613ddde880c9bc163161d7bf4ff (diff)
downloadphp-git-31dade5280849135b00fd1c5e53d057732a72776.tar.gz
MFB: Update bundled SQLite to 3.5.6
Diffstat (limited to 'ext/pdo_sqlite/sqlite/src/fault.c')
-rw-r--r--ext/pdo_sqlite/sqlite/src/fault.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/ext/pdo_sqlite/sqlite/src/fault.c b/ext/pdo_sqlite/sqlite/src/fault.c
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+/*
+** 2008 Jan 22
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code to implement a fault-injector used for
+** testing and verification of SQLite.
+**
+** Subsystems within SQLite can call sqlite3FaultStep() to see if
+** they should simulate a fault. sqlite3FaultStep() normally returns
+** zero but will return non-zero if a fault should be simulated.
+** Fault injectors can be used, for example, to simulate memory
+** allocation failures or I/O errors.
+**
+** The fault injector is omitted from the code if SQLite is
+** compiled with -DSQLITE_OMIT_FAULTINJECTOR=1. There is a very
+** small performance hit for leaving the fault injector in the code.
+** Commerical products will probably want to omit the fault injector
+** from production builds. But safety-critical systems who work
+** under the motto "fly what you test and test what you fly" may
+** choose to leave the fault injector enabled even in production.
+*/
+#include "sqliteInt.h"
+
+#ifndef SQLITE_OMIT_FAULTINJECTOR
+
+/*
+** There can be various kinds of faults. For example, there can be
+** a memory allocation failure. Or an I/O failure. For each different
+** fault type, there is a separate FaultInjector structure to keep track
+** of the status of that fault.
+*/
+static struct FaultInjector {
+ int iCountdown; /* Number of pending successes before we hit a failure */
+ int nRepeat; /* Number of times to repeat the failure */
+ int nBenign; /* Number of benign failures seen since last config */
+ int nFail; /* Number of failures seen since last config */
+ u8 enable; /* True if enabled */
+ u8 benign; /* Ture if next failure will be benign */
+} aFault[SQLITE_FAULTINJECTOR_COUNT];
+
+/*
+** This routine configures and enables a fault injector. After
+** calling this routine, aFaultStep() will return false (zero)
+** nDelay times, then it will return true nRepeat times,
+** then it will again begin returning false.
+*/
+void sqlite3FaultConfig(int id, int nDelay, int nRepeat){
+ assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
+ aFault[id].iCountdown = nDelay;
+ aFault[id].nRepeat = nRepeat;
+ aFault[id].nBenign = 0;
+ aFault[id].nFail = 0;
+ aFault[id].enable = nDelay>=0;
+ aFault[id].benign = 0;
+}
+
+/*
+** Return the number of faults (both hard and benign faults) that have
+** occurred since the injector was last configured.
+*/
+int sqlite3FaultFailures(int id){
+ assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
+ return aFault[id].nFail;
+}
+
+/*
+** Return the number of benign faults that have occurred since the
+** injector was last configured.
+*/
+int sqlite3FaultBenignFailures(int id){
+ assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
+ return aFault[id].nBenign;
+}
+
+/*
+** Return the number of successes that will occur before the next failure.
+** If no failures are scheduled, return -1.
+*/
+int sqlite3FaultPending(int id){
+ assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
+ if( aFault[id].enable ){
+ return aFault[id].iCountdown;
+ }else{
+ return -1;
+ }
+}
+
+/*
+** After this routine causes subsequent faults to be either benign
+** or hard (not benign), according to the "enable" parameter.
+**
+** Most faults are hard. In other words, most faults cause
+** an error to be propagated back up to the application interface.
+** However, sometimes a fault is easily recoverable. For example,
+** if a malloc fails while resizing a hash table, this is completely
+** recoverable simply by not carrying out the resize. The hash table
+** will continue to function normally. So a malloc failure during
+** a hash table resize is a benign fault.
+*/
+void sqlite3FaultBenign(int id, int enable){
+ assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
+ aFault[id].benign = enable;
+}
+
+/*
+** This routine exists as a place to set a breakpoint that will
+** fire on any simulated fault.
+*/
+static void sqlite3Fault(void){
+ static int cnt = 0;
+ cnt++;
+}
+
+
+/*
+** Check to see if a fault should be simulated. Return true to simulate
+** the fault. Return false if the fault should not be simulated.
+*/
+int sqlite3FaultStep(int id){
+ assert( id>=0 && id<SQLITE_FAULTINJECTOR_COUNT );
+ if( likely(!aFault[id].enable) ){
+ return 0;
+ }
+ if( aFault[id].iCountdown>0 ){
+ aFault[id].iCountdown--;
+ return 0;
+ }
+ sqlite3Fault();
+ aFault[id].nFail++;
+ if( aFault[id].benign ){
+ aFault[id].nBenign++;
+ }
+ aFault[id].nRepeat--;
+ if( aFault[id].nRepeat<=0 ){
+ aFault[id].enable = 0;
+ }
+ return 1;
+}
+
+#endif /* SQLITE_OMIT_FAULTINJECTOR */